Induction of antigen-specific CD4+ HLA-DR-restricted cytotoxic T lymphocytes as well as nonspecific nonrestricted killer cells by the recombinant mycobacterial 65-kDa heat-shock protein

Eur J Immunol. 1990 Feb;20(2):369-77. doi: 10.1002/eji.1830200221.

Abstract

Acquired cell-mediated immunity to intracellular parasites like mycobacteria is dependent on antigen-specific T lymphocytes. We have recently found that mycobacteria not only induce helper T cells but also cytotoxic CD4+ and/or CD8+ T cells as well as nonspecific killer cells that lyse human macrophages in vitro. In addition, we have described that the recombinant heat-shock protein (hsp) 65 of Mycobacterium bovis BCG/M, tuberculosis is an important target antigen for CD4+CD8- cytotoxic T cells. We have now further investigated the cytotoxic effector cells that are induced by the hsp65 of BCG. Purified protein derivative of tuberculin (PPD)- or hsp65-specific cytotoxic T cells specifically lysed PPD, hsp65 of BCG and hsp65 of M. leprae-pulsed macrophages in an HLA-DR-restricted manner. Nonpulsed macrophages were lysed to a much lower but still significant extent. hsp65-induced effector cells expressed CD3, CD5, CD4, CD8 and CD56 markers. Depletion experiments showed that the antigen-specific HLA-DR-restricted killer cell was of the CD5+CD4+CD8-CD56- phenotype. Experiments using N-terminal truncated hsp65 fusion (cro-lacZ) proteins suggested that the N-terminal 65 amino acid residues of the 540 amino acid molecule are critical for the expression of the cytotoxic target epitope(s) in two individuals tested. In addition to inducing antigen-specific cytotoxic effector cells, the hsp65 also triggered nonspecific nonrestricted effector cells with lytic activity against nonpulsed autologous or allogeneic macrophages as well as K-562 and Daudi tumor cells. hsp65-stimulated effector cells produced both interferon and tumor necrosis factor-alpha. An important finding was that hsp65-stimulated effector cells strongly inhibited colony-forming unit formation from live BCG-infected autologous macrophages.

Publication types

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

MeSH terms

  • Antigens, Bacterial / immunology*
  • Antigens, CD / analysis
  • Blood Bactericidal Activity
  • CD4-Positive T-Lymphocytes / immunology*
  • Cytotoxicity, Immunologic*
  • Epitopes
  • HLA-DR Antigens / immunology
  • Heat-Shock Proteins / immunology*
  • Humans
  • In Vitro Techniques
  • Interferons / biosynthesis
  • Killer Cells, Natural / immunology*
  • Macrophages / immunology
  • Mycobacterium / immunology*
  • Recombinant Proteins
  • T-Lymphocytes, Cytotoxic / immunology*
  • Tuberculin / immunology
  • Tumor Necrosis Factor-alpha / biosynthesis

Substances

  • Antigens, Bacterial
  • Antigens, CD
  • Epitopes
  • HLA-DR Antigens
  • Heat-Shock Proteins
  • Recombinant Proteins
  • Tuberculin
  • Tumor Necrosis Factor-alpha
  • Interferons