Tuberculosis remains a major health problem worldwide. The disease is caused by Mycobacterium tuberculosis whose preferred habitat is the host macrophage. The immune response against tuberculosis is mediated by different subsets of T cells including both conventional CD4 and CD8 T cells as well as unconventional CD1 restricted and gammadelta T cells. The CD1 restricted T cells are particularly ...

Interferon-γ (Interferon gamma, IFNG) is an important cytokine involved in providing resistance to mycobacterial diseases. Common variants of IFNG, such as IFNG +874 T/A(rs2430561), may be related to tuberculosis susceptibility, but this association has not been consistently observed. We performed an updated meta-analysis to evaluate the association between the IFNG +874 T/A (rs2430561) polymor...

The immune protection initiated by γδ T cells plays an important role in mycobacterial infection. The γδ T cells activated by Mycobacterium tuberculosis-derived nonpeptidic, phosphorylated biometabolites (phosphoantigens) provide only partial immune protection against mycobacterium, while evidence has suggested that protein antigen-activated γδ T cells elicit effective protective immune respons...

Although CD4 T cells are required for host resistance to Mycobacterium tuberculosis, they may also contribute to pathology. In this study, we examine the role of the inhibitory receptor PD-1 and its ligand PD-L1 during M. tuberculosis infection. After aerosol exposure, PD-1 knockout (KO) mice develop high numbers of M. tuberculosis-specific CD4 T cells but display markedly increased susceptibil...

Mycobacterium tuberculosis is the etiologic agent of human tuberculosis and is estimated to infect one-third of the world’s population. Control of M. tuberculosis requires T cells and macrophages. T-cell function is modulated by the cytokine environment, which in mycobacterial infection is a balance of proinflammatory (interleukin-1 [IL-1], IL-6, IL-8, IL-12, and tumor necrosis factor alpha) an...

BACKGROUND Tuberculosis (TB) is a disease caused by the chronic and continuous infection of the pathogen Mycobacterium tuberculosis (M. tuberculosis). M. tuberculosis is an intracellular bacterial pathogen and is eliminated mainly through CD4(+) effector Th cells. M. tuberculosis induces regulatory T lymphocytes (Tregs) that mediate immune suppression by cell-to-cell contact or by secreting cyt...

OBJECTIVE To study the association of anergic pulmonary tuberculosis with Vδ2(+) T cells and related cytokine levels. METHODS 82 pulmonary tuberculosis patients were divided into two groups according to their purified protein derivative tuberculin skin test (TST) results: 39 with TST-negative anergic pulmonary tuberculosis and 43 with TST-positive pulmonary tuberculosis, while 40 healthy volu...

Central nervous system tuberculosis remains a clinical diagnostic challenge. The ex vivo Mycobacterium tuberculosis-specific enzyme-linked immunospot assay (ELISPOT) is a novel assay for the rapid detection of M. tuberculosis-specific T-lymphocytes in the peripheral blood. However, when performed on peripheral blood, this assay cannot distinguish between active tuberculosis or latent tuberculos...

The 30-kDa protein (P32) is a mycobacterial secreted antigen which is homologous in Mycobacterium bovis and M. tuberculosis. In vitro, P32 induced T-cell proliferation. M. tuberculosis- or P32-stimulated T-cell lines lysed macrophages pulsed with P32 or M. tuberculosis, respectively. We conclude that P32 stimulates cytotoxic T cells specifically.

Mycobacterium tuberculosis infection induces complex CD4 T cell responses that include T helper type 1 (Th1) cells and regulatory T cells. Although Th1 cells control infection, they are unable to fully eliminate M. tuberculosis, suggesting that Th1-mediated immunity is restrained from its full sterilizing potential. Investigation into T cell-mediated defense is hindered by difficulties in expan...