Swimming Against the Current: MAIT Cell Function Is Preserved in the Peritoneum of Advanced Liver Disease Patients

Mucosal-associated invariant T (MAIT) cells are a population of unconventional T cells displaying features of both the adaptive and the innate arms of the immune system. They are characterized by the expression of an evolutionary highly conserved invariant alpha chain (Vα7.2-Jα33 in humans) in combination with a biased repertoire of beta chains and respond to bacterial and yeast riboflavin metabolite ligands presented by the major histocompatibility complex Ib-molecule MR1. MAIT cells are enriched in the human liver and also account for 1%–10% of the T cells found in peripheral blood.