Viruses

2024

Jump to: 2023, 2022, 2021, 2020

22 pages, 13869 KiB

Open AccessArticle

Identification and Analysis of Biomarkers Associated with Lipophagy and Therapeutic Agents for COVID-19

by Yujia Wu, Zhenlin Wu, Qiying Jin, Jinyuan Liu and Peiping Xu

Viruses 2024, 16(6), 923; https://doi.org/10.3390/v16060923 - 7 Jun 2024

Cited by 2 | Viewed by 1378

Abstract

Background: Lipids, as a fundamental cell component, play an regulating role in controlling the different cellular biological processes involved in viral infections. A notable feature of coronavirus disease 2019 (COVID-19) is impaired lipid metabolism. The function of lipophagy-related genes in COVID-19 is unknown. [...] Read more.

Background: Lipids, as a fundamental cell component, play an regulating role in controlling the different cellular biological processes involved in viral infections. A notable feature of coronavirus disease 2019 (COVID-19) is impaired lipid metabolism. The function of lipophagy-related genes in COVID-19 is unknown. The present study aimed to investigate biomarkers and drug targets associated with lipophagy and lipophagy-based therapeutic agents for COVID-19 through bioinformatics analysis. Methods: Lipophagy-related biomarkers for COVID-19 were identified using machine learning algorithms such as random forest, Support Vector Machine-Recursive Feature Elimination, Generalized Linear Model, and Extreme Gradient Boosting in three COVID-19-associated GEO datasets: scRNA-seq (GSE145926) and bulk RNA-seq (GSE183533 and GSE190496). The cMAP database was searched for potential COVID-19 medications. Results: The lipophagy pathway was downregulated, and the lipid droplet formation pathway was upregulated, resulting in impaired lipid metabolism. Seven lipophagy-related genes, including ACADVL, HYOU1, DAP, AUP1, PRXAB2, LSS, and PLIN2, were used as biomarkers and drug targets for COVID-19. Moreover, lipophagy may play a role in COVID-19 pathogenesis. As prospective drugs for treating COVID-19, seven potential downregulators (phenoxybenzamine, helveticoside, lanatoside C, geldanamycin, loperamide, pioglitazone, and trichostatin A) were discovered. These medication candidates showed remarkable binding energies against the seven biomarkers. Conclusions: The lipophagy-related genes ACADVL, HYOU1, DAP, AUP1, PRXAB2, LSS, and PLIN2 can be used as biomarkers and drug targets for COVID-19. Seven potential downregulators of these seven biomarkers may have therapeutic effects for treating COVID-19. Full article

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11 pages, 1118 KiB

Open AccessCommunication

Detection of SARS-CoV-2-Specific Secretory IgA and Neutralizing Antibodies in the Nasal Secretions of Exposed Seronegative Individuals

by Jason S. Chwa, Minjun Kim, Yesun Lee, Wesley A. Cheng, Yunho Shin, Jaycee Jumarang, Jeffrey M. Bender and Pia S. Pannaraj

Viruses 2024, 16(6), 852; https://doi.org/10.3390/v16060852 - 27 May 2024

Viewed by 1662

Abstract

Mucosal immunity may contribute to clearing SARS-CoV-2 infection prior to systemic infection, thereby allowing hosts to remain seronegative. We describe the meaningful detection of SARS-CoV-2-specific nasal mucosal antibodies in a group of exposed-household individuals that evaded systemic infection. Between June 2020 and February [...] Read more.

Mucosal immunity may contribute to clearing SARS-CoV-2 infection prior to systemic infection, thereby allowing hosts to remain seronegative. We describe the meaningful detection of SARS-CoV-2-specific nasal mucosal antibodies in a group of exposed-household individuals that evaded systemic infection. Between June 2020 and February 2023, nasopharyngeal swab (NPS) and acute and convalescent blood were collected from individuals exposed to a SARS-CoV-2-confirmed household member. Nasal secretory IgA (SIgA) antibodies targeting the SARS-CoV-2 spike protein were measured using a modified ELISA. Of the 36 exposed individuals without SARS-CoV-2 detected by the RT-PCR of NPS specimens and seronegative for SARS-CoV-2-specific IgG at enrollment and convalescence, 13 (36.1%) had positive SARS-CoV-2-specific SIgA levels detected in the nasal mucosa at enrollment. These individuals had significantly higher nasal SIgA (median 0.52 AU/mL) compared with never-exposed, never-infected controls (0.001 AU/mL) and infected-family participants (0.0002 AU/mL) during the acute visit, respectively (both p < 0.001). The nasal SARS-CoV-2-specific SIgA decreased rapidly over two weeks in the exposed seronegative individuals compared to a rise in SIgA in infected-family members. The nasal SARS-CoV-2-specific SIgA may have a protective role in preventing systemic infection. Full article

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15 pages, 3549 KiB

Open AccessArticle

Transcriptomic Analysis of PDCoV-Infected HIEC-6 Cells and Enrichment Pathways PI3K-Akt and P38 MAPK

by Yuhang Jiang, Guoqing Zhang, Letian Li, Maopeng Wang, Jing Chen, Pengfei Hao, Zihan Gao, Jiayi Hao, Chang Li and Ningyi Jin

Viruses 2024, 16(4), 579; https://doi.org/10.3390/v16040579 - 9 Apr 2024

Viewed by 1410

Abstract

Porcine Deltacoronavirus (PDCoV) is a newly identified coronavirus that causes severe intestinal lesions in piglets. However, the understanding of how PDCoV interacts with human hosts is limited. In this study, we aimed to investigate the interactions between PDCoV and human intestinal cells (HIEC-6) [...] Read more.

Porcine Deltacoronavirus (PDCoV) is a newly identified coronavirus that causes severe intestinal lesions in piglets. However, the understanding of how PDCoV interacts with human hosts is limited. In this study, we aimed to investigate the interactions between PDCoV and human intestinal cells (HIEC-6) by analyzing the transcriptome at different time points post-infection (12 h, 24 h, 48 h). Differential gene analysis revealed a total of 3560, 5193, and 4147 differentially expressed genes (DEGs) at 12 h, 24 h, and 48 h, respectively. The common genes among the DEGs at all three time points were enriched in biological processes related to cytokine production, extracellular matrix, and cytokine activity. KEGG pathway analysis showed enrichment of genes involved in the p53 signaling pathway, PI3K-Akt signaling pathway, and TNF signaling pathway. Further analysis of highly expressed genes among the DEGs identified significant changes in the expression levels of BUB1, DDIT4, ATF3, GBP2, and IRF1. Comparison of transcriptome data at 24 h with other time points revealed 298 DEGs out of a total of 6276 genes. KEGG analysis of these DEGs showed significant enrichment of pathways related to viral infection, specifically the PI3K-Akt and P38 MAPK pathways. Furthermore, the genes EFNA1 and KITLG, which are associated with viral infection, were found in both enriched pathways, suggesting their potential as therapeutic or preventive targets for PDCoV infection. The enhancement of PDCoV infection in HIEC-6 was observed upon inhibition of the PI3K-Akt and P38 MAPK signaling pathways using sophoridine. Overall, these findings contribute to our understanding of the molecular mechanisms underlying PDCoV infection in HIEC-6 cells and provide insights for developing preventive and therapeutic strategies against PDCoV infection. Full article

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20 pages, 2284 KiB

Open AccessArticle

Acellular Human Amniotic Fluid-Derived Extracellular Vesicles as Novel Anti-Inflammatory Therapeutics against SARS-CoV-2 Infection

by Debarati Chanda, Tania Del Rivero, Roshan Ghimire, Sunil More, Maria Ines Mitrani, Michael A. Bellio and Rudragouda Channappanavar

Viruses 2024, 16(2), 273; https://doi.org/10.3390/v16020273 - 9 Feb 2024

Cited by 1 | Viewed by 1952

Abstract

The ongoing COVID-19 pandemic caused by SARS-CoV-2 is associated with acute respiratory distress syndrome (ARDS) and fatal pneumonia. Excessive inflammation caused by SARS-CoV-2 is the key driver of ARDS and lethal disease. Several FDA-approved drugs that suppress virus replication are in clinical use. [...] Read more.

The ongoing COVID-19 pandemic caused by SARS-CoV-2 is associated with acute respiratory distress syndrome (ARDS) and fatal pneumonia. Excessive inflammation caused by SARS-CoV-2 is the key driver of ARDS and lethal disease. Several FDA-approved drugs that suppress virus replication are in clinical use. However, despite strong evidence for the role of virus-induced inflammation in severe COVID-19, no effective anti-inflammatory drug is available to control fatal inflammation as well as efficiently clear the virus. Therefore, there is an urgent need to identify biologically derived immunomodulators that suppress inflammation and promote antiviral immunity. In this study, we evaluated acellular human amniotic fluid (acAF) containing extracellular vesicles (hAF-EVs) as a potential non-toxic and safe biologic for immunomodulation during COVID-19. Our in vitro results showed that acAF significantly reduced inflammatory cytokine production in TLR2/4/7 and SARS-CoV-2 structural protein-stimulated mouse macrophages. Importantly, an intraperitoneal administration of acAF reduced morbidity and mortality in SARS-CoV-2-infected mice. A detailed examination of SARS-CoV-2-infected lungs revealed that the increased protection in acAF-treated mice was associated with reduced viral titers and levels of inflammatory myeloid cell infiltration. Collectively, our results identify a novel biologic that has potential to suppress excessive inflammation and enhance survival following SARS-CoV-2 infection, highlighting the translational potential of acAF against COVID-19. Full article

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15 pages, 3123 KiB

Open AccessArticle

Sulfated Glycans Inhibit the Interaction of MERS-CoV Receptor Binding Domain with Heparin

by Jiyuan Yang, Yuefan Song, Weihua Jin, Ke Xia, Grace C. Burnett, Wanjin Qiao, John T. Bates, Vitor H. Pomin, Chunyu Wang, Mingqiang Qiao, Robert J. Linhardt, Jonathan S. Dordick and Fuming Zhang

Viruses 2024, 16(2), 237; https://doi.org/10.3390/v16020237 - 2 Feb 2024

Cited by 2 | Viewed by 1676

Abstract

Middle East respiratory syndrome coronavirus (MERS-CoV) is a zoonotic virus with high contagion and mortality rates. Heparan sulfate proteoglycans (HSPGs) are ubiquitously expressed on the surface of mammalian cells. Owing to its high negatively charged property, heparan sulfate (HS) on the surface of [...] Read more.

Middle East respiratory syndrome coronavirus (MERS-CoV) is a zoonotic virus with high contagion and mortality rates. Heparan sulfate proteoglycans (HSPGs) are ubiquitously expressed on the surface of mammalian cells. Owing to its high negatively charged property, heparan sulfate (HS) on the surface of host cells is used by many viruses as cofactor to facilitate viral attachment and initiate cellular entry. Therefore, inhibition of the interaction between viruses and HS could be a promising target to inhibit viral infection. In the current study, the interaction between the receptor-binding domain (RBD) of MERS-CoV and heparin was exploited to assess the inhibitory activity of various sulfated glycans such as glycosaminoglycans, marine-sourced glycans (sulfated fucans, fucosylated chondroitin sulfates, fucoidans, and rhamnan sulfate), pentosan polysulfate, and mucopolysaccharide using Surface Plasmon Resonance. We believe this study provides valuable insights for the development of sulfated glycan-based inhibitors as potential antiviral agents. Full article

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2023

Jump to: 2024, 2022, 2021, 2020

12 pages, 3838 KiB

Open AccessArticle

Virological Characteristics of Five SARS-CoV-2 Variants, Including Beta, Delta and Omicron BA.1, BA.2, BA.5

by Yan Zeng, Fei Xia, Changfu Guo, Chunxia Hu, Yuwei Li, Xiang Wang, Qin Wu, Zhuo Chen, Jia Lu and Zejun Wang

Viruses 2023, 15(12), 2394; https://doi.org/10.3390/v15122394 - 8 Dec 2023

Viewed by 1334

Abstract

SARS-CoV-2 variants of concern (VOCs) show increasing transmissibility and infectivity and induce substantial injuries to human health and the ecology. Therefore, it is vital to understand the related features for controlling infection. In this study, SARS-CoV-2 WIV04 (prototype) and five VOCs (Beta, Delta, [...] Read more.

SARS-CoV-2 variants of concern (VOCs) show increasing transmissibility and infectivity and induce substantial injuries to human health and the ecology. Therefore, it is vital to understand the related features for controlling infection. In this study, SARS-CoV-2 WIV04 (prototype) and five VOCs (Beta, Delta, Omicron BA.1, BA.2 and BA.5 variants) were inoculated in Vero cells to observe their growth activities. Apart from evaluating the environmental stability at different temperatures, residual virus titers and infectivity at different temperatures (4 °C, room temperature (RT) and 37 °C) were measured over 7 days. The experiment also assessed the infectivity for different incubation durations. The growth capacity assay suggested that the WIV04, Beta and Delta variants replicated efficiently in Vero cells compared with Omicron Variants, and BA.2 replicated more efficiently in Vero cells than BA.1 and BA.5. In addition, all variants exhibited longer survivals at 4 °C and could remain infectious after 7 days, compared to RT’ survival after 5 days and at 37 °C after 1 day. The virus infection assay indicated that the Omicron variant had a weaker ability to infect cells compared to the WIV04, Beta and Delta strains, and a longer infection time was required for these strains, except for BA.2. Full article

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11 pages, 1036 KiB

Open AccessArticle

Evaluation of SARS-CoV-2-Positive Patients with Suspected Reinfection

by Aytaj Allahverdiyeva, Ali Ağaçfidan, Lerzan Dogan, Mustafa Önel, Hayriye Kırkoyun Uysal, Alpay Medetalibeyoğlu, Naci Şenkal, Elvin Alaskarov and Sevim Meşe

Viruses 2023, 15(11), 2222; https://doi.org/10.3390/v15112222 - 7 Nov 2023

Cited by 1 | Viewed by 1590

Abstract

The aim of this study was to investigate the reinfection rates and characteristics of SARS-CoV-2 in individuals with SARS-CoV-2 RNA present in their clinical specimens for COVID-19. Our data from the COVID-19 Laboratory of Istanbul University were analyzed for 27,240 cases between 27 [...] Read more.

The aim of this study was to investigate the reinfection rates and characteristics of SARS-CoV-2 in individuals with SARS-CoV-2 RNA present in their clinical specimens for COVID-19. Our data from the COVID-19 Laboratory of Istanbul University were analyzed for 27,240 cases between 27 March 2020 to 8 February 2022. Demographic characteristics, vaccination statuses, comorbidities, and laboratory findings were evaluated in cases with suspected reinfection, as determined by the presence of SARS-CoV-2 RNA at a rate of 0.3% in clinical specimens. When comparing laboratory values, leukocyte counts were lower in the second and third infections compared with the first infection (p = 0.035), and neutrophil counts were lower in the second infection (p = 0.009). Symptoms varied, with coughing being common in the first infection and malaise being common in subsequent infections. These results suggest that it is important to continue to monitor reinfection rates and develop strategies to prevent reinfection. Our results also suggest that clinicians should be aware of the possibility of reinfection and monitor patients for recurrent symptoms. Full article

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24 pages, 4245 KiB

Open AccessArticle

COVID-19 Incidence Proportion as a Function of Regional Testing Strategy, Vaccination Coverage, and Vaccine Type

by Areg A. Totolian, Viacheslav S. Smirnov, Alexei A. Krasnov, Edward S. Ramsay, Vladimir G. Dedkov and Anna Y. Popova

Viruses 2023, 15(11), 2181; https://doi.org/10.3390/v15112181 - 30 Oct 2023

Cited by 2 | Viewed by 1509

Abstract

Introduction: The COVID-19 pandemic has become a serious challenge for humanity almost everywhere globally. Despite active vaccination around the world, the incidence proportion in different countries varies significantly as of May 2022. The reason may be a combination of demographic, immunological, and epidemiological [...] Read more.

Introduction: The COVID-19 pandemic has become a serious challenge for humanity almost everywhere globally. Despite active vaccination around the world, the incidence proportion in different countries varies significantly as of May 2022. The reason may be a combination of demographic, immunological, and epidemiological factors. The purpose of this study was to analyze possible relationships between COVID-19 incidence proportion in the population and the types of SARS-CoV-2 vaccines used in different countries globally, taking into account demographic and epidemiological factors. Materials and methods: An initial database was created of demographic and immunoepidemiological information about the COVID-19 situation in 104 countries collected from published official sources and repository data. The baseline included, for each country, population size and density; SARS-CoV-2 testing coverage; vaccination coverage; incidence proportion; and a list of vaccines that were used, including their relative share among all vaccinations. Subsequently, the initial data set was stratified by population and vaccination coverage. The final data set was subjected to statistical processing both in general and taking into account population testing coverage. Results: After formation of the final data set (including 53 countries), it turned out that reported COVID-19 case numbers correlated most strongly with testing coverage and the proportions of vaccine types used, specifically, mRNA (V1); vector (V2); peptide/protein (V3); and whole-virion/inactivated (V4). Due to the fact that an inverse correlation was found between ‘reported COVID-19 case numbers’ with V2, V3, and V4, these three vaccine types were also combined into one analytic group, ‘non-mRNA group’ vaccines (Vnmg). When the relationship between vaccine type and incidence proportion was examined, minimum incidence proportion was noted at V1:Vnmg ratios (%:%) from 0:100 to 30:70. Maximum incidence proportion was seen with V1:Vnmg from 80:20 to 100:0. On the other hand, we have shown that the number of reported COVID-19 cases in different countries largely depends on testing coverage. To offset this factor, countries with low and extremely high levels of testing were excluded from the data set; it was then confirmed that the largest number of reported COVID-19 cases occurred in countries with a dominance of V1 vaccines. The fewest reported cases were seen in countries with a dominance of Vnmg vaccines. Conclusion: In this paper, we have shown for the first time that the level of reported COVID-19 incidence proportion depends not only on SARS-CoV-2 testing and vaccination coverage, which is quite logical, but probably also on the vaccine types used. With the same vaccination level and testing coverage, those countries that predominantly use vector and whole-virion vaccines feature incidence proportion that is significantly lower than countries that predominantly use mRNA vaccines. Full article

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21 pages, 4851 KiB

Open AccessArticle

The Ubiquitin-Proteasome System Facilitates Membrane Fusion and Uncoating during Coronavirus Entry

by Xiao Yuan, Xiaoman Zhang, Huan Wang, Xiang Mao, Yingjie Sun, Lei Tan, Cuiping Song, Xusheng Qiu, Chan Ding and Ying Liao

Viruses 2023, 15(10), 2001; https://doi.org/10.3390/v15102001 - 26 Sep 2023

Cited by 2 | Viewed by 2105

Abstract

Although the involvement of the ubiquitin-proteasome system (UPS) in several coronavirus-productive infections has been reported, whether the UPS is required for infectious bronchitis virus (IBV) and porcine epidemic diarrhea virus (PEDV) infections is unclear. In this study, the role of UPS in the [...] Read more.

Although the involvement of the ubiquitin-proteasome system (UPS) in several coronavirus-productive infections has been reported, whether the UPS is required for infectious bronchitis virus (IBV) and porcine epidemic diarrhea virus (PEDV) infections is unclear. In this study, the role of UPS in the IBV and PEDV life cycles was investigated. When the UPS was suppressed by pharmacological inhibition at the early infection stage, IBV and PEDV infectivity were severely impaired. Further study showed that inhibition of UPS did not change the internalization of virus particles; however, by using R18 and DiOC-labeled virus particles, we found that inhibition of UPS prevented the IBV and PEDV membrane fusion with late endosomes or lysosomes. In addition, proteasome inhibitors blocked the degradation of the incoming viral protein N, suggesting the uncoating process and genomic RNA release were suppressed. Subsequently, the initial translation of genomic RNA was blocked. Thus, UPS may target the virus-cellular membrane fusion to facilitate the release of incoming viruses from late endosomes or lysosomes, subsequently blocking the following virus uncoating, initial translation, and replication events. Similar to the observation of proteasome inhibitors, ubiquitin-activating enzyme E1 inhibitor PYR-41 also impaired the entry of IBV, enhanced the accumulation of ubiquitinated proteins, and depleted mono-ubiquitin. In all, this study reveals an important role of UPS in coronavirus entry by preventing membrane fusion and identifies UPS as a potential target for developing antiviral therapies for coronavirus. Full article

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8 pages, 1116 KiB

Open AccessCommunication

Dynamic Evolution of SARS-CoV-2 in a Patient on Chemotherapy

by Weihua Huang, Changhong Yin, Kimberly P. Briley, William A. B. Dalzell and John T. Fallon

Viruses 2023, 15(8), 1759; https://doi.org/10.3390/v15081759 - 18 Aug 2023

Cited by 1 | Viewed by 1835

Abstract

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has evolved significantly during the pandemic and resulted in daunting numbers of genomic sequences. Tracking SARS-CoV-2 evolution during persistent cases could provide insight into the origins and dynamics of new variants. We report here a case [...] Read more.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has evolved significantly during the pandemic and resulted in daunting numbers of genomic sequences. Tracking SARS-CoV-2 evolution during persistent cases could provide insight into the origins and dynamics of new variants. We report here a case of B-cell acute lymphocytic leukemia on chemotherapy with infection of SARS-CoV-2 for more than two months. Genomic surveillance of his serial SARS-CoV-2-positive specimens revealed two unprecedented large deletions, Δ15–26 and Δ138–145, in the viral spike protein N-terminal domain (NTD) and demonstrated their dynamic shifts in generating these new variants. Located at antigenic supersites, these large deletions are anticipated to dramatically change the spike protein NTD in three-dimensional protein structure prediction, which may lead to immune escape but reduce their viral transmissibility. In summary, we present here a new viral evolutionary trajectory in a patient on chemotherapy. Full article

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17 pages, 2772 KiB

Open AccessArticle

Mutation Analysis of SARS-CoV-2 Variants Isolated from Symptomatic Cases from Andhra Pradesh, India

by Mudhigeti Nagaraja, Kodavala Sireesha, Anagoni Srikar, Katari Sudheer Kumar, Alladi Mohan, Bhuma Vengamma, Chejarla Tirumala, Anju Verma and Usha Kalawat

Viruses 2023, 15(8), 1656; https://doi.org/10.3390/v15081656 - 29 Jul 2023

Cited by 1 | Viewed by 1644

Abstract

There has been a continuous evolution in the SARS-CoV-2 genome; therefore, it is necessary to monitor the shifts in the SARS-CoV-2 variants. This study aimed to detect various SARS-CoV-2 variants circulating in the state of Andhra Pradesh, India. The study attempted to sequence [...] Read more.

There has been a continuous evolution in the SARS-CoV-2 genome; therefore, it is necessary to monitor the shifts in the SARS-CoV-2 variants. This study aimed to detect various SARS-CoV-2 variants circulating in the state of Andhra Pradesh, India. The study attempted to sequence the complete S-gene of SARS-CoV-2 of 104 clinical samples using Sanger’s method to analyze and compare the mutations with the global prevalence. The method standardized in this study was able to amplify the complete length of the S-gene (3822 bp). The resulting nucleotide and amino acid mutations were analyzed and compared with the local and global SARS-CoV-2 databases using Nextclade and GISAID tools. The Delta variant was the most common variant reported in the present study, followed by the Omicron variant. A variant name was not assigned to thirteen samples using the Nextclade tool. There were sixty-nine types of amino acid substitutions reported (excluding private mutations) throughout the spike gene. The T95I mutation was observed predominantly in Delta variants (15/38), followed by Kappa (3/8) and Omicron (1/31). Nearly all Alpha and Omicron lineages had the N501Y substitution; Q493R was observed only in the Omicron lineage; and other mutations (L445, F486, and S494) were not observed in the present study. Most of these mutations found in the Omicron variant are located near the furin cleavage site, which may play a role in the virulence, pathogenicity, and transmission of the virus. Phylogenetic analysis showed that the 104 complete CDS of SARS-CoV-2 belonged to different phylogenetic clades like 20A, 20B, 20I (Alpha), 21A (Delta), 21B (Kappa), 21I (Delta), 21J (Delta), and 21L (Omicron). Full article

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16 pages, 4324 KiB

Open AccessArticle

Risk Assessment of the Possible Intermediate Host Role of Pigs for Coronaviruses with a Deep Learning Predictor

by Shuyang Jiang, Sen Zhang, Xiaoping Kang, Ye Feng, Yadan Li, Maoshun Nie, Yuchang Li, Yuehong Chen, Shishun Zhao, Tao Jiang and Jing Li

Viruses 2023, 15(7), 1556; https://doi.org/10.3390/v15071556 - 15 Jul 2023

Cited by 5 | Viewed by 1590

Abstract

Swine coronaviruses (CoVs) have been found to cause infection in humans, suggesting that Suiformes might be potential intermediate hosts in CoV transmission from their natural hosts to humans. The present study aims to establish convolutional neural network (CNN) models to predict host adaptation [...] Read more.

Swine coronaviruses (CoVs) have been found to cause infection in humans, suggesting that Suiformes might be potential intermediate hosts in CoV transmission from their natural hosts to humans. The present study aims to establish convolutional neural network (CNN) models to predict host adaptation of swine CoVs. Decomposing of each ORF1ab and Spike sequence was performed with dinucleotide composition representation (DCR) and other traits. The relationship between CoVs from different adaptive hosts was analyzed by unsupervised learning, and CNN models based on DCR of ORF1ab and Spike were built to predict the host adaptation of swine CoVs. The rationality of the models was verified with phylogenetic analysis. Unsupervised learning showed that there is a multiple host adaptation of different swine CoVs. According to the adaptation prediction of CNN models, swine acute diarrhea syndrome CoV (SADS-CoV) and porcine epidemic diarrhea virus (PEDV) are adapted to Chiroptera, swine transmissible gastroenteritis virus (TGEV) is adapted to Carnivora, porcine hemagglutinating encephalomyelitis (PHEV) might be adapted to Primate, Rodent, and Lagomorpha, and porcine deltacoronavirus (PDCoV) might be adapted to Chiroptera, Artiodactyla, and Carnivora. In summary, the DCR trait has been confirmed to be representative for the CoV genome, and the DCR-based deep learning model works well to assess the adaptation of swine CoVs to other mammals. Suiformes might be intermediate hosts for human CoVs and other mammalian CoVs. The present study provides a novel approach to assess the risk of adaptation and transmission to humans and other mammals of swine CoVs. Full article

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18 pages, 2479 KiB

Open AccessArticle

Generation of a SARS-CoV-2 Reverse Genetics System and Novel Human Lung Cell Lines That Exhibit High Virus-Induced Cytopathology

by Juveriya Qamar Khan, Megha Rohamare, Karthic Rajamanickam, Kalpana K. Bhanumathy, Jocelyne Lew, Anil Kumar, Darryl Falzarano, Franco J. Vizeacoumar and Joyce A. Wilson

Viruses 2023, 15(6), 1281; https://doi.org/10.3390/v15061281 - 30 May 2023

Cited by 4 | Viewed by 2651

Abstract

The global COVID-19 pandemic continues with continued cases worldwide and the emergence of new SARS-CoV-2 variants. In our study, we have developed novel tools with applications for screening antivirals, identifying virus–host dependencies, and characterizing viral variants. Using reverse genetics, we rescued SARS-CoV-2 Wuhan1 [...] Read more.

The global COVID-19 pandemic continues with continued cases worldwide and the emergence of new SARS-CoV-2 variants. In our study, we have developed novel tools with applications for screening antivirals, identifying virus–host dependencies, and characterizing viral variants. Using reverse genetics, we rescued SARS-CoV-2 Wuhan1 (D614G variant) wild type (WTFL) and reporter virus (NLucFL) using molecular BAC clones. The replication kinetics, plaque morphology, and titers were comparable between viruses rescued from molecular clones and a clinical isolate (VIDO-01 strain). Furthermore, the reporter SARS-CoV-2 NLucFL virus exhibited robust luciferase values over the time course of infection and was used to develop a rapid antiviral assay using remdesivir as proof-of-principle. In addition, as a tool to study lung-relevant virus–host interactions, we established novel human lung cell lines that support SARS-CoV-2 infection with high virus-induced cytopathology. Six lung cell lines (NCI-H23, A549, NCI-H1703, NCI-H520, NCI-H226, and HCC827) and HEK293T cells were transduced to stably express ACE2 and tested for their ability to support virus infection. A549ACE2 B1 and HEK293TACE2 A2 cell lines exhibited more than 70% virus-induced cell death, and a novel lung cell line, NCI-H23ACE2 A3, showed about ~99% cell death post-infection. These cell lines are ideal for assays relying on live–dead selection, such as CRISPR knockout and activation screens. Full article

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11 pages, 2971 KiB

Open AccessArticle

Porcine Deltacoronavirus-like Particles Produced by a Single Recombinant Baculovirus Elicit Virus-Specific Immune Responses in Mice

by Yangkun Liu, Xueying Han, Yaqi Qiao, Tiejun Wang and Lunguang Yao

Viruses 2023, 15(5), 1095; https://doi.org/10.3390/v15051095 - 29 Apr 2023

Cited by 2 | Viewed by 2253

Abstract

Porcine deltacoronavirus (PDCoV) causes diarrhea and vomiting in neonatal piglets worldwide and has the potential for cross-species transmission. Therefore, virus-like particles (VLPs) are promising vaccine candidates because of their safety and strong immunogenicity. To the best of our knowledge, the present study reported [...] Read more.

Porcine deltacoronavirus (PDCoV) causes diarrhea and vomiting in neonatal piglets worldwide and has the potential for cross-species transmission. Therefore, virus-like particles (VLPs) are promising vaccine candidates because of their safety and strong immunogenicity. To the best of our knowledge, the present study reported for the first time the generation of PDCoV VLPs using a baculovirus expression vector system, and electron micrograph analyses revealed that PDCoV VLPs appeared as spherical particles with a diameter similar to that of the native virions. Furthermore, PDCoV VLPs effectively induced mice to produce PDCoV-specific IgG and neutralizing antibodies. In addition, VLPs could stimulate mouse splenocytes to produce high levels of cytokines IL-4 and IFN-γ. Moreover, the combination of PDCoV VLPs and Freund’s adjuvant could improve the level of the immune response. Together, these data showed that PDCoV VLPs could effectively elicit humoral and cellular immunity in mice, laying a solid foundation for developing VLP-based vaccines to prevent PDCoV infections. Full article

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2 pages, 170 KiB

Open AccessCorrection

Correction: Yu et al. Comparison of Physical and Biochemical Characterizations of SARS-CoV-2 Inactivated by Different Treatments. Viruses 2022, 14, 1938

by Shouzhi Yu, Yangyang Wei, Hongyang Liang, Wenheng Ji, Zhen Chang, Siman Xie, Yichuan Wang, Wanli Li, Yingwei Liu, Hao Wu, Jie Li, Hui Wang and Xiaoming Yang

Viruses 2023, 15(5), 1035; https://doi.org/10.3390/v15051035 - 23 Apr 2023

Viewed by 870

Abstract

In the original publication [...] Full article

11 pages, 1112 KiB

Open AccessReview

SARS-CoV-2 Reinfection and Severity of the Disease: A Systematic Review and Meta-Analysis

by Nhu Ngoc Nguyen, Y Ngoc Nguyen, Van Thuan Hoang, Matthieu Million and Philippe Gautret

Viruses 2023, 15(4), 967; https://doi.org/10.3390/v15040967 - 14 Apr 2023

Cited by 33 | Viewed by 15125

Abstract

Since the discovery of SARS-CoV-2, changes in genotype and reinfection with different variants have been observed in COVID-19-recovered patients, raising questions around the clinical pattern and severity of primary infection and reinfection. In this systematic review, we summarize the results of 23 studies [...] Read more.

Since the discovery of SARS-CoV-2, changes in genotype and reinfection with different variants have been observed in COVID-19-recovered patients, raising questions around the clinical pattern and severity of primary infection and reinfection. In this systematic review, we summarize the results of 23 studies addressing SARS-CoV-2 reinfections. A total of 23,231 reinfected patients were included, with pooled estimated reinfection rates ranging from 0.1 to 6.8%. Reinfections were more prevalent during the Omicron variant period. The mean age of reinfected patients was 38.0 ± 6. years and females were predominant among reinfected patients (M/F = 0.8). The most common symptoms during the first and second infection were fever (41.1%), cough (35.7% and 44.6%), myalgia (34.5% and 33.3%), fatigue (23.8% and 25.6%), and headaches (24.4% and 21.4%). No significant differences of clinical pattern were observed between primary infection and reinfection. No significant differences in the severity of infection were observed between primary infection and reinfection. Being female, being a patient with comorbidities, lacking anti-nucleocapsid IgG after the first infection, being infected during the Delta and Omicron wave, and being unvaccinated were associated with a higher risk of reinfection. Conflicting age-related findings were found in two studies. Reinfection with SARS-CoV-2 suggests that natural immunity is not long-lasting in COVID-19 patients. Full article

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10 pages, 855 KiB

Open AccessArticle

Real-World Experience of the Comparative Effectiveness and Safety of Molnupiravir and Nirmatrelvir/Ritonavir in High-Risk Patients with COVID-19 in a Community Setting

by Yoshikazu Mutoh, Takumi Umemura, Takeshi Nishikawa, Kaho Kondo, Yuta Nishina, Kazuaki Soejima, Yoichiro Noguchi, Tomohiro Bando, Sho Ota, Tatsuki Shimahara, Shuko Hirota, Satoshi Hagimoto, Reoto Takei, Jun Fukihara, Hajime Sasano, Yasuhiko Yamano, Toshiki Yokoyama, Kensuke Kataoka, Toshiaki Matsuda, Tomoki Kimura, Toshihiko Ichihara and Yasuhiro Kondoh Show full author list Hide full author list

Viruses 2023, 15(3), 811; https://doi.org/10.3390/v15030811 - 22 Mar 2023

Cited by 10 | Viewed by 3762

Abstract

Molnupiravir (MOV) and nirmatrelvir/ritonavir (NMV/r) are efficacious oral antiviral agents for patients with the 2019 coronavirus (COVID-19). However, little is known about their effectiveness in older adults and those at high risk of disease progression. This retrospective single-center observational study assessed and compared [...] Read more.

Molnupiravir (MOV) and nirmatrelvir/ritonavir (NMV/r) are efficacious oral antiviral agents for patients with the 2019 coronavirus (COVID-19). However, little is known about their effectiveness in older adults and those at high risk of disease progression. This retrospective single-center observational study assessed and compared the outcomes of COVID-19 treated with MOV and NMV/r in a real-world community setting. We included patients with confirmed COVID-19 combined with one or more risk factors for disease progression from June to October 2022. Of 283 patients, 79.9% received MOV and 20.1% NMV/r. The mean patient age was 71.7 years, 56.5% were men, and 71.7% had received ≥3 doses of vaccine. COVID-19-related hospitalization (2.8% and 3.5%, respectively; p = 0.978) or death (0.4% and 3.5%, respectively; p = 0.104) did not differ significantly between the MOV and NMV/r groups. The incidence of adverse events was 2.7% and 5.3%, and the incidence of treatment discontinuation was 2.7% and 5.3% in the MOV and NMV/r groups, respectively. The real-world effectiveness of MOV and NMV/r was similar among older adults and those at high risk of disease progression. The incidence of hospitalization or death was low. Full article

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18 pages, 7178 KiB

Open AccessArticle

Evaluation of SARS-CoV-2 ORF7a Deletions from COVID-19-Positive Individuals and Its Impact on Virus Spread in Cell Culture

by Maria Clara da Costa Simas, Sara Mesquita Costa, Priscila da Silva Figueiredo Celestino Gomes, Nádia Vaez Gonçalves da Cruz, Isadora Alonso Corrêa, Marcos Romário Matos de Souza, Marcos Dornelas-Ribeiro, Tatiana Lucia Santos Nogueira, Caleb Guedes Miranda dos Santos, Luísa Hoffmann, Amilcar Tanuri, Rodrigo Soares de Moura-Neto, Clarissa R. Damaso, Luciana Jesus da Costa and Rosane Silva

Viruses 2023, 15(3), 801; https://doi.org/10.3390/v15030801 - 21 Mar 2023

Cited by 4 | Viewed by 3008

Abstract

The spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), causing the COVID-19 outbreak, posed a primary concern of public health worldwide. The most common changes in SARS-CoV-2 are single nucleotide substitutions, also reported insertions and deletions. This work investigates the presence of [...] Read more.

The spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), causing the COVID-19 outbreak, posed a primary concern of public health worldwide. The most common changes in SARS-CoV-2 are single nucleotide substitutions, also reported insertions and deletions. This work investigates the presence of SARS-CoV-2 ORF7a deletions identified in COVID-19-positive individuals. Sequencing of SARS-CoV-2 complete genomes showed three different ORF7a size deletions (190-nt, 339-nt and 365-nt). Deletions were confirmed through Sanger sequencing. The ORF7a∆190 was detected in a group of five relatives with mild symptoms of COVID-19, and the ORF7a∆339 and ORF7a∆365 in a couple of co-workers. These deletions did not affect subgenomic RNAs (sgRNA) production downstream of ORF7a. Still, fragments associated with sgRNA of genes upstream of ORF7a showed a decrease in size when corresponding to samples with deletions. In silico analysis suggests that the deletions impair protein proper function; however, isolated viruses with partial deletion of ORF7a can replicate in culture cells similarly to wild-type viruses at 24 hpi, but with less infectious particles after 48 hpi. These findings on deleted ORF7a accessory protein gene, contribute to understanding SARS-CoV-2 phenotypes such as replication, immune evasion and evolutionary fitness as well insights into the role of SARS-CoV-2_ORF7a in the mechanism of virus-host interactions. Full article

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10 pages, 4741 KiB

Open AccessArticle

Crystal Structures of Inhibitor-Bound Main Protease from Delta- and Gamma-Coronaviruses

by Sarah N. Zvornicanin, Ala M. Shaqra, Qiuyu J. Huang, Elizabeth Ornelas, Mallika Moghe, Mark Knapp, Stephanie Moquin, Dustin Dovala, Celia A. Schiffer and Nese Kurt Yilmaz

Viruses 2023, 15(3), 781; https://doi.org/10.3390/v15030781 - 18 Mar 2023

Cited by 5 | Viewed by 2551

Abstract

With the spread of SARS-CoV-2 throughout the globe causing the COVID-19 pandemic, the threat of zoonotic transmissions of coronaviruses (CoV) has become even more evident. As human infections have been caused by alpha- and beta-CoVs, structural characterization and inhibitor design mostly focused on [...] Read more.

With the spread of SARS-CoV-2 throughout the globe causing the COVID-19 pandemic, the threat of zoonotic transmissions of coronaviruses (CoV) has become even more evident. As human infections have been caused by alpha- and beta-CoVs, structural characterization and inhibitor design mostly focused on these two genera. However, viruses from the delta and gamma genera also infect mammals and pose a potential zoonotic transmission threat. Here, we determined the inhibitor-bound crystal structures of the main protease (M^pro) from the delta-CoV porcine HKU15 and gamma-CoV SW1 from the beluga whale. A comparison with the apo structure of SW1 M^pro, which is also presented here, enabled the identification of structural arrangements upon inhibitor binding at the active site. The cocrystal structures reveal binding modes and interactions of two covalent inhibitors, PF-00835231 (active form of lufotrelvir) bound to HKU15, and GC376 bound to SW1 M^pro. These structures may be leveraged to target diverse coronaviruses and toward the structure-based design of pan-CoV inhibitors. Full article

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14 pages, 1791 KiB

Open AccessArticle

Effects of SARS-CoV-2 Omicron BA.1 Spike Mutations on T-Cell Epitopes in Mice

by Yudong Wang, Busen Wang, Zhenghao Zhao, Jinghan Xu, Zhe Zhang, Jinlong Zhang, Yi Chen, Xiaohong Song, Wanru Zheng, Lihua Hou, Shipo Wu and Wei Chen

Viruses 2023, 15(3), 763; https://doi.org/10.3390/v15030763 - 16 Mar 2023

Cited by 5 | Viewed by 2333

Abstract

T-cell immunity plays an important role in the control of SARS-CoV-2 and has a great cross-protective effect on the variants. The Omicron BA.1 variant contains more than 30 mutations in the spike and severely evades humoral immunity. To understand how Omicron BA.1 spike [...] Read more.

T-cell immunity plays an important role in the control of SARS-CoV-2 and has a great cross-protective effect on the variants. The Omicron BA.1 variant contains more than 30 mutations in the spike and severely evades humoral immunity. To understand how Omicron BA.1 spike mutations affect cellular immunity, the T-cell epitopes of SARS-CoV-2 wild-type and Omicron BA.1 spike in BALB/c (H-2^d) and C57BL/6 mice (H-2^b) were mapped through IFNγ ELISpot and intracellular cytokine staining assays. The epitopes were identified and verified in splenocytes from mice vaccinated with the adenovirus type 5 vector encoding the homologous spike, and the positive peptides involved in spike mutations were tested against wide-type and Omicron BA.1 vaccines. A total of eleven T-cell epitopes of wild-type and Omicron BA.1 spike were identified in BALB/c mice, and nine were identified in C57BL/6 mice, only two of which were CD4⁺ T-cell epitopes and most of which were CD8⁺ T-cell epitopes. The A67V and Del 69-70 mutations in Omicron BA.1 spike abolished one epitope in wild-type spike, and the T478K, E484A, Q493R, G496S and H655Y mutations resulted in three new epitopes in Omicron BA.1 spike, while the Y505H mutation did not affect the epitope. These data describe the difference of T-cell epitopes in SARS-CoV-2 wild-type and Omicron BA.1 spike in H-2^b and H-2^d mice, providing a better understanding of the effects of Omicron BA.1 spike mutations on cellular immunity. Full article

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12 pages, 6796 KiB

Open AccessCommunication

SARS-CoV-2 Is More Efficient than HCoV-NL63 in Infecting a Small Subpopulation of ACE2+ Human Respiratory Epithelial Cells

by Gino Castillo, Rahul K. Nelli, Kruttika S. Phadke, Marlene Bravo-Parra, Juan Carlos Mora-Díaz, Bryan H. Bellaire and Luis G. Giménez-Lirola

Viruses 2023, 15(3), 736; https://doi.org/10.3390/v15030736 - 13 Mar 2023

Cited by 1 | Viewed by 2325

Abstract

Human coronavirus (HCoV)-NL63 is an important contributor to upper and lower respiratory tract infections, mainly in children, while severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the etiological agent of COVID-19, can cause lower respiratory tract infections, and more severe, respiratory and systemic disease, [...] Read more.

Human coronavirus (HCoV)-NL63 is an important contributor to upper and lower respiratory tract infections, mainly in children, while severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the etiological agent of COVID-19, can cause lower respiratory tract infections, and more severe, respiratory and systemic disease, which leads to fatal consequences in many cases. Using microscopy, immunohistochemistry (IHC), virus-binding assay, reverse transcriptase qPCR (RT-qPCR) assay, and flow cytometry, we compared the characteristics of the susceptibility, replication dynamics, and morphogenesis of HCoV-NL63 and SARS-CoV-2 in monolayer cultures of primary human respiratory epithelial cells (HRECs). Less than 10% HRECs expressed ACE2, and SARS-CoV-2 seemed much more efficient than HCoV-NL63 at infecting the very small proportion of HRECs expressing the ACE2 receptors. Furthermore, SARS-CoV-2 replicated more efficiently than HCoV-NL63 in HREC, which correlates with the cumulative evidence of the differences in their transmissibility. Full article

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10 pages, 2358 KiB

Open AccessCommunication

Use of a Preclinical Natural Transmission Model to Study Antiviral Effects of a Carbohydrate-Binding Module Therapy against SARS-CoV-2 in Hamsters

by Daniel Knott, Rachel Fell, Jane A. Potter, Samantha Yuille, Franscisco J. Salguero, Victoria A. Graham, Roger Hewson, David Howat and Stuart D. Dowall

Viruses 2023, 15(3), 725; https://doi.org/10.3390/v15030725 - 11 Mar 2023

Cited by 2 | Viewed by 1780

Abstract

The emergence of severe acute respiratory syndrome coronavirus (SARS-CoV-2) and its expansion to a worldwide pandemic resulted in efforts to assess and develop interventions to reduce the disease burden. Despite the introduction of vaccine programmes against SARS-CoV-2, global incidence levels in early 2022 [...] Read more.

The emergence of severe acute respiratory syndrome coronavirus (SARS-CoV-2) and its expansion to a worldwide pandemic resulted in efforts to assess and develop interventions to reduce the disease burden. Despite the introduction of vaccine programmes against SARS-CoV-2, global incidence levels in early 2022 remained high, demonstrating a need for the development of physiologically relevant models, which are essential for the identification of alternative antiviral strategies. The hamster model of SARS-CoV-2 infection has been widely adopted due to similarities with humans in terms of host cell entry mechanism (via ACE2), and aspects of symptomology and virus shedding. We have previously described a natural transmission hamster model that better represents the natural course of infection. In the present study, we have conducted further testing of the model using the first-in-class antiviral Neumifil, which has previously shown promise against SARS-CoV-2 after a direct intranasal challenge. Neumifil is an intranasally delivered carbohydrate-binding module (CBM) which reduces the binding of viruses to their cellular receptor. By targeting the host cell, Neumifil has the potential to provide broad protection against multiple pathogens and variants. This study demonstrates that using a combination of a prophylactic and therapeutic delivery of Neumifil significantly reduces the severity of clinical signs in animals infected via a natural route of transmission and indicates a reduction of viral loads in the upper respiratory tract. Further refinements of the model are required in order to ensure the adequate transmission of the virus. However, our results provide additional data to the evidence base of Neumifil efficacy against respiratory virus infection and demonstrate that the transmission model is a potentially valuable tool for testing antiviral compounds against SARS-CoV-2. Full article

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19 pages, 1077 KiB

Open AccessReview

SARS-CoV-2 Spike-Mediated Entry and Its Regulation by Host Innate Immunity

by Shi Yu, Huina Hu, Qiangyun Ai, Rong Bai, Kaixiong Ma, Minmin Zhou and Shaobo Wang

Viruses 2023, 15(3), 639; https://doi.org/10.3390/v15030639 - 27 Feb 2023

Cited by 2 | Viewed by 3567

Abstract

The constantly evolving severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants of concern (VOC) fuel the worldwide coronavirus disease (COVID-19) pandemic. The spike protein is essential for the SARS-CoV-2 viral entry and thus has been extensively targeted by therapeutic antibodies. However, mutations along [...] Read more.

The constantly evolving severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants of concern (VOC) fuel the worldwide coronavirus disease (COVID-19) pandemic. The spike protein is essential for the SARS-CoV-2 viral entry and thus has been extensively targeted by therapeutic antibodies. However, mutations along the spike in SARS-CoV-2 VOC and Omicron subvariants have caused more rapid spread and strong antigenic drifts, rendering most of the current antibodies ineffective. Hence, understanding and targeting the molecular mechanism of spike activation is of great interest in curbing the spread and development of new therapeutic approaches. In this review, we summarize the conserved features of spike-mediated viral entry in various SARS-CoV-2 VOC and highlight the converging proteolytic processes involved in priming and activating the spike. We also summarize the roles of innate immune factors in preventing spike-driven membrane fusion and provide outlines for the identification of novel therapeutics against coronavirus infections. Full article

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23 pages, 5984 KiB

Open AccessArticle

SKI-1/S1P Facilitates SARS-CoV-2 Spike Induced Cell-to-Cell Fusion via Activation of SREBP-2 and Metalloproteases, Whereas PCSK9 Enhances the Degradation of ACE2

by Rachid Essalmani, Ursula Andréo, Alexandra Evagelidis, Maïlys Le Dévéhat, Oscar Henrique Pereira Ramos, Carole Fruchart Gaillard, Delia Susan-Resiga, Éric A. Cohen and Nabil G. Seidah

Viruses 2023, 15(2), 360; https://doi.org/10.3390/v15020360 - 27 Jan 2023

Cited by 7 | Viewed by 2906

Abstract

Proprotein convertases activate various envelope glycoproteins and participate in cellular entry of many viruses. We recently showed that the convertase furin is critical for the infectivity of SARS-CoV-2, which requires cleavage of its spike protein (S) at two sites: S1/S2 and S2′. This [...] Read more.

Proprotein convertases activate various envelope glycoproteins and participate in cellular entry of many viruses. We recently showed that the convertase furin is critical for the infectivity of SARS-CoV-2, which requires cleavage of its spike protein (S) at two sites: S1/S2 and S2′. This study investigates the implication of the two cholesterol-regulating convertases SKI-1 and PCSK9 in SARS-CoV-2 entry. The assays used were cell-to-cell fusion in HeLa cells and pseudoparticle entry into Calu-3 cells. SKI-1 increased cell-to-cell fusion by enhancing the activation of SREBP-2, whereas PCSK9 reduced cell-to-cell fusion by promoting the cellular degradation of ACE2. SKI-1 activity led to enhanced S2′ formation, which was attributed to increased metalloprotease activity as a response to enhanced cholesterol levels via activated SREBP-2. However, high metalloprotease activity resulted in the shedding of S2′ into a new C-terminal fragment (S2″), leading to reduced cell-to-cell fusion. Indeed, S-mutants that increase S2″ formation abolished S2′ and cell-to-cell fusion, as well as pseudoparticle entry, indicating that the formation of S2″ prevents SARS-CoV-2 cell-to-cell fusion and entry. We next demonstrated that PCSK9 enhanced the cellular degradation of ACE2, thereby reducing cell-to-cell fusion. However, different from the LDLR, a canonical target of PCSK9, the C-terminal CHRD domain of PCSK9 is dispensable for the PCSK9-induced degradation of ACE2. Molecular modeling suggested the binding of ACE2 to the Pro/Catalytic domains of mature PCSK9. Thus, both cholesterol-regulating convertases SKI-1 and PCSK9 can modulate SARS-CoV-2 entry via two independent mechanisms. Full article

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19 pages, 4916 KiB

Open AccessArticle

Coronaviruses Are Abundant and Genetically Diverse in West and Central African Bats, including Viruses Closely Related to Human Coronaviruses

by Dowbiss Meta Djomsi, Audrey Lacroix, Abdoul Karim Soumah, Eddy Kinganda Lusamaki, Asma Mesdour, Raisa Raulino, Amandine Esteban, Innocent Ndong Bass, Flaubert Auguste Mba Djonzo, Souana Goumou, Simon Pierre Ndimbo-Kimugu, Guy Lempu, Placide Mbala Kingebeni, Daniel Mukadi Bamuleka, Jacques Likofata, Jean-Jacques Muyembe Tamfum, Abdoulaye Toure, Eitel Mpoudi Ngole, Charles Kouanfack, Eric Delaporte, Alpha Kabinet Keita, Steve Ahuka-Mundeke, Ahidjo Ayouba and Martine Peeters Show full author list Hide full author list

Viruses 2023, 15(2), 337; https://doi.org/10.3390/v15020337 - 25 Jan 2023

Cited by 7 | Viewed by 2874

Abstract

Bats are at the origin of human coronaviruses, either directly or via an intermediate host. We tested swabs from 4597 bats (897 from the Democratic Republic of Congo (DRC), 2191 from Cameroon and 1509 from Guinea) with a broadly reactive PCR in the [...] Read more.

Bats are at the origin of human coronaviruses, either directly or via an intermediate host. We tested swabs from 4597 bats (897 from the Democratic Republic of Congo (DRC), 2191 from Cameroon and 1509 from Guinea) with a broadly reactive PCR in the RdRp region. Coronaviruses were detected in 903 (19.6%) bats and in all species, with more than 25 individuals tested. The highest prevalence was observed in Eidolon helvum (239/733; 39.9%) and Rhinolophus sp. (306/899; 34.1%), followed by Hipposideros sp. (61/291; 20.9%). Frugivorous bats were predominantly infected with beta coronaviruses from the Nobecovirus subgenus (93.8%), in which at least 6 species/genus-specific subclades were observed. In contrast, insectivorous bats were infected with beta-coronaviruses from different subgenera (Nobecovirus (8.5%), Hibecovirus (32.8%), Merbecovirus (0.5%) and Sarbecovirus (57.6%)) and with a high diversity of alpha-coronaviruses. Overall, our study shows a high prevalence and genetic diversity of coronaviruses in bats and illustrates that Rhinolophus bats in Africa are infected at high levels with the Sarbecovirus subgenus, to which SARS-CoV-2 belongs. It is important to characterize in more detail the different coronavirus lineages from bats for their potential to infect human cells, their evolution and to study frequency and modes of contact between humans and bats in Africa. Full article

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2022

Jump to: 2024, 2023, 2021, 2020

10 pages, 980 KiB

Open AccessBrief Report

Clinical Severity in Different Waves of SARS-CoV-2 Infection in Sicily: A Model of Smith’s “Law of Declining Virulence” from Real-World Data

by Emanuele Amodio, Dario Genovese, Alessandra Fallucca, Patrizia Ferro, Benedetta Sparacia, Luciano D’Azzo, Angelo Fertitta, Carmelo Massimo Maida and Francesco Vitale

Viruses 2023, 15(1), 125; https://doi.org/10.3390/v15010125 - 31 Dec 2022

Cited by 6 | Viewed by 2351

Abstract

Background: The COVID-19 epidemic had a rapid spread worldwide with a continuous and fast mutation of the virus, resulting in the emergence of several variants of concern (VOC). The aim of this study was to evaluate the severity of each VOC among SARS-CoV-2 [...] Read more.

Background: The COVID-19 epidemic had a rapid spread worldwide with a continuous and fast mutation of the virus, resulting in the emergence of several variants of concern (VOC). The aim of this study was to evaluate the severity of each VOC among SARS-CoV-2 infected subjects by investigating deaths, ICU admissions, intubations, and severe critical symptoms. Methods: An ecological observational study was performed to evaluate mortality rates and clinical characteristics of 321,490 unvaccinated Sicilian SARS-CoV-2 cases observed from 2 March 2020 to 27 March 2022. Odds ratios (OR) and 95% confidence intervals (CI) were calculated by multivariate logistic regression analysis evaluating factors determining a clinical worsening. Results: Delta (adj-OR 3.00, 95% Cls 2.70–3.33) and wild-type (adj-OR 2.41, 95% Cls 2.2–2.62) variants had a higher risk than the Omicron strain for developing critical COVID-19 necessitating intubation and eventually undergoing death. Moreover, males appeared to be significantly more susceptible to developing the worst clinical outcome considered, as did older subjects. Conclusions: The present study provides evidence of factors implicated in the worsening of SARS-CoV-2-infection-related clinical outcomes. The study highlighted the different roles of VOC, in particular Delta and wild-type, and being male and elderly in the development of a worse clinical outcome. Full article

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6 pages, 683 KiB

Open AccessCommunication

Pharmacokinetic and Pharmacodynamic Effects of Polyclonal Antibodies against SARS-CoV2 in Mice

by Aruni Jha, Melanie Doyle-Eisele, David Revelli, Trevor Carnelley, Douglas Barker and Shantha Kodihalli

Viruses 2023, 15(1), 123; https://doi.org/10.3390/v15010123 - 30 Dec 2022

Cited by 2 | Viewed by 2124

Abstract

Despite ongoing vaccination efforts to prevent SARS-CoV-2 infections, treatment tools are still necessary to address the ongoing COVID-19 pandemic. We report here that COVID-HIGIV, a human immunoglobulin product for treatment of COVID-19, provided a significant survival benefit in SARS-CoV-2 infected transgenic mice compared [...] Read more.

Despite ongoing vaccination efforts to prevent SARS-CoV-2 infections, treatment tools are still necessary to address the ongoing COVID-19 pandemic. We report here that COVID-HIGIV, a human immunoglobulin product for treatment of COVID-19, provided a significant survival benefit in SARS-CoV-2 infected transgenic mice compared to controls. COVID-HIGIV also has similar pharmacokinetic profiles in healthy and SARS-CoV-2 infected mice over time after intravenous administration, with identical or comparable Tmax, Cmax, AUC_0–∞ and Cl. AUC_0–last increased and mean residence time, T_1/2, and Vd reduced in infected animals compared to healthy animals. These data suggest that COVID-HIGIV may be an effective treatment for SARS-CoV-2 infection when given early after exposure. Full article

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15 pages, 2614 KiB

Open AccessArticle

Epidemiology of Non-SARS-CoV2 Human Coronaviruses (HCoVs) in People Presenting with Influenza-like Illness (ILI) or Severe Acute Respiratory Infections (SARI) in Senegal from 2012 to 2020

by Modeste Name Faye, Mamadou Aliou Barry, Mamadou Malado Jallow, Serigne Fallou Wade, Marie Pedapa Mendy, Sara Sy, Amary Fall, Davy Evrard Kiori, Ndiende Koba Ndiaye, Deborah Goudiaby, Arfang Diamanka, Mbayame Ndiaye Niang and Ndongo Dia

Viruses 2023, 15(1), 20; https://doi.org/10.3390/v15010020 - 21 Dec 2022

Cited by 6 | Viewed by 2430

Abstract

In addition to emerging coronaviruses (SARS-CoV, MERS, SARS-CoV-2), there are seasonal human coronaviruses (HCoVs): HCoV-OC43, HCoV-229E, HCoV-NL63 and HCoV-HKU1. With a wide distribution around the world, HCoVs are usually associated with mild respiratory disease. In the elderly, young children and immunocompromised patients, more [...] Read more.

In addition to emerging coronaviruses (SARS-CoV, MERS, SARS-CoV-2), there are seasonal human coronaviruses (HCoVs): HCoV-OC43, HCoV-229E, HCoV-NL63 and HCoV-HKU1. With a wide distribution around the world, HCoVs are usually associated with mild respiratory disease. In the elderly, young children and immunocompromised patients, more severe or even fatal respiratory infections may be observed. In Africa, data on seasonal HCoV are scarce. This retrospective study investigated the epidemiology and genetic diversity of seasonal HCoVs during nine consecutive years of influenza-like illness surveillance in Senegal. Nasopharyngeal swabs were collected from ILI outpatients or from SARI hospitalized patients. HCoVs were diagnosed by qRT-PCR and the positive samples were selected for molecular characterization. Among 9337 samples tested for HCoV, 406 (4.3%) were positive: 235 (57.9%) OC43, 102 (25.1%) NL63, 58 (14.3%) 229E and 17 (4.2%) HKU1. The four types circulated during the study period and a peak was noted between November and January. Children under five were the most affected. Co-infections were observed between HCoV types (1.2%) or with other viruses (76.1%). Genetically, HCoVs types showed diversity. The results highlighted that the impact of HCoVs must be taken into account in public health; monitoring them is therefore particularly necessary both in the most sensitive populations and in animals. Full article

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8 pages, 1331 KiB

Open AccessCommunication

Evaluation of Rapid Lateral-Flow Tests Directed against the SARS-CoV-2 Nucleoprotein Using Viral Suspensions Belonging to Different Lineages of SARS-CoV-2

by Sylvie Pillet, Julien Courtieux, Sylvie Gonzalo, Issam Bechri, Thomas Bourlet, Martine Valette, Antonin Bal and Bruno Pozzetto

Viruses 2022, 14(12), 2628; https://doi.org/10.3390/v14122628 - 25 Nov 2022

Cited by 1 | Viewed by 1451

Abstract

Within the successive waves that occurred during the SARS-CoV-2 pandemic, recommendations arose to test symptomatic and contact subjects by using rapid antigen devices directed against the viral nucleocapsid protein with the aim to isolate contagious patients without delay. The objective of this study [...] Read more.

Within the successive waves that occurred during the SARS-CoV-2 pandemic, recommendations arose to test symptomatic and contact subjects by using rapid antigen devices directed against the viral nucleocapsid protein with the aim to isolate contagious patients without delay. The objective of this study was to evaluate the ability of four rapid lateral-flow tests (RLFT) that were commercially available on the French market in 2022 to recognize various strains of SARS-CoV-2. Series of five-fold dilutions of seven viral suspensions belonging to different lineages of SARS-CoV-2 (19A, 20A, Alpha, Beta, Gamma, Delta and Omicron) were used to evaluate the analytical sensitivity of four commercially available RLFTs (manufacturers: Abbott, AAZ, Becton-Dickinson and Biospeedia). Cell culture and quantitative RT-PCR were used as references. Excellent correlations were observed for each lineage strain between the viral titer obtained via cell culture and the number of RNA copies measured by quantitative RT-PCR. Although the four tests were able to recognize all the tested variants, significant differences in terms of sensitivity were observed between the four RLFTs. Despite the limitation represented by the small number of devices and clinical isolates that were tested, this study contributed by rapidly comparing the sensitivity of SARS-CoV-2 RLFTs in the Omicron era. Full article

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12 pages, 2404 KiB

Open AccessArticle

Heparin Inhibits SARS-CoV-2 Replication in Human Nasal Epithelial Cells

by Leo Yi Yang Lee, Randy Suryadinata, Conor McCafferty, Vera Ignjatovic, Damian F. J. Purcell, Phil Robinson, Craig J. Morton, Michael W. Parker, Gary P. Anderson, Paul Monagle, Kanta Subbarao and Jessica A. Neil

Viruses 2022, 14(12), 2620; https://doi.org/10.3390/v14122620 - 24 Nov 2022

Cited by 5 | Viewed by 3547

Abstract

SARS-CoV-2 is the causative agent of the COVID-19 pandemic. Vaccination, supported by social and public health measures, has proven efficacious for reducing disease severity and virus spread. However, the emergence of highly transmissible viral variants that escape prior immunity highlights the need for [...] Read more.

SARS-CoV-2 is the causative agent of the COVID-19 pandemic. Vaccination, supported by social and public health measures, has proven efficacious for reducing disease severity and virus spread. However, the emergence of highly transmissible viral variants that escape prior immunity highlights the need for additional mitigation approaches. Heparin binds the SARS-CoV-2 spike protein and can inhibit virus entry and replication in susceptible human cell lines and bronchial epithelial cells. Primary infection predominantly occurs via the nasal epithelium, but the nasal cell biology of SARS-CoV-2 is not well studied. We hypothesized that prophylactic intranasal administration of heparin may provide strain-agnostic protection for household contacts or those in high-risk settings against SARS-CoV-2 infection. Therefore, we investigated the ability of heparin to inhibit SARS-CoV-2 infection and replication in differentiated human nasal epithelial cells and showed that prolonged exposure to heparin inhibits virus infection. Furthermore, we establish a method for PCR detection of SARS-CoV-2 viral genomes in heparin-treated samples that can be adapted for the detection of viruses in clinical studies. Full article

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13 pages, 2871 KiB

Open AccessArticle

Prevalence of Human Coronaviruses in Children and Phylogenetic Analysis of HCoV-OC43 during 2016–2022 in Riyadh, Saudi Arabia

by Khalid A. Alamri, Mohamed A. Farrag, Ibrahim M. Aziz, Gani Asa Dudin, Arif Ahmed Mohammed and Fahad N. Almajhdi

Viruses 2022, 14(12), 2592; https://doi.org/10.3390/v14122592 - 22 Nov 2022

Cited by 3 | Viewed by 2240

Abstract

With the emergence of SARS-CoV-2, routine surveillance combined with sequence and phylogenetic analysis of coronaviruses is urgently required. In the current study, the four common human coronaviruses (HCoVs), OC43, NL63, HKU1, and 229E, were screened in 361 clinical samples collected from hospitalized children [...] Read more.

With the emergence of SARS-CoV-2, routine surveillance combined with sequence and phylogenetic analysis of coronaviruses is urgently required. In the current study, the four common human coronaviruses (HCoVs), OC43, NL63, HKU1, and 229E, were screened in 361 clinical samples collected from hospitalized children with respiratory symptoms during four winter seasons. RT-PCR-based detection and typing revealed different prevalence rates of HCoVs across the four seasons. Interestingly, none of the four HCoVs were detected in the samples (n = 100) collected during the winter season of the COVID-19 pandemic. HCoV-OC43 (4.15%) was the most frequently detected, followed by 229E (1.1%). Partial sequences of S and N genes of OC43 from the winter seasons of 2015/2016 and 2021/2022 were used for sequence and phylogenetic analysis. Multiple sequence alignment of the two Saudi OC43s strains with international strains revealed the presence of sequence deletions and several mutations, of which some changed their corresponding amino acids. Glycosylation profiles revealed a number of O-and N-glycosylation sites in both genes. Based on phylogenetic analysis, four genotypes were observed with Riyadh strains grouped into the genotype C. Further long-term surveillance with a large number of clinical samples and sequences is necessary to resolve the circulation patterns and evolutionary kinetics of OC43 in Saudi Arabia. Full article

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14 pages, 4105 KiB

Open AccessArticle

New Insights into Avian Infectious Bronchitis Virus in Colombia from Whole-Genome Analysis

by Gloria Ramirez-Nieto, Daiana Mir, Diego Almansa-Villa, Geovanna Cordoba-Argotti, Magda Beltran-Leon, Nelida Rodriguez-Osorio, Jone Garai, Jovanny Zabaleta and Arlen P. Gomez

Viruses 2022, 14(11), 2562; https://doi.org/10.3390/v14112562 - 19 Nov 2022

Cited by 5 | Viewed by 2610

Abstract

Infectious Bronchitis (IB) is a respiratory disease caused by a highly variable Gammacoronavirus, which generates a negative impact on poultry health worldwide. GI-11 and GI-16 lineages have been identified in South America based on Infectious Bronchitis virus (IBV) partial S1 sequences. However, [...] Read more.

Infectious Bronchitis (IB) is a respiratory disease caused by a highly variable Gammacoronavirus, which generates a negative impact on poultry health worldwide. GI-11 and GI-16 lineages have been identified in South America based on Infectious Bronchitis virus (IBV) partial S1 sequences. However, full genome sequence information is limited. In this study we report, for the first time, the whole-genome sequence of IBV from Colombia. Seven IBV isolates obtained during 2012 and 2013 from farms with respiratory disease compatible with IB were selected and the complete genome sequence was obtained by NGS. According to S1 sequence phylogenetic analysis, six isolates belong to lineage GI-1 and one to lineage GVI-1. When whole genome was analyzed, five isolates were related to the vaccine strain Ma5 2016 and two showed mosaic genomes. Results from complete S1 sequence analysis provides further support for the hypothesis that GVI-1, considered a geographically confined lineage in Asia, could have originated in Colombia. Complete genome information reported in this research allow a deeper understanding of the phylogenetic evolution of variants and the recombination events between strains that are circulating worldwide, contributing to the knowledge of coronavirus in Latin America and the world. Full article

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14 pages, 784 KiB

Open AccessReview

Host Protective Immunity against Severe Acute Respiratory Coronavirus 2 (SARS-CoV-2) and the COVID-19 Vaccine-Induced Immunity against SARS-CoV-2 and Its Variants

by Rashed Noor

Viruses 2022, 14(11), 2541; https://doi.org/10.3390/v14112541 - 17 Nov 2022

Cited by 6 | Viewed by 2798

Abstract

The world is now apparently at the last/recovery stage of the COVID-19 pandemic, starting from 29 December 2019, caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). With the progression of time, several mutations have taken place in the original SARS-CoV-2 Wuhan [...] Read more.

The world is now apparently at the last/recovery stage of the COVID-19 pandemic, starting from 29 December 2019, caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). With the progression of time, several mutations have taken place in the original SARS-CoV-2 Wuhan strain, which have generated variants of concern (VOC). Therefore, combatting COVID-19 has required the development of COVID-19 vaccines using several platforms. The immunity induced by those vaccines is vital to study in order to assure total protection against SARS-CoV-2 and its emerging variants. Indeed, understanding and identifying COVID-19 protection mechanisms or the host immune responses are of significance in terms of designing both new and repurposed drugs as well as the development of novel vaccines with few to no side effects. Detecting the immune mechanisms for host protection against SARS-CoV-2 and its variants is crucial for the development of novel COVID-19 vaccines as well as to monitor the effectiveness of the currently used vaccines worldwide. Immune memory in terms of the production of neutralizing antibodies (NAbs) during reinfection is also very crucial to formulate the vaccine administration schedule/vaccine doses. The response of antigen-specific antibodies and NAbs as well as T cell responses, along with the protective cytokine production and the innate immunity generated upon COVID-19 vaccination, are discussed in the current review in comparison to the features of naturally induced protective immunity. Full article

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7 pages, 882 KiB

Open AccessCommunication

An ACE2-Based Decoy Inhibitor Effectively Neutralizes SARS-CoV-2 Omicron BA.5 Variant

by Haoran Zhang, Bing Hu, Panjing Lv, Yahui Liu, Meng Guo, Zhi Wu, Kangping Zhou, Minglu Dai, Xiao Yu, Zhang Liu, Bo Yu, Liqiong Xu, Min Guo, Kun Cai and Yan Li

Viruses 2022, 14(11), 2387; https://doi.org/10.3390/v14112387 - 28 Oct 2022

Cited by 2 | Viewed by 2403

Abstract

The recently circulating SARS-CoV-2 Omicron BA.5 is rampaging the world with elevated transmissibility compared to the original SARS-CoV-2 strain. Immune escape of BA.5 was observed after treatment with many monoclonal antibodies, calling for broad-spectrum, immune-escape-evading therapeutics. In retrospect, we previously reported Kansetin as [...] Read more.

The recently circulating SARS-CoV-2 Omicron BA.5 is rampaging the world with elevated transmissibility compared to the original SARS-CoV-2 strain. Immune escape of BA.5 was observed after treatment with many monoclonal antibodies, calling for broad-spectrum, immune-escape-evading therapeutics. In retrospect, we previously reported Kansetin as an ACE2 mimetic and a protein antagonist against SARS-CoV-2, which proved potent neutralization bioactivity on the Reference, Alpha, Beta, Delta, and Omicron strains of SARS-CoV-2. Since BA.5 is expected to rely on the interaction of the Spike complex with human ACE2 for cell entry, we reasonably assumed the lasting efficacy of the ACE2-mimicking Kansetin for neutralizing the new SARS-CoV-2 variant. The investigation was accordingly performed on in vitro Kansetin-Spike binding affinity by SPR and cell infection inhibition ability with pseudovirus and live virus assays. As a result, Kansetin showed dissociation constant K_D and half inhibition concentration IC₅₀ at the nanomolar to picomolar level, featuring a competent inhibition effect against the BA.5 sublineage. Conclusively, Kansetin is expected to be a promising therapeutic option against BA.5 and future SARS-CoV-2 sublineages. Full article

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13 pages, 1104 KiB

Open AccessArticle

Association of the Transmembrane Serine Protease-2 (TMPRSS2) Polymorphisms with COVID-19

by Rosalinda Posadas-Sánchez, José Manuel Fragoso, Fausto Sánchez-Muñoz, Gustavo Rojas-Velasco, Julian Ramírez-Bello, Alberto López-Reyes, Laura E. Martínez-Gómez, Carlos Sierra-Fernández, Tatiana Rodríguez-Reyna, Nora Elemi Regino-Zamarripa, Gustavo Ramírez-Martínez, Joaquín Zuñiga-Ramos and Gilberto Vargas-Alarcón

Viruses 2022, 14(9), 1976; https://doi.org/10.3390/v14091976 - 7 Sep 2022

Cited by 12 | Viewed by 3048

Abstract

SARS-CoV-2 uses the ACE2 receptor and the cellular protease TMPRSS2 for entry into target cells. The present study aimed to establish if the TMPRSS2 polymorphisms are associated with COVID-19 disease. The study included 609 patients with COVID-19 confirmed by RT-PCR test and 291 [...] Read more.

SARS-CoV-2 uses the ACE2 receptor and the cellular protease TMPRSS2 for entry into target cells. The present study aimed to establish if the TMPRSS2 polymorphisms are associated with COVID-19 disease. The study included 609 patients with COVID-19 confirmed by RT-PCR test and 291 individuals negative for the SARS-CoV-2 infection confirmed by RT-PCR test and without antibodies anti-SARS-CoV-2. Four TMPRSS2 polymorphisms (rs12329760, rs2298659, rs456298, and rs462574) were determined using the 5′exonuclease TaqMan assays. Under different inheritance models, the rs2298659 (p_codominant2 = 0.018, p_recessive = 0.006, p_additive = 0.019), rs456298 (p_codominant1 = 0.014, p_codominant2 = 0.004; p_dominant = 0.009, p_recessive = 0.004, p_additive = 0.0009), and rs462574 (p_codominant1 = 0.017, p_codominant2 = 0.004, p_dominant = 0.041, p_recessive = 0.002, p_additive = 0.003) polymorphisms were associated with high risk of developing COVID-19. Two risks (ATGC and GAAC) and two protectives (GAGC and GAGT) haplotypes were detected. High levels of lactic acid dehydrogenase (LDH) were observed in patients with the rs462574AA and rs456298TT genotypes (p = 0.005 and p = 0.020, respectively), whereas, high heart rate was present in patients with the rs462574AA genotype (p = 0.028). Our data suggest that the rs2298659, rs456298, and rs462574 polymorphisms independently and as haplotypes are associated with the risk of COVID-19. The rs456298 and rs462574 genotypes are related to high levels of LDH and heart rate. Full article

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13 pages, 2863 KiB

Open AccessArticle

Comparison of Physical and Biochemical Characterizations of SARS-CoV-2 Inactivated by Different Treatments

by Shouzhi Yu, Yangyang Wei, Hongyang Liang, Wenheng Ji, Zhen Chang, Siman Xie, Yichuan Wang, Wanli Li, Yingwei Liu, Hao Wu, Jie Li, Hui Wang and Xiaoming Yang

Viruses 2022, 14(9), 1938; https://doi.org/10.3390/v14091938 - 31 Aug 2022

Cited by 9 | Viewed by 2633 | Correction

Abstract

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused huge social and economic distress. Given its rapid spread and the lack of specific treatment options, SARS-CoV-2 needs to be inactivated according to strict biosafety measures during laboratory diagnostics and vaccine development. The inactivation [...] Read more.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused huge social and economic distress. Given its rapid spread and the lack of specific treatment options, SARS-CoV-2 needs to be inactivated according to strict biosafety measures during laboratory diagnostics and vaccine development. The inactivation method for SARS-CoV-2 affects research related to the natural virus and its immune activity as an antigen in vaccines. In this study, we used size exclusion chromatography, western blotting, ELISA, an electron microscope, dynamic light scattering, circular dichroism, and surface plasmon resonance to evaluate the effects of four different chemical inactivation methods on the physical and biochemical characterization of SARS-CoV-2. Formaldehyde and β-propiolactone (BPL) treatment can completely inactivate the virus and have no significant effects on the morphology of the virus. None of the four tested inactivation methods affected the secondary structure of the virus, including the α-helix, antiparallel β-sheet, parallel β-sheet, β-turn, and random coil. However, formaldehyde and long-term BPL treatment (48 h) resulted in decreased viral S protein content and increased viral particle aggregation, respectively. The BPL treatment for 24 h can completely inactivate SARS-CoV-2 with the maximum retention of the morphology, physical properties, and the biochemical properties of the potential antigens of the virus. In summary, we have established a characterization system for the comprehensive evaluation of virus inactivation technology, which has important guiding significance for the development of vaccines against SARS-CoV-2 variants and research on natural SARS-CoV-2. Full article

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7 pages, 511 KiB

Open AccessArticle

Regional Association between Mean Air Temperature and Case Numbers of Multiple SARS-CoV-2 Lineages throughout the Pandemic

by Camilla Mattiuzzi, Brandon M. Henry and Giuseppe Lippi

Viruses 2022, 14(9), 1913; https://doi.org/10.3390/v14091913 - 30 Aug 2022

Cited by 11 | Viewed by 1810

Abstract

The association between mean air temperature and new SARS-CoV-2 case numbers throughout the ongoing coronavirus disease 2019 (COVID-19) pandemic was investigated to identify whether diverse SARS-CoV-2 lineages may exhibit diverse environmental behaviors. The number of new COVID-19 daily cases in the province of [...] Read more.

The association between mean air temperature and new SARS-CoV-2 case numbers throughout the ongoing coronavirus disease 2019 (COVID-19) pandemic was investigated to identify whether diverse SARS-CoV-2 lineages may exhibit diverse environmental behaviors. The number of new COVID-19 daily cases in the province of Verona was obtained from the Veneto Regional Healthcare Service, whilst the mean daily air temperature during the same period was retrieved from the Regional Agency for Ambient Prevention and Protection of Veneto. A significant inverse correlation was found between new COVID-19 daily cases and mean air temperature in Verona up to Omicron BA.1/BA.2 predominance (correlation coefficients between −0.79 and −0.41). The correlation then became positive when the Omicron BA.4/BA.5 lineages were prevalent (r = 0.32). When the median value (and interquartile range; IQR) of new COVID-19 daily cases recorded during the warmer period of the year in Verona (June–July) was compared across the three years of the pandemic, a gradual increase could be seen over time, from 1 (IQR, 0–2) in 2020, to 22 (IQR, 11–113) in 2021, up to 890 (IQR, 343–1345) in 2022. These results suggest that measures for preventing SARS-CoV-2 infection should not be completely abandoned during the warmer periods of the year. Full article

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14 pages, 1756 KiB

Open AccessArticle

SARS-CoV-2 RBD-Specific Antibodies Induced Early in the Pandemic by Natural Infection and Vaccination Display Cross-Variant Binding and Inhibition

by Melanie R. Walker, Daria Podlekareva, Stine Johnsen, Bonna Leerhøy, Cyrielle Fougeroux, Max Søgaard, Ali Salanti, Sisse Bolm Ditlev and Lea Barfod

Viruses 2022, 14(9), 1861; https://doi.org/10.3390/v14091861 - 24 Aug 2022

Cited by 4 | Viewed by 2564

Abstract

The development of vaccine candidates for COVID-19 has been rapid, and those that are currently approved display high efficacy against the original circulating strains. However, recently, new variants of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have emerged with increased transmission rates and [...] Read more.

The development of vaccine candidates for COVID-19 has been rapid, and those that are currently approved display high efficacy against the original circulating strains. However, recently, new variants of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have emerged with increased transmission rates and less susceptibility to vaccine induced immunity. A greater understanding of protection mechanisms, including antibody longevity and cross-reactivity towards the variants of concern (VoCs), is needed. In this study, samples collected in Denmark early in the pandemic from paucisymptomatic subjects (n = 165) and symptomatic subjects (n = 57) infected with SARS-CoV-2 were used to assess IgG binding and inhibition in the form of angiotensin-converting enzyme 2 receptor (ACE2) competition against the wild-type and four SARS-CoV-2 VoCs (Alpha, Beta, Gamma, and Omicron). Antibodies induced early in the pandemic via natural infection were cross-reactive and inhibited ACE2 binding of the VoC, with reduced inhibition observed for the Omicron variant. When examined longitudinally, sustained cross-reactive inhibitory responses were found to exist in naturally infected paucisymptomatic subjects. After vaccination, receptor binding domain (RBD)-specific IgG binding increased by at least 3.5-fold and inhibition of ACE2 increased by at least 2-fold. When vaccination regimens were compared (two doses of Pfizer-BioNTech BNT162b2 (n = 50), or one dose of Oxford-AstraZeneca ChAdOx1 nCoV-19 followed by Pfizer-BioNTech BNT162b2 (ChAd/BNT) (n = 15)), higher levels of IgG binding and inhibition were associated with mix and match (ChAd/BNT) prime-boosting and time since vaccination. These results are particularly relevant for countries where vaccination levels are low. Full article

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11 pages, 2509 KiB

Open AccessArticle

Development of a Genetically Engineered Bivalent Vaccine against Porcine Epidemic Diarrhea Virus and Porcine Rotavirus

by Wan Li, Mingkai Lei, Zhuofei Li, Huimin Li, Zheng Liu, Qigai He and Rui Luo

Viruses 2022, 14(8), 1746; https://doi.org/10.3390/v14081746 - 9 Aug 2022

Cited by 14 | Viewed by 4014

Abstract

Porcine epidemic diarrhea virus (PEDV) is an enteric coronavirus that causes acute diarrhea, vomiting, dehydration, and a high mortality rate in neonatal piglets. In recent years, PEDV has been associated with co-infections with other swine enteric viruses, including porcine rotavirus (PoRV), resulting in [...] Read more.

Porcine epidemic diarrhea virus (PEDV) is an enteric coronavirus that causes acute diarrhea, vomiting, dehydration, and a high mortality rate in neonatal piglets. In recent years, PEDV has been associated with co-infections with other swine enteric viruses, including porcine rotavirus (PoRV), resulting in increased mortality among newborn piglets. In this paper, we developed a bivalent vaccine against PEDV and PoRV by constructing a recombinant PEDV encoding PoRV VP7 (rPEDV-PoRV-VP7). The recombinant virus was constructed by replacing the entire open reading frame 3 (ORF3) in the genome of an attenuated PEDV strain YN150 with the PoRV VP7 gene using reverse genetic systems. Similar plaque morphology and replication kinetics were observed in Vero cells with the recombinant PEDV compared to the wild-type PEDV. It is noteworthy that the VP7 protein could be expressed stably in rPEDV-PoRV-VP7-infected cells. To evaluate the immunogenicity and safety of rPEDV-PoRV-VP7, 10-day-old piglets were vaccinated with the recombinant virus. After inoculation, no piglet displayed clinical symptoms such as vomiting, diarrhea, or anorexia. The PoRV VP7- and PEDV spike-specific IgG in serum and IgA in saliva were detected in piglets after rPEDV-PoRV-VP7 vaccination. Moreover, both PoRV and PEDV neutralizing antibodies were produced simultaneously in the inoculated piglets. Collectively, we engineered a recombinant PEDV expressing PoRV VP7 that could be used as an effective bivalent vaccine against PEDV and PoRV. Full article

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10 pages, 1980 KiB

Open AccessCommunication

Distinct Antibody Responses to Endemic Coronaviruses Pre- and Post-SARS-CoV-2 Infection in Kenyan Infants and Mothers

by Caitlin I. Stoddard, Kevin Sung, Ednah Ojee, Judith Adhiambo, Emily R. Begnel, Jennifer Slyker, Soren Gantt, Frederick A. Matsen IV, John Kinuthia, Dalton Wamalwa, Julie Overbaugh and Dara A. Lehman

Viruses 2022, 14(7), 1517; https://doi.org/10.3390/v14071517 - 12 Jul 2022

Cited by 9 | Viewed by 2189

Abstract

Pre-existing antibodies that bind endemic human coronaviruses (eHCoVs) can cross-react with SARS-CoV-2, which is the betacoronavirus that causes COVID-19, but whether these responses influence SARS-CoV-2 infection is still under investigation and is particularly understudied in infants. In this study, we measured eHCoV and [...] Read more.

Pre-existing antibodies that bind endemic human coronaviruses (eHCoVs) can cross-react with SARS-CoV-2, which is the betacoronavirus that causes COVID-19, but whether these responses influence SARS-CoV-2 infection is still under investigation and is particularly understudied in infants. In this study, we measured eHCoV and SARS-CoV-1 IgG antibody titers before and after SARS-CoV-2 seroconversion in a cohort of Kenyan women and their infants. Pre-existing eHCoV antibody binding titers were not consistently associated with SARS-CoV-2 seroconversion in infants or mothers; however, we observed a very modest association between pre-existing HCoV-229E antibody levels and a lack of SARS-CoV-2 seroconversion in the infants. After seroconversion to SARS-CoV-2, antibody binding titers to the endemic betacoronaviruses HCoV-OC43 and HCoV-HKU1, and the highly pathogenic betacoronavirus SARS-CoV-1, but not the endemic alphacoronaviruses HCoV-229E and HCoV-NL63, increased in the mothers. However, eHCoV antibody levels did not increase following SARS-CoV-2 seroconversion in the infants, suggesting the increase seen in the mothers was not simply due to cross-reactivity to naively generated SARS-CoV-2 antibodies. In contrast, the levels of antibodies that could bind SARS-CoV-1 increased after SARS-CoV-2 seroconversion in both the mothers and infants, both of whom were unlikely to have had a prior SARS-CoV-1 infection, supporting prior findings that SARS-CoV-2 responses cross-react with SARS-CoV-1. In summary, we found evidence of increased eHCoV antibody levels following SARS-CoV-2 seroconversion in the mothers but not the infants, suggesting eHCoV responses can be boosted by SARS-CoV-2 infection when a prior memory response has been established, and that pre-existing cross-reactive antibodies are not strongly associated with SARS-CoV-2 infection risk in mothers or infants. Full article

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14 pages, 2942 KiB

Open AccessArticle

Human ACE2 Polymorphisms from Different Human Populations Modulate SARS-CoV-2 Infection

by Pan Hu, Vanessa L. Bauer, Sara L. Sawyer and Felipe Diaz-Griffero

Viruses 2022, 14(7), 1451; https://doi.org/10.3390/v14071451 - 30 Jun 2022

Cited by 4 | Viewed by 2720

Abstract

The COVID-19 pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has resulted in over 6 million deaths worldwide. The high variability in COVID-19 symptoms remains one of the most interesting mysteries of the pandemic. Genetic and environmental factors are likely to [...] Read more.

The COVID-19 pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has resulted in over 6 million deaths worldwide. The high variability in COVID-19 symptoms remains one of the most interesting mysteries of the pandemic. Genetic and environmental factors are likely to be key determinants of COVID-19 symptomatology. Here, we explored ACE2 as a genetic determinant for SARS-CoV-2 infection and COVID-19 symptomatology. Each human genome encodes two alleles of ACE2, which encodes the cell entry receptor for SARS-CoV-2. Here, we determined whether naturally occurring human ACE2 (hACE2) polymorphisms in the human population affect SARS-CoV-2 infection and the severity of COVID-19 symptoms. ACE2 variants S19P, I21V, E23K, K26R, K31R, N33I, H34R, E35K, and T92I showed increased virus infection compared to wild-type ACE2; thus, these variants could increase the risk for COVID-19. In contrast, variants D38V, Y83H, I468V, and N638S showed reduced infection, indicating a potential protective effect. hACE2 variants K26R and T92I increased infection by three-fold without changing the levels of ACE2 on the surface of the cells, suggesting that these variants may increase the risk of severe COVID-19. On the contrary, hACE2 variants D38V and Y83H decreased SARS-CoV-2 infection by four- and ten-fold, respectively, without changing surface expression, suggesting that these variants may protect against severe COVID-19. Remarkably, all protective hACE2 Polymorphisms were found almost exclusively in Asian populations, which may provide a partial explanation for the low COVID-19 mortality rates in Asian countries. Thus, hACE2 polymorphisms may modulate susceptibility to SARS-CoV-2 in the host and partially account for the differences in severity of COVID-19 among different ethnic groups. Full article

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18 pages, 757 KiB

Open AccessArticle

Weekly Nowcasting of New COVID-19 Cases Using Past Viral Load Measurements

by Athar Khalil, Khalil Al Handawi, Zeina Mohsen, Afif Abdel Nour, Rita Feghali, Ibrahim Chamseddine and Michael Kokkolaras

Viruses 2022, 14(7), 1414; https://doi.org/10.3390/v14071414 - 28 Jun 2022

Cited by 4 | Viewed by 2335

Abstract

The rapid spread of the coronavirus disease COVID-19 has imposed clinical and financial burdens on hospitals and governments attempting to provide patients with medical care and implement disease-controlling policies. The transmissibility of the disease was shown to be correlated with the patient’s viral [...] Read more.

The rapid spread of the coronavirus disease COVID-19 has imposed clinical and financial burdens on hospitals and governments attempting to provide patients with medical care and implement disease-controlling policies. The transmissibility of the disease was shown to be correlated with the patient’s viral load, which can be measured during testing using the cycle threshold (Ct). Previous models have utilized Ct to forecast the trajectory of the spread, which can provide valuable information to better allocate resources and change policies. However, these models combined other variables specific to medical institutions or came in the form of compartmental models that rely on epidemiological assumptions, all of which could impose prediction uncertainties. In this study, we overcome these limitations using data-driven modeling that utilizes Ct and previous number of cases, two institution-independent variables. We collected three groups of patients (n = 6296, n = 3228, and n = 12,096) from different time periods to train, validate, and independently validate the models. We used three machine learning algorithms and three deep learning algorithms that can model the temporal dynamic behavior of the number of cases. The endpoint was 7-week forward number of cases, and the prediction was evaluated using mean square error (MSE). The sequence-to-sequence model showed the best prediction during validation (MSE = 0.025), while polynomial regression (OLS) and support vector machine regression (SVR) had better performance during independent validation (MSE = 0.1596, and MSE = 0.16754, respectively), which exhibited better generalizability of the latter. The OLS and SVR models were used on a dataset from an external institution and showed promise in predicting COVID-19 incidences across institutions. These models may support clinical and logistic decision-making after prospective validation. Full article

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18 pages, 3684 KiB

Open AccessArticle

Characterization of the Cross-Species Transmission Potential for Porcine Deltacoronaviruses Expressing Sparrow Coronavirus Spike Protein in Commercial Poultry

by Moyasar A. Alhamo, Patricia A. Boley, Mingde Liu, Xiaoyu Niu, Kush Kumar Yadav, Carolyn Lee, Linda J. Saif, Qiuhong Wang and Scott P. Kenney

Viruses 2022, 14(6), 1225; https://doi.org/10.3390/v14061225 - 5 Jun 2022

Cited by 6 | Viewed by 3121

Abstract

Avian species often serve as transmission vectors and sources of recombination for viral infections due to their ability to travel vast distances and their gregarious behaviors. Recently a novel deltacoronavirus (DCoV) was identified in sparrows. Sparrow deltacoronavirus (SpDCoV), coupled with close contact between [...] Read more.

Avian species often serve as transmission vectors and sources of recombination for viral infections due to their ability to travel vast distances and their gregarious behaviors. Recently a novel deltacoronavirus (DCoV) was identified in sparrows. Sparrow deltacoronavirus (SpDCoV), coupled with close contact between sparrows and swine carrying porcine deltacoronavirus (PDCoV) may facilitate recombination of DCoVs resulting in novel CoV variants. We hypothesized that the spike (S) protein or receptor-binding domain (RBD) from sparrow coronaviruses (SpCoVs) may enhance infection in poultry. We used recombinant chimeric viruses, which express S protein or the RBD of SpCoV (icPDCoV-S_HKU17, and icPDCoV-RBD_ISU) on the genomic backbone of an infectious clone of PDCoV (icPDCoV). Chimeric viruses were utilized to infect chicken derived DF-1 cells, turkey poults, and embryonated chicken eggs (ECEs) to examine permissiveness, viral replication kinetics, pathogenesis and pathology. We demonstrated that DF-1 cells in addition to the positive control LLC-PK1 cells are susceptible to SpCoV spike- and RBD- recombinant chimeric virus infections. However, the replication of chimeric viruses in DF-1 cells, but not LLC-PK1 cells, was inefficient. Inoculated 8-day-old turkey poults appeared resistant to icPDCoV-, icPDCoV-S_HKU17- and icPDCoV-RBD_ISU virus infections. In 5-day-old ECEs, significant mortality was observed in PDCoV inoculated eggs with less in the spike chimeras, while in 11-day-old ECEs there was no evidence of viral replication, suggesting that PDCoV is better adapted to cross species infection and differentiated ECE cells are not susceptible to PDCoV infection. Collectively, we demonstrate that the SpCoV chimeric viruses are not more infectious in turkeys, nor ECEs than wild type PDCoV. Therefore, understanding the cell and host factors that contribute to resistance to PDCoV and avian-swine chimeric virus infections may aid in the design of novel antiviral therapies against DCoVs. Full article

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16 pages, 6108 KiB

Open AccessArticle

Non-Productive Infection of Glial Cells with SARS-CoV-2 in Hamster Organotypic Cerebellar Slice Cultures

by Lise Lamoureux, Babu Sajesh, Jessy A. Slota, Sarah J. Medina, Matthew Mayor, Kathy L. Frost, Bryce Warner, Kathy Manguiat, Heidi Wood, Darwyn Kobasa and Stephanie A. Booth

Viruses 2022, 14(6), 1218; https://doi.org/10.3390/v14061218 - 3 Jun 2022

Viewed by 2841

Abstract

The numerous neurological syndromes associated with COVID-19 implicate an effect of viral pathogenesis on neuronal function, yet reports of direct SARS-CoV-2 infection in the brain are conflicting. We used a well-established organotypic brain slice culture to determine the permissivity of hamster brain tissues [...] Read more.

The numerous neurological syndromes associated with COVID-19 implicate an effect of viral pathogenesis on neuronal function, yet reports of direct SARS-CoV-2 infection in the brain are conflicting. We used a well-established organotypic brain slice culture to determine the permissivity of hamster brain tissues to SARS-CoV-2 infection. We found levels of live virus waned after inoculation and observed no evidence of cell-to-cell spread, indicating that SARS-CoV-2 infection was non-productive. Nonetheless, we identified a small number of infected cells with glial phenotypes; however, no evidence of viral infection or replication was observed in neurons. Our data corroborate several clinical studies that have assessed patients with COVID-19 and their association with neurological involvement. Full article

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10 pages, 1222 KiB

Open AccessEditor’s ChoiceArticle

Longitudinal Analysis of Coronavirus-Neutralizing Activity in COVID-19 Patients

by Florian D. Hastert, Lisa Henss, Christine von Rhein, Julia Gerbeth, Imke Wieters, Frauke Borgans, Yascha Khodamoradi, Kai Zacharowski, Gernot Rohde, Maria J.G.T. Vehreschild and Barbara S. Schnierle

Viruses 2022, 14(5), 882; https://doi.org/10.3390/v14050882 - 23 Apr 2022

Cited by 3 | Viewed by 3986

Abstract

The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) pandemic has now been continuing for more than two years. The infection causes COVID-19, a disease of the respiratory and cardiovascular system of variable severity. Here, the humoral immune response of 80 COVID-19 patients from the [...] Read more.

The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) pandemic has now been continuing for more than two years. The infection causes COVID-19, a disease of the respiratory and cardiovascular system of variable severity. Here, the humoral immune response of 80 COVID-19 patients from the University Hospital Frankfurt/Main, Germany, was characterized longitudinally. The SARS-CoV-2 neutralization activity of serum waned over time. The neutralizing potential of serum directed towards the human alpha-coronavirus NL-63 (NL63) also waned, indicating that no cross-priming against alpha-coronaviruses occurred. A subset of the recovered patients (n = 13) was additionally vaccinated with the mRNA vaccine Comirnaty. Vaccination increased neutralization activity against SARS-CoV-2 wild-type (WT), Delta, and Omicron, although Omicron-specific neutralization was not detectable prior to vaccination. In addition, the vaccination induced neutralizing antibodies against the more distantly related SARS-CoV-1 but not against NL63. The results indicate that although SARS-CoV-2 humoral immune responses induced by infection wane, vaccination induces a broad neutralizing activity against multiple SARS-CoVs, but not to the common cold alpha-coronavirus NL63. Full article

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18 pages, 1333 KiB

Open AccessArticle

Longitudinal Survey of Coronavirus Circulation and Diversity in Insectivorous Bat Colonies in Zimbabwe

by Vimbiso Chidoti, Hélène De Nys, Valérie Pinarello, Getrude Mashura, Dorothée Missé, Laure Guerrini, Davies Pfukenyi, Julien Cappelle, Ngoni Chiweshe, Ahidjo Ayouba, Gift Matope, Martine Peeters, Elizabeth Gori, Mathieu Bourgarel and Florian Liégeois

Viruses 2022, 14(4), 781; https://doi.org/10.3390/v14040781 - 9 Apr 2022

Cited by 10 | Viewed by 3951

Abstract

Background: Studies have linked bats to outbreaks of viral diseases in human populations such as SARS-CoV-1 and MERS-CoV and the ongoing SARS-CoV-2 pandemic. Methods: We carried out a longitudinal survey from August 2020 to July 2021 at two sites in Zimbabwe with bat–human [...] Read more.

Background: Studies have linked bats to outbreaks of viral diseases in human populations such as SARS-CoV-1 and MERS-CoV and the ongoing SARS-CoV-2 pandemic. Methods: We carried out a longitudinal survey from August 2020 to July 2021 at two sites in Zimbabwe with bat–human interactions: Magweto cave and Chirundu farm. A total of 1732 and 1866 individual bat fecal samples were collected, respectively. Coronaviruses and bat species were amplified using PCR systems. Results: Analysis of the coronavirus sequences revealed a high genetic diversity, and we identified different sub-viral groups in the Alphacoronavirus and Betacoronavirus genus. The established sub-viral groups fell within the described Alphacoronavirus sub-genera: Decacovirus, Duvinacovirus, Rhinacovirus, Setracovirus and Minunacovirus and for Betacoronavirus sub-genera: Sarbecoviruses, Merbecovirus and Hibecovirus. Our results showed an overall proportion for CoV positive PCR tests of 23.7% at Chirundu site and 16.5% and 38.9% at Magweto site for insectivorous bats and Macronycteris gigas, respectively. Conclusions: The higher risk of bat coronavirus exposure for humans was found in December to March in relation to higher viral shedding peaks of coronaviruses in the parturition, lactation and weaning months of the bat populations at both sites. We also highlight the need to further document viral infectious risk in human/domestic animal populations surrounding bat habitats in Zimbabwe. Full article

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14 pages, 1570 KiB

Open AccessPerspective

TP53 Gene Therapy as a Potential Treatment for Patients with COVID-19

by Joe B. Harford, Sang Soo Kim, Kathleen F. Pirollo and Esther H. Chang

Viruses 2022, 14(4), 739; https://doi.org/10.3390/v14040739 - 31 Mar 2022

Cited by 21 | Viewed by 3954

Abstract

SGT-53 is a novel investigational agent that comprises an immunoliposome carrying a plasmid vector driving expression of the human TP53 gene that encodes wild-type human p53. SGT-53 is currently in phase II human trials for advanced pancreatic cancer. Although p53 is best known [...] Read more.

SGT-53 is a novel investigational agent that comprises an immunoliposome carrying a plasmid vector driving expression of the human TP53 gene that encodes wild-type human p53. SGT-53 is currently in phase II human trials for advanced pancreatic cancer. Although p53 is best known as a tumor suppressor, its participation in both innate and adaptive immune responses is well documented. It is now clear that p53 is an important component of the host response to various viral infections. To facilitate their viral life cycles, viruses have developed a diverse repertoire of strategies for counteracting the antiviral activities of host immune system by manipulating p53-dependent pathways in host cells. Coronaviruses reduce endogenous p53 levels in the cells they infect by enhancing the degradation of p53 in proteasomes. Thus, interference with p53 function is an important component in viral pathogenesis. Transfection of cells by SGT-53 has been shown to transiently produce exogenous p53 that is active as a pleiotropic transcription factor. We herein summarize the rationale for repurposing SGT-53 as a therapy for infection by SARS-CoV-2, the pathogen responsible for the COVID-19 pandemic. Because p53 regulation was found to play a crucial role in different infection stages of a wide variety of viruses, it is rational to believe that restoring p53 function based on SGT-53 treatment may lead to beneficial therapeutic outcomes for infectious disease at large including heretofore unknown viral pathogens that may emerge in the future. Full article

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16 pages, 2856 KiB

Open AccessArticle

Targeting of Protein Kinase CK2 Elicits Antiviral Activity on Bovine Coronavirus Infection

by Ailyn C. Ramón, George V. Pérez, Evelin Caballero, Mauro Rosales, Daylén Aguilar, Dania Vázquez-Blomquist, Yassel Ramos, Arielis Rodríguez-Ulloa, Viviana Falcón, María Pilar Rodríguez-Moltó, Ke Yang, Yasser Perera and Silvio E. Perea

Viruses 2022, 14(3), 552; https://doi.org/10.3390/v14030552 - 7 Mar 2022

Cited by 6 | Viewed by 2714

Abstract

Coronaviruses constitute a global threat to the human population; therefore, effective pan-coronavirus antiviral drugs are required to tackle future re-emerging virus outbreaks. Protein kinase CK2 has been suggested as a promising therapeutic target in COVID-19 owing to the in vitro antiviral activity observed [...] Read more.

Coronaviruses constitute a global threat to the human population; therefore, effective pan-coronavirus antiviral drugs are required to tackle future re-emerging virus outbreaks. Protein kinase CK2 has been suggested as a promising therapeutic target in COVID-19 owing to the in vitro antiviral activity observed after both pharmacologic and genetic inhibition of the enzyme. Here, we explored the putative antiviral effect of the anti-CK2 peptide CIGB-325 on bovine coronavirus (BCoV) infection using different in vitro viral infected cell-based assays. The impact of the peptide on viral mRNA and protein levels was determined by qRT-PCR and Western blot, respectively. Finally, pull-down experiments followed by Western blot and/or mass spectrometry analysis were performed to identify CIGB-325-interacting proteins. We found that CIGB-325 inhibited both the cytopathic effect and the number of plaque-forming units. Accordingly, intracellular viral protein levels were clearly reduced after treatment of BCoV-infected cells, with CIGB-325 determined by immunocytochemistry. Pull-down assay data revealed the physical interaction of CIGB-325 with viral nucleocapsid (N) protein and a group of bona fide CK2 cellular substrates. Our findings evidence in vitro antiviral activity of CIGB-325 against bovine coronavirus as well as some molecular clues that might support such effect. Altogether, data provided here strengthen the rationale of inhibiting CK2 to treat betacoronavirus infections. Full article

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13 pages, 1338 KiB

Open AccessArticle

Antibody Evaluation and Mutations of Antigenic Epitopes in the Spike Protein of the Porcine Epidemic Diarrhea Virus from Pig Farms with Repeated Intentional Exposure (Feedback)

by Thu Hien Nguyen Thi, Chi-Chih Chen, Wen-Bin Chung, Hso-Chi Chaung, Yen-Li Huang, Li-Ting Cheng and Guan-Ming Ke

Viruses 2022, 14(3), 551; https://doi.org/10.3390/v14030551 - 7 Mar 2022

Cited by 4 | Viewed by 2765

Abstract

The feedback strategy, or controlled exposure of pig herd to the porcine epidemic diarrhea virus (PEDV), significantly decreased losses during a severe outbreak in late 2013 in Taiwan. However, some pig farms still suffered from recurrent outbreaks. To evaluate the association between antibody [...] Read more.

The feedback strategy, or controlled exposure of pig herd to the porcine epidemic diarrhea virus (PEDV), significantly decreased losses during a severe outbreak in late 2013 in Taiwan. However, some pig farms still suffered from recurrent outbreaks. To evaluate the association between antibody titers and clinical manifestations, sera and colostra were analyzed from one pig farm that employed the feedback strategy. Furthermore, spike (S) gene full sequences from six positive samples of two farms with and without using feedback were compared to investigate the evolution of PEDV variants circulating in pig herds. The results in this study showed that high PEDV antibody titers do not correlate with the high rate of protection from PEDV infection. In addition, repeated feedback generated the emergence of PEDV variants with unique substitutions of N537S and Y561H in the COE domain and S769F in the SS6 epitopes. These mutations indicated the pathogenetic evolution of PEDV strains existing in the cycle of the feedback method. A very strict biosecurity practice to block the routes of pathogen transfer should be followed to achieve successful control of PEDV infections in pig herds. Full article

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17 pages, 2882 KiB

Open AccessArticle

Direct Lysis RT-qPCR of SARS-CoV-2 in Cell Culture Supernatant Allows for Fast and Accurate Quantification

by Nicky Craig, Sarah L. Fletcher, Alison Daniels, Caitlin Newman, Marie O’Shea, Wenfang Spring Tan, Amanda Warr and Christine Tait-Burkard

Viruses 2022, 14(3), 508; https://doi.org/10.3390/v14030508 - 28 Feb 2022

Cited by 11 | Viewed by 5304

Abstract

Studying the entire virus replication cycle of SARS-CoV-2 is essential to identify the host factors involved and treatments to combat infection. Quantification of released virions often requires lengthy procedures, whereas quantification of viral RNA in supernatant is faster and applicable to clinical isolates. [...] Read more.

Studying the entire virus replication cycle of SARS-CoV-2 is essential to identify the host factors involved and treatments to combat infection. Quantification of released virions often requires lengthy procedures, whereas quantification of viral RNA in supernatant is faster and applicable to clinical isolates. Viral RNA purification is expensive in terms of time and resources, and is often unsuitable for high-throughput screening. Direct lysis protocols were explored for patient swab samples, but the lack of virus inactivation, cost, sensitivity, and accuracy is hampering their application and usefulness for in vitro studies. Here, we show a highly sensitive, accurate, fast, and cheap direct lysis RT-qPCR method for quantification of SARS-CoV-2 in culture supernatant. This method inactivates the virus and permits detection limits of 0.043 TCID₅₀ virus and <1.89 copy RNA template per reaction. Comparing direct lysis with RNA extraction, a mean difference of +0.69 ± 0.56 cycles was observed. Application of the method to established qPCR methods for RSV (-ve RNA), IAV (segmented -ve RNA), and BHV (dsDNA) showed wider applicability to other enveloped viruses, whereby IAV showed poorer sensitivity. This shows that accurate quantification of SARS-CoV-2 and other enveloped viruses can be achieved using direct lysis protocols, facilitating a wide range of high- and low-throughput applications. Full article

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7 pages, 2263 KiB

Open AccessBrief Report

Isolation and Genomic Characterization of SARS-CoV-2 Omicron Variant Obtained from Human Clinical Specimens

by Pragya D. Yadav, Nivedita Gupta, Varsha Potdar, Sreelekshmy Mohandas, Rima R. Sahay, Prasad Sarkale, Anita M. Shete, Alpana Razdan, Deepak Y. Patil, Dimpal A. Nyayanit, Yash Joshi, Savita Patil, Triparna Majumdar, Hitesh Dighe, Bharti Malhotra, Jayanthi Shastri and Priya Abraham

Viruses 2022, 14(3), 461; https://doi.org/10.3390/v14030461 - 24 Feb 2022

Cited by 8 | Viewed by 3034

Abstract

Due to the failure of virus isolation of the Omicron variant in Vero CCL-81 from the clinical specimens of COVID-19 cases, an initial in vivo and subsequent in vitro approach was utilized for the isolation of the virus. A total of 74 oropharyngeal/nasopharyngeal [...] Read more.

Due to the failure of virus isolation of the Omicron variant in Vero CCL-81 from the clinical specimens of COVID-19 cases, an initial in vivo and subsequent in vitro approach was utilized for the isolation of the virus. A total of 74 oropharyngeal/nasopharyngeal specimens were collected from SARS-CoV-2 positive international travellers and a contact case at Delhi and Mumbai, India. All the specimens were sequenced using next-generation sequencing and simultaneously inoculated onto Vero CCL-81 cells for virus isolation. Subsequently, two omicron positive specimens were inoculated into Syrian hamsters for two passages. The initial passage of the positive hamster specimens was inoculated onto Vero CCL-81 cells. The clinical specimens, hamster specimens, and Vero CCL-81 passages were sequenced to assess the mutational changes in different host species. The replication of the Omicron variant in hamsters was confirmed with the presence of a high viral load in nasal turbinate and lung specimens of both passages. The successful isolation of the virus from hamster specimens with Vero CCL-81 was observed with cytopathic effect in infected cells and high viral load in the cell suspension. The genome analysis revealed the presence of L212C mutation, Tyrosine 69 deletion, and C25000T nucleotide change in spike gene of hamster passage sequences and an absence of V17I mutation in E gene in hamster passage sequences, unlike human clinical specimen and Vero CCL-81 passages. No change was observed in the furin cleavage site in any of the specimen sequences, suggesting intact pathogenicity of the virus isolate. Our data demonstrated successful isolation of the Omicron variant with the in vivo method first followed by in vitro method. The virus isolate could be used in the future to explore different aspects of the Omicron variant. Full article

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37 pages, 50150 KiB

Open AccessReview

Known Cellular and Receptor Interactions of Animal and Human Coronaviruses: A Review

by Holly Everest, Phoebe Stevenson-Leggett, Dalan Bailey, Erica Bickerton and Sarah Keep

Viruses 2022, 14(2), 351; https://doi.org/10.3390/v14020351 - 8 Feb 2022

Cited by 13 | Viewed by 5591

Abstract

This article aims to review all currently known interactions between animal and human coronaviruses and their cellular receptors. Over the past 20 years, three novel coronaviruses have emerged that have caused severe disease in humans, including SARS-CoV-2 (severe acute respiratory syndrome virus 2); [...] Read more.

This article aims to review all currently known interactions between animal and human coronaviruses and their cellular receptors. Over the past 20 years, three novel coronaviruses have emerged that have caused severe disease in humans, including SARS-CoV-2 (severe acute respiratory syndrome virus 2); therefore, a deeper understanding of coronavirus host–cell interactions is essential. Receptor-binding is the first stage in coronavirus entry prior to replication and can be altered by minor changes within the spike protein—the coronavirus surface glycoprotein responsible for the recognition of cell-surface receptors. The recognition of receptors by coronaviruses is also a major determinant in infection, tropism, and pathogenesis and acts as a key target for host-immune surveillance and other potential intervention strategies. We aim to highlight the need for a continued in-depth understanding of this subject area following on from the SARS-CoV-2 pandemic, with the possibility for more zoonotic transmission events. We also acknowledge the need for more targeted research towards glycan–coronavirus interactions as zoonotic spillover events from animals to humans, following an alteration in glycan-binding capability, have been well-documented for other viruses such as Influenza A. Full article

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12 pages, 2151 KiB

Open AccessArticle

Alphacoronaviruses Are Common in Bats in the Upper Midwestern United States

by Reagan Schaeffer, Gun Temeeyasen and Ben M. Hause

Viruses 2022, 14(2), 184; https://doi.org/10.3390/v14020184 - 19 Jan 2022

Cited by 2 | Viewed by 3069

Abstract

Bats are a reservoir for coronaviruses (CoVs) that periodically spill over to humans, as evidenced by severe acute respiratory syndrome coronavirus (SARS-CoV) and SARS-CoV-2. A collection of 174 bat samples originating from South Dakota, Minnesota, Iowa, and Nebraska submitted for rabies virus testing [...] Read more.

Bats are a reservoir for coronaviruses (CoVs) that periodically spill over to humans, as evidenced by severe acute respiratory syndrome coronavirus (SARS-CoV) and SARS-CoV-2. A collection of 174 bat samples originating from South Dakota, Minnesota, Iowa, and Nebraska submitted for rabies virus testing due to human exposure were analyzed using a pan-coronavirus PCR. A previously partially characterized CoV, Eptesicus bat CoV, was identified in 12 (6.9%) samples by nested RT-PCR. Six near-complete genomes were determined. Genetic analysis found a high similarity between all CoV-positive samples, Rocky Mountain bat CoV 65 and alphacoronavirus HCQD-2020 recently identified in South Korea. Phylogenetic analysis of genome sequences showed EbCoV is closely related to bat CoV HKU2 and swine acute diarrhea syndrome CoV; however, topological incongruences were noted for the spike gene that was more closely related to porcine epidemic diarrhea virus. Similar to some alphaCoVs, a novel gene, ORF7, was discovered downstream of the nucleocapsid, whose protein lacked similarity to known proteins. The widespread circulation of EbCoV with similarities to bat viruses that have spilled over to swine warrants further surveillance. Full article

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14 pages, 2058 KiB

Open AccessArticle

GNS561 Exhibits Potent Antiviral Activity against SARS-CoV-2 through Autophagy Inhibition

by Eloïne Bestion, Keivan Zandi, Sandrine Belouzard, Julien Andreani, Hubert Lepidi, Marie Novello, Clara Rouquairol, Jean-Pierre Baudoin, Madani Rachid, Bernard La Scola, Jean-Louis Mege, Jean Dubuisson, Raymond F. Schinazi, Soraya Mezouar and Philippe Halfon

Viruses 2022, 14(1), 132; https://doi.org/10.3390/v14010132 - 12 Jan 2022

Cited by 15 | Viewed by 3479

Abstract

Since December 2019, SARS-CoV-2 has spread quickly worldwide, leading to more than 280 million confirmed cases, including over 5,000,000 deaths. Interestingly, coronaviruses were found to subvert and hijack autophagic process to allow their viral replication. Autophagy-modulating compounds thus rapidly emerged as an attractive [...] Read more.

Since December 2019, SARS-CoV-2 has spread quickly worldwide, leading to more than 280 million confirmed cases, including over 5,000,000 deaths. Interestingly, coronaviruses were found to subvert and hijack autophagic process to allow their viral replication. Autophagy-modulating compounds thus rapidly emerged as an attractive strategy to fight SARS-CoV-2 infection, including the well-known chloroquine (CQ). Here, we investigated the antiviral activity and associated mechanism of GNS561/Ezurpimtrostat, a small lysosomotropic molecule inhibitor of late-stage autophagy. Interestingly, GNS561 exhibited antiviral activity of 6–40 nM depending on the viral strain considered, currently positioning it as the most powerful molecule investigated in SARS-CoV-2 infection. We then showed that GNS561 was located in lysosome-associated-membrane-protein-2-positive (LAMP2-positive) lysosomes, together with SARS-CoV-2. Moreover, GNS561 increased LC3-II spot size and caused the accumulation of autophagic vacuoles and the presence of multilamellar bodies, suggesting that GNS561 disrupted the autophagy mechanism. To confirm our findings, we used the K18-hACE2 mouse model and highlighted that GNS561 treatment led to a decline in SARS-CoV-2 virions in the lungs associated with a disruption of the autophagy pathway. Overall, our study highlights GNS561 as a powerful drug in the treatment of SARS-CoV-2 infection and supports the hypothesis that autophagy blockers could be an alternative strategy for COVID-19. Full article

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2021

Jump to: 2024, 2023, 2022, 2020

12 pages, 2277 KiB

Open AccessArticle

SARS-CoV-2 ORF3a Induces Incomplete Autophagy via the Unfolded Protein Response

by Wen-qing Su, Xue-jie Yu and Chuan-min Zhou

Viruses 2021, 13(12), 2467; https://doi.org/10.3390/v13122467 - 9 Dec 2021

Cited by 26 | Viewed by 4864

Abstract

In the past year and a half, SARS-CoV-2 has caused 240 million confirmed cases and 5 million deaths worldwide. Autophagy is a conserved process that either promotes or inhibits viral infections. Although coronaviruses are known to utilize the transport of autophagy-dependent vesicles for [...] Read more.

In the past year and a half, SARS-CoV-2 has caused 240 million confirmed cases and 5 million deaths worldwide. Autophagy is a conserved process that either promotes or inhibits viral infections. Although coronaviruses are known to utilize the transport of autophagy-dependent vesicles for the viral life cycle, the underlying autophagy-inducing mechanisms remain largely unexplored. Using several autophagy-deficient cell lines and autophagy inhibitors, we demonstrated that SARS-CoV-2 ORF3a was able to induce incomplete autophagy in a FIP200/Beclin-1-dependent manner. Moreover, ORF3a was involved in the induction of the UPR (unfolded protein response), while the IRE1 and ATF6 pathways, but not the PERK pathway, were responsible for mediating the ORF3a-induced autophagy. These results identify the role of the UPR pathway in the ORF3a-induced classical autophagy process, which may provide us with a better understanding of SARS-CoV-2 and suggest new therapeutic modalities in the treatment of COVID-19. Full article

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17 pages, 2978 KiB

Open AccessArticle

Inhibiting ACSL1-Related Ferroptosis Restrains Murine Coronavirus Infection

by Huawei Xia, Zeming Zhang and Fuping You

Viruses 2021, 13(12), 2383; https://doi.org/10.3390/v13122383 - 28 Nov 2021

Cited by 21 | Viewed by 5615

Abstract

Murine hepatitis virus strain A59 (MHV-A59) was shown to induce pyroptosis, apoptosis, and necroptosis of infected cells, especially in the murine macrophages. However, whether ferroptosis, a recently identified form of lytic cell death, was involved in the pathogenicity of MHV-A59 is unknown. We [...] Read more.

Murine hepatitis virus strain A59 (MHV-A59) was shown to induce pyroptosis, apoptosis, and necroptosis of infected cells, especially in the murine macrophages. However, whether ferroptosis, a recently identified form of lytic cell death, was involved in the pathogenicity of MHV-A59 is unknown. We utilized murine macrophages and a C57BL/6 mice intranasal infection model to address this. In primary macrophages, the ferroptosis inhibitor inhibited viral propagation, inflammatory cytokines released, and cell syncytia formed after MHV-A59 infection. In the mouse model, we found that in vivo administration of liproxstatin-1 ameliorated lung inflammation and tissue injuries caused by MHV-A59 infection. To find how MHV-A59 infection influenced the expression of ferroptosis-related genes, we performed RNA-seq in primary macrophages and found that MHV-A59 infection upregulates the expression of the acyl-CoA synthetase long-chain family member 1 (ACSL1), a novel ferroptosis inducer. Using ferroptosis inhibitors and a TLR4 inhibitor, we showed that MHV-A59 resulted in the NF-kB-dependent, TLR4-independent ACSL1 upregulation. Accordingly, ACSL1 inhibitor Triacsin C suppressed MHV-A59-infection-induced syncytia formation and viral propagation in primary macrophages. Collectively, our study indicates that ferroptosis inhibition protects hosts from MHV-A59 infection. Targeting ferroptosis may serve as a potential treatment approach for dealing with hyper-inflammation induced by coronavirus infection. Full article

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15 pages, 1490 KiB

Open AccessArticle

Apoptosis Enhances the Replication of Human Coronavirus OC43

by Sony Maharjan, Mijeong Kang, Jinsoo Kim, Dongbum Kim, Sangkyu Park, Minyoung Kim, Kyeongbin Baek, Younghee Lee and Hyung-Joo Kwon

Viruses 2021, 13(11), 2199; https://doi.org/10.3390/v13112199 - 1 Nov 2021

Cited by 9 | Viewed by 3561

Abstract

Human coronavirus OC43 (HCoV-OC43) is one of the coronaviruses causing a mild common cold, but few studies have been made on this strain. Here, we identified the molecular mechanisms involved in HCoV-OC43-induced apoptosis and its implications for viral reproduction in Vero cells and [...] Read more.

Human coronavirus OC43 (HCoV-OC43) is one of the coronaviruses causing a mild common cold, but few studies have been made on this strain. Here, we identified the molecular mechanisms involved in HCoV-OC43-induced apoptosis and its implications for viral reproduction in Vero cells and MRC-5 cells. HCoV-OC43 infection induced apoptosis that was accompanied by cleavage of caspase-3 and PARP, degradation of cyclin D1, and cell cycle arrest at S and G2M phases. Dephosphorylation of STAT1 and STAT3, induced by HCoV-OC43 infection, was also associated with HCoV-OC43-mediated apoptosis. The pan-caspase inhibitor effectively prevented HCoV-OC43-induced apoptosis and reduced viral replication, suggesting that apoptosis contributes to viral replication. Collectively our results indicate that HCoV-OC43 induces caspase-dependent apoptosis to promote viral replication in Vero cells and MRC-5 cells. Full article

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11 pages, 16352 KiB

Open AccessBrief Report

Efficacy of Ion-Channel Inhibitors Amantadine, Memantine and Rimantadine for the Treatment of SARS-CoV-2 In Vitro

by Yuyong Zhou, Karen A. Gammeltoft, Andrea Galli, Anna Offersgaard, Ulrik Fahnøe, Santseharay Ramirez, Jens Bukh and Judith M. Gottwein

Viruses 2021, 13(10), 2082; https://doi.org/10.3390/v13102082 - 15 Oct 2021

Cited by 23 | Viewed by 4038

Abstract

We report the in vitro efficacy of ion-channel inhibitors amantadine, memantine and rimantadine against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). In VeroE6 cells, rimantadine was most potent followed by memantine and amantadine (50% effective concentrations: 36, 80 and 116 µM, respectively). Rimantadine [...] Read more.

We report the in vitro efficacy of ion-channel inhibitors amantadine, memantine and rimantadine against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). In VeroE6 cells, rimantadine was most potent followed by memantine and amantadine (50% effective concentrations: 36, 80 and 116 µM, respectively). Rimantadine also showed the highest selectivity index, followed by amantadine and memantine (17.3, 12.2 and 7.6, respectively). Similar results were observed in human hepatoma Huh7.5 and lung carcinoma A549-hACE2 cells. Inhibitors interacted in a similar antagonistic manner with remdesivir and had a similar barrier to viral escape. Rimantadine acted mainly at the viral post-entry level and partially at the viral entry level. Based on these results, rimantadine showed the most promise for treatment of SARS-CoV-2. Full article

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10 pages, 1228 KiB

Open AccessArticle

Development of a Recombinant RBD Subunit Vaccine for SARS-CoV-2

by Yi-Sheng Sun, Jing-Jing Zhou, Han-Ping Zhu, Fang Xu, Wen-Bin Zhao, Hang-Jing Lu, Zhen Wang, Shu-Qing Chen, Ping-Ping Yao, Jian-Min Jiang and Zhan Zhou

Viruses 2021, 13(10), 1936; https://doi.org/10.3390/v13101936 - 26 Sep 2021

Cited by 14 | Viewed by 4361

Abstract

The novel coronavirus pneumonia (COVID-19) pandemic is a great threat to human society and now is still spreading. Although several vaccines have been authorized for emergency use, only one recombinant subunit vaccine has been permitted for widespread use. More subunit vaccines for COVID-19 [...] Read more.

The novel coronavirus pneumonia (COVID-19) pandemic is a great threat to human society and now is still spreading. Although several vaccines have been authorized for emergency use, only one recombinant subunit vaccine has been permitted for widespread use. More subunit vaccines for COVID-19 should be developed in the future. The receptor binding domain (RBD), located at the S protein of SARS-CoV-2, contains most of the neutralizing epitopes. However, the immunogenicity of RBD monomers is not strong enough. In this study, we fused the RBD-monomer with a modified Fc fragment of human IgG1 to form an RBD-Fc fusion protein. The recombinant vaccine candidate based on the RBD-Fc protein could induce high levels of IgG and neutralizing antibody in mice, and these could last for at least three months. The secretion of IFN-γ, IL-2 and IL-10 in the RBD-stimulated splenocytes of immunized mice also increased significantly. Our results first showed that the RBD-Fc vaccine could induce both humoral and cellular immune responses and might be an optional strategy to control COVID-19. Full article

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12 pages, 2086 KiB

Open AccessArticle

Multiple Occurrences of a 168-Nucleotide Deletion in SARS-CoV-2 ORF8, Unnoticed by Standard Amplicon Sequencing and Variant Calling Pipelines

by David Brandt, Marina Simunovic, Tobias Busche, Markus Haak, Peter Belmann, Sebastian Jünemann, Tizian Schulz, Levin Joe Klages, Svenja Vinke, Michael Beckstette, Ehmke Pohl, Christiane Scherer, Alexander Sczyrba and Jörn Kalinowski

Viruses 2021, 13(9), 1870; https://doi.org/10.3390/v13091870 - 18 Sep 2021

Cited by 8 | Viewed by 6096

Abstract

Genomic surveillance of the SARS-CoV-2 pandemic is crucial and mainly achieved by amplicon sequencing protocols. Overlapping tiled-amplicons are generated to establish contiguous SARS-CoV-2 genome sequences, which enable the precise resolution of infection chains and outbreaks. We investigated a SARS-CoV-2 outbreak in a local [...] Read more.

Genomic surveillance of the SARS-CoV-2 pandemic is crucial and mainly achieved by amplicon sequencing protocols. Overlapping tiled-amplicons are generated to establish contiguous SARS-CoV-2 genome sequences, which enable the precise resolution of infection chains and outbreaks. We investigated a SARS-CoV-2 outbreak in a local hospital and used nanopore sequencing with a modified ARTIC protocol employing 1200 bp long amplicons. We detected a long deletion of 168 nucleotides in the ORF8 gene in 76 samples from the hospital outbreak. This deletion is difficult to identify with the classical amplicon sequencing procedures since it removes two amplicon primer-binding sites. We analyzed public SARS-CoV-2 sequences and sequencing read data from ENA and identified the same deletion in over 100 genomes belonging to different lineages of SARS-CoV-2, pointing to a mutation hotspot or to positive selection. In almost all cases, the deletion was not represented in the virus genome sequence after consensus building. Additionally, further database searches point to other deletions in the ORF8 coding region that have never been reported by the standard data analysis pipelines. These findings and the fact that ORF8 is especially prone to deletions, make a clear case for the urgent necessity of public availability of the raw data for this and other large deletions that might change the physiology of the virus towards endemism. Full article

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17 pages, 40146 KiB

Open AccessArticle

Hypericin Inhibit Alpha-Coronavirus Replication by Targeting 3CL Protease

by Yue Zhang, Huijie Chen, Mengmeng Zou, Rick Oerlemans, Changhao Shao, Yudong Ren, Ruili Zhang, Xiaodan Huang, Guangxing Li and Yingying Cong

Viruses 2021, 13(9), 1825; https://doi.org/10.3390/v13091825 - 14 Sep 2021

Cited by 23 | Viewed by 3980

Abstract

The porcine epidemic diarrhea virus (PEDV) is an Alphacoronavirus (α-CoV) that causes high mortality in infected piglets, resulting in serious economic losses in the farming industry. Hypericin is a dianthrone compound that has been shown as an antiviral activity on several viruses. Here, [...] Read more.

The porcine epidemic diarrhea virus (PEDV) is an Alphacoronavirus (α-CoV) that causes high mortality in infected piglets, resulting in serious economic losses in the farming industry. Hypericin is a dianthrone compound that has been shown as an antiviral activity on several viruses. Here, we first evaluated the antiviral effect of hypericin in PEDV and found the viral replication and egression were significantly reduced with hypericin post-treatment. As hypericin has been shown in SARS-CoV-2 that it is bound to viral 3CLpro, we thus established a molecular docking between hypericin and PEDV 3CLpro using different software and found hypericin bound to 3CLpro through two pockets. These binding pockets were further verified by another docking between hypericin and PEDV 3CLpro pocket mutants, and the fluorescence resonance energy transfer (FRET) assay confirmed that hypericin inhibits the PEDV 3CLpro activity. Moreover, the alignments of α-CoV 3CLpro sequences or crystal structure revealed that the pockets mediating hypericin and PEDV 3CLpro binding were highly conserved, especially in transmissible gastroenteritis virus (TGEV). We then validated the anti-TGEV effect of hypericin through viral replication and egression. Overall, our results push forward that hypericin was for the first time shown to have an inhibitory effect on PEDV and TGEV by targeting 3CLpro, and it deserves further attention as not only a pan-anti-α-CoV compound but potentially also as a compound of other coronaviral infections. Full article

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7 pages, 501 KiB

Open AccessBrief Report

Prevalence of Neutralising Antibodies to HCoV-NL63 in Healthy Adults in Australia

by Sean A. Lynch, Kanta Subbarao, Siddhartha Mahanty, Bridget E. Barber, Eileen V. Roulis, Lia van der Hoek, James S. McCarthy and Kirsten M. Spann

Viruses 2021, 13(8), 1618; https://doi.org/10.3390/v13081618 - 16 Aug 2021

Cited by 4 | Viewed by 3430

Abstract

The COVID-19 pandemic has highlighted the importance of understanding the immune response to seasonal human coronavirus (HCoV) infections such as HCoV-NL63, how existing neutralising antibodies to HCoV may modulate responses to SARS-CoV-2 infection, and the utility of seasonal HCoV as human challenge models. [...] Read more.

The COVID-19 pandemic has highlighted the importance of understanding the immune response to seasonal human coronavirus (HCoV) infections such as HCoV-NL63, how existing neutralising antibodies to HCoV may modulate responses to SARS-CoV-2 infection, and the utility of seasonal HCoV as human challenge models. Therefore, in this study we quantified HCoV-NL63 neutralising antibody titres in a healthy adult population using plasma from 100 blood donors in Australia. A microneutralisation assay was performed with plasma diluted from 1:10 to 1:160 and tested with the HCoV-NL63 Amsterdam-1 strain. Neutralising antibodies were detected in 71% of the plasma samples, with a median geometric mean titre of 14. This titre was similar to those reported in convalescent sera taken from individuals 3–7 months following asymptomatic SARS-CoV-2 infection, and 2–3 years post-infection from symptomatic SARS-CoV-1 patients. HCoV-NL63 neutralising antibody titres decreased with increasing age (R² = 0.042, p = 0.038), but did not differ by sex. Overall, this study demonstrates that neutralising antibody to HCoV-NL63 is detectable in approximately 71% of the healthy adult population of Australia. Similar titres did not impede the use of another seasonal human coronavirus (HCoV-229E) in a human challenge model, thus, HCoV-NL63 may be useful as a human challenge model for more pathogenic coronaviruses. Full article

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13 pages, 1491 KiB

Open AccessArticle

Epidemiology and Seasonality of Endemic Human Coronaviruses in South African and Zambian Children: A Case-Control Pneumonia Study

by Vicky L. Baillie, David P. Moore, Azwifarwi Mathunjwa, Daniel E. Park, Donald M. Thea, Geoffrey Kwenda, Lawrence Mwananyanda and Shabir A. Madhi

Viruses 2021, 13(8), 1513; https://doi.org/10.3390/v13081513 - 31 Jul 2021

Cited by 10 | Viewed by 2604

Abstract

Endemic human coronaviruses (HCoV) are capable of causing a range of diseases from the common cold to pneumonia. We evaluated the epidemiology and seasonality of endemic HCoVs in children hospitalized with clinical pneumonia and among community controls living in countries with a high [...] Read more.

Endemic human coronaviruses (HCoV) are capable of causing a range of diseases from the common cold to pneumonia. We evaluated the epidemiology and seasonality of endemic HCoVs in children hospitalized with clinical pneumonia and among community controls living in countries with a high HIV burden, namely South Africa and Zambia, between August 2011 to October 2013. Nasopharyngeal/oropharyngeal swabs were collected from all cases and controls and tested for endemic HCoV species and 12 other respiratory viruses using a multiplex real-time PCR assay. We found that the likelihood of detecting endemic HCoV species was higher among asymptomatic controls than cases (11% vs. 7.2%; 95% CI: 1.2–2.0). This was however only observed among children > 6 months and was mainly driven by the Betacoronavirus endemic species (HCoV-OC43 and –HKU1). Endemic HCoV species were detected through the year; however, in Zambia, the endemic Betacoronavirus species tended to peak during the winter months (May–August). There was no association between HIV status and endemic HCoV detection. Full article

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7 pages, 644 KiB

Open AccessCommunication

Elicitation of Broadly Neutralizing Antibodies against B.1.1.7, B.1.351, and B.1.617.1 SARS-CoV-2 Variants by Three Prototype Strain-Derived Recombinant Protein Vaccines

by Yong Yang, Jinkai Zang, Shiqi Xu, Xueyang Zhang, Sule Yuan, Haikun Wang, Dimitri Lavillette, Chao Zhang and Zhong Huang

Viruses 2021, 13(8), 1421; https://doi.org/10.3390/v13081421 - 22 Jul 2021

Cited by 7 | Viewed by 3181

Abstract

The ongoing coronavirus disease 2019 (COVID-19) pandemic is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Most of the currently approved SARS-CoV-2 vaccines use the prototype strain-derived spike (S) protein or its receptor-binding domain (RBD) as the vaccine antigen. The emergence of [...] Read more.

The ongoing coronavirus disease 2019 (COVID-19) pandemic is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Most of the currently approved SARS-CoV-2 vaccines use the prototype strain-derived spike (S) protein or its receptor-binding domain (RBD) as the vaccine antigen. The emergence of several novel SARS-CoV-2 variants has raised concerns about potential immune escape. In this study, we performed an immunogenicity comparison of prototype strain-derived RBD, S1, and S ectodomain trimer (S-trimer) antigens and evaluated their induction of neutralizing antibodies against three circulating SARS-CoV-2 variants, including B.1.1.7, B.1.351, and B.1.617.1. We found that, at the same antigen dose, the RBD and S-trimer vaccines were more potent than the S1 vaccine in eliciting long-lasting, high-titer broadly neutralizing antibodies in mice. The RBD immune sera remained highly effective against the B.1.1.7, B.1.351, and B.1.617.1 variants despite the corresponding neutralizing titers decreasing by 1.2-, 2.8-, and 3.5-fold relative to that against the wild-type strain. Significantly, the S-trimer immune sera exhibited comparable neutralization potency (less than twofold variation in neutralizing GMTs) towards the prototype strain and all three variants tested. These findings provide valuable information for further development of recombinant protein-based SARS-CoV-2 vaccines and support the continued use of currently approved SARS-CoV-2 vaccines in the regions/countries where variant viruses circulate. Full article

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12 pages, 558 KiB

Open AccessArticle

Human Coronaviruses Do Not Transfer Efficiently between Surfaces in the Absence of Organic Materials

by Matthew Dallner, Jennifer Harlow and Neda Nasheri

Viruses 2021, 13(7), 1352; https://doi.org/10.3390/v13071352 - 13 Jul 2021

Cited by 18 | Viewed by 4785

Abstract

Human coronaviruses, including SARS-CoV-2, are known to spread mainly via close contact and respiratory droplets. However, other potential means of transmission may be present. Fomite-mediated transmission occurs when viruses are deposited onto a surface and then transfer to a subsequent individual. Surfaces can [...] Read more.

Human coronaviruses, including SARS-CoV-2, are known to spread mainly via close contact and respiratory droplets. However, other potential means of transmission may be present. Fomite-mediated transmission occurs when viruses are deposited onto a surface and then transfer to a subsequent individual. Surfaces can become contaminated directly from respiratory droplets or from a contaminated hand. Due to mask mandates in many countries around the world, the former is less likely. Hands can become contaminated if respiratory droplets are deposited on them (i.e., coughing or sneezing) or through contact with fecal material where human coronaviruses (HCoVs) can be shed. The focus of this paper is on whether human coronaviruses can transfer efficiently from contaminated hands to food or food contact surfaces. The surfaces chosen were: stainless steel, plastic, cucumber and apple. Transfer was first tested with cellular maintenance media and three viruses: two human coronaviruses, 229E and OC43, and murine norovirus-1, as a surrogate for human norovirus. There was no transfer for either of the human coronaviruses to any of the surfaces. Murine norovirus-1 did transfer to stainless steel, cucumber and apple, with transfer efficiencies of 9.19%, 5.95% and 0.329%, respectively. Human coronavirus OC43 transfer was then tested in the presence of fecal material, and transfer was observed for stainless steel (0.52%), cucumber (19.82%) and apple (15.51%) but not plastic. This study indicates that human coronaviruses do not transfer effectively from contaminated hands to contact surfaces without the presence of fecal material. Full article

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21 pages, 2968 KiB

Open AccessReview

Anti-SARS-CoV-2 Vaccines and Monoclonal Antibodies Facing Viral Variants

by Ahlam Chaqroun, Cédric Hartard and Evelyne Schvoerer

Viruses 2021, 13(6), 1171; https://doi.org/10.3390/v13061171 - 18 Jun 2021

Cited by 25 | Viewed by 5713

Abstract

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is genetically variable, allowing it to adapt to various hosts including humans. Indeed, SARS-CoV-2 has accumulated around two mutations per genome each month. The first relevant event in this context was the occurrence of the [...] Read more.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is genetically variable, allowing it to adapt to various hosts including humans. Indeed, SARS-CoV-2 has accumulated around two mutations per genome each month. The first relevant event in this context was the occurrence of the mutant D614G in the Spike gene. Moreover, several variants have emerged, including the well-characterized 20I/501Y.V1, 20H/501Y.V2, and 20J/501Y.V3 strains, in addition to those that have been detected within clusters, such as 19B/501Y or 20C/655Y in France. Mutants have also emerged in animals, including a variant transmitted to humans, namely, the Mink variant detected in Denmark. The emergence of these variants has affected the transmissibility of the virus (for example, 20I/501Y.V1, which was up to 82% more transmissible than other preexisting variants), its severity, and its ability to escape natural, adaptive, vaccine, and therapeutic immunity. In this respect, we review the literature on variants that have currently emerged, and their effect on vaccines and therapies, and, in particular, monoclonal antibodies (mAbs). The emergence of SARS-CoV-2 variants must be examined to allow effective preventive and curative control strategies to be developed. Full article

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7 pages, 2608 KiB

Open AccessArticle

Evaluation of Production Lots of a Rapid Point-of-Care Lateral Flow Serological Test Intended for Identification of IgM and IgG against the N-Terminal Part of the Spike Protein (S1) of SARS-CoV-2

by Tove Hoffman, Linda Kolstad, Bengt Rönnberg and Åke Lundkvist

Viruses 2021, 13(6), 1043; https://doi.org/10.3390/v13061043 - 31 May 2021

Cited by 5 | Viewed by 3377

Abstract

The potential of rapid point-of-care (POC) tests has been subject of doubt due to an eventual risk of production errors. The aim was therefore to evaluate the two separate production lots of a commercial POC lateral flow test, intended for the detection of [...] Read more.

The potential of rapid point-of-care (POC) tests has been subject of doubt due to an eventual risk of production errors. The aim was therefore to evaluate the two separate production lots of a commercial POC lateral flow test, intended for the detection of IgM and IgG against the SARS-CoV-2 spike protein (S1). Control samples consisted of serum from individuals with confirmed SARS-CoV-2 infection and pre-COVID-19 negative sera gathered from a biobank. The presence of anti-S1 IgM/IgG in the sera was verified by an in-house Luminex-based serological assay (COVID-19 SIA). One hundred samples were verified as positive for anti-S1 IgG and 74 for anti-S1 IgM. Two hundred samples were verified as negative for anti-S1 IgM/IgG. For the two lots of the POC-test, the sensitivities were 93.2% and 87.8% for IgM and 93.0% and 100% for IgG. The specificities were 100% for IgM and 99.5% for IgG. The positive predictive value was 100% for IgM and 98.9% and 99.0% for IgG. The negative predictive value was 97.6% and 95.7% for IgM, and 96.6% and 100% for IgG. The evaluated POC-test is suitable to assess anti-SARS-CoV-2 S1 IgM and IgG, as a measure of previous virus exposure on an individual level. The external validation of separate lots of rapid POC-tests is encouraged to ensure high sensitivity before market introduction. Full article

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12 pages, 1761 KiB

Open AccessArticle

GABA_A-Receptor Agonists Limit Pneumonitis and Death in Murine Coronavirus-Infected Mice

by Jide Tian, Blake Middleton and Daniel L. Kaufman

Viruses 2021, 13(6), 966; https://doi.org/10.3390/v13060966 - 23 May 2021

Cited by 20 | Viewed by 5155

Abstract

There is an urgent need for new approaches to limit the severity of coronavirus infections. Many cells of the immune system express receptors for the neurotransmitter γ-aminobutyric acid (GABA), and GABA-receptor (GABA-R) agonists have anti-inflammatory effects. Lung epithelial cells also express GABA-Rs, and [...] Read more.

There is an urgent need for new approaches to limit the severity of coronavirus infections. Many cells of the immune system express receptors for the neurotransmitter γ-aminobutyric acid (GABA), and GABA-receptor (GABA-R) agonists have anti-inflammatory effects. Lung epithelial cells also express GABA-Rs, and GABA-R modulators have been shown to limit acute lung injuries. There is currently, however, no information on whether GABA-R agonists might impact the course of a viral infection. Here, we assessed whether clinically applicable GABA-R agonists could be repurposed for the treatment of a lethal coronavirus (murine hepatitis virus 1, MHV-1) infection in mice. We found that oral GABA administration before, or after the appearance of symptoms, very effectively limited MHV-1-induced pneumonitis, severe illness, and death. GABA treatment also reduced viral load in the lungs, suggesting that GABA-Rs may provide a new druggable target to limit coronavirus replication. Treatment with the GABA_A-R-specific agonist homotaurine, but not the GABA_B-R-specific agonist baclofen, significantly reduced the severity of pneumonitis and death rates in MHV-1-infected mice, indicating that the therapeutic effects were mediated primarily through GABA_A-Rs. Since GABA and homotaurine are safe for human consumption, they are promising candidates to help treat coronavirus infections. Full article

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8 pages, 688 KiB

Open AccessArticle

Symptomatic SARS-CoV-2 Reinfection in a Healthy Healthcare Worker in Italy Confirmed by Whole-Genome Sequencing

by Daniela Loconsole, Anna Sallustio, Marisa Accogli, Francesca Centrone, Daniele Casulli, Antonino Madaro, Ersilia Tedeschi, Antonio Parisi and Maria Chironna

Viruses 2021, 13(5), 899; https://doi.org/10.3390/v13050899 - 12 May 2021

Cited by 6 | Viewed by 2886

Abstract

This study describes a case of SARS-CoV-2 reinfection confirmed by whole-genome sequencing in a healthy physician who had been working in a COVID-19 hospital in Italy since the beginning of the pandemic. Nasopharyngeal swabs were obtained from the patient at each presentation as [...] Read more.

This study describes a case of SARS-CoV-2 reinfection confirmed by whole-genome sequencing in a healthy physician who had been working in a COVID-19 hospital in Italy since the beginning of the pandemic. Nasopharyngeal swabs were obtained from the patient at each presentation as part of routine surveillance. Nucleic acid amplification testing was performed on the two samples to confirm SARS-CoV-2 infection, and serological tests were used to detect SARS-CoV-2 IgG antibodies. Comparative genome analysis with whole-genome sequencing was performed on nasopharyngeal swabs collected during the two episodes of COVID-19. The first COVID-19 episode was in March 2020, and the second was in January 2021. Both SARS-CoV-2 infections presented with mild symptoms, and seroconversion for SARS-CoV-2 IgG was documented. Genomic analysis showed that the viral genome from the first infection belonged to the lineage B.1.1.74, while that from the second infection to the lineage B.1.177. Epidemiological, clinical, serological, and genomic analyses confirmed that the second episode of SARS-CoV-2 infection in the healthcare worker met the qualifications for “best evidence” for reinfection. Further studies are urgently needed to assess the frequency of such a worrisome occurrence, particularly in the light of the recent diffusion of SARS-CoV-2 variants of concern. Full article

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10 pages, 6094 KiB

Open AccessArticle

Influence of SARS-CoV-2 Variant B.1.1.7, Vaccination, and Public Health Measures on the Spread of SARS-CoV-2

by Chloé Dimeglio, Marine Milhes, Jean-Michel Loubes, Noémie Ranger, Jean-Michel Mansuy, Pauline Trémeaux, Nicolas Jeanne, Justine Latour, Florence Nicot, Cécile Donnadieu and Jacques Izopet

Viruses 2021, 13(5), 898; https://doi.org/10.3390/v13050898 - 12 May 2021

Cited by 5 | Viewed by 3743

Abstract

The spread of SARS-CoV-2 and the resulting disease COVID-19 has killed over 2.6 million people as of 18 March 2021. We have used a modified susceptible, infected, recovered (SIR) epidemiological model to predict how the spread of the virus in regions of France [...] Read more.

The spread of SARS-CoV-2 and the resulting disease COVID-19 has killed over 2.6 million people as of 18 March 2021. We have used a modified susceptible, infected, recovered (SIR) epidemiological model to predict how the spread of the virus in regions of France will vary depending on the proportions of variants and on the public health strategies adopted, including anti-COVID-19 vaccination. The proportion of SARS-CoV-2 variant B.1.1.7, which was not detected in early January, increased to become 60% of the forms of SARS-CoV-2 circulating in the Toulouse urban area at the beginning of February 2021, but there was no increase in positive nucleic acid tests. Our prediction model indicates that maintaining public health measures and accelerating vaccination are efficient strategies for the sustained control of SARS-CoV-2. Full article

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12 pages, 4892 KiB

Open AccessArticle

Prognostic Values of Serum Ferritin and D-Dimer Trajectory in Patients with COVID-19

by Fares Qeadan, Benjamin Tingey, Lily Y. Gu, Ashley Hafen Packard, Esther Erdei and Ali I. Saeed

Viruses 2021, 13(3), 419; https://doi.org/10.3390/v13030419 - 5 Mar 2021

Cited by 53 | Viewed by 6505

Abstract

Cytokine storm syndrome in patients with COVID-19 is mediated by pro-inflammatory cytokines resulting in acute lung injury and multiorgan failure. Elevation in serum ferritin and D-dimer is observed in COVID-19 patients. To determine prognostic values of optimal serum cutoff with trajectory plots for [...] Read more.

Cytokine storm syndrome in patients with COVID-19 is mediated by pro-inflammatory cytokines resulting in acute lung injury and multiorgan failure. Elevation in serum ferritin and D-dimer is observed in COVID-19 patients. To determine prognostic values of optimal serum cutoff with trajectory plots for both serum ferritin and D-dimer in COVID-19 patients with invasive ventilator dependence and in-hospital mortality. We used retrospective longitudinal data from the Cerner COVID-19 de-identified cohort. COVID-19 infected patients with valid repeated values of serum ferritin and D-dimer during hospitalization were used in mixed-effects logistic-regression models. Among 52,411 patients, 28.5% (14,958) had valid serum ferritin and 28.6% (15,005) D-dimer laboratory results. Optimal cutoffs of ferritin (714 ng/mL) and D-dimer (2.1 mg/L) revealed AUCs ≥ 0.99 for in-hospital mortality. Optimal cutoffs for ferritin (502 ng/mL) and D-dimer (2.0 mg/L) revealed AUCs ≥ 0.99 for invasive ventilator dependence. Optimal cutoffs for in-house mortality, among females, were lower in serum ferritin (433 ng/mL) and D-dimer (1.9 mg/L) compared to males (740 ng/mL and 2.5 mg/L, respectively). Optimal cutoffs for invasive ventilator dependence, among females, were lower in ferritin (270 ng/mL) and D-dimer (1.3 mg/L) compared to males (860 ng/mL and 2.3 mg/L, respectively). Optimal prognostic cutoffs for serum ferritin and D-dimer require considering the entire trajectory of laboratory values during the disease course. Females have an overall lower optimal cutoff for both serum ferritin and D-dimer. The presented research allows health professionals to predict clinical outcomes and appropriate allocation of resources during the COVID-19 pandemic, especially early recognition of COVID-19 patients needing higher levels of care. Full article

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19 pages, 4427 KiB

Open AccessArticle

Comparative Transcriptome Profiling of Human and Pig Intestinal Epithelial Cells after Porcine Deltacoronavirus Infection

by Diana Cruz-Pulido, Patricia A. Boley, Wilberforce Zachary Ouma, Moyasar A. Alhamo, Linda J. Saif and Scott P. Kenney

Viruses 2021, 13(2), 292; https://doi.org/10.3390/v13020292 - 13 Feb 2021

Cited by 17 | Viewed by 4546

Abstract

Porcine deltacoronavirus (PDCoV) is an emerging infectious disease of swine with zoonotic potential. Phylogenetic analysis suggests that PDCoV originated recently from a host-switching event between birds and mammals. Little is known about how PDCoV interacts with its differing hosts. Human-derived cell lines are [...] Read more.

Porcine deltacoronavirus (PDCoV) is an emerging infectious disease of swine with zoonotic potential. Phylogenetic analysis suggests that PDCoV originated recently from a host-switching event between birds and mammals. Little is known about how PDCoV interacts with its differing hosts. Human-derived cell lines are susceptible to PDCoV infection. Herein, we compare the gene expression profiles of an established host swine cells to potential emerging host human cells after infection with PDCoV. Cell lines derived from intestinal lineages were used to reproduce the primary sites of viral infection in the host. Porcine intestinal epithelial cells (IPEC-J2) and human intestinal epithelial cells (HIEC) were infected with PDCoV. RNA-sequencing was performed on total RNA extracted from infected cells. Human cells exhibited a more pronounced response to PDCoV infection in comparison to porcine cells with more differentially expressed genes (DEGs) in human, 7486, in comparison to pig cells, 1134. On the transcriptional level, the adoptive host human cells exhibited more DEGs in response to PDCoV infection in comparison to the primary pig host cells, where different types of cytokines can control PDCoV replication and virus production. Key immune-associated DEGs and signaling pathways are shared between human and pig cells during PDCoV infection. These included genes related to the NF-kappa-B transcription factor family, the interferon (IFN) family, the protein-kinase family, and signaling pathways such as the apoptosis signaling pathway, JAK-STAT signaling pathway, inflammation/cytokine–cytokine receptor signaling pathway. MAP4K4 was unique in up-regulated DEGs in humans in the apoptosis signaling pathway. While similarities exist between human and pig cells in many pathways, our research suggests that the adaptation of PDCoV to the porcine host required the ability to down-regulate many response pathways including the interferon pathway. Our findings provide an important foundation that contributes to an understanding of the mechanisms of PDCoV infection across different hosts. To our knowledge, this is the first report of transcriptome analysis of human cells infected by PDCoV. Full article

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12 pages, 2128 KiB

Open AccessBrief Report

Titers of Neutralizing Antibodies against SARS-CoV-2 Are Independent of Symptoms of Non-Severe COVID-19 in Young Adults

by Hulda R. Jonsdottir, Michel Bielecki, Denise Siegrist, Thomas W. Buehrer, Roland Züst and Jeremy W. Deuel

Viruses 2021, 13(2), 284; https://doi.org/10.3390/v13020284 - 12 Feb 2021

Cited by 15 | Viewed by 3758

Abstract

Neutralizing antibodies are an important part of the humoral immune response to SARS-CoV-2. It is currently unclear to what extent such antibodies are produced after non-severe disease or asymptomatic infection. We studied a cluster of SARS-CoV-2 infections among a homogeneous population of 332 [...] Read more.

Neutralizing antibodies are an important part of the humoral immune response to SARS-CoV-2. It is currently unclear to what extent such antibodies are produced after non-severe disease or asymptomatic infection. We studied a cluster of SARS-CoV-2 infections among a homogeneous population of 332 predominantly male Swiss soldiers and determined the neutralizing antibody response with a serum neutralization assay using a recombinant SARS-CoV-2-GFP. All patients with non-severe COVID-19 showed a swift humoral response within two weeks after the onset of symptoms, which remained stable for the duration of the study. One month after the outbreak, titers in COVID-19 convalescents did not differ from the titers of asymptomatically infected individuals. Furthermore, symptoms of COVID-19 did not correlate with neutralizing antibody titers. Therefore, we conclude that asymptomatic infection can induce the same humoral immunity as non-severe COVID-19 in young adults. Full article

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18 pages, 3277 KiB

Open AccessArticle

Berberine and Obatoclax Inhibit SARS-Cov-2 Replication in Primary Human Nasal Epithelial Cells In Vitro

by Finny S. Varghese, Esther van Woudenbergh, Gijs J. Overheul, Marc J. Eleveld, Lisa Kurver, Niels van Heerbeek, Arjan van Laarhoven, Pascal Miesen, Gerco den Hartog, Marien I. de Jonge and Ronald P. van Rij

Viruses 2021, 13(2), 282; https://doi.org/10.3390/v13020282 - 11 Feb 2021

Cited by 53 | Viewed by 6578

Abstract

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged as a new human pathogen in late 2019 and it has infected over 100 million people in less than a year. There is a clear need for effective antiviral drugs to complement current preventive measures, [...] Read more.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged as a new human pathogen in late 2019 and it has infected over 100 million people in less than a year. There is a clear need for effective antiviral drugs to complement current preventive measures, including vaccines. In this study, we demonstrate that berberine and obatoclax, two broad-spectrum antiviral compounds, are effective against multiple isolates of SARS-CoV-2. Berberine, a plant-derived alkaloid, inhibited SARS-CoV-2 at low micromolar concentrations and obatoclax, which was originally developed as an anti-apoptotic protein antagonist, was effective at sub-micromolar concentrations. Time-of-addition studies indicated that berberine acts on the late stage of the viral life cycle. In agreement, berberine mildly affected viral RNA synthesis, but it strongly reduced infectious viral titers, leading to an increase in the particle-to-pfu ratio. In contrast, obatoclax acted at the early stage of the infection, which is in line with its activity to neutralize the acidic environment in endosomes. We assessed infection of primary human nasal epithelial cells that were cultured on an air-liquid interface and found that SARS-CoV-2 infection induced and repressed expression of specific sets of cytokines and chemokines. Moreover, both obatoclax and berberine inhibited SARS-CoV-2 replication in these primary target cells. We propose berberine and obatoclax as potential antiviral drugs against SARS-CoV-2 that could be considered for further efficacy testing. Full article

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10 pages, 1663 KiB

Open AccessArticle

Genomic Signatures of SARS-CoV-2 Associated with Patient Mortality

by Eric Dumonteil, Dahlene Fusco, Arnaud Drouin and Claudia Herrera

Viruses 2021, 13(2), 227; https://doi.org/10.3390/v13020227 - 2 Feb 2021

Cited by 6 | Viewed by 3894

Abstract

Infections with SARS-CoV-2 can progress toward multiple clinical outcomes, and the identification of factors associated with disease severity would represent a major advance to guide care and improve prognosis. We tested for associations between SARS-CoV-2 genomic variants from an international cohort of 2508 [...] Read more.

Infections with SARS-CoV-2 can progress toward multiple clinical outcomes, and the identification of factors associated with disease severity would represent a major advance to guide care and improve prognosis. We tested for associations between SARS-CoV-2 genomic variants from an international cohort of 2508 patients and mortality rates. Findings were validated in a second cohort. Phylogenetic analysis of SARS-CoV-2 genome sequences revealed four well-resolved clades which had significantly different mortality rates, even after adjusting for patient demographic and geographic characteristics. We further identified ten single-nucleotide polymorphisms (SNPs) in the SARS-CoV-2 genome that were associated with patient mortality. Three SNPs remained associated with mortality in a generalized linear model (GLM) that also included patient age, sex, geographic region, and month of sample collection. Multiple SNPs were confirmed in the validation cohort. These SNPs represent targets to assess the mechanisms underlying COVID-19 disease severity and warrant straightforward validation in functional studies. Full article

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25 pages, 849 KiB

Open AccessReview

COVID-19: A Review on the Novel Coronavirus Disease Evolution, Transmission, Detection, Control and Prevention

by Anshika Sharma, Isra Ahmad Farouk and Sunil Kumar Lal

Viruses 2021, 13(2), 202; https://doi.org/10.3390/v13020202 - 29 Jan 2021

Cited by 376 | Viewed by 43111

Abstract

Three major outbreaks of the coronavirus, a zoonotic virus known to cause respiratory disease, have been reported since 2002, including SARS-CoV, MERS-CoV and the most recent 2019-nCoV, or more recently known as SARS-CoV-2. Bats are known to be the primary animal reservoir for [...] Read more.

Three major outbreaks of the coronavirus, a zoonotic virus known to cause respiratory disease, have been reported since 2002, including SARS-CoV, MERS-CoV and the most recent 2019-nCoV, or more recently known as SARS-CoV-2. Bats are known to be the primary animal reservoir for coronaviruses. However, in the past few decades, the virus has been able to mutate and adapt to infect humans, resulting in an animal-to-human species barrier jump. The emergence of a novel coronavirus poses a serious global public health threat and possibly carries the potential of causing a major pandemic outbreak in the naïve human population. The recent outbreak of COVID-19, the disease caused by SARS-CoV-2, in Wuhan, Hubei Province, China has infected over 36.5 million individuals and claimed over one million lives worldwide, as of 8 October 2020. The novel virus is rapidly spreading across China and has been transmitted to 213 other countries/territories across the globe. Researchers have reported that the virus is constantly evolving and spreading through asymptomatic carriers, further suggesting a high global health threat. To this end, current up-to-date information on the coronavirus evolution and SARS-CoV-2 modes of transmission, detection techniques and current control and prevention strategies are summarized in this review. Full article

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20 pages, 3614 KiB

Open AccessReview

Biological and Clinical Consequences of Integrin Binding via a Rogue RGD Motif in the SARS CoV-2 Spike Protein

by Lee Makowski, William Olson-Sidford and John W. Weisel

Viruses 2021, 13(2), 146; https://doi.org/10.3390/v13020146 - 20 Jan 2021

Cited by 63 | Viewed by 23483

Abstract

Although ACE2 (angiotensin converting enzyme 2) is considered the primary receptor for CoV-2 cell entry, recent reports suggest that alternative pathways may contribute. This paper considers the hypothesis that viral binding to cell-surface integrins may contribute to the high infectivity and widespread extra-pulmonary [...] Read more.

Although ACE2 (angiotensin converting enzyme 2) is considered the primary receptor for CoV-2 cell entry, recent reports suggest that alternative pathways may contribute. This paper considers the hypothesis that viral binding to cell-surface integrins may contribute to the high infectivity and widespread extra-pulmonary impacts of the SARS-CoV-2 virus. This potential is suggested on the basis of the emergence of an RGD (arginine-glycine-aspartate) sequence in the receptor-binding domain of the spike protein. RGD is a motif commonly used by viruses to bind cell-surface integrins. Numerous signaling pathways are mediated by integrins and virion binding could lead to dysregulation of these pathways, with consequent tissue damage. Integrins on the surfaces of pneumocytes, endothelial cells and platelets may be vulnerable to CoV-2 virion binding. For instance, binding of intact virions to integrins on alveolar cells could enhance viral entry. Binding of virions to integrins on endothelial cells could activate angiogenic cell signaling pathways; dysregulate integrin-mediated signaling pathways controlling developmental processes; and precipitate endothelial activation to initiate blood clotting. Such a procoagulant state, perhaps together with enhancement of platelet aggregation through virions binding to integrins on platelets, could amplify the production of microthrombi that pose the threat of pulmonary thrombosis and embolism, strokes and other thrombotic consequences. The susceptibility of different tissues to virion–integrin interactions may be modulated by a host of factors, including the conformation of relevant integrins and the impact of the tissue microenvironment on spike protein conformation. Patient-specific differences in these factors may contribute to the high variability of clinical presentation. There is danger that the emergence of receptor-binding domain mutations that increase infectivity may also enhance access of the RGD motif for integrin binding, resulting in viral strains with ACE2 independent routes of cell entry and novel integrin-mediated biological and clinical impacts. The highly infectious variant, B.1.1.7 (or VUI 202012/01), includes a receptor-binding domain amino acid replacement, N501Y, that could potentially provide the RGD motif with enhanced access to cell-surface integrins, with consequent clinical impacts. Full article

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16 pages, 2784 KiB

Open AccessArticle

Structural Mapping of Mutations in Spike, RdRp and Orf3a Genes of SARS-CoV-2 in Influenza Like Illness (ILI) Patients

by Bandar Alosaimi, Asif Naeem, Majed F. Alghoribi, Lilian Okdah, Maaweya E. Hamed, Ahmad S. AlYami, Athari Alotaibi and Mushira Enani

Viruses 2021, 13(1), 136; https://doi.org/10.3390/v13010136 - 19 Jan 2021

Cited by 4 | Viewed by 3970

Abstract

In December 2019, the emergence of SARS-CoV-2 virus in China led to a pandemic. Since both Influenza Like Illness (ILI) and COVID-19 case definitions overlap, we re-investigated the ILI cases using PCR for the presence of SARS-CoV-2 in 739 nasopharyngeal swabs collected from [...] Read more.

In December 2019, the emergence of SARS-CoV-2 virus in China led to a pandemic. Since both Influenza Like Illness (ILI) and COVID-19 case definitions overlap, we re-investigated the ILI cases using PCR for the presence of SARS-CoV-2 in 739 nasopharyngeal swabs collected from November 2019 to March 2020. SARS-CoV-2 RNA was found in 37 samples (5%) collected mostly during February 2020. It was followed by confirmation of evolutionary and spatial relationships using next generation sequencing (NGS). We observed that the overall incidence of ILI cases during 2019–2020 influenza season was considerably higher than previous years and was gradually replaced with SARS-CoV-2, which indicated a silent transmission among ambulatory patients. Sequencing of representative isolates confirmed independent introductions and silent transmission earlier than previously thought. Evolutionary and spatial analyses revealed clustering in the GH clade, characterized by three amino acid substitutions in spike gene (D614G), RdRp (P323L) and NS3 (Q57H). P323L causes conformational change near nsp8 binding site that might affect virus replication and transcription. In conclusion, assessment of the community transmission among patients with mild COVID-19 illness, particularly those without epidemiological link for acquiring the virus, is of utmost importance to guide policy makers to optimize public health interventions. The detection of SARS-CoV-2 in ILI cases shows the importance of ILI surveillance systems and warrants its further strengthening to mitigate the ongoing transmission of SARS-CoV-2. The effect of NS3 substitutions on oligomerization or membrane channel function (intra- and extracellular) needs functional validation. Full article

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22 pages, 5748 KiB

Open AccessArticle

Computational Analysis of SARS-CoV-2 and SARS-Like Coronavirus Diversity in Human, Bat and Pangolin Populations

by Nicholas J. Dimonaco, Mazdak Salavati and Barbara B. Shih

Viruses 2021, 13(1), 49; https://doi.org/10.3390/v13010049 - 30 Dec 2020

Cited by 17 | Viewed by 7935

Abstract

In 2019, a novel coronavirus, SARS-CoV-2/nCoV-19, emerged in Wuhan, China, and has been responsible for the current COVID-19 pandemic. The evolutionary origins of the virus remain elusive and understanding its complex mutational signatures could guide vaccine design and development. As part of the [...] Read more.

In 2019, a novel coronavirus, SARS-CoV-2/nCoV-19, emerged in Wuhan, China, and has been responsible for the current COVID-19 pandemic. The evolutionary origins of the virus remain elusive and understanding its complex mutational signatures could guide vaccine design and development. As part of the international “CoronaHack” in April 2020, we employed a collection of contemporary methodologies to compare the genomic sequences of coronaviruses isolated from human (SARS-CoV-2; n = 163), bat (bat-CoV; n = 215) and pangolin (pangolin-CoV; n = 7) available in public repositories. We have also noted the pangolin-CoV isolate MP789 to bare stronger resemblance to SARS-CoV-2 than other pangolin-CoV. Following de novo gene annotation prediction, analyses of gene–gene similarity network, codon usage bias and variant discovery were undertaken. Strong host-associated divergences were noted in ORF3a, ORF6, ORF7a, ORF8 and S, and in codon usage bias profiles. Last, we have characterised several high impact variants (in-frame insertion/deletion or stop gain) in bat-CoV and pangolin-CoV populations, some of which are found in the same amino acid position and may be highlighting loci of potential functional relevance. Full article

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15 pages, 14383 KiB

Open AccessArticle

SARS-CoV-2 Nucleocapsid Protein Interacts with RIG-I and Represses RIG-Mediated IFN-β Production

by Keli Chen, Feng Xiao, Dingwen Hu, Weiwei Ge, Mingfu Tian, Wenbiao Wang, Pan Pan, Kailang Wu and Jianguo Wu

Viruses 2021, 13(1), 47; https://doi.org/10.3390/v13010047 - 30 Dec 2020

Cited by 117 | Viewed by 7612

Abstract

SARS-CoV-2 is highly pathogenic in humans and poses a great threat to public health worldwide. Clinical data shows a disturbed type I interferon (IFN) response during the virus infection. In this study, we discovered that the nucleocapsid (N) protein of SARS-CoV-2 plays an [...] Read more.

SARS-CoV-2 is highly pathogenic in humans and poses a great threat to public health worldwide. Clinical data shows a disturbed type I interferon (IFN) response during the virus infection. In this study, we discovered that the nucleocapsid (N) protein of SARS-CoV-2 plays an important role in the inhibition of interferon beta (IFN-β) production. N protein repressed IFN-β production induced by poly(I:C) or upon Sendai virus (SeV) infection. We noted that N protein also suppressed IFN-β production, induced by several signaling molecules downstream of the retinoic acid-inducible gene I (RIG-I) pathway, which is the crucial pattern recognition receptor (PRR) responsible for identifying RNA viruses. Moreover, our data demonstrated that N protein interacted with the RIG-I protein through the DExD/H domain, which has ATPase activity and plays an important role in the binding of immunostimulatory RNAs. These results suggested that SARS-CoV-2 N protein suppresses the IFN-β response through targeting the initial step, potentially the cellular PRR–RNA-recognition step in the innate immune pathway. Therefore, we propose that the SARS-CoV-2 N protein represses IFN-β production by interfering with RIG-I. Full article

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8 pages, 1130 KiB

Open AccessBrief Report

PSGL-1 Inhibits the Incorporation of SARS-CoV and SARS-CoV-2 Spike Glycoproteins into Pseudovirions and Impairs Pseudovirus Attachment and Infectivity

by Sijia He, Abdul A. Waheed, Brian Hetrick, Deemah Dabbagh, Ivan V. Akhrymuk, Kylene Kehn-Hall, Eric O. Freed and Yuntao Wu

Viruses 2021, 13(1), 46; https://doi.org/10.3390/v13010046 - 30 Dec 2020

Cited by 22 | Viewed by 4056

Abstract

P-selectin glycoprotein ligand-1 (PSGL-1) is a cell surface glycoprotein that binds to P-, E-, and L-selectins to mediate the tethering and rolling of immune cells on the surface of the endothelium for cell migration into inflamed tissues. PSGL-1 has been identified as an [...] Read more.

P-selectin glycoprotein ligand-1 (PSGL-1) is a cell surface glycoprotein that binds to P-, E-, and L-selectins to mediate the tethering and rolling of immune cells on the surface of the endothelium for cell migration into inflamed tissues. PSGL-1 has been identified as an interferon-γ (INF-γ)-regulated factor that restricts HIV-1 infectivity, and has recently been found to possess broad-spectrum antiviral activities. Here we report that the expression of PSGL-1 in virus-producing cells impairs the incorporation of SARS-CoV and SARS-CoV-2 spike (S) glycoproteins into pseudovirions and blocks pseudovirus attachment and infection of target cells. These findings suggest that PSGL-1 may potentially inhibit coronavirus replication in PSGL-1⁺ cells Full article

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13 pages, 3998 KiB

Open AccessArticle

Early Humoral Response Correlates with Disease Severity and Outcomes in COVID-19 Patients

by Anwar M. Hashem, Abdullah Algaissi, Sarah A. Almahboub, Mohamed A. Alfaleh, Turki S. Abujamel, Sawsan S. Alamri, Khalid A. Alluhaybi, Haya I. Hobani, Rahaf H. AlHarbi, Reem M. Alsulaiman, M-Zaki ElAssouli, Sharif Hala, Naif K. Alharbi, Rowa Y. Alhabbab, Ahdab A. AlSaieedi, Wesam H. Abdulaal, Abdullah Bukhari, Afrah A. AL-Somali, Fadwa S. Alofi, Asim A. Khogeer, Arnab Pain, Almohanad A. Alkayyal, Naif A. M. Almontashiri, Bakur Mahmoud Ahmad and Xuguang Li Show full author list Hide full author list

Viruses 2020, 12(12), 1390; https://doi.org/10.3390/v12121390 - 4 Dec 2020

Cited by 44 | Viewed by 5734

Abstract

The Coronavirus Disease 2019 (COVID-19), caused by SARS-CoV-2, continues to spread globally with significantly high morbidity and mortality rates. Antigen-specific responses are of unquestionable value for clinical management of COVID-19 patients. Here, we investigated the kinetics of IgM, IgG against the spike (S) [...] Read more.

The Coronavirus Disease 2019 (COVID-19), caused by SARS-CoV-2, continues to spread globally with significantly high morbidity and mortality rates. Antigen-specific responses are of unquestionable value for clinical management of COVID-19 patients. Here, we investigated the kinetics of IgM, IgG against the spike (S) and nucleoproteins (N) proteins and their neutralizing capabilities in hospitalized COVID-19 patients with different disease presentations (i.e., mild, moderate or severe), need for intensive care units (ICU) admission or outcomes (i.e., survival vs death). We show that SARS-CoV-2 specific IgG, IgM and neutralizing antibodies (nAbs) were readily detectable in almost all COVID-19 patients with various clinical presentations. Interestingly, significantly higher levels of nAbs as well as anti-S1 and -N IgG and IgM antibodies were found in patients with more severe symptoms, patients requiring admission to ICU or those with fatal outcomes. More importantly, early after symptoms onset, we found that the levels of anti-N antibodies correlated strongly with disease severity. Collectively, these findings provide new insights into the kinetics of antibody responses in COVID-19 patients with different disease severity. Full article

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8 pages, 1192 KiB

Open AccessArticle

Persisting Neutralizing Activity to SARS-CoV-2 over Months in Sera of COVID-19 Patients

by Bertram Flehmig, Michael Schindler, Natalia Ruetalo, Ramona Businger, Manfred Bayer, Angelika Haage, Thomas Kirchner, Karin Klingel, Andrea Normann, Lutz Pridzun, Despina Tougianidou and Michael B. Ranke

Viruses 2020, 12(12), 1357; https://doi.org/10.3390/v12121357 - 27 Nov 2020

Cited by 13 | Viewed by 3550

Abstract

The relationship between the nasopharyngeal virus load, IgA and IgG antibodies to both the S1-RBD-protein and the N-protein, as well as the neutralizing activity (NAbs) against SARS-CoV-2 in the blood of moderately afflicted COVID-19 patients, needs further longitudinal investigation. Several new serological methods [...] Read more.

The relationship between the nasopharyngeal virus load, IgA and IgG antibodies to both the S1-RBD-protein and the N-protein, as well as the neutralizing activity (NAbs) against SARS-CoV-2 in the blood of moderately afflicted COVID-19 patients, needs further longitudinal investigation. Several new serological methods to examine these parameters were developed, validated and applied in three patients of a family which underwent an ambulatory course of COVID-19 for six months. The virus load had almost completely disappeared after about four weeks. Serum IgA levels to the S1-RBD-protein and, to a lesser extent, to the N-protein, peaked about three weeks after clinical disease onset but declined soon thereafter. IgG levels rose continuously, reaching a plateau at approximately six weeks, and stayed elevated over the observation period. Virus-neutralizing activity reached a peak about 4 weeks after disease onset but dropped slowly. The longitudinal associations of virus neutralization and the serological immune response suggest immunity in patients even after a mild clinical course of COVID-19. Full article

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4 pages, 848 KiB

Open AccessEditorial

COVID-19 and School Activities in Italy

by Giovanni Sebastiani and Giorgio Palù

Viruses 2020, 12(11), 1339; https://doi.org/10.3390/v12111339 - 23 Nov 2020

Cited by 19 | Viewed by 7070

Abstract

After a linear growth during September, the diffusion in Italy of SARS-CoV-2, responsible for COVID-19, has been growing exponentially since the end of that month with a doubling time approximately equal to one week [...] Full article

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13 pages, 1097 KiB

Open AccessArticle

CD4 and CD8 Lymphocyte Counts as Surrogate Early Markers for Progression in SARS-CoV-2 Pneumonia: A Prospective Study

by Joan Calvet, Jordi Gratacós, María José Amengual, Maria Llop, Marta Navarro, Amàlia Moreno, Antoni Berenguer-Llergo, Alejandra Serrano, Cristóbal Orellana and Manel Cervantes

Viruses 2020, 12(11), 1277; https://doi.org/10.3390/v12111277 - 9 Nov 2020

Cited by 20 | Viewed by 3841

Abstract

Background: COVID-19 pathophysiology and the predictive factors involved are not fully understood, but lymphocytes dysregulation appears to play a role. This paper aims to evaluate lymphocyte subsets in the pathophysiology of COVID-19 and as predictive factors for severe disease. Patient and methods: A [...] Read more.

Background: COVID-19 pathophysiology and the predictive factors involved are not fully understood, but lymphocytes dysregulation appears to play a role. This paper aims to evaluate lymphocyte subsets in the pathophysiology of COVID-19 and as predictive factors for severe disease. Patient and methods: A prospective cohort study of patients with SARS-CoV-2 bilateral pneumonia recruited at hospital admission. Demographics, medical history, and data regarding SARS-CoV-2 infection were recorded. Patients systematically underwent complete laboratory tests, including parameters related to COVID-19 as well as lymphocyte subsets study at the time of admission. Severe disease criteria were established at admission, and patients were classified on remote follow-up according to disease evolution. Linear regression models were used to assess associations with disease evolution, and Receiver Operating Characteristic (ROC) and the corresponding Area Under the Curve (AUC) were used to evaluate predictive values. Results: Patients with critical COVID-19 showed a decrease in CD3+CD4+ T cells count compared to non-critical (278 (485 IQR) vs. 545 (322 IQR)), a decrease in median CD4+/CD8+ ratio (1.7, (1.7 IQR) vs. 3.1 (2.4 IQR)), and a decrease in median CD4+MFI (21,820 (4491 IQR) vs. 26,259 (3256 IQR)), which persisted after adjustment. CD3+CD8+ T cells count had a high correlation with time to hospital discharge (PC = −0.700 (−0.931, −0.066)). ROC curves for predictive value showed lymphocyte subsets achieving the best performances, specifically CD3+CD4+ T cells (AUC = 0.756), CD4+/CD8+ ratio (AUC = 0.767), and CD4+MFI (AUC = 0.848). Conclusions: A predictive value and treatment considerations for lymphocyte subsets are suggested, especially for CD3CD4+ T cells. Lymphocyte subsets determination at hospital admission is recommended. Full article

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11 pages, 584 KiB

Open AccessBrief Report

A Cell-Based ELISA to Improve the Serological Analysis of Anti-SARS-CoV-2 IgG

by Gianpaolo Zarletti, Massimo Tiberi, Veronica De Molfetta, Maurizio Bossù, Elisa Toppi, Paola Bossù and Giuseppe Scapigliati

Viruses 2020, 12(11), 1274; https://doi.org/10.3390/v12111274 - 8 Nov 2020

Cited by 9 | Viewed by 4310

Abstract

Knowledge of the antibody-mediated immune response to SARS-CoV-2 is crucial to understand virus immunogenicity, establish seroprevalence, and determine whether subjects or recovered patients are at risk for infection/reinfection and would therefore benefit from vaccination. Here, we describe a novel and simple cell-ELISA specifically [...] Read more.

Knowledge of the antibody-mediated immune response to SARS-CoV-2 is crucial to understand virus immunogenicity, establish seroprevalence, and determine whether subjects or recovered patients are at risk for infection/reinfection and would therefore benefit from vaccination. Here, we describe a novel and simple cell-ELISA specifically designed to measure viral spike S1-specific IgG produced in vitro by B cells in peripheral blood mononuclear cell (PBMC) cultures from a cohort of 45 asymptomatic (n = 24) and symptomatic (n = 21) individuals, with age ranging from 8 to 99 years. All subjects underwent ELISA serological screening twice, at the same time as the cell-ELISA (T2) as well as 35–60 days earlier (T1). Cryopreserved PBMCs of healthy donors obtained years before the COVID-19 pandemic were also included in the analysis. The preliminary results presented here show that out of 45 tested subjects, 16 individuals (35.5%) were positive to the cell-ELISA, 11 (24.5%) were concomitantly positive in the serological screening (T1 and/or T2), and only one person was exclusively positive in ELISA (T1) and negative in cell-ELISA, though values were close to the cutoff. Of note, five individuals (11.2%) tested negative in ELISA but positive in cell-ELISA and thus, they appear to have circulating B cells that produce antibodies against SARS-CoV-2, likely at levels that are undetectable in the serum, which challenges the negative results of the serological screening. The relative level of in vitro secreted IgG was measurable in positive subjects, ranging from 7 to 50 ng/well. Accordingly, all anti-SARS-CoV-2 antibody-positive subjects previously reported moderate to severe symptoms attributable to COVID-19, even though the RT-PCR data were rarely available to confirm viral infection. Overall, the described cell-ELISA might be an effective method for detecting subjects who encountered the virus in the past, and thus helpful to improve serological ELISA tests in the case of undetectable/equivocal circulating IgG levels, and a suitable and improved tool to better evaluate SARS-CoV-2-specific humoral immunity in the COVID-19 pandemic. Full article

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11 pages, 2157 KiB

Open AccessArticle

First Phylogenetic Analysis of Malian SARS-CoV-2 Sequences Provides Molecular Insights into the Genomic Diversity of the Sahel Region

by Bourema Kouriba, Angela Dürr, Alexandra Rehn, Abdoul Karim Sangaré, Brehima Y. Traoré, Malena S. Bestehorn-Willmann, Judicael Ouedraogo, Asli Heitzer, Elisabeth Sogodogo, Abderrhamane Maiga, Mathias C. Walter, Fee Zimmermann, Roman Wölfel and Markus H. Antwerpen

Viruses 2020, 12(11), 1251; https://doi.org/10.3390/v12111251 - 2 Nov 2020

Cited by 8 | Viewed by 4384

Abstract

We are currently facing a pandemic of COVID-19, caused by a spillover from an animal-originating coronavirus to humans occurring in the Wuhan region of China in December 2019. From China, the virus has spread to 188 countries and regions worldwide, reaching the Sahel [...] Read more.

We are currently facing a pandemic of COVID-19, caused by a spillover from an animal-originating coronavirus to humans occurring in the Wuhan region of China in December 2019. From China, the virus has spread to 188 countries and regions worldwide, reaching the Sahel region on 2 March 2020. Since whole genome sequencing (WGS) data is very crucial to understand the spreading dynamics of the ongoing pandemic, but only limited sequencing data is available from the Sahel region to date, we have focused our efforts on generating the first Malian sequencing data available. Screening 217 Malian patient samples for the presence of SARS-CoV-2 resulted in 38 positive isolates, from which 21 whole genome sequences were generated. Our analysis shows that both the early A (19B) and the later observed B (20A/C) clade are present in Mali, indicating multiple and independent introductions of SARS-CoV-2 to the Sahel region. Full article

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12 pages, 659 KiB

Open AccessReview

COVID-19: Look to the Future, Learn from the Past

by Zhangkai J. Cheng, Hui-Qi Qu, Lifeng Tian, Zhifeng Duan and Hakon Hakonarson

Viruses 2020, 12(11), 1226; https://doi.org/10.3390/v12111226 - 29 Oct 2020

Cited by 10 | Viewed by 4325

Abstract

There is a current pandemic of a new type of coronavirus, the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The number of confirmed infected cases has been rapidly increasing. This paper analyzes the characteristics of SARS-CoV-2 in comparison with Severe Acute Respiratory Syndrome [...] Read more.

There is a current pandemic of a new type of coronavirus, the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The number of confirmed infected cases has been rapidly increasing. This paper analyzes the characteristics of SARS-CoV-2 in comparison with Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV), Middle East Respiratory Syndrome Coronavirus (MERS-CoV) and influenza. COVID-19 is similar to the diseases caused by SARS-CoV and MERS-CoV virologically and etiologically, but closer to influenza in epidemiology and virulence. The comparison provides a new perspective for the future of the disease control, and offers some ideas in the prevention and control management strategy. The large number of infectious people from the origin, and the highly infectious and occult nature have been two major problems, making the virus difficult to eradicate. We thus need to contemplate the possibility of long-term co-existence with COVID-19. Full article

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4 pages, 183 KiB

Open AccessEditorial

The Importance of Research on the Origin of SARS-CoV-2

by Kenneth Lundstrom, Murat Seyran, Damiano Pizzol, Parise Adadi, Tarek Mohamed Abd El-Aziz, Sk. Sarif Hassan, Antonio Soares, Ramesh Kandimalla, Murtaza M. Tambuwala, Alaa A. A. Aljabali, Gajendra Kumar Azad, Pabitra Pal Choudhury, Vladimir N. Uversky, Samendra P. Sherchan, Bruce D. Uhal, Nima Rezaei and Adam M. Brufsky

Viruses 2020, 12(11), 1203; https://doi.org/10.3390/v12111203 - 22 Oct 2020

Cited by 23 | Viewed by 11360

Abstract

The origin of the severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) virus causing the COVID-19 pandemic has not yet been fully determined. Despite the consensus about the SARS-CoV-2 origin from bat CoV RaTG13, discrepancy to host tropism to other human Coronaviruses exist. SARS-CoV-2 also [...] Read more.

The origin of the severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) virus causing the COVID-19 pandemic has not yet been fully determined. Despite the consensus about the SARS-CoV-2 origin from bat CoV RaTG13, discrepancy to host tropism to other human Coronaviruses exist. SARS-CoV-2 also possesses some differences in its S protein receptor-binding domain, glycan-binding N-terminal domain and the surface of the sialic acid-binding domain. Despite similarities based on cryo-EM and biochemical studies, the SARS-CoV-2 shows higher stability and binding affinity to the ACE2 receptor. The SARS-CoV-2 does not appear to present a mutational “hot spot” as only the D614G mutation has been identified from clinical isolates. As laboratory manipulation is highly unlikely for the origin of SARS-CoV-2, the current possibilities comprise either natural selection in animal host before zoonotic transfer or natural selection in humans following zoonotic transfer. In the former case, despite SARS-CoV-2 and bat RaTG13 showing 96% identity some pangolin Coronaviruses exhibit very high similarity to particularly the receptor-binding domain of SARS-CoV-2. In the latter case, it can be hypothesized that the SARS-CoV-2 genome has adapted during human-to-human transmission and based on available data, the isolated SARS-CoV-2 genomes derive from a common origin. Before the origin of SARS-CoV-2 can be confirmed additional research is required Full article

12 pages, 2189 KiB

Open AccessArticle

Frequency and Duration of SARS-CoV-2 Shedding in Oral Fluid Samples Assessed by a Modified Commercial Rapid Molecular Assay

by Licia Bordi, Giuseppe Sberna, Eleonora Lalle, Pierluca Piselli, Francesca Colavita, Emanuele Nicastri, Andrea Antinori, Evangelo Boumis, Nicola Petrosillo, Luisa Marchioni, Giulia Minnucci, Elena D’Agostini, Concetta Castilletti, Franco Locatelli, Alimuddin Zumla, Giuseppe Ippolito, Maria Rosaria Capobianchi and on behalf of INMI ReCOVeRI Study Group

Viruses 2020, 12(10), 1184; https://doi.org/10.3390/v12101184 - 20 Oct 2020

Cited by 18 | Viewed by 6981

Abstract

Background: RT-PCR on nasopharyngeal (NPS)/oropharyngeal swabs is the gold standard for diagnosis of SARS-CoV-2 infection and viral load monitoring. Oral fluid (OF) is an alternate clinical sample, easy and safer to collect and could be useful for COVID-19 diagnosis, monitoring viral load and [...] Read more.

Background: RT-PCR on nasopharyngeal (NPS)/oropharyngeal swabs is the gold standard for diagnosis of SARS-CoV-2 infection and viral load monitoring. Oral fluid (OF) is an alternate clinical sample, easy and safer to collect and could be useful for COVID-19 diagnosis, monitoring viral load and shedding. Methods: Optimal assay conditions and analytical sensitivity were established for the commercial Simplexa™ COVID-19 Direct assay adapted to OF matrix. The assay was used to test 337 OF and NPS specimens collected in parallel from 164 hospitalized patients; 50 bronchoalveolar lavage (BAL) specimens from a subgroup of severe COVID-19 cases were also analysed. Results: Using Simplexa™ COVID-19 Direct on OF matrix, 100% analytical detection down to 1 TCID50/mL (corresponding to 4 × 10³ copies (cp)/mL) was observed. No crossreaction with other viruses transmitted through the respiratory toute was observed. Parallel testing of 337 OF and NPS samples showed highly concordant results (κ = 0.831; 95 % CI = 0.771–0.891), and high correlation of Ct values (r = 0.921; p < 0.0001). High concordance and elevated correlation was observed also between OF and BAL. Prolonged viral RNA shedding was observed up to 100 days from symptoms onset (DSO), with 32% and 29% positivity observed in OF and NPS samples, respectively, collected between 60 and 100 DSO. Conclusions: Simplexa™ COVID-19 Direct assays on OF have high sensitivity and specificity to detect SARS-CoV-2 RNA and provide an alternative to NPS for diagnosis and monitoring SARS-CoV-2 shedding. Full article

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5 pages, 591 KiB

Open AccessCommunication

Expression Pattern of the SARS-CoV-2 Entry Genes ACE2 and TMPRSS2 in the Respiratory Tract

by Yichuan Liu, Hui-Qi Qu, Jingchun Qu, Lifeng Tian and Hakon Hakonarson

Viruses 2020, 12(10), 1174; https://doi.org/10.3390/v12101174 - 16 Oct 2020

Cited by 25 | Viewed by 3784

Abstract

To address the expression pattern of the SARS-CoV-2 receptor ACE2 and the viral priming protease TMPRSS2 in the respiratory tract, this study investigated RNA sequencing transcriptome profiling of samples of airway and oral mucosa. As shown, ACE2 has medium levels of expression in [...] Read more.

To address the expression pattern of the SARS-CoV-2 receptor ACE2 and the viral priming protease TMPRSS2 in the respiratory tract, this study investigated RNA sequencing transcriptome profiling of samples of airway and oral mucosa. As shown, ACE2 has medium levels of expression in both small airway epithelium and masticatory mucosa, and high levels of expression in nasal epithelium. The expression of ACE2 is low in mucosal-associated invariant T (MAIT) cells and cannot be detected in alveolar macrophages. TMPRSS2 is highly expressed in small airway epithelium and nasal epithelium and has lower expression in masticatory mucosa. Our results provide the molecular basis that the nasal mucosa is the most susceptible locus in the respiratory tract for SARS-CoV-2 infection and consequently for subsequent droplet transmission and should be the focus for protection against SARS-CoV-2 infection. Full article

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16 pages, 1992 KiB

Open AccessArticle

Amplicon-Based Detection and Sequencing of SARS-CoV-2 in Nasopharyngeal Swabs from Patients With COVID-19 and Identification of Deletions in the Viral Genome That Encode Proteins Involved in Interferon Antagonism

by Shona C. Moore, Rebekah Penrice-Randal, Muhannad Alruwaili, Nadine Randle, Stuart Armstrong, Catherine Hartley, Sam Haldenby, Xiaofeng Dong, Abdulrahman Alrezaihi, Mai Almsaud, Eleanor Bentley, Jordan Clark, Isabel García-Dorival, Paul Gilmore, Ximeng Han, Benjamin Jones, Lisa Luu, Parul Sharma, Ghada Shawli, Yani Sun, Qin Zhao, Steven T. Pullan, Daniel P. Carter, Kevin Bewley, Jake Dunning, En-min Zhou, Tom Solomon, Michael Beadsworth, James Cruise, Derrick W. Crook, David A. Matthews, Andrew D. Davidson, Zana Mahmood, Waleed Aljabr, Julian Druce, Richard Vipond, Lisa Ng, Laurent Renia, Peter J. M. Openshaw, J. Kenneth Baillie, Miles W. Carroll, James Stewart, Alistair Darby, Malcolm Semple, Lance Turtle and Julian A. Hiscox Show full author list Hide full author list

Viruses 2020, 12(10), 1164; https://doi.org/10.3390/v12101164 - 14 Oct 2020

Cited by 39 | Viewed by 9832

Abstract

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative agent of coronavirus disease 2019 (COVID-19). Sequencing the viral genome as the outbreak progresses is important, particularly in the identification of emerging isolates with different pathogenic potential and to identify whether nucleotide changes [...] Read more.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative agent of coronavirus disease 2019 (COVID-19). Sequencing the viral genome as the outbreak progresses is important, particularly in the identification of emerging isolates with different pathogenic potential and to identify whether nucleotide changes in the genome will impair clinical diagnostic tools such as real-time PCR assays. Although single nucleotide polymorphisms and point mutations occur during the replication of coronaviruses, one of the biggest drivers in genetic change is recombination. This can manifest itself in insertions and/or deletions in the viral genome. Therefore, sequencing strategies that underpin molecular epidemiology and inform virus biology in patients should take these factors into account. A long amplicon/read length-based RT-PCR sequencing approach focused on the Oxford Nanopore MinION/GridION platforms was developed to identify and sequence the SARS-CoV-2 genome in samples from patients with or suspected of COVID-19. The protocol, termed Rapid Sequencing Long Amplicons (RSLAs) used random primers to generate cDNA from RNA purified from a sample from a patient, followed by single or multiplex PCRs to generate longer amplicons of the viral genome. The base protocol was used to identify SARS-CoV-2 in a variety of clinical samples and proved sensitive in identifying viral RNA in samples from patients that had been declared negative using other nucleic acid-based assays (false negative). Sequencing the amplicons revealed that a number of patients had a proportion of viral genomes with deletions. Full article

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17 pages, 2420 KiB

Open AccessArticle

Tracking SARS-CoV-2 in Sewage: Evidence of Changes in Virus Variant Predominance during COVID-19 Pandemic

by Javier Martin, Dimitra Klapsa, Thomas Wilton, Maria Zambon, Emma Bentley, Erika Bujaki, Martin Fritzsche, Ryan Mate and Manasi Majumdar

Viruses 2020, 12(10), 1144; https://doi.org/10.3390/v12101144 - 9 Oct 2020

Cited by 108 | Viewed by 11714

Abstract

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), responsible for the ongoing coronavirus disease (COVID-19) pandemic, is frequently shed in faeces during infection, and viral RNA has recently been detected in sewage in some countries. We have investigated the presence of SARS-CoV-2 RNA in [...] Read more.

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), responsible for the ongoing coronavirus disease (COVID-19) pandemic, is frequently shed in faeces during infection, and viral RNA has recently been detected in sewage in some countries. We have investigated the presence of SARS-CoV-2 RNA in wastewater samples from South-East England between 14th January and 12th May 2020. A novel nested RT-PCR approach targeting five different regions of the viral genome improved the sensitivity of RT-qPCR assays and generated nucleotide sequences at sites with known sequence polymorphisms among SARS-CoV-2 isolates. We were able to detect co-circulating virus variants, some specifically prevalent in England, and to identify changes in viral RNA sequences with time consistent with the recently reported increasing global dominance of Spike protein G614 pandemic variant. Low levels of viral RNA were detected in a sample from 11th February, 3 days before the first case was reported in the sewage plant catchment area. SARS-CoV-2 RNA concentration increased in March and April, and a sharp reduction was observed in May, showing the effects of lockdown measures. We conclude that viral RNA sequences found in sewage closely resemble those from clinical samples and that environmental surveillance can be used to monitor SARS-CoV-2 transmission, tracing virus variants and detecting virus importations. Full article

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20 pages, 34327 KiB

Open AccessArticle

Host Immune Response Driving SARS-CoV-2 Evolution

by Rui Wang, Yuta Hozumi, Yong-Hui Zheng, Changchuan Yin and Guo-Wei Wei

Viruses 2020, 12(10), 1095; https://doi.org/10.3390/v12101095 - 27 Sep 2020

Cited by 55 | Viewed by 7931

Abstract

The transmission and evolution of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are of paramount importance in controlling and combating the coronavirus disease 2019 (COVID-19) pandemic. Currently, over 15,000 SARS-CoV-2 single mutations have been recorded, which have a great impact on the development [...] Read more.

The transmission and evolution of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are of paramount importance in controlling and combating the coronavirus disease 2019 (COVID-19) pandemic. Currently, over 15,000 SARS-CoV-2 single mutations have been recorded, which have a great impact on the development of diagnostics, vaccines, antibody therapies, and drugs. However, little is known about SARS-CoV-2’s evolutionary characteristics and general trend. In this work, we present a comprehensive genotyping analysis of existing SARS-CoV-2 mutations. We reveal that host immune response via APOBEC and ADAR gene editing gives rise to near 65% of recorded mutations. Additionally, we show that children under age five and the elderly may be at high risk from COVID-19 because of their overreaction to the viral infection. Moreover, we uncover that populations of Oceania and Africa react significantly more intensively to SARS-CoV-2 infection than those of Europe and Asia, which may explain why African Americans were shown to be at increased risk of dying from COVID-19, in addition to their high risk of COVID-19 infection caused by systemic health and social inequities. Finally, our study indicates that for two viral genome sequences of the same origin, their evolution order may be determined from the ratio of mutation type, C > T over T > C. Full article

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13 pages, 2477 KiB

Open AccessArticle

Identification of a Membrane Binding Peptide in the Envelope Protein of MHV Coronavirus

by Entedar A. J. Alsaadi, Benjamin W. Neuman and Ian M. Jones

Viruses 2020, 12(9), 1054; https://doi.org/10.3390/v12091054 - 22 Sep 2020

Cited by 8 | Viewed by 5137

Abstract

Coronaviruses (CoVs) are enveloped, positive sense, single strand RNA viruses that cause respiratory, intestinal and neurological diseases in mammals and birds. Following replication, CoVs assemble on intracellular membranes including the endoplasmic reticulum Golgi intermediate compartment (ERGIC) where the envelope protein (E) functions in [...] Read more.

Coronaviruses (CoVs) are enveloped, positive sense, single strand RNA viruses that cause respiratory, intestinal and neurological diseases in mammals and birds. Following replication, CoVs assemble on intracellular membranes including the endoplasmic reticulum Golgi intermediate compartment (ERGIC) where the envelope protein (E) functions in virus assembly and release. In consequence, E potentially contains membrane-modifying peptides. To search for such peptides, the E coding sequence of Mouse Hepatitis Virus (MHV) was inspected for its amino acid conservation, proximity to the membrane and/or predicted amphipathic helices. Peptides identified in silico were synthesized and tested for membrane-modifying activity in the presence of giant unilamellar vesicles (GUVs) consisting of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC), sphingomyelin and cholesterol. To confirm the presence of membrane binding peptides identified in the context of a full-length E protein, the wild type and a number of mutants in the putative membrane binding peptide were expressed in Lenti-X-293T mammalian and insect cells, and the distribution of E antigen within the expressing cell was assessed. Our data identify a role for the post-transmembrane region of MHV E in membrane binding. Full article

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9 pages, 2016 KiB

Open AccessArticle

RNAemia Corresponds to Disease Severity and Antibody Response in Hospitalized COVID-19 Patients

by Kirsten Alexandra Eberhardt, Charlotte Meyer-Schwickerath, Eva Heger, Elena Knops, Clara Lehmann, Jan Rybniker, Philipp Schommers, Dennis A. Eichenauer, Florian Kurth, Michael Ramharter, Rolf Kaiser, Udo Holtick, Florian Klein, Norma Jung and Veronica Di Cristanziano

Viruses 2020, 12(9), 1045; https://doi.org/10.3390/v12091045 - 18 Sep 2020

Cited by 46 | Viewed by 4865

Abstract

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) represents a global health emergency. To improve the understanding of the systemic component of SARS-CoV-2, we investigated if viral load dynamics in plasma and respiratory samples are associated with antibody response and severity of coronavirus disease [...] Read more.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) represents a global health emergency. To improve the understanding of the systemic component of SARS-CoV-2, we investigated if viral load dynamics in plasma and respiratory samples are associated with antibody response and severity of coronavirus disease 2019 (COVID-19). SARS-CoV-2 RNA was found in plasma samples from 14 (44%) out of 32 patients. RNAemia was detected in 5 out of 6 fatal cases. Peak IgG values were significantly lower in mild/moderate than in severe (0.6 (interquartile range, IQR, 0.4–3.2) vs. 11.8 (IQR, 9.9–13.0), adjusted p = 0.003) or critical cases (11.29 (IQR, 8.3–12.0), adjusted p = 0.042). IgG titers were significantly associated with virus Ct (Cycle threshold) value in plasma and respiratory specimens ((ß = 0.4, 95% CI (confidence interval, 0.2; 0.5), p < 0.001 and ß = 0.5, 95% CI (0.2; 0.6), p = 0.002). A classification as severe or a critical case was additionally inversely associated with Ct values in plasma in comparison to mild/moderate cases (ß = −3.3, 95% CI (−5.8; 0.8), p = 0.024 and ß = −4.4, 95% CI (−7.2; 1.6), p = 0.007, respectively). Based on the present data, our hypothesis is that the early stage of SARS-CoV-2 infection is characterized by a primary RNAemia, as a potential manifestation of a systemic infection. Additionally, the viral load in plasma seems to be associated with a worse disease outcome. Full article

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14 pages, 2522 KiB

Open AccessArticle

Spatio-Temporal Mutational Profile Appearances of Swedish SARS-CoV-2 during the Early Pandemic

by Jiaxin Ling, Rachel A. Hickman, Jinlin Li, Xi Lu, Johanna F. Lindahl, Åke Lundkvist and Josef D. Järhult

Viruses 2020, 12(9), 1026; https://doi.org/10.3390/v12091026 - 14 Sep 2020

Cited by 9 | Viewed by 4482

Abstract

Background: During the COVID-19 pandemic, the virus evolved, and we therefore aimed to provide an insight into which genetic variants were enriched, and how they spread in Sweden. Methods: We analyzed 348 Swedish SARS-CoV-2 sequences freely available from GISAID obtained from 7 February [...] Read more.

Background: During the COVID-19 pandemic, the virus evolved, and we therefore aimed to provide an insight into which genetic variants were enriched, and how they spread in Sweden. Methods: We analyzed 348 Swedish SARS-CoV-2 sequences freely available from GISAID obtained from 7 February 2020 until 14 May 2020. Results: We identified 14 variant sites ≥5% frequency in the population. Among those sites, the D936Y substitution in the viral Spike protein was under positive selection. The variant sites can distinguish 11 mutational profiles in Sweden. Nine of the profiles appeared in Stockholm in March 2020. Mutational profiles 3 (B.1.1) and 6 (B.1), which contain the D936Y mutation, became the predominant profiles over time, spreading from Stockholm to other Swedish regions during April and the beginning of May. Furthermore, Bayesian phylogenetic analysis indicated that SARS-CoV-2 could have emerged in Sweden on 27 December 2019, and community transmission started on February 1st with an evolutionary rate of 1.5425 × 10⁻³ substitutions per year. Conclusions: Our study provides novel knowledge on the spatio-temporal dynamics of Swedish SARS-CoV-2 variants during the early pandemic. Characterization of these viral variants can provide precious insights on viral pathogenesis and can be valuable for diagnostic and drug development approaches. Full article

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19 pages, 3926 KiB

Open AccessArticle

Artificial Intelligence-Assisted Loop Mediated Isothermal Amplification (AI-LAMP) for Rapid Detection of SARS-CoV-2

by Mohammed A. Rohaim, Emily Clayton, Irem Sahin, Julianne Vilela, Manar E. Khalifa, Mohammad Q. Al-Natour, Mahmoud Bayoumi, Aurore C. Poirier, Manoharanehru Branavan, Mukunthan Tharmakulasingam, Nouman S. Chaudhry, Ravinder Sodi, Amy Brown, Peter Burkhart, Wendy Hacking, Judy Botham, Joe Boyce, Hayley Wilkinson, Craig Williams, Jayde Whittingham-Dowd, Elisabeth Shaw, Matt Hodges, Lisa Butler, Michelle D. Bates, Roberto La Ragione, Wamadeva Balachandran, Anil Fernando and Muhammad Munir Show full author list Hide full author list

Viruses 2020, 12(9), 972; https://doi.org/10.3390/v12090972 - 1 Sep 2020

Cited by 48 | Viewed by 10039

Abstract

Until vaccines and effective therapeutics become available, the practical solution to transit safely out of the current coronavirus disease 19 (CoVID-19) lockdown may include the implementation of an effective testing, tracing and tracking system. However, this requires a reliable and clinically validated diagnostic [...] Read more.

Until vaccines and effective therapeutics become available, the practical solution to transit safely out of the current coronavirus disease 19 (CoVID-19) lockdown may include the implementation of an effective testing, tracing and tracking system. However, this requires a reliable and clinically validated diagnostic platform for the sensitive and specific identification of SARS-CoV-2. Here, we report on the development of a de novo, high-resolution and comparative genomics guided reverse-transcribed loop-mediated isothermal amplification (LAMP) assay. To further enhance the assay performance and to remove any subjectivity associated with operator interpretation of results, we engineered a novel hand-held smart diagnostic device. The robust diagnostic device was further furnished with automated image acquisition and processing algorithms and the collated data was processed through artificial intelligence (AI) pipelines to further reduce the assay run time and the subjectivity of the colorimetric LAMP detection. This advanced AI algorithm-implemented LAMP (ai-LAMP) assay, targeting the RNA-dependent RNA polymerase gene, showed high analytical sensitivity and specificity for SARS-CoV-2. A total of ~200 coronavirus disease (CoVID-19)-suspected NHS patient samples were tested using the platform and it was shown to be reliable, highly specific and significantly more sensitive than the current gold standard qRT-PCR. Therefore, this system could provide an efficient and cost-effective platform to detect SARS-CoV-2 in resource-limited laboratories. Full article

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13 pages, 1131 KiB

Open AccessArticle

A Comparison of Whole Genome Sequencing of SARS-CoV-2 Using Amplicon-Based Sequencing, Random Hexamers, and Bait Capture

by Jalees A. Nasir, Robert A. Kozak, Patryk Aftanas, Amogelang R. Raphenya, Kendrick M. Smith, Finlay Maguire, Hassaan Maan, Muhannad Alruwaili, Arinjay Banerjee, Hamza Mbareche, Brian P. Alcock, Natalie C. Knox, Karen Mossman, Bo Wang, Julian A. Hiscox, Andrew G. McArthur and Samira Mubareka

Viruses 2020, 12(8), 895; https://doi.org/10.3390/v12080895 - 15 Aug 2020

Cited by 73 | Viewed by 11780

Abstract

Genome sequencing of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is increasingly important to monitor the transmission and adaptive evolution of the virus. The accessibility of high-throughput methods and polymerase chain reaction (PCR) has facilitated a growing ecosystem of protocols. Two differing protocols [...] Read more.

Genome sequencing of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is increasingly important to monitor the transmission and adaptive evolution of the virus. The accessibility of high-throughput methods and polymerase chain reaction (PCR) has facilitated a growing ecosystem of protocols. Two differing protocols are tiling multiplex PCR and bait capture enrichment. Each method has advantages and disadvantages but a direct comparison with different viral RNA concentrations has not been performed to assess the performance of these approaches. Here we compare Liverpool amplification, ARTIC amplification, and bait capture using clinical diagnostics samples. All libraries were sequenced using an Illumina MiniSeq with data analyzed using a standardized bioinformatics workflow (SARS-CoV-2 Illumina GeNome Assembly Line; SIGNAL). One sample showed poor SARS-CoV-2 genome coverage and consensus, reflective of low viral RNA concentration. In contrast, the second sample had a higher viral RNA concentration, which yielded good genome coverage and consensus. ARTIC amplification showed the highest depth of coverage results for both samples, suggesting this protocol is effective for low concentrations. Liverpool amplification provided a more even read coverage of the SARS-CoV-2 genome, but at a lower depth of coverage. Bait capture enrichment of SARS-CoV-2 cDNA provided results on par with amplification. While only two clinical samples were examined in this comparative analysis, both the Liverpool and ARTIC amplification methods showed differing efficacy for high and low concentration samples. In addition, amplification-free bait capture enriched sequencing of cDNA is a viable method for generating a SARS-CoV-2 genome sequence and for identification of amplification artifacts. Full article

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