Mucosal Associated Invariant T (MAIT) cells are evolutionary conserved innate-like T cells able to recognize bacterial and fungal ligands derived from vitamin B biosynthesis. These cells are particularly present in liver and blood but also populate mucosal sites including skin, oral, intestinal, respiratory, and urogenital tracts that are in contact with the environment and microbiota of their host. Growing evidence suggests important involvement of MAIT cells in safeguarding the mucosa against external microbial threats. Simultaneously, mucosal MAIT cells have been implicated in immune and inflammatory pathologies affecting these organs. Here, we review the specificities of mucosal MAIT cells, their functions in the protection and maintenance of mucosal barriers, and their interactions with other mucosal cells.

粘膜相关不变 T (MAIT) 细胞是进化上保守的先天样 T 细胞，能够识别源自维生素 B 生物合成的细菌和真菌配体。这些细胞特别存在于肝脏和血液中，但也存在于与宿主的环境和微生物群接触的粘膜部位，包括皮肤、口腔、肠道、呼吸道和泌尿生殖道。越来越多的证据表明 MAIT 细胞在保护粘膜免受外部微生物威胁方面发挥着重要作用。同时，粘膜 MAIT 细胞与影响这些器官的免疫和炎症病理有关。在这里，我们回顾了粘膜 MAIT 细胞的特异性、它们在保护和维持粘膜屏障中的功能，以及它们与其他粘膜细胞的相互作用。