Mucosal-associated invariant T cell receptor recognition of small molecules presented by MR1

Wael Awad, Jérôme Le Nours, Lars Kjer-Nielsen, James Mccluskey, Jamie Rossjohn

Research output: Contribution to journalReview ArticleOtherpeer-review

21 Citations (Scopus)


The major histocompatibility complex (MHC) class-I related molecule MR1 is a monomorphic and evolutionary conserved antigen (Ag)-presenting molecule that shares the overall architecture of MHC-I and CD1 proteins. However, in contrast to MHC-I and the CD1 family that present peptides and lipids, respectively, MR1 specifically presents small organic molecules. During microbial infection of mammalian cells, MR1 captures and presents vitamin B precursors, derived from the microbial biosynthesis of riboflavin, on the surface of antigen-presenting cells. These MR1-Ag complexes are recognized by the mucosal-associated invariant T cell receptor (MAIT TCR), which subsequently leads to MAIT cell activation. Recently, MR1 was shown to trap chemical scaffolds including drug and drug-like molecules. Here, we review this metabolite Ag-presenting molecule and further define the key molecular interactions underlying the recognition and reactivity of MAIT TCRs to MR1 in an Ag-dependent manner.

Original languageEnglish
Pages (from-to)588-597
Number of pages10
JournalImmunology and Cell Biology
Issue number6
Publication statusPublished - Jul 2018


  • Antigen presentation
  • Metabolite antigens
  • MR1
  • Mucosal immunity

Cite this