Protective Role of Commensals against Clostridium difficile Infection via an IL-1β–Mediated Positive-Feedback Loop

作者：Mizuho Hasegawa, Nobuhiko Kamada, Yizu Jiao, Meng Zhen Liu, Gabriel Núñez, Naohiro Inohara · 发表于：The Journal of Immunology · 年份：2012 · DOI：10.4049/jimmunol.1200821 · 被引用次数：133 · 研究领域：Clostridium difficile and Clostridium perfringens research、Microscopic Colitis、Helicobacter pylori-related gastroenterology studies

Clostridium difficile is a Gram-positive obligate anaerobic pathogen that causes pseudomembranous colitis in antibiotic-treated individuals. Commensal bacteria are known to have a significant role in the intestinal accumulation of C. difficile after antibiotic treatment, but little is known about how they affect host immunity during C. difficile infection. In this article, we report that C. difficile infection results in translocation of commensals across the intestinal epithelial barrier that is critical for neutrophil recruitment through the induction of an IL-1β-mediated positive-feedback loop. Mice lacking ASC, an essential mediator of IL-1β and IL-18 processing and secretion, were highly susceptible to C. difficile infection. ASC(-/-) mice exhibited enhanced translocation of commensals to multiple organs after C. difficile infection. Notably, ASC(-/-) mice exhibited impaired CXCL1 production and neutrophil influx into intestinal tissues in response to C. difficile infection. The impairment in neutrophil recruitment resulted in reduced production of IL-1β and CXCL1 but not IL-18. Importantly, translocated commensals were required for ASC/Nlrp3-dependent IL-1β secretion by neutrophils. Mice lacking IL-1β were deficient in inducing CXCL1 secretion, suggesting that IL-1β is the dominant inducer of ASC-mediated CXCL1 production during C. difficile infection. These results indicate that translocated commensals play a crucial role in CXCL1-dependent recruitment of neutrophils t...