结核分支杆菌诱导宿主细胞肌动蛋白重排和表达改变

目的：研究结核分支杆菌感染对宿主细胞肌动蛋白的影响。方法：应用共聚焦显微镜及Western blot技术观察被结核分支杆菌H37Ra、H37Rv感染的巨噬细胞在感染后6h、12h和24h纤丝状肌动蛋白（F－肌动蛋白）的形态分布及肌动蛋白表达变化。同时用未感染及H37Rv死菌处理的巨噬细胞作对照。结果：结核分支杆菌H37Ra、H37Rv感染巨噬细胞后诱导宿主细胞F－肌动蛋白聚集并抑制肌动蛋白的表达，有毒株H37Rv较无毒株H37Ra能更早地产生这种效应，而用H37Rv死菌处理的巨噬细胞肌动蛋白不受影响。结论：结核分支杆菌在感染宿主细胞的过程中，可能通过分泌某些蛋白或因子影响细胞的肌动蛋白，达到逃避宿主细胞杀伤的目的。

Rearrangement and altered expression of actin in macrop hages induced by Mycobacterium tuberculosis

Objective To investigate the effect of M tuberculosis infection on actin in host cells Methods The form and distribution of fibrous actin and changes of actin expression were observed by confocal microscopy and Western blot analysis in macrophages infected with either M tuberculosis H 37 R a or H 37 R v at 6 h, 12 h and 24 h after infection Non infected macrophages or macrophages treated with dead M tuberculosis H 37 R v served as controls Results F actin aggregated and the actin expression was suppressed in macrophages infected with H 37 R a or H 37 R v,and the effect appeared earlier in cells infected by the virulent H 37 R v strain than in cells infected by the avirulent H 37 R a strain In macrophages treated with the dead H 37 R v,actin was not affected Conclusion The results suggest that in the process of infection, M tuberculosis evades the bactericidal mechanisms possibly by secretion of certain proteins or factors which affect the host cell actin.