EBioMedicine (Feb 2022)

Effects of BCG vaccination on donor unrestricted T cells in two prospective cohort studies

  • Anele Gela,
  • Melissa Murphy,
  • Miguel Rodo,
  • Kate Hadley,
  • Willem A. Hanekom,
  • W.Henry Boom,
  • John L. Johnson,
  • Daniel F. Hoft,
  • Simone A. Joosten,
  • Tom H.M. Ottenhoff,
  • Sara Suliman,
  • D.Branch Moody,
  • David M. Lewinsohn,
  • Mark Hatherill,
  • Chetan Seshadri,
  • Elisa Nemes,
  • Thomas J. Scriba,
  • Libby Briel,
  • Hellen Veldtsman,
  • Nondumiso Khomba,
  • Bernadette Pienaar,
  • Hadn Africa,
  • Marcia Steyn

Journal volume & issue
Vol. 76
p. 103839

Abstract

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Summary: Background: Non-protein antigen classes can be presented to T cells by near-monomorphic antigen-presenting molecules such as CD1, MR1, and butyrophilin 3A1. Such T cells, referred to as donor unrestricted T (DURT) cells, typically express stereotypic T cell receptors. The near-unrestricted nature of DURT cell antigen recognition is of particular interest for vaccine development, and we sought to define the roles of DURT cells, including MR1-restricted MAIT cells, CD1b-restricted glucose monomycolate (GMM)-specific T cells, CD1d-restricted NKT cells, and γδ T cells, in vaccination against Mycobacterium tuberculosis. Methods: We compared and characterized DURT cells following primary bacille Calmette-Guerin (BCG) vaccination in a cohort of vaccinated and unvaccinated infants, as well as before and after BCG-revaccination in adults. Findings: BCG (re)vaccination did not modulate peripheral blood frequencies, T cell activation or memory profiles of MAIT cells, CD1b-restricted GMM-specific and germline-encoded mycolyl-reactive (GEM) cells or CD1d-restricted NKT cells. By contrast, primary BCG vaccination was associated with increased frequencies of γδ T cells as well as a novel subset of CD26+CD161+TRAV1-2− IFN-γ-expressing CD4+ T cells in infants. Interpretation: Our findings, that most DURT cell populations were not modulated by BCG, do not preclude a role of BCG in modulating other qualitative aspects of DURT cells. More studies are required to understand the full potential of DURT cells in new TB vaccine strategies. Funding: Aeras, the National Institutes of Health, and the Bill and Melinda Gates Foundation.

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