Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, United States.
Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, United States.
Elife. 2020 Aug 18;9:e58057. doi: 10.7554/eLife.58057.
Pathogens find diverse niches for survival including inside a host cell where replication occurs in a relatively protective environment. is a facultative intracellular pathogen that uses its type 3 secretion system 2 (T3SS2) to invade and replicate inside host cells. Analysis of the T3SS2 pathogenicity island encoding the T3SS2 appeared to lack a mechanism for egress of this bacterium from the invaded host cell. Using a combination of molecular tools, we found that VPA0226, a constitutively secreted lipase, is required for escape of from the host cells. This lipase must be delivered into the host cytoplasm where it preferentially uses fatty acids associated with innate immune response to esterify cholesterol, weakening the plasma membrane and allowing egress of the bacteria. This study reveals the resourcefulness of microbes and the interplay between virulence systems and host cell resources to evolve an ingenious scheme for survival and escape.
病原体在宿主细胞内找到了多种生存的小生境,包括在相对受保护的环境中进行复制的地方。是一种兼性细胞内病原体,它利用其 III 型分泌系统 2(T3SS2)入侵并在宿主细胞内复制。对编码 T3SS2 的 T3SS2 致病性岛的分析似乎缺乏一种使这种细菌从被入侵的宿主细胞中逸出的机制。我们使用一系列分子工具,发现 VPA0226,一种组成型分泌的脂肪酶,是从宿主细胞中逸出所必需的。这种脂肪酶必须被递送到宿主细胞质中,在那里它优先使用与先天免疫反应相关的脂肪酸来酯化胆固醇,削弱质膜并允许细菌逸出。这项研究揭示了微生物的机智和毒力系统与宿主细胞资源之间的相互作用,以进化出一种巧妙的生存和逃逸方案。