A tuberculosis vaccine based on phosphoantigens and fusion proteins induces distinct gammadelta and alphabeta T cell responses in primates

Eur J Immunol. 2007 Feb;37(2):549-65. doi: 10.1002/eji.200636343.

Abstract

Phosphoantigens are mycobacterial non-peptide antigens that might enhance the immunogenicity of current subunit candidate vaccines for tuberculosis. However, their testing requires monkeys, the only animal models suitable for gammadelta T cell responses to mycobacteria. Thus here, the immunogenicity of 6-kDa early secretory antigenic target-mycolyl transferase complex antigen 85B (ESAT-6-Ag85B) (H-1 hybrid) fusion protein associated or not to a synthetic phosphoantigen was compared by a prime-boost regimen of two groups of eight cynomolgus. Although phosphoantigen activated immediately a strong release of systemic Th1 cytokines (IL-2, IL-6, IFN-gamma, TNF-alpha), it further anergized blood gammadelta T lymphocytes selectively. By contrast, the hybrid H-1 induced only memory alphabeta T cell responses, regardless of phosphoantigen. These latter essentially comprised cytotoxic T lymphocytes specific for Ag85B (on average + 430 cells/million PBMC) and few IFN-gamma-secreting cells (+ 40 cells/million PBMC, equally specific for ESAT-6 and for Ag85B). Hence, in macaques, a prime-boost with the H-1/phosphoantigen subunit combination induces two waves of immune responses, successively by gammadelta T and alphabeta T lymphocytes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antigens, Bacterial / immunology*
  • Bacterial Proteins / immunology*
  • Cytokines / immunology
  • Diphosphates / immunology*
  • Female
  • Flow Cytometry
  • Macaca fascicularis
  • Male
  • Receptors, Antigen, T-Cell, alpha-beta / immunology
  • Recombinant Fusion Proteins / immunology*
  • T-Lymphocyte Subsets / immunology*
  • T-Lymphocytes / immunology
  • Tuberculosis Vaccines / immunology*
  • Tuberculosis, Pulmonary / prevention & control*

Substances

  • Antigens, Bacterial
  • Bacterial Proteins
  • Cytokines
  • Diphosphates
  • ESAT-6 protein, Mycobacterium tuberculosis
  • Receptors, Antigen, T-Cell, alpha-beta
  • Recombinant Fusion Proteins
  • Tuberculosis Vaccines
  • bromohydrin pyrophosphate