[The expression of T-bet is negatively correlated with the expressions of IFN-γ and TNF-α in CD4+ T cells of patients with active pulmonary tuberculosis].

Objective To investigate the relationship between T box expressed in T cells (T-bet) and the production of interferon γ (IFN-γ), tumor necrosis factor α (TNF-α) and interleukin 2 (IL-2) in CD4+T cells of patients with active pulmonary tuberculosis. Methods Peripheral blood mononuclear cells (PBMCs) were isolated from peripheral blood by density gradient centrifugation. Individuals with latent Mycobacterium tuberculosis (MTB) infection were screened by enzyme-linked immunospot assay (ELISPOT). The expressions of T-bet, IFN-γ, TNF-α and IL-2 in CD4+T cells were detected by flow cytometry. Results The expression of IFN-γ significantly increased in PBMCs from the individuals with latent tuberculosis infection when stimulated with MTB H37Rv strain lysates. T-bet expression in CD4+IFN-γ+ cells from the patients with active pulmonary tuberculosis was significantly higher than that from the individuals with latent tuberculosis infection when stimulated with MTB H37Rv strain lysates. The expressions of IFN-γ and TNF-α in T-bet- MTB antigen-specific CD4+T cells were obviously higher than those in T-bet+ cells; however, the expression of IL-2 showed no significant difference between T-bet- cells and T-bet+ cells. Conclusion The expression of T-bet in MTB antigen-specific CD4+T cells from patients with active pulmonary tuberculosis is negatively correlated with IFN-γ and TNF-α.