Open AccessGamma delta T cell responses associated with the development of tuberculosis in health care workers
Author(s) -
Ordway Diane J.,
Pinto Luisa,
Costa Leonor,
Martins Marta,
Leandro Clara,
Viveiros Miguel,
Amaral Leonard,
Arroz Maria J.,
Ventura Fernando A.,
Dockrell Hazel M.
Publication year - 2005
Publication title -
fems immunology & medical microbiology
Language(s) - English
Resource type - Journals
eISSN - 1574-695X
pISSN - 0928-8244
DOI - 10.1016/j.femsim.2004.09.005
Subject(s) - medicine , tuberculosis , peripheral blood mononuclear cell , cd8 , immunology , cytotoxic t cell , mycobacterium tuberculosis , t cell receptor , t cell , cd3 , il 2 receptor , cytotoxicity , immune system , biology , pathology , in vitro , biochemistry
This study evaluated T cell immune responses to purified protein derivative (PPD) and Mycobacterium tuberculosis (Mtb) in health care workers who remained free of active tuberculosis (HCWs w/o TB), health care workers who went on to develop active TB (HCWs w/TB), non‐health care workers who were TB free (Non‐HCWs) and tuberculosis patients presenting with minimal (Min TB) or advanced (Adv TB) disease. Peripheral blood mononuclear cells (PBMC) were stimulated with Mtb and PPD and the expression of T cell activation markers CD25+ and HLA‐DR+, intracellular IL‐4 and IFN‐γ production and cytotoxic responses were evaluated. PBMC from HCWs who developed TB showed decreased percentages of cells expressing CD8+CD25+ in comparison to HCWs who remained healthy. HCWs who developed TB showed increased γδ TCR+ cell cytotoxicity and decreased CD3+γδ TCR+ cell cytotoxicity in comparison to HCWs who remained healthy. PBMC from TB patients with advanced disease showed decreased percentages of CD25+CD4+ and CD25+CD8+ T cells that were associated with increased IL‐4 production in CD8+ and γδ TCR+ phenotypes, in comparison with TB patients presenting minimal disease. TB patients with advanced disease showed increased γδ TCR+ cytotoxicity and reduced CD3+γδ TCR+ cell cytotoxicity. Our results suggest that HCWs who developed TB show an early compensatory mechanism involving an increase in lytic responses of γδ TCR+ cells which did not prevent TB.