Abstract
CD8 T cells contribute to protective immunity against Mycobacterium tuberculosis. In humans, M. tuberculosis reactive CD8 T cells typically recognize peptides associated to classical MHC class Ia molecules, but little information is available on CD8 T cells recognizing M. tuberculosis Ags presented by nonclassical MHC class Ib molecules. We show here that CD8 T cells from tuberculosis (TB) patients recognize HLA-E-binding M. tuberculosis peptides in a CD3/TCR αβ mediated and CD8-dependent manner, and represent an additional type of effector cells playing a role in immune response to M. tuberculosis during active infection. HLA-E-restricted recognition of M. tuberculosis peptides is detectable by a significant enhanced ex vivo frequency of tetramer-specific circulating CD8 T cells during active TB. These CD8 T cells produce type 2 cytokines upon antigenic in vitro stimulation, help B cells for Ab production, and mediate limited TRAIL-dependent cytolytic and microbicidal activity toward M. tuberculosis infected target cells. Our results, together with the finding that HLA-E/M. tuberculosis peptide specific CD8 T cells are detected in TB patients with or without HIV coinfection, suggest that this is a new human T-cell population that participates in immune response in TB.
Original language | English |
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Pages (from-to) | 1069-1081 |
Number of pages | 13 |
Journal | European Journal of Immunology |
Volume | 45 |
Issue number | 4 |
DOIs | |
Publication status | Published - Apr 1 2015 |
Keywords
- CD8 T lymphocytes
- HLA-E
- Mycobacterium tuberculosis
- TB
- Tetramers
- Type 2 cytokines
ASJC Scopus subject areas
- Immunology
- Immunology and Allergy
- Medicine(all)