Mucosal-associated invariant T cells: unconventional development and function

Trends Immunol. 2011 May;32(5):212-8. doi: 10.1016/ Epub 2011 Apr 2.


Mucosal-associated invariant T (MAIT) cells are a population of T cells that display a semi-invariant T cell receptor (TCR) and are restricted by the evolutionarily conserved major histocompatibility complex related molecule, MR1. Here, we review recent knowledge of this T cell population. MAIT cells are abundant in human blood, gut and liver, and display an effector phenotype. They follow an atypical pathway of development and preferentially locate to peripheral tissues. Human and mouse MAIT cells react to bacterially infected cells in an MR1-dependent manner. They migrate to the infection site and can be protective in experimental infection models. MAIT cells secrete interferon-γ, and interleukin-17 under certain conditions. The species conservation, as well as the wide microbial reactivity, infer an important role for this cell population in immunity.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Animals
  • Bacterial Infections / immunology*
  • Histocompatibility Antigens Class I / genetics
  • Histocompatibility Antigens Class I / metabolism*
  • Humans
  • Interferon-gamma / metabolism
  • Interleukin-17 / metabolism
  • Lymphocyte Activation
  • Mice
  • Minor Histocompatibility Antigens
  • Mucous Membrane / immunology*
  • Receptors, Antigen, T-Cell / metabolism
  • T-Lymphocyte Subsets / cytology*
  • T-Lymphocyte Subsets / immunology*
  • T-Lymphocyte Subsets / metabolism


  • Histocompatibility Antigens Class I
  • Interleukin-17
  • MR1 protein, human
  • Minor Histocompatibility Antigens
  • Receptors, Antigen, T-Cell
  • Interferon-gamma