Antimicrobial activity of MHC class I-restricted CD8+ T cells in human tuberculosis

Proc Natl Acad Sci U S A. 2000 Oct 24;97(22):12210-5. doi: 10.1073/pnas.210391497.

Abstract

Studies of mouse models of tuberculosis (TB) infection have indicated a central role for MHC class I-restricted CD8+ T cells in protective immunity. To define antigens and epitopes of Mycobacterium tuberculosis (MTB) proteins that are presented by infected cells to CD8+ T cells, we screened 40 MTB proteins for HLA class I A*0201-binding motifs. Peptides that bound with high affinity to purified HLA molecules were subsequently analyzed for recognition by CD8+ cytotoxic T lymphocytes. We identified three epitopes recognized by CD8+ T cells from patients recovering from TB infection. Those three epitopes were derived from three different antigens: thymidylate synthase (ThyA(30-38)), RNA polymerase beta-subunit (RpoB(127-135)), and a putative phosphate transport system permease protein A-1 (PstA1(75-83)). In addition, CD8+ T cell lines specific for three peptides (ThyA(30-38), PstA1(75-83), and 85B(15-23)) were generated from peripheral blood mononuclear cells of normal HLA-A*0201 donors. These CD8+ T cell lines specifically recognized MTB-infected macrophages, as demonstrated by production of IFN-gamma and lysis of the infected target cells. Finally, CD8+ cytotoxic T lymphocytes reduced the viability of the intracellular MTB, providing evidence that CD8+ T cell recognition of MHC class I-restricted epitopes of these MTB antigens can contribute to effective immunity against the pathogen.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • CD8-Positive T-Lymphocytes / immunology*
  • Cytotoxicity, Immunologic
  • Histocompatibility Antigens Class I / immunology*
  • Humans
  • Interferon-gamma / immunology
  • Interferon-gamma / metabolism
  • Macrophages / immunology
  • Macrophages / metabolism
  • Mice
  • Mycobacterium tuberculosis / immunology*
  • Tuberculosis / immunology*

Substances

  • Histocompatibility Antigens Class I
  • Interferon-gamma