Characterization of Legionella pneumophila genes with impact on bacterial uptake into host cells and on bacterial virulence

嗜肺军团菌基因对细菌摄取宿主细胞和细菌毒力的影响的表征

• 批准号: 45258236
• 负责人: Professorin Dr. Antje Flieger
• 金额: --
• 依托单位: Fachgebiet 11: Bakterielle darmpathogene Erreger und Legionellen
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2007
• 资助国家: 德国
• 起止时间: 2006-12-31 至 2010-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/45258236?language=en
• 关键词: Characterization; Legionella; pneumophila; genes; impact

Legionella pneumophila is an intracellularly replicating bacterium and the causative agent of Legionnaires' disease. Successful parasitism of host cells involves efficient adherence and entry of the bacteria. Some of the Legionella adherence- and uptake-promoting factors have been already described, however specific underlying mechanisms have not been extensively evaluated. In our prework, we screened 11,300 transposon-mutagenized L. pneumophila clones in an amoebae-infection model and we identified 98 apathogenous clones. Selected mutants were furthermore tested for adherence/uptake properties in macrophages and seven clones were found dramatically deficient. In two of the clones, the transposon hit well known Legionella adherence/uptake genes, but five genes in that respect were novel. Three of those five genes have not yet been functionally evaluated for L. pneumophila. The aim of the presented study is therefore to examine whether the respective proteins directly or indirectly contribute to bacterial adherence/uptake processes. Furthermore, one selected protein will be purified, its effect on uptake processes examined, and its eukaryotic interaction partner will be identified. Additionally, the protein localization during bacterial growth in laboratory medium and in eukaryotic cells will be determined and in parallel the changes in host cell cytoskeleton due to the protein will be monitored.

嗜肺军团菌是一种细胞内复制细菌，也是军团病的病原体。宿主细胞的成功寄生涉及细菌的有效粘附和进入。一些军团菌粘附和吸收促进因素已经被描述，但具体的潜在机制尚未得到广泛评估。在我们的前期工作中，我们在阿米巴感染模型中筛选了 11,300 个转座子诱变的嗜肺军团菌克隆，并鉴定了 98 个非致病性克隆。此外，还测试了所选突变体在巨噬细胞中的粘附/摄取特性，发现七个克隆明显缺陷。在其中两个克隆中，转座子击中了众所周知的军团菌粘附/摄取基因，但在这方面有五个基因是新的。这五个基因中的三个尚未针对嗜肺军团菌进行功能评估。因此，本研究的目的是检查各个蛋白质是否直接或间接有助于细菌粘附/摄取过程。此外，将纯化一种选定的蛋白质，检查其对摄取过程的影响，并鉴定其真核相互作用伴侣。此外，将确定细菌在实验室培养基和真核细胞中生长期间的蛋白质定位，同时将监测由蛋白质引起的宿主细胞细胞骨架的变化。