The mammalian mucosal immune system acts as a multitasking mediator between bodily function and a vast diversity of microbial colonists. Depending on host–microbial interaction type, mucosal immune responses have distinct functions. Immunity to pathogen infection functions to limit tissue damage, clear or contain primary infection, and prevent or lower the severity of a secondary infection by conferring specific long-term adaptive immunity. Responses to nonpathogenic commensal or mutualistic microbes instead function to tolerate continuous colonization. Mucosal innate immune and epithelial cells employ a limited repertoire of innate receptors to program the adaptive immune response accordingly. Pathogen versus nonpathogen immune discrimination appears to be very robust, as most individuals successfully maintain life-long mutualism with their nonpathogenic microbiota, while mounting immune defense to pathogenic microbe infection specifically. However, the process is imperfect, which can have immunopathological consequences, but may also be exploited medically. Normally innocuous intestinal commensals in some individuals may drive serious inflammatory autoimmunity, whereas harmless vaccines can be used to fool the immune system into mounting a protective anti-pathogen immune response. In this article, we review the current knowledge on mucosal intestinal bacterial immune recognition focusing on T_H17 responses and identify commonalities between intestinal pathobiont and vaccine-induced T_H17 responses.

哺乳动物粘膜免疫系统充当身体功能和大量微生物殖民者之间的多任务调解人。根据宿主-微生物相互作用的类型，粘膜免疫反应具有不同的功能。对病原体感染的免疫功能可限制组织损伤，清除或遏制原发感染，并通过赋予特异性长期适应性免疫来预防或降低继发感染的严重程度。对非致病性共生或共生微生物的反应反而起到容忍持续定植的作用。粘膜先天免疫和上皮细胞使用有限的先天受体库来相应地编程适应性免疫反应。病原体与非病原体的免疫歧视似乎非常强大，因为大多数人成功地与非致病微生物群保持了终生共生，同时对致病微生物感染进行了免疫防御。然而，该过程并不完善，可能会产生免疫病理学后果，但也可能在医学上得到利用。某些个体通常无害的肠道共生菌可能会引发严重的炎症性自身免疫，而无害的疫苗可用于欺骗免疫系统，使其产生保护性的抗病原体免疫反应。在这篇文章中，我们回顾了目前关于粘膜肠道细菌免疫识别的知识，重点是 T 某些个体通常无害的肠道共生菌可能会引发严重的炎症性自身免疫，而无害的疫苗可用于欺骗免疫系统，使其产生保护性的抗病原体免疫反应。在这篇文章中，我们回顾了目前关于粘膜肠道细菌免疫识别的知识，重点是 T 某些个体通常无害的肠道共生菌可能会引发严重的炎症性自身免疫，而无害的疫苗可用于欺骗免疫系统，使其产生保护性的抗病原体免疫反应。在这篇文章中，我们回顾了目前关于粘膜肠道细菌免疫识别的知识，重点是 T_H17反应并确定肠道致病菌和疫苗诱导的 T _H17反应之间的共性。