Stabilizing short-lived Schiff base derivatives of 5-aminouracils that activate mucosal-associated invariant T cells

Nat Commun. 2017 Mar 8:8:14599. doi: 10.1038/ncomms14599.

Abstract

Mucosal-associated invariant T (MAIT) cells are activated by unstable antigens formed by reactions of 5-amino-6-D-ribitylaminouracil (a vitamin B2 biosynthetic intermediate) with glycolysis metabolites such as methylglyoxal. Here we show superior preparations of antigens in dimethylsulfoxide, avoiding their rapid decomposition in water (t1/2 1.5 h, 37 °C). Antigen solution structures, MAIT cell activation potencies (EC50 3-500 pM), and chemical stabilities are described. Computer analyses of antigen structures reveal stereochemical and energetic influences on MAIT cell activation, enabling design of a water stable synthetic antigen (EC50 2 nM). Like native antigens, this antigen preparation induces MR1 refolding and upregulates surface expression of human MR1, forms MR1 tetramers that detect MAIT cells in human PBMCs, and stimulates cytokine expression (IFNγ, TNF) by human MAIT cells. These antigens also induce MAIT cell accumulation in mouse lungs after administration with a co-stimulant. These chemical and immunological findings provide new insights into antigen properties and MAIT cell activation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antigens / chemistry
  • Antigens / immunology
  • Glycolysis
  • Histocompatibility Antigens Class I / metabolism
  • Humans
  • Hydrogen Bonding
  • Interferon-gamma / genetics
  • Jurkat Cells
  • Lymphocyte Activation / drug effects*
  • Male
  • Mice, Inbred C57BL
  • Minor Histocompatibility Antigens / metabolism
  • Mucosal-Associated Invariant T Cells / drug effects*
  • Mucosal-Associated Invariant T Cells / immunology
  • Mucous Membrane / cytology*
  • Protein Refolding
  • Schiff Bases / chemistry*
  • Tumor Necrosis Factor-alpha / genetics
  • Uracil / analogs & derivatives*
  • Uracil / chemistry
  • Uracil / pharmacology

Substances

  • Antigens
  • Histocompatibility Antigens Class I
  • MR1 protein, human
  • Minor Histocompatibility Antigens
  • Schiff Bases
  • Tumor Necrosis Factor-alpha
  • Uracil
  • Interferon-gamma
  • 5-aminouracil