Molecular Insights Into MR1-Mediated T Cell Immunity: Lessons Learned and Unanswered Questions

Abstract

The major histocompatibility complex class-I related protein, MR1, is an evolutionarily conserved antigen presenting molecule that binds and displays organic metabolites to T cells, including mucosal associated invariant T (MAIT) cells and diverse MR1-restricted T cells (MR1T). Structural studies have elucidated how MR1 can accommodate a range of chemical scaffolds that arise from foreign, synthetic, and self-metabolites, although the full spectrum of metabolites that MR1 presents remains unclear. Presently, MAIT and MR1T cell recognition of MR1-antigen complexes represents a new immune recognition paradigm and is emerging as a critical player in protective immunity, aberrant immunity, tumor..