结核分枝杆菌持续感染致T细胞功能障碍的研究

Objective To explore whether the long-term infection sustained activation of the immune response leads to T-cell dysfunction or not and study the mechanism which chronic severe TB patients lower immunity against Mycobacterium tuberculosis. Methods We collected 35 cases tuberculosis patients from Lanzhou Pulmonary Hospital，including 12 sputum smear-positive cavitary TB patients. Analyze the level of T lymphocyte secreting IFN-γ and IL-2. Analyze the ability of T cell proliferation by cell proliferation assay. Detect the expression of CD4+, CD8+ T cell surface immunosuppression related molecules Tim-3 by flow cytometry. Results For sputum smear-positive cavitary TB patients, the abilities of T cells secreting IFN-γ and IL-2 were significantly reduced, the proliferation of T cells was significantly weakened, the expression of immunosuppression-related molecules Tim-3 was significantly increased comparing with the healthy donors. For sputum smear-positive cavitary TB patients, the abilities of T cells secreting IFN-γ were significantly reduced comparing with the sputum smear-positive non- cavitary TB patients. Conclusion With persistent Mycobacterium tuberculosis infection, the T lymphocytes function in patients was waning. What's more, the exhaustion of T lymphocyte function happened finally.