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

Commensals rule the MAITrix Mucosal-associated invariant T (MAIT) cells play an important role in mucosal homeostasis. MAIT cells recognize microbial small molecules presented by the major histocompatibility complex class Ib molecule MR1. MAIT cells are absent in germ-free mice, and the mechanisms by which microbiota control MAIT cell development are unknown (see the Perspective by Oh and Unutmaz). Legoux et al. show that, in mice, development of MAIT cells within the thymus is governed by the bacterial product 5-(2-oxopropylideneamino)-6- d -ribitylaminouracil, which rapidly traffics from the mucosa to the thymus, where it is captured by MR1 and presented to developing MAIT cells. Constantinides et al. report…

• HH
  Howard Hughes Medical Institute
• CR
  Cancer Research Institute
• EM
  European Molecular Biology Organization
• DO
  Division of Intramural Research, National Institute of Allergy and Infectious Diseases

  Awards: ZIA-AI001115, ZIA-AI001132
• NI
  National Institutes of Health

  Awards: R01-DK110174, DP1-DK113598, U19-AI111143
• NI
  National Institute of General Medical Sciences