Factors affecting the escape of Francisella tularensis from the phagolysosome
Factors affecting the escape of Francisella tularensis from the phagolysosome
复制标题
DOI：
10.1099/jmm.0.45685-0
复制
发表时间：
2004-10-01
影响因子：
3
通讯作者：
Sjöstedt, A
中科院分区：
文献类型：
--
作者：
Lindgren, H;Golovliov, I;Sjöstedt, A
高毒性细菌土拉热弗朗西丝菌很好地适应了细胞内的栖息地，但其细胞内生存背后的机制一直难以捉摸。最近，研究表明该细菌能够从人和小鼠单核细胞的吞噬体中逃逸。在这里，它表明，这种逃逸是受γ干扰素（IFN-γ）治疗的小鼠腹膜渗出液细胞，因为在处理的细胞逃逸的比例是显着低于（80%）比未处理的细胞（97%），通过透射电子显微镜测定。相比之下，< 1%的突变细菌缺乏23 kDa的表达。IgIC蛋白能够从吞噬体中逃逸。用补充有IG/C基因的Deltaig/C菌株感染导致60%的细菌从吞噬体逃逸。IFN-γ处理对细胞内野生型细菌具有静态作用，而该处理对Deltaig/C菌株具有杀菌作用。结果表明，感染细胞的活化状态影响F.来自吞噬体的土拉菌。对这种逃避的更深远的影响与F.土拉热。它的缺失使突变细菌不能从吞噬体中逃脱，也不能在细胞内繁殖。
The highly virulent bacterium Francisella tularensis is well adapted to the intracellular habitat but the mechanisms behind its intracellular survival have been elusive. Recently, it was shown that the bacterium is capable of escaping from the phagosome of human and mouse monocytic cells. Here it is shown that this escape is affected by gamma interferon (IFN-gamma) treatment of mouse peritoneal exudate cells since in treated cells the proportion that escaped was significantly lower (80%) than in untreated cells (97%) as determined by transmission electron microscopy. By contrast, < 1% of mutant bacteria lacking expression of a 23 kDa. protein denoted IgIC were able to escape from the phagosome. Infection with the Deltaig/C strain complemented with the ig/C gene resulted in 60% of the bacteria escaping from the phagosome. Whereas IFN-gamma treatment conferred a static effect on intracellular wild-type bacteria, the treatment had a bactericidal effect on the Deltaig/C strain. The results show that the activation status of infected cells affects the escape of F. tularensis from the phagosome. An even more profound effect on this escape is related to expression of IgIC by F. tularensis. Its absence rendered the mutant bacteria incapable of escaping from the phagosome and of multiplying intracellularly.