论文部分内容阅读
目的:通过体外构建军团菌感染的细胞模型,探索caspase3激活与军团菌逃逸巨噬细胞杀伤作用的相互关系。方法:军团菌感染巨噬细胞后,用激光共聚焦显微镜和荧光阅读机测定胞内caspase3的活性。并在caspase3抑制剂应用前后对军团菌在发生凋亡的巨噬细胞内的生长复制状况进行检测。结果:激光共聚焦显微术以及caspase3荧光底物的分析结果显示,嗜肺性军团菌毒力株感染巨噬细胞后能够大幅度激活caspase3,而去除毒力的突变菌株不具备这种能力。军团菌在感染巨噬细胞后不同的时间内,军团菌在胞内不断地复制繁殖,而毒力去除的突变株却没有复制能力。当胞内caspase3的活性被抑制后,军团菌毒力株的复制繁殖能力也有了显著性的抑制。结论:军团菌感染巨噬细胞后能够在极短的时间内激活caspase3,并通过诱导巨噬细胞的凋亡来逃逸巨噬细胞的杀菌作用和发挥致病效应。
OBJECTIVE: To explore the relationship between caspase3 activation and the cytotoxicity of Legionella escaped macrophages by constructing a cell model of Legionella infection in vitro. Methods: The intracellular caspase 3 activity was detected by laser confocal microscopy and fluorescence reader after the Legionella infection of macrophages. The growth and replication of Legionella in apoptotic macrophages were detected before and after the caspase3 inhibitor was applied. Results: Confocal laser scanning microscopy and caspase3 fluorescent substrate analysis showed that the virulence of Legionella pneumophila infected macrophages can significantly activate caspase3, and remove the virulence of mutant strains do not have this ability. Legionella infect the macrophages at different times, the Legionella bacteria continue to reproduce in the intracellular, while the virulence of the mutant strain has no ability to replicate. When the activity of intracellular caspase3 was inhibited, Legionella virulence strains also had a significant reproductive capacity. CONCLUSION: Legionella pneumophila infection of macrophages activates caspase3 in a very short time and escapes the bactericidal effect and pathogenic effect of macrophages by inducing macrophage apoptosis.