MAIT cells in immune-mediated tissue injury and repair.

Mucosal-associated invariant T (MAIT) cells are T cells that express a semi-invariant αβ T cell receptor (TCR), recognising non-peptide antigens, such as microbial-derived Vitamin B2 metabolites, presented by the non-polymorphic MHC class I related-1 molecule (MR1). Like NKT cells and γδT cells, MAIT cells belong to the group of innate-like T cells that combine properties of the innate and adaptive immune systems. They account for up to 10% of the blood T-cell population in humans and are particularly abundant at mucosal sites. Beyond the emerging role of MAIT cells in antibacterial and antiviral defences, increasing evidence suggests additional functions in non-infectious settings, including immune-mediated inflammatory diseases and tissue repair. Here, we discuss recent advances in the understanding of MAIT cell functions in sterile tissue inflammation, with a particular focus on autoimmunity, chronic inflammatory diseases, and tissue repair. This article is protected by copyright. All rights reserved.