8vz9

Structural highlights

Function

HMR1_MOUSE Antigen-presenting molecule specialized in displaying microbial pyrimidine-based metabolites to alpha-beta T cell receptors (TCR) on innate-type mucosal-associated invariant T (MAIT) cells. In complex with B2M preferentially presents riboflavin-derived metabolites to semi-invariant TRAV1 TCRs on MAIT cells, guiding immune surveillance of the microbial metabolome at mucosal epithelial barriers (PubMed:20581831, PubMed:15802267). Signature pyrimidine-based microbial antigens are generated via non-enzymatic condensation of metabolite intermediates of the riboflavin pathway with by-products arising from other metabolic pathways such as glycolysis. Typical potent antigenic metabolites are 5-(2-oxoethylideneamino)-6-D-ribitylaminouracil (5-OE-RU) and 5-(2-oxopropylideneamino)-6-D-ribitylaminouracil (5-OP-RU), products of condensation of 5-amino-6-D-ribityaminouracil (5-A-RU) with glyoxal or methylglyoxal by-products, respectively. May present microbial antigens to various TRAV1-negative MAIT cell subsets, providing for unique recognition of diverse microbes, including pathogens that do not synthesize riboflavin. Upon antigen recognition, elicits rapid innate-type MAIT cell activation to eliminate pathogenic microbes by directly killing infected cells (By similarity). During T cell development, drives thymic selection and post-thymic terminal differentiation of MAIT cells in a process dependent on commensal microflora (PubMed:12634786, PubMed:31113973). Acts as an immune sensor of cancer cell metabolome. May present a tumor-specific or -associated metabolite essential for cancer cell survival to a pan-cancer TCR on a non-MAIT CD8-positive T cell clone, triggering T cell-mediated killing of a wide range of cancer cell types (By similarity).[UniProtKB:Q95460]^{[1] [2] [3] [4]}

References

1. ↑ Treiner E, Duban L, Bahram S, Radosavljevic M, Wanner V, Tilloy F, Affaticati P, Gilfillan S, Lantz O. Selection of evolutionarily conserved mucosal-associated invariant T cells by MR1. Nature. 2003 Mar 13;422(6928):164-9. PMID:12634786 doi:10.1038/nature01433
2. ↑ Huang S, Gilfillan S, Cella M, Miley MJ, Lantz O, Lybarger L, Fremont DH, Hansen TH. Evidence for MR1 antigen presentation to mucosal-associated invariant T cells. J Biol Chem. 2005 Jun 3;280(22):21183-93. Epub 2005 Mar 31. PMID:15802267 doi:10.1074/jbc.M501087200
3. ↑ Le Bourhis L, Martin E, Péguillet I, Guihot A, Froux N, Coré M, Lévy E, Dusseaux M, Meyssonnier V, Premel V, Ngo C, Riteau B, Duban L, Robert D, Huang S, Rottman M, Soudais C, Lantz O. Antimicrobial activity of mucosal-associated invariant T cells. Nat Immunol. 2010 Aug;11(8):701-8. PMID:20581831 doi:10.1038/ni.1890
4. ↑ Koay HF, Gherardin NA, Xu C, Seneviratna R, Zhao Z, Chen Z, Fairlie DP, McCluskey J, Pellicci DG, Uldrich AP, Godfrey DI. Diverse MR1-restricted T cells in mice and humans. Nat Commun. 2019 May 21;10(1):2243. PMID:31113973 doi:10.1038/s41467-019-10198-w