%0 Journal Article %T Bacillus anthracis lethal toxin negatively modulates ILC3 function through perturbation of IL-23-mediated MAPK signaling %A David S. J. Allan %A James R. Carlyle %A Lauren A. Zenewicz %A Sudarshan Seshadri %J - %D 2017 %R 10.1371/journal.ppat.1006690 %X Bacillus anthracis, the causative agent of anthrax, secretes lethal toxin that down-regulates immune functions. Translocation of B. anthracis across mucosal epithelia is key for its dissemination and pathogenesis. Group 3 innate lymphocytes (ILC3s) are important in mucosal barrier maintenance due to their expression of the cytokine IL-22, a critical regulator of tissue responses and repair during homeostasis and inflammation. We found that B. anthracis lethal toxin perturbed ILC3 function in vitro and in vivo, revealing an unknown IL-23-mediated MAPK signaling pathway. Lethal toxin had no effects on the canonical STAT3-mediated IL-23 signaling pathway. Rather lethal toxin triggered the loss of several MAP2K kinases, which correlated with reduced activation of downstream ERK1/2 and p38, respectively. Inhibition studies showed the importance of MAPK signaling in IL-23-mediated production of IL-22. Our finding that MAPK signaling is required for optimal IL-22 production in ILC3s may lead to new approaches for targeting IL-22 biology %K Toxins %K MAPK signaling cascades %K Lethality (bacteriology) %K Lymphocytes %K Cytokines %K Phosphorylation %K Bacillus anthracis %K Cell staining %U https://journals.plos.org/plospathogens/article?id=10.1371/journal.ppat.1006690