Peripheral blood T cell TNF-α and IFN-γ production stimulated by low molecular peptide of Mycobacterium tuberculosis heat-resistant antigen for differential diagnosis between pulmonary tuberculosis and latent tuberculosis infection
TANG Jie
CHEN Ce
ZHA Chen
CHANG Jianrong
FANG Qiang
WANG Zhaohua
LI Baiqing
Abstract：Objective To investigate the effects of low molecular peptide of Mycobacterium tuberculosis heat-resistant antigen (Mtb-HAg-10k) on the production of tumor necrosis factor-α(TNF-α) and interferon-γ(IFN-γ) in peripheral blood T cells and test the feasibility of differential diagnosis between pulmonary tuberculosis (PTB) and latent tuberculosis infection (LTBI) by assessing the number of Mtb-HAg-10k-stimulated IFN-γ-producing T cells. Methods Peripheral blood mononuclear cells (PBMCs) were separated from the peripheral blood of 10 healthy adults, 6 individuals with LTBI and 13 patients with PTB. The PBMCs were cultured in the presence of Mtb-HAg-10k obtained by ultrafiltration centrifugation, with Mtb-HAg and phytohaemagglutinin (PHA) as the controls. The proportions of TNF-α-and IFN-γ-producing cells in the T cell subsets were detected by flow cytometry (FCM), and the number of IFN-γ-producing cells from patients with PTB and LTBI was detected with ELISPOT. Results Flow cytometry showed that Mtb-HAg-10k exposure resulted in a significantly higher proportion of TNF-α-producingγδT cells than that of IFN-γ-producingγδT cells in the PBMCs (P<0.01). Compared with the PBMCs exposed to PHA, the PBMCs exposed to Mtb-HAg-10k exhibited a significantly greater proportion of γδT cells that produced both TNF-α and IFN-γ (P<0.01) but a significantly lower proportion of αβT cells producing both TNF-α and IFN-γ (P<0.01). Mtb-HAg-10k exposure of the PBMCs caused a significant reduction in the number of IFN-γ-producing cells as compared with Mtb-HAg and PHA treatments (P<0.01), and this reduction was more obvious in PBMCs from patients with PTB than in those from individuals with LTBI (P<0.01). Conclusion Mtb-HAg-10k can markedly induce γδT cells in the PBMCs to produce TNF-α and IFN-γ, and detection of the number of IFN-γ-producing cells in the PBMCs following Mtb-HAg-10k stimulation helps in the differential diagnosis between pulmonary tuberculosis and latent tuberculosis infection.
Keywords：Mycobacterium tuberculosis heat resistant antigenγδT cellstumor necrosis factor-αinterferon-γpulmonary tuberculosislatent tuberculosis infection
Publication Date：2017-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：6( 1442-1447 )