美国国立卫生研究院Yasmine Belkaid课题组研究发现，粘膜相关恒定T（MAIT）细胞在生命早期被微生物群所印记，并促进组织修复。该项研究成果发表在10月25日出版的《科学》杂志上。

研究人员认为MAIT细胞的发育依赖于特定的时间窗口，此后MAIT细胞的发育受到永久性损害。这种印记取决于生命早期暴露于合成核黄素来源抗原的特定微生物。在成年人中，皮肤MAIT细胞是产生白介素17A（IL-17A）淋巴细胞的主要群体，其显示出独特的转录特征，随后能够以IL-1、IL-18以及抗原依赖的方式对在皮肤中的共生作出应答。因此，皮肤MAIT细胞的局部活化促进伤口愈合。

总之，他们的工作揭示了微生物群与MAIT细胞的特定成员之间的相互作用，而后者依次调控组织印迹和随后的损伤应答。

据了解，早期定植和随后的微生物群接触如何影响长期组织免疫仍了解甚少。

附：英文原文

Title: MAIT cells are imprinted by the microbiota in early life and promote tissue repair

Author: Michael G. Constantinides, Verena M. Link, Samira Tamoutounour, Andrea C. Wong, P. Juliana Perez-Chaparro, Seong-Ji Han, Y. Erin Chen, Kelin Li, Sepideh Farhat, Antonin Weckel, Siddharth R. Krishnamurthy, Ivan Vujkovic-Cvijin, Jonathan L. Linehan, Nicolas Bouladoux, E. Dean Merrill, Sobhan Roy, Daniel J. Cua, Erin J. Adams, Avinash Bhandoola, Tiffany C. Scharschmidt, Jeffrey Aubé, Michael A. Fischbach, Yasmine Belkaid

Issue&Volume: 2019/10/25

Abstract: How early-life colonization and subsequent exposure to the microbiota affect long-term tissue immunity remains poorly understood. Here, we show that the development of mucosal-associated invariant T (MAIT) cells relies on a specific temporal window, after which MAIT cell development is permanently impaired. This imprinting depends on early-life exposure to defined microbes that synthesize riboflavin-derived antigens. In adults, cutaneous MAIT cells are a dominant population of interleukin-17A (IL-17A)–producing lymphocytes, which display a distinct transcriptional signature and can subsequently respond to skin commensals in an IL-1–, IL-18–, and antigen-dependent manner. Consequently, local activation of cutaneous MAIT cells promotes wound healing. Together, our work uncovers a privileged interaction between defined members of the microbiota and MAIT cells, which sequentially controls both tissue-imprinting and subsequent responses to injury.

DOI: 10.1126/science.aax6624

Source: https://science.sciencemag.org/content/366/6464/eaax6624