Antibodies

12 pages, 1364 KiB

Open AccessArticle

Comparison between Neutralization Capacity of Antibodies Elicited by COVID-19 Natural Infection and Vaccination in Indonesia: A Prospective Cohort

by Sitti Nurisyah, Mitsuhiro Iyori, Ammar Abdurrahman Hasyim, Akihiko Sakamoto, Hinata Hashimoto, Kyouhei Yamagata, Saya Yamauchi, Khaeriah Amru, Kartika Hardianti Zainal, Irfan Idris, Shigeto Yoshida, Irawaty Djaharuddin, Din Syafruddin, Agussalim Bukhari, Puji Budi Setia Asih and Yenni Yusuf

Antibodies 2023, 12(3), 60; https://doi.org/10.3390/antib12030060 - 21 Sep 2023

Cited by 4 | Viewed by 2293

Abstract

Background: To fight the COVID-19 pandemic, immunity against SARS-CoV-2 should be achieved not only through natural infection but also by vaccination. The effect of COVID-19 vaccination on previously infected persons is debatable. Methods: A prospective cohort was undergone to collect sera from unvaccinated [...] Read more.

Background: To fight the COVID-19 pandemic, immunity against SARS-CoV-2 should be achieved not only through natural infection but also by vaccination. The effect of COVID-19 vaccination on previously infected persons is debatable. Methods: A prospective cohort was undergone to collect sera from unvaccinated survivors and vaccinated persons—with and without COVID-19 pre-infection. The sera were analyzed for the anti-receptor binding domain (RBD) titers by ELISA and for the capacity to neutralize the pseudovirus of the Wuhan-Hu-1 strain by luciferase assays. Results: Neither the antibody titers nor the neutralization capacity was significantly different between the three groups. However, the correlation between the antibody titers and the percentage of viral neutralization derived from sera of unvaccinated survivors was higher than that from vaccinated persons with pre-infection and vaccinated naïve individuals (Spearman correlation coefficient (r) = −0.8558; 95% CI, −0.9259 to −0.7288), p < 0.0001 vs. −0.7855; 95% CI, −0.8877 to −0.6096, p < 0.0001 and −0.581; 95% CI, −0.7679 to −0.3028, p = 0.0002, respectively), indicating the capacity to neutralize the virus is most superior by infection alone. Conclusions: Vaccines induce anti-RBD titers as high as the natural infection with lower neutralization capacity, and it does not boost immunity in pre-infected persons. Full article

(This article belongs to the Special Issue Coronavirus-Targeting Antibodies)

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13 pages, 2965 KiB

Open AccessArticle

Characterization of N-Terminal Asparagine Deamidation and Clipping of a Monoclonal Antibody

by Jing Zhen, Jennifer Lee, Yueyang Wang, Lena McLaughlin, Fei Yang, Zhengjian Li and Jihong Wang

Antibodies 2023, 12(3), 59; https://doi.org/10.3390/antib12030059 - 19 Sep 2023

Cited by 2 | Viewed by 2781

Abstract

This study presents a novel degradation pathway of a human immunoglobulin G (IgG) molecule featuring a light chain N-terminal asparagine. We thoroughly characterize this pathway and investigate its charge profiles using cation exchange chromatography (CEX) and capillary isoelectric focusing (cIEF). Beyond the well-documented [...] Read more.

This study presents a novel degradation pathway of a human immunoglobulin G (IgG) molecule featuring a light chain N-terminal asparagine. We thoroughly characterize this pathway and investigate its charge profiles using cation exchange chromatography (CEX) and capillary isoelectric focusing (cIEF). Beyond the well-documented asparagine deamidation into isoaspartic acid, aspartic acid, and succinimide intermediate, a previously unreported clipping degradation pathway is uncovered. This newly identified clipped N-terminal IgG variant exhibits a delayed elution in CEX, categorized as a “basic variant”, while retaining the same main peak isoelectric point (pI) in cIEF. The influence of temperature and pH on N-terminal asparagine stability is assessed across various stressed conditions. A notable correlation between deamidation percentage and clipped products is established, suggesting a potential hydrolytic chemical reaction underlying the clipping process. Furthermore, the impact of N-terminal asparagine modifications on potency is evaluated through ELISA binding assays, revealing minimal effects on binding affinity. Sequence alignment reveals homology to a human IgG with the germline gene from Immunoglobulin Lambda Variable 6-57 (IGLV6-57), which has implications for amyloid light-chain (AL) amyloidosis. This discovery of the N-terminal clipping degradation pathway contributes to our understanding of immunoglobulin light chain misfolding and amyloid fibril deposition under physiological conditions. Full article

(This article belongs to the Section Antibody-Based Therapeutics)

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13 pages, 4269 KiB

Open AccessArticle

Evaluation of Molecular Simulations and Deep Learning Prediction of Antibodies’ Recognition of TRBC1 and TRBC2

by Xincheng Zeng, Tianqun Wang, Yue Kang, Ganggang Bai and Buyong Ma

Antibodies 2023, 12(3), 58; https://doi.org/10.3390/antib12030058 - 17 Sep 2023

Cited by 3 | Viewed by 2810

Abstract

T cell receptor β-chain constant (TRBC) is a promising class of cancer targets consisting of two highly homologous proteins, TRBC1 and TRBC2. Developing targeted antibody therapeutics against TRBC1 or TRBC2 is expected to eradicate the malignant T cells and preserve half of the [...] Read more.

T cell receptor β-chain constant (TRBC) is a promising class of cancer targets consisting of two highly homologous proteins, TRBC1 and TRBC2. Developing targeted antibody therapeutics against TRBC1 or TRBC2 is expected to eradicate the malignant T cells and preserve half of the normal T cells. Recently, several antibody engineering strategies have been used to modulate the TRBC1 and TRBC2 specificity of antibodies. Here, we used molecular simulation and artificial intelligence methods to quantify the affinity difference in antibodies with various mutations for TRBC1 and TRBC2. The affinity of the existing mutants was verified by FEP calculations aided by the AI. We also performed long-time molecular dynamics simulations to reveal the dynamical antigen recognition mechanisms of the TRBC antibodies. Full article

(This article belongs to the Special Issue Antibodies: 10th Anniversary)

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20 pages, 3646 KiB

Open AccessArticle

Generation of Antibodies Selectively Recognizing Epitopes in a Formaldehyde-Fixed Cell-Surface Antigen Using Virus-like Particle Display and Hybridoma Technology

by Stefanie Schatz, Lena Willnow, Monika Winkels, Jamila Franca Rosengarten, Benjamin Theek, Ian C. D. Johnston and Jörn Stitz

Antibodies 2023, 12(3), 57; https://doi.org/10.3390/antib12030057 - 5 Sep 2023

Viewed by 2555

Abstract

Efficient induction of target-specific antibodies can be elicited upon immunization with highly immunogenic virus-like particles (VLPs) decorated with desired membrane-anchored target antigens (Ags). However, for example, for diagnostic purposes, monoclonal antibodies (mAbs) are required to enable the histological examination of formaldehyde-fixed paraffin-embedded (FFPE) [...] Read more.

Efficient induction of target-specific antibodies can be elicited upon immunization with highly immunogenic virus-like particles (VLPs) decorated with desired membrane-anchored target antigens (Ags). However, for example, for diagnostic purposes, monoclonal antibodies (mAbs) are required to enable the histological examination of formaldehyde-fixed paraffin-embedded (FFPE) biopsy tissue samples. Aiming at the generation of FFPE-antigen-specific mAbs and as a proof of concept (POC), we first established a simplified protocol using only formaldehyde and 90 °C heat fixation (FF90) of cells expressing the target Ag nerve growth factor receptor (NGFR). The FF90 procedure was validated using flow cytometric analysis and two mAbs recognizing either the native and FFPE-Ag or exclusively the native Ag. C-terminally truncated NGFR (trNGFR)-displaying native and FF90-treated VLPs derived from HIV-1 did not reveal distinctive changes in particle morphology using transmission electron microscopy (TEM) and dynamic light scattering (DLS) analysis. Mice were subsequently repetitively immunized with trNGFR-decorated FF90-VLPs and hybridoma technology was used to establish mAb-producing cell clones. In multiple screening rounds, nine cell clones were identified producing mAbs distinctively recognizing epitopes in FF90- and FFPE-NGFR. This POC of a new methodology should foster the future generation of mAbs selectively targeting FFPE-fixed cell-surface Ags. Full article

(This article belongs to the Section Antibody Discovery and Engineering)

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23 pages, 5334 KiB

Open AccessReview

From Cereal Grains to Immunochemistry—What Role Have Antibodies Played in the History of the Home Pregnancy Test

by Kinga Lis

Antibodies 2023, 12(3), 56; https://doi.org/10.3390/antib12030056 - 31 Aug 2023

Viewed by 6526

Abstract

Today, the home pregnancy test is the most frequently performed laboratory test for self-diagnosis (home diagnostic test). It is also the first laboratory test that has been adapted for self-use at home. This is probably because women have always wanted to know the [...] Read more.

Today, the home pregnancy test is the most frequently performed laboratory test for self-diagnosis (home diagnostic test). It is also the first laboratory test that has been adapted for self-use at home. This is probably because women have always wanted to know the answer to the question: “Am I pregnant or not?” and always preferred to know the answer to this question intimately and in a discreet way. The history of the pregnancy test is also an interesting example of how the discovery of antibodies and the development of in vitro diagnostic methods based on the antigen–antibody reaction were important for the development of laboratory and clinical diagnostics. Immunodiagnostic techniques (based on the antigen–antibody reaction) are currently the basis of modern specialist laboratory diagnostics, which is essential in clinical diagnosis. The history of the pregnancy test is an interesting one and dates back to ancient times. A pregnancy test is defined as a procedure intended to reveal the presence or absence of pregnancy. Nowadays, every pregnancy test is based on the detection of human chorionic gonadotropin (hCG) in urine or blood. Human chorionic gonadotropin is secreted by the placenta right after a fertilized egg cell implants in the uterus and can be detected in both the urine and blood of pregnant women. Urine pregnancy tests are convenient for self-use at home. Blood tests are performed in medical laboratories. Specialized laboratory methods not only detect hCG but also determine the concentration of this hormone. However, both of these methods are highly accurate and common. Throughout the ages, many different methods were used to detect pregnancy at the earliest stage. Grain, wine, and various small animals were used as research tools. These were both long-term and often unreliable; most were based on folk beliefs and superstitions. Animal pregnancy tests were the first biological tests used in this field. This was a significant advance in the accurate detection of relatively early pregnancy. Animal tests in modern times are considered cruel and inhumane, no matter how reliable their results can be. Their place is now taken by much more specific, more sensitive, and definitely more ethical immunochemical tests. The pregnancy test and the methods to find out whether a woman is pregnant have gone through massive transformations, from bioassays using plants to bioassays on animals to advanced immunochemical techniques and biosensors. Modern pregnancy tests are not invasive and are very sensitive. Nowadays, it takes only about 3 min to know the answer to the question: “Am I pregnant or not?”. However, it was not always as simple as it is today. This manuscript aims to show the important role played by antibodies in the development of laboratory and clinical diagnostics in the example of the interesting history of the pregnancy test. Full article

(This article belongs to the Section Antibody-Based Diagnostics)

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13 pages, 1476 KiB

Open AccessReview

Conditionally Active, pH-Sensitive Immunoregulatory Antibodies Targeting VISTA and CTLA-4 Lead an Emerging Class of Cancer Therapeutics

by F. Donelson Smith, Robert H. Pierce, Thomas Thisted and Edward H. van der Horst

Antibodies 2023, 12(3), 55; https://doi.org/10.3390/antib12030055 - 30 Aug 2023

Cited by 3 | Viewed by 4858

Abstract

Immune checkpoints and other immunoregulatory targets can be difficult to precisely target due to expression on non-tumor immune cells critical to maintaining immune homeostasis in healthy tissues. On-target/off-tumor binding of therapeutics results in significant pharmacokinetic and pharmacodynamic problems. Target-mediated drug disposition (TMDD) significantly [...] Read more.

Immune checkpoints and other immunoregulatory targets can be difficult to precisely target due to expression on non-tumor immune cells critical to maintaining immune homeostasis in healthy tissues. On-target/off-tumor binding of therapeutics results in significant pharmacokinetic and pharmacodynamic problems. Target-mediated drug disposition (TMDD) significantly limits effective intratumoral drug levels and adversely affects anti-tumor efficacy. Target engagement outside the tumor environment may lead to severe immune-related adverse events (irAEs), resulting in a narrowing of the therapeutic window, sub-optimal dosing, or cessation of drug development altogether. Overcoming these challenges has become tractable through recent advances in antibody engineering and screening approaches. Here, we review the discovery and development of conditionally active antibodies with minimal binding to target at physiologic pH but high-affinity target binding at the low pH of the tumor microenvironment by focusing on the discovery and improved properties of pH-dependent mAbs targeting two T cell checkpoints, VISTA and CTLA-4. Full article

(This article belongs to the Special Issue Novel Strategies and Technologies for the Development of Tumor-Specific Antibodies)

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15 pages, 3440 KiB

Open AccessArticle

Profiling the Biophysical Developability Properties of Common IgG1 Fc Effector Silencing Variants

by Robert Pejchal, Anthony B. Cooper, Michael E. Brown, Maximiliano Vásquez and Eric M. Krauland

Antibodies 2023, 12(3), 54; https://doi.org/10.3390/antib12030054 - 22 Aug 2023

Cited by 6 | Viewed by 5296

Abstract

Therapeutic antibodies represent the most significant modality in biologics, with around 150 approved drugs on the market. In addition to specific target binding mediated by the variable fragments (Fvs) of the heavy and light chains, antibodies possess effector functions through binding of the [...] Read more.

Therapeutic antibodies represent the most significant modality in biologics, with around 150 approved drugs on the market. In addition to specific target binding mediated by the variable fragments (Fvs) of the heavy and light chains, antibodies possess effector functions through binding of the constant region (Fc) to Fcγ receptors (FcγR), which allow immune cells to attack and kill target cells using a variety of mechanisms. However, for some applications, including T-cell-engaging bispecifics, this effector function is typically undesired. Mutations within the lower hinge and the second constant domain (CH2) of IgG1 that comprise the FcγR binding interface reduce or eliminate effector function (“Fc silencing”) while retaining binding to the neonatal Fc receptor (FcRn), important for normal antibody pharmacokinetics (PKs). Comprehensive profiling of biophysical developability properties would benefit the choice of constant region variants for development. Here, we produce a large panel of representative mutations previously described in the literature and in many cases in clinical or approved molecules, generate select combinations thereof, and characterize their binding and biophysical properties. We find that some commonly used CH2 mutations, including D265A and P331S, are effective in reducing binding to FcγR but significantly reduce stability, promoting aggregation, particularly under acidic conditions commonly employed in manufacturing. We highlight mutation sets that are particularly effective for eliminating Fc effector function with the retention of WT-like stability, including L234A, L235A, and S267K (LALA-S267K), L234A, L235E, and S267K (LALE-S267K), L234A, L235A, and P329A (LALA-P329A), and L234A, L235E, and P329G (LALE-P329G). Full article

(This article belongs to the Special Issue Novel Strategies and Technologies for the Development of Tumor-Specific Antibodies)

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17 pages, 5488 KiB

Open AccessArticle

Exploring Parametric and Mechanistic Differences between Expi293F^TM and ExpiCHO-S^TM Cells for Transient Antibody Production Optimization

by Jing Zhou, Guoying Grace Yan, David Cluckey, Caryl Meade, Margaret Ruth, Rhady Sorm, Amy S. Tam, Sean Lim, Constantine Petridis, Laura Lin, Aaron M. D’Antona and Xiaotian Zhong

Antibodies 2023, 12(3), 53; https://doi.org/10.3390/antib12030053 - 10 Aug 2023

Cited by 2 | Viewed by 4062

Abstract

Rapidly producing drug-like antibody therapeutics for lead molecule discovery and candidate optimization is typically accomplished by large-scale transient gene expression technologies (TGE) with cultivated mammalian cells. The TGE methodologies have been extensively developed over the past three decades, yet produce significantly lower yields [...] Read more.

Rapidly producing drug-like antibody therapeutics for lead molecule discovery and candidate optimization is typically accomplished by large-scale transient gene expression technologies (TGE) with cultivated mammalian cells. The TGE methodologies have been extensively developed over the past three decades, yet produce significantly lower yields than the stable cell line approach, facing the technical challenge of achieving universal high expression titers for a broad range of antibodies and therapeutics modalities. In this study, we explored various parameters for antibody production in the TGE cell host Expi293F^TM and ExpiCHO-S^TM with the transfection reagents ExpiFectamine^TM and polyethylenimine. We discovered that there are significant differences between Expi293F^TM and ExpiCHO-S^TM cells with regards to DNA complex formation time and ratio, complex formation buffers, DNA complex uptake trafficking routes, responses to dimethyl sulfoxide and cell cycle inhibitors, as well as light-chain isotype expression preferences. This investigation mechanistically dissected the TGE processes and provided a new direction for future transient antibody production optimization. Full article

(This article belongs to the Section Antibody Discovery and Engineering)

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14 pages, 2437 KiB

Open AccessEditor’s ChoiceReview

Recent Progress in Antibody Epitope Prediction

by Xincheng Zeng, Ganggang Bai, Chuance Sun and Buyong Ma

Antibodies 2023, 12(3), 52; https://doi.org/10.3390/antib12030052 - 8 Aug 2023

Cited by 10 | Viewed by 7088

Abstract

Recent progress in epitope prediction has shown promising results in the development of vaccines and therapeutics against various diseases. However, the overall accuracy and success rate need to be improved greatly to gain practical application significance, especially conformational epitope prediction. In this review, [...] Read more.

Recent progress in epitope prediction has shown promising results in the development of vaccines and therapeutics against various diseases. However, the overall accuracy and success rate need to be improved greatly to gain practical application significance, especially conformational epitope prediction. In this review, we examined the general features of antibody–antigen recognition, highlighting the conformation selection mechanism in flexible antibody–antigen binding. We recently highlighted the success and warning signs of antibody epitope predictions, including linear and conformation epitope predictions. While deep learning-based models gradually outperform traditional feature-based machine learning, sequence and structure features still provide insight into antibody–antigen recognition problems. Full article

(This article belongs to the Special Issue Antibodies: 10th Anniversary)

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13 pages, 1995 KiB

Open AccessArticle

Cost-Effective Protein Production in CHO Cells Following Polyethylenimine-Mediated Gene Delivery Showcased by the Production and Crystallization of Antibody Fabs

by Klaudia Meskova, Katarina Martonova, Patricia Hrasnova, Kristina Sinska, Michaela Skrabanova, Lubica Fialova, Stefana Njemoga, Ondrej Cehlar, Olga Parmar, Petr Kolenko, Vladimir Pevala and Rostislav Skrabana

Antibodies 2023, 12(3), 51; https://doi.org/10.3390/antib12030051 - 4 Aug 2023

Viewed by 4402

Abstract

Laboratory production of recombinant mammalian proteins, particularly antibodies, requires an expression pipeline assuring sufficient yield and correct folding with appropriate posttranslational modifications. Transient gene expression (TGE) in the suspension-adapted Chinese Hamster Ovary (CHO) cell lines has become the method of choice for this [...] Read more.

Laboratory production of recombinant mammalian proteins, particularly antibodies, requires an expression pipeline assuring sufficient yield and correct folding with appropriate posttranslational modifications. Transient gene expression (TGE) in the suspension-adapted Chinese Hamster Ovary (CHO) cell lines has become the method of choice for this task. The antibodies can be secreted into the media, which facilitates subsequent purification, and can be glycosylated. However, in general, protein production in CHO cells is expensive and may provide variable outcomes, namely in laboratories without previous experience. While achievable yields may be influenced by the nucleotide sequence, there are other aspects of the process which offer space for optimization, like gene delivery method, cultivation process or expression plasmid design. Polyethylenimine (PEI)-mediated gene delivery is frequently employed as a low-cost alternative to liposome-based methods. In this work, we are proposing a TGE platform for universal medium-scale production of antibodies and other proteins in CHO cells, with a novel expression vector allowing fast and flexible cloning of new genes and secretion of translated proteins. The production cost has been further reduced using recyclable labware. Nine days after transfection, we routinely obtain milligrams of antibody Fabs or human lactoferrin in a 25 mL culture volume. Potential of the platform is established based on the production and crystallization of antibody Fabs and their complexes. Full article

(This article belongs to the Special Issue Design, Production and Characterization of Peptide Antibodies—Volume II)

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14 pages, 668 KiB

Open AccessReview

Diagnosis and Treatment of Paraneoplastic Neurologic Syndromes

by Daniel Chiu, John Rhee and L. Nicolas Gonzalez Castro

Antibodies 2023, 12(3), 50; https://doi.org/10.3390/antib12030050 - 31 Jul 2023

Cited by 5 | Viewed by 5840

Abstract

Paraneoplastic antibody syndromes result from the anti-tumor antibody response against normal antigens ectopically expressed by tumor cells. Although this antibody response plays an important role in helping clear a nascent or established tumor, the engagement of antigens expressed in healthy tissues can lead [...] Read more.

Paraneoplastic antibody syndromes result from the anti-tumor antibody response against normal antigens ectopically expressed by tumor cells. Although this antibody response plays an important role in helping clear a nascent or established tumor, the engagement of antigens expressed in healthy tissues can lead to complex clinical syndromes with challenging diagnosis and management. The majority of known paraneoplastic antibody syndromes have been found to affect the central and peripheral nervous system. The present review provides an update on the pathophysiology of paraneoplastic neurologic syndromes, as well as recommendations for their diagnosis and treatment. Full article

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12 pages, 565 KiB

Open AccessReview

Psychiatric Symptoms in Acute and Persisting Forms of COVID-19 Associated with Neural Autoantibodies

by Niels Hansen

Antibodies 2023, 12(3), 49; https://doi.org/10.3390/antib12030049 - 27 Jul 2023

Cited by 2 | Viewed by 2311

Abstract

(1) Background: In this narrative review, we focus on neural autoantibodies in patients with coronavirus disease 2019 (COVID-19) as a consequence of severe acute respiratory syndrome coronavirus type 2 infection and persisting symptoms of post-COVID-19 syndrome with a psychiatric presentation. (2) Methods: Our [...] Read more.

(1) Background: In this narrative review, we focus on neural autoantibodies in patients with coronavirus disease 2019 (COVID-19) as a consequence of severe acute respiratory syndrome coronavirus type 2 infection and persisting symptoms of post-COVID-19 syndrome with a psychiatric presentation. (2) Methods: Our methods include using the PubMed database to search for appropriate articles. (3) Results: We first describe the phenomenon of the psychiatric manifestation of COVID-19 in acute and persistent forms, associated with neural autoantibodies, often attributable to encephalopathy or encephalitis. We discuss the spectrum of neural autoantibodies in neuropsychiatric patients affected by COVID-19 and post-COVID-19 syndrome. Evidence from our research suggests that it is highly likely that neural autoantibody production is facilitated by SARS-CoV-2 infection, and that more neuropsychiatric patients than control subjects will present neural autoantibodies. (4) Conclusions: These observations support the hypothesis that acute and persisting forms of COVID-19 promote autoimmune diseases. Our patients therefore require comprehensive evaluation to avoid overlooking such autoantibody-associated psychiatric disorders associated with COVID-19. Full article

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22 pages, 1741 KiB

Open AccessReview

The Usefulness of Thyroid Antibodies in the Diagnostic Approach to Autoimmune Thyroid Disease

by Hernando Vargas-Uricoechea, Juan Patricio Nogueira, María V. Pinzón-Fernández and Diego Schwarzstein

Antibodies 2023, 12(3), 48; https://doi.org/10.3390/antib12030048 - 22 Jul 2023

Cited by 13 | Viewed by 6848

Abstract

Autoimmune thyroid disease (AITD) refers to a spectrum of various diseases, with two extremes of clinical presentation, hypothyroidism (Hashimoto’s thyroiditis (HT) and hyperthyroidism (Graves–Basedow disease (GBD)). Both conditions are characterized by presenting a cellular and humoral autoimmune reaction, with an increase in the [...] Read more.

Autoimmune thyroid disease (AITD) refers to a spectrum of various diseases, with two extremes of clinical presentation, hypothyroidism (Hashimoto’s thyroiditis (HT) and hyperthyroidism (Graves–Basedow disease (GBD)). Both conditions are characterized by presenting a cellular and humoral autoimmune reaction, with an increase in the synthesis and secretion of antibodies directed toward various thyroid antigens, together with a phenomenon of thyrocyte necrosis and apoptosis (in HT) and a persistent thyrotropin-receptor stimulation (in GBD). The diagnosis of both entities is based on clinical, laboratory, and imaging findings. Three major anti-thyroid antibodies have been described, those directed against the TSH receptor (TRAb), against thyroid peroxidase (TPOAb), and against thyroglobulin (TgAb). Each of these autoantibodies plays a fundamental role in the diagnostic approach of autoimmune thyroid disease. TRAbs are the hallmark of GBD, and additionally, they are predictors of response to disease treatment, among other utilities. Likewise, TPOAb and TgAb allow for identifying individuals with a higher risk of progression to hypothyroidism; the positivity of one or both autoantibodies defines the presence of thyroid autoimmunity. In this review, the usefulness of anti-thyroid antibodies in the diagnostic approach to autoimmune thyroid disease is described. Full article

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14 pages, 2257 KiB

Open AccessEditor’s ChoiceArticle

Suppression of MUC1-Overexpressing Tumors by a Novel MUC1/CD3 Bispecific Antibody

by Jun Fang, Shifa Lai, Haoyang Yu and Lan Ma

Antibodies 2023, 12(3), 47; https://doi.org/10.3390/antib12030047 - 13 Jul 2023

Cited by 4 | Viewed by 2961

Abstract

Mucin1 (MUC1) is abnormally glycosylated and overexpressed in a variety of epithelial cancers and plays a critical role in tumor progression. MUC1 has received remark attention as an oncogenic molecule and is considered a valuable tumor target for immunotherapy, while many monoclonal antibodies [...] Read more.

Mucin1 (MUC1) is abnormally glycosylated and overexpressed in a variety of epithelial cancers and plays a critical role in tumor progression. MUC1 has received remark attention as an oncogenic molecule and is considered a valuable tumor target for immunotherapy, while many monoclonal antibodies (mAbs) targeting MUC1-positive cancers in clinical studies lack satisfactory results. It would be highly desirable to develop an effective therapy against MUC1-expressing cancers. In this study, we constructed a novel T cell-engaging bispecific antibody (BsAb) targeting MUC1 and CD3 with the Fab-ScFv-IgG format. A high quality of MUC1-CD3 BsAb can be acquired through a standard method. Our study suggested that this BsAb could specifically bind to MUC1- and CD3-positive cells and efficiently enhance T cell activation, cytokine release, and cytotoxicity. Furthermore, our study demonstrated that this BsAb could potently redirect T cells to eliminate MUC1-expressing tumor cells in vitro and significantly suppress MUC1-positive tumor growth in a xenograft mouse model. Thus, T cell-engaging MUC1/CD3 BsAb could be an effective therapeutic approach to combat MUC1-positive tumors and our MUC1/CD3 BsAb could be a promising candidate in clinical applications for the treatment of MUC1-positive cancer patients. Full article

(This article belongs to the Special Issue Novel Strategies and Technologies for the Development of Tumor-Specific Antibodies)

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21 pages, 923 KiB

Open AccessEditor’s ChoiceReview

Expanding the Reach of Monoclonal Antibodies: A Review of Synthetic Nucleic Acid Delivery in Immunotherapy

by Christopher Chung, Sagar B. Kudchodkar, Curtis N. Chung, Young K. Park, Ziyang Xu, Norbert Pardi, Mohamed Abdel-Mohsen and Kar Muthumani

Antibodies 2023, 12(3), 46; https://doi.org/10.3390/antib12030046 - 6 Jul 2023

Cited by 11 | Viewed by 8283

Abstract

Harnessing the immune system to combat disease has revolutionized medical treatment. Monoclonal antibodies (mAbs), in particular, have emerged as important immunotherapeutic agents with clinical relevance in treating a wide range of diseases, including allergies, autoimmune diseases, neurodegenerative disorders, cancer, and infectious diseases. These [...] Read more.

Harnessing the immune system to combat disease has revolutionized medical treatment. Monoclonal antibodies (mAbs), in particular, have emerged as important immunotherapeutic agents with clinical relevance in treating a wide range of diseases, including allergies, autoimmune diseases, neurodegenerative disorders, cancer, and infectious diseases. These mAbs are developed from naturally occurring antibodies and target specific epitopes of single molecules, minimizing off-target effects. Antibodies can also be designed to target particular pathogens or modulate immune function by activating or suppressing certain pathways. Despite their benefit for patients, the production and administration of monoclonal antibody therapeutics are laborious, costly, and time-consuming. Administration often requires inpatient stays and repeated dosing to maintain therapeutic levels, limiting their use in underserved populations and developing countries. Researchers are developing alternate methods to deliver monoclonal antibodies, including synthetic nucleic acid-based delivery, to overcome these limitations. These methods allow for in vivo production of monoclonal antibodies, which would significantly reduce costs and simplify administration logistics. This review explores new methods for monoclonal antibody delivery, including synthetic nucleic acids, and their potential to increase the accessibility and utility of life-saving treatments for several diseases. Full article

(This article belongs to the Section Antibody-Based Therapeutics)

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17 pages, 3584 KiB

Open AccessArticle

Development of a Novel Anti-CD44 Variant 8 Monoclonal Antibody C₄₄Mab-94 against Gastric Carcinomas

by Hiroyuki Suzuki, Nohara Goto, Tomohiro Tanaka, Tsunenori Ouchida, Mika K. Kaneko and Yukinari Kato

Antibodies 2023, 12(3), 45; https://doi.org/10.3390/antib12030045 - 4 Jul 2023

Cited by 2 | Viewed by 2494

Abstract

Gastric cancer (GC) is the third leading cause of cancer-related deaths worldwide. GC with peritoneal metastasis exhibits a poor prognosis due to the lack of effective therapy. A comprehensive analysis of malignant ascites identified the genomic alterations and significant amplifications of cancer driver [...] Read more.

Gastric cancer (GC) is the third leading cause of cancer-related deaths worldwide. GC with peritoneal metastasis exhibits a poor prognosis due to the lack of effective therapy. A comprehensive analysis of malignant ascites identified the genomic alterations and significant amplifications of cancer driver genes, including CD44. CD44 and its splicing variants are overexpressed in tumors, and play crucial roles in the acquisition of invasiveness, stemness, and resistance to treatments. Therefore, the development of CD44-targeted monoclonal antibodies (mAbs) is important for GC diagnosis and therapy. In this study, we immunized mice with CD44v3–10-overexpressed PANC-1 cells and established several dozens of clones that produce anti-CD44v3–10 mAbs. One of the clones (C₄₄Mab-94; IgG₁, kappa) recognized the variant-8-encoded region and peptide, indicating that C₄₄Mab-94 is a specific mAb for CD44v8. Furthermore, C₄₄Mab-94 could recognize CHO/CD44v3–10 cells, oral squamous cell carcinoma cell line (HSC-3), or GC cell lines (MKN45 and NUGC-4) in flow cytometric analyses. C₄₄Mab-94 could detect the exogenous CD44v3–10 and endogenous CD44v8 in western blotting and stained the formalin-fixed paraffin-embedded gastric cancer cells. These results indicate that C₄₄Mab-94 is useful for detecting CD44v8 in a variety of experimental methods and is expected to become usefully applied to GC diagnosis and therapy. Full article

(This article belongs to the Section Antibody-Based Diagnostics)

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20 pages, 3558 KiB

Open AccessArticle

Detection of Antibody-Dependent Cell-Mediated Cytotoxicity—Supporting Antibodies by NK-92-CD16A Cell Externalization of CD107a: Recognition of Antibody Afucosylation and Assay Optimization

by Judith Cruz Amaya, Bruce Walcheck, Julie Smith-Gagen, Vincent C. Lombardi and Dorothy Hudig

Antibodies 2023, 12(3), 44; https://doi.org/10.3390/antib12030044 - 27 Jun 2023

Viewed by 2575

Abstract

Antibody-dependent cell-mediated cytotoxicity (ADCC) by natural killer (NK) lymphocytes eliminates cells infected with viruses. Anti-viral ADCC requires three components: (1) antibody; (2) effector lymphocytes with the Fc-IgG receptor CD16A; and (3) viral proteins in infected cell membranes. Fc-afucosylated antibodies bind with greater affinity [...] Read more.

Antibody-dependent cell-mediated cytotoxicity (ADCC) by natural killer (NK) lymphocytes eliminates cells infected with viruses. Anti-viral ADCC requires three components: (1) antibody; (2) effector lymphocytes with the Fc-IgG receptor CD16A; and (3) viral proteins in infected cell membranes. Fc-afucosylated antibodies bind with greater affinity to CD16A than fucosylated antibodies; individuals’ variation in afucosylation contributes to differences in ADCC. Current assays for afucosylated antibodies involve expensive methods. We report an improved bioassay for antibodies that supports ADCC, which encompasses afucosylation. This assay utilizes the externalization of CD107a by NK-92-CD16A cells after antibody recognition. We used anti-CD20 monoclonal antibodies, GA101 WT or glycoengineered (GE), 10% or ~50% afucosylated, and CD20-positive Raji target cells. CD107a increased detection 7-fold compared to flow cytometry to detect Raji-bound antibodies. WT and GE antibody effective concentrations (EC₅₀s) for CD107a externalization differed by 20-fold, with afucosylated GA101-GE more detectable. The EC₅₀s for CD107a externalization vs. ⁵¹Cr cell death were similar for NK-92-CD16A and blood NK cells. Notably, the % CD107a-positive cells were negatively correlated with dead Raji cells and were nearly undetectable at high NK:Raji ratios required for cytotoxicity. This bioassay is very sensitive and adaptable to assess anti-viral antibodies but unsuitable as a surrogate assay to monitor cell death after ADCC. Full article

(This article belongs to the Special Issue Antibodies: 10th Anniversary)

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21 pages, 2940 KiB

Open AccessEditor’s ChoiceReview

Proteolysis-Targeting Chimera (PROTAC) Delivery into the Brain across the Blood-Brain Barrier

by Toshihiko Tashima

Antibodies 2023, 12(3), 43; https://doi.org/10.3390/antib12030043 - 26 Jun 2023

Cited by 8 | Viewed by 6749

Abstract

Drug development for neurodegenerative diseases such as Alzheimer’s disease, Parkinson’s disease, and Huntington’s disease has challenging difficulties due to the pharmacokinetic impermeability based on the blood-brain barrier (BBB) as well as the blurriness of pharmacodynamic targets based on their unclarified pathogenesis and complicated [...] Read more.

Drug development for neurodegenerative diseases such as Alzheimer’s disease, Parkinson’s disease, and Huntington’s disease has challenging difficulties due to the pharmacokinetic impermeability based on the blood-brain barrier (BBB) as well as the blurriness of pharmacodynamic targets based on their unclarified pathogenesis and complicated progression mechanisms. Thus, in order to produce innovative central nervous system (CNS) agents for patients suffering from CNS diseases, effective, selective delivery of CNS agents into the brain across the BBB should be developed. Currently, proteolysis-targeting chimeras (PROTACs) attract rising attention as a new modality to degrade arbitrary intracellular proteins by the ubiquitin-proteasome system. The internalizations of peptide-based PROTACs by cell-penetrating peptides and that of small molecule-based PROTACs through passive diffusion lack cell selectivity. Therefore, these approaches may bring off-target side effects due to wrong distribution. Furthermore, efflux transporters such as multiple drug resistance 1 (MDR1) expressed at the BBB might interrupt the entry of small molecule-based PROTACs into the brain. Nonetheless, intelligent delivery using machinery systems to absorb the nutrition into the brain for homeostasis, such as carrier-mediated transport (CMT) or receptor-mediated transcytosis (RMT), can be established. PROTACs with N-containing groups that are recognized by the proton-coupled organic cation antiporter might cross the BBB through CMT. PROTAC-antibody conjugates (PACs) might cross the BBB through RMT. Subsequently, such small molecule-based PROTACs released in the brain interstitial fluid would be transported into cells such as neurons through passive diffusion and then demonstrate arbitrary protein degradation. In this review, I introduce the potential and advantages of PROTAC delivery into the brain across the BBB through CMT or RMT using PACs in a non-invasive way. Full article

(This article belongs to the Special Issue Antibodies: 10th Anniversary)

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11 pages, 1332 KiB

Open AccessCommunication

EMab-300 Detects Mouse Epidermal Growth Factor Receptor-Expressing Cancer Cell Lines in Flow Cytometry

by Nohara Goto, Hiroyuki Suzuki, Tomohiro Tanaka, Kenichiro Ishikawa, Tsunenori Ouchida, Mika K. Kaneko and Yukinari Kato

Antibodies 2023, 12(3), 42; https://doi.org/10.3390/antib12030042 - 21 Jun 2023

Cited by 4 | Viewed by 2237

Abstract

Epidermal Growth Factor Receptor (EGFR) overexpression or its mutation mediates the sustaining proliferative signaling, which is an important hallmark of cancer. Human EGFR-targeting monoclonal antibody (mAb) therapy such as cetuximab has been approved for clinical use in patients with colorectal cancers and head [...] Read more.

Epidermal Growth Factor Receptor (EGFR) overexpression or its mutation mediates the sustaining proliferative signaling, which is an important hallmark of cancer. Human EGFR-targeting monoclonal antibody (mAb) therapy such as cetuximab has been approved for clinical use in patients with colorectal cancers and head and neck squamous cell carcinomas. A reliable preclinical mouse model is essential to further develop the mAb therapy against EGFR. Therefore, sensitive mAbs against mouse EGFR (mEGFR) should be established. In this study, we developed a specific and sensitive mAb for mEGFR using the Cell-Based Immunization and Screening (CBIS) method. The established anti-mEGFR mAb, EMab-300 (rat IgG₁, kappa), reacted with mEGFR-overexpressed Chinese hamster ovary-K1 (CHO/mEGFR) and endogenously mEGFR-expressed cell lines, including NMuMG (a mouse mammary gland epithelial cell) and Lewis lung carcinoma cells, using flow cytometry. The kinetic analysis using flow cytometry indicated that the K_D of EMab-300 for CHO/mEGFR and NMuMG was 4.3 × 10⁻⁸ M and 1.9 × 10⁻⁸ M, respectively. These results indicated that EMab-300 applies to the detection of mEGFR using flow cytometry and may be useful to obtain the proof of concept in preclinical studies. Full article

(This article belongs to the Section Antibody-Based Therapeutics)

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Antibodies, Volume 12, Issue 3 (September 2023) – 19 articles

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