期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2014
卷号：111
期号：38
页码：13942-13947
DOI：10.1073/pnas.1323852111
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：SignificanceCommensal microbiota are known to be required for the elicitation of host Th17 responses, which may mediate autoimmune diseases. Here, we demonstrate that the IL-23 pathway dynamically regulates the abundance of certain commensals and maintains barrier function. Barrier disruption results in systemic dissemination of microbial products, which invokes the IL-23 pathway, with both beneficial and potentially deleterious consequences. Through induction of IL-22, IL-23 contributes to barrier repair, and through induction of the Th17 response, it aims to neutralize escaped commensal microbes. Thus, barrier disruption results in a pro-Th17 environment in which not only antimicrobial but also potentially antihost Th17 cells can develop. Mammalian hosts are colonized with commensal microbes in various mucosal and epithelial tissues, including the intestinal tract. In mice, the presence of segmented filamentous bacteria (SFB) promotes Th17 differentiation and the development of autoimmune disease. Here, we demonstrate that the IL-23 pathway dynamically regulates the abundance of SFB as well as mucosal barrier function in the adult animal. Genetic or pharmacological inactivation of the pathway selectively perturbs the abundance of a small group of commensals, including SFB, and results in an impaired mucosal barrier. Defective barrier function leads to systemic dissemination of microbial products, provoking induction of the IL-23 pathway with dual consequences: IL-23 drives IL-22 production to reinforce mucosal barrier function and elicit antimicrobial activities, and it also drives the differentiation of Th17 cells in an attempt to combat escaped microbes in the lamina propria and in distal tissues. Thus, barrier defects generate a systemic environment that facilitates Th17 development.
