中文摘要：

目的探讨不同毒力结核分枝杆菌感染对巨噬细胞凋亡的调控作用及其机制。方法用结核分枝杆菌国际标准强毒株H37Rv株和卡介苗（BCG）分别感染巨噬细胞RAW264．7株，同时设空白对照组。分别在感染后1、6、12及24h，应用Westernblot和RT-PCR检测Caspase-3和Bcl-2蛋白及其基因表达水平。结果巨噬细胞感染H37Rv和BCG后Caspase-3蛋白表达均增高，与对照组比较差异有统计学意义（P〈0．05）；BCG感染组在感染后1、12和24hCaspase-3蛋白表达量与H37Rv感染组比较差异有统计学意义（P〈0．05）。H37Rv和BCG感染组Caspase-3基因相对表达量增高，与对照组比较差异有统计学意义（P〈0．05）；BCG感染组在感染1h和24hCaspase-3基因表达水平与H37Rv组比较差异有统计学意义（P〈0．05）。H37Rv和BCG感染组Bcl-2蛋白表达量降低，与对照组比较差异有统计学意义（P〈0．05）；H37Rv感染组在感染后1、6和24hBcl-2蛋白表达量与BCG感染组比较差异有统计学意义（P〈0．05）。H37Rv和BCG感染组Bcl-2基因相对表达量降低，与对照组比较差异具有统计学意义（P〈0．05）；H37Rv株感染组感染后1、12和24hBcl-2基因表达量与BCG感染组比较差异有统计学意义（P〈0．05）。结论不同毒力结核分枝杆菌感染巨噬细胞Caspase-3及Bcl-2的表达存在差异。

英文摘要：

Objective To explore the regulation and mechanism of apoptosis of macrophages infected with Mycobacteri- um tuberculosis. Methods RAW264.7 macrophages were infected with M. tuberculosis H37Rv and BCG （international- ly used as standards） at the same time as a blank control group. One h, 6 h, 12 h, and 24 h after infection, the levels of caspase-3 and Bcl-2 proteins were detected with Western blotting, and the levels of gene expression were determined with RT-PCR. Results After infection with M. tuberculosis and BCG, the expression of the Caspase-3 protein in macropha- ges increased; this level of expression differed significantly （P〈0.05） from that in the control group. One h, 6 h, 12 h, and 24 h after infection, the level of expression of the Caspase-3 protein in cells infected with BCG differed significantly （P〈0.05） from that in cells infected with M. tuberculosis. The level in cells infected with H37Rv and BCG increased in comparison to the control group, and the difference was statistically significant （P〈0.05）. One h and 24 h after infec- tion, the level of expression of the Caspase-3 gene in cells infected with BCG differed significantly （P〈0.05） from that in cells infected with H37Rv. The level of expression of Bcl-2 protein in cells infected with M. tuberculosis and cells infected with BCG decreased significantly （P〈0.05） from that in the control group. One h, 6 h and 24 h after infection, the ex- pression of Bcl-2 protein in cells infected with H37Rv differed significantly （P〈0.05） from that in cells infected with BCG. One h, 12 h and 24 h after infection, the level of Bcl-2 expression in cells infected with H37Rv differed significantly （P〈0.05） from that in cells infected with BCG. Conclusion After infection with M. tuberculosis with different levels of virulence, the level of expression of Caspase-3 and Bcl-2 differed in macrophages.