Proinflammation can predispose the body to autoimmunity and cancer. We have reported that iPLA
2β
−/− mice are susceptible to autoimmune hepatitis and colitis. Here we determined whether cytokine release by immune cells could be affected by iPLA
2β deficiency alone
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Proinflammation can predispose the body to autoimmunity and cancer. We have reported that iPLA
2β
−/− mice are susceptible to autoimmune hepatitis and colitis. Here we determined whether cytokine release by immune cells could be affected by iPLA
2β deficiency alone or combined with CD95/FasL-antibody treatment
in vivo. We also determined whether cancer risk could be increased in aged mutant mice. Immune cells were isolated from 3-month old male WT and iPLA
2β
−/− mice, and some were injected with anti-CD95/FasL antibody for 6 h. Kupffer cells (KC) or splenocytes and liver lymphocytes were stimulated
in vitro by lipopolysaccharide or concanavalinA, respectively. Whole-body iPLA
2β deficiency caused increased apoptosis in liver, spleen, and mesenteric lymph node (MLN). KC from mutant mice showed suppressed release of TNFα and IL-6, while their splenocytes secreted increased levels of IFNγ and IL-17a. Upon CD95/FasL activation, the mutant KC in turn showed exaggerated cytokine release, this was accompanied by an increased release of IFNγ and IL-17a by liver lymphocytes. Aged iPLA
2β
−/− mice did not show follicular MLN lymphoma commonly seen in aged C57/BL6 mice. Thus, iPLA
2β deficiency renders M1- and Th1/Th17-proinflammation potentially leading to a reduction in age-related MLN lymphoma during aging.
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