Ligand-dependent modulation of MR1-restricted antigen presentation

Mucosal-associated invariant T (MAIT) cells are innate T cells recognising intermediates of the vitamin B2 biosynthetic pathway presented by the monomorphic MR1 molecule. We have demonstrated that in addition to their cytolytic activity important in antimicrobial defence, MAIT cells have also immune-modulatory functions, enhancing DC maturation, in vitro and in vivo. Furthermore, through an in silico and in vitro screening of commercial libraries, we have identified novel compounds capable of activating MAIT cells and the first compounds that inhibits of MAIT cell activation through downregulation of MR1 expression. Identification of novel agonists and antagonists of MAIT cell function paves the way for potentially harnessing MAIT cell function in vivo .