中文摘要：

目的探讨结核分枝杆菌MPT64抗原对RAW264.7巨噬细胞的影响及相关机制。方法将MPT64基因在大肠杆菌中表达、纯化,获得的纯化蛋白用于后续实验。将用佛波醇酯（PMA）分化的RAW264.7巨噬细胞分为对照组、卡介菌纯蛋白衍生物（BCGPPD）诱导组、BCG-PPD＋MPT64共同作用组,分别给予相应的处理。孵育16 h后,采用流式细胞术检测细胞凋亡情况,用ELISA试剂盒检测培养细胞上清的细胞因子TNF-α及IL-10水平。结果 BCG-PPD可以诱导RAW264.7巨噬细胞凋亡,BCG-PPD＋MPT64组的细胞凋亡水平低于BCG-PPD组（P0.05）。细胞因子上清检测结果表明,与对照组相比,BCG-PPD作用组的TNF-α水平升高（P0.01）,而IL-10水平无明显变化;与BCG-PPD组相比,BCG-PPD＋MPT64共同孵育组的IL-10水平升高（P0.01）,而TNF-α水平无明显变化。结论 MPT64抗原可能是一种毒力因子,能够抑制BCG-PPD诱导的巨噬细胞凋亡,该作用可能是通过提高IL-10水平来实现的。

英文摘要：

Objective To explore the effect of MPT64 antigen from Mycobacterium tuberculosis on RAW264. 7 macrophages and the related mechanism. Methods MPT64 was purified after expression in E. coli and verified by Western blotting analysis. The RAW264.7 differentiation was induced by phorbol myristate acetate （PMA） and the resultant cells were divided into three groups according to different treatments： negative control, purified protein derivative of BCG（BCG-PPD） and BCG-PPD＋MPT64 treatment groups. After 16 h incubation, flow cytometry was used to examine apoptosis of macrophages, and the levels of TNF-α and IL-10 in the supernatants were determined by ELISA. Results BCG-PPD treatment induced apoptosis of RAW264. 7 macrophages, and compared with BCG-PPD group, the apoptotic level of macrophages was significantly lower in BCG-PPD＋MPT64 group （P〈0.05）. We also found that the supernatant TNF-α level in the BCG-PPD group was significantly higher than that in negative group （P〈0.01） and the IL-10 levels were not significantly defferent between the two groups. Compared with BCG-PPD group, the IL-10 level was significantly increased in BCG-PPD＋ MPT64 group （P〈0.01） and the TNF-α levels were not significantly different between the two groups. Conclusion MPT64 may act as a virulence factor and can inhibit the apoptosis of macrophages induced by BCG-PPD, which is probably through increasing IL-10 level.