Impact of the Heat Shock Protein 100 on the Intracellular Survival of Leishmania Amastigote Stages

热激蛋白 100 对利什曼原虫无鞭毛体阶段细胞内存活的影响

• 批准号: 5374613
• 负责人: Privatdozent Dr. Joachim Clos
• 金额: --
• 依托单位: Bernhard-Nocht-Institut für Tropenmedizin (BNITM)
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2002
• 资助国家: 德国
• 起止时间: 2001-12-31 至 2004-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/5374613?language=en
• 关键词: Impact; Heat; Shock; Protein; 100

Following entry into a mammalian host organism, Leishmania spp. are phagocytised by macrophages. Inside the phagosome, the elongated, flagellated promastigote stage converts into the round, aflagellated amastigote stage. As amastigotes, Leishmania parasites persist and proliferate, thereby destroying their host cells. The ability of Leishmania amastigotes to survive within the phagolysosome and to escape destruction is a key factor to their pathogenicity. The 100-kDa heat shock protein, Hsp100, of Leishmania plays a selective and crucial role in this process. delta clpB gene replacement mutants that lack Hsp100 are perfectly viable under axenic culture conditions. By contrast, inside mouse macrophages or during experimental infection of mice, these gene replacement strains show a marked decrease of virulence and an impaired intracellular survival. The expression of some amastigote-specific proteins is affected in the Hsp100-- mutants. We plan to identify the affected proteins and/or their corresponding genes and establish their importance for intracellular survival and virulence. To this end we propose a two-pronged approach: i) comparative proteome analysis of wild type and delta clpB mutants during and after amastigote differentiation, and ii) functional genetic complementation. The goal of this study is to gain insight into the processes that allow Leishmania species to escape destruction inside the macrophages and to proliferate within a hostile intracellular environment.

进入哺乳动物宿主生物体后，利什曼原虫属。被巨噬细胞吞噬。在吞噬体内，细长的、有鞭毛的前鞭毛体阶段转变为圆形、有鞭毛的无鞭毛体阶段。作为无鞭毛体，利什曼原虫寄生虫持续存在并增殖，从而破坏其宿主细胞。利什曼原虫无鞭毛体在吞噬溶酶体内存活并逃避破坏的能力是其致病性的关键因素。利什曼原虫的 100 kDa 热休克蛋白 Hsp100 在此过程中发挥着选择性且至关重要的作用。缺乏 Hsp100 的 delta clpB 基因替换突变体在无菌培养条件下完全可行。相比之下，在小鼠巨噬细胞内部或在小鼠的实验性感染过程中，这些基因替换菌株表现出毒力显着下降和细胞内存活受损。 Hsp100 突变体中一些无鞭毛体特异性蛋白的表达受到影响。我们计划鉴定受影响的蛋白质和/或其相应基因，并确定它们对细胞内存活和毒力的重要性。为此，我们提出了一种双管齐下的方法：i）在无鞭毛体分化期间和之后对野生型和delta clpB突变体进行比较蛋白质组分析，以及ii）功能性遗传互补。这项研究的目的是深入了解利什曼原虫物种逃避巨噬细胞内部破坏并在不利的细胞内环境中增殖的过程。