Human mucosal-associated invariant T cells respond to Mucorales species in a MR1-dependent manner

Med Mycol. 2021 May 4;59(5):505-509. doi: 10.1093/mmy/myaa103.

Abstract

Activation of mucosal-associated invariant T cells (MAIT cells) by certain bacteria, viruses, and yeast is well studied, but the activation potential of filamentous moulds from the order Mucorales is not known. Here, we show a rapid response of human MAIT cells against the Mucorales species Mucor circinelloides, Rhizopus arrhizus, and Rhizopus microsporus. This activation included upregulation of CD69 and degranulation marked by increased CD107a expression, while intracellular perforin and granzyme A expression were reduced. Furthermore, blocking of the antigen-presenting molecule major histocompatibility complex class I-related abrogated MAIT cell activation demonstrating a T cell receptor-dependent stimulation by Mucorales.

Keywords: MAIT cell; MR1; moulds; mucorales; riboflavin.

MeSH terms

  • Antigens, CD / metabolism
  • Antigens, Differentiation, T-Lymphocyte / metabolism
  • Granzymes / metabolism
  • Histocompatibility Antigens Class I / metabolism*
  • Host Microbial Interactions
  • Humans
  • Lectins, C-Type / metabolism
  • Lymphocyte Activation
  • Lysosomal-Associated Membrane Protein 1 / metabolism
  • Minor Histocompatibility Antigens / metabolism*
  • Mucor / immunology
  • Mucorales / immunology*
  • Mucormycosis / immunology*
  • Mucormycosis / metabolism*
  • Mucormycosis / microbiology
  • Mucosal-Associated Invariant T Cells / immunology*
  • Mucosal-Associated Invariant T Cells / metabolism*
  • Perforin / metabolism
  • Rhizopus / immunology
  • Rhizopus oryzae / immunology
  • Riboflavin / metabolism*
  • Up-Regulation

Substances

  • Antigens, CD
  • Antigens, Differentiation, T-Lymphocyte
  • CD69 antigen
  • Histocompatibility Antigens Class I
  • Lectins, C-Type
  • Lysosomal-Associated Membrane Protein 1
  • MR1 protein, human
  • Minor Histocompatibility Antigens
  • Perforin
  • Granzymes
  • Riboflavin

Supplementary concepts

  • Mucor circinelloides
  • Rhizopus microsporus