Leishmania amazonensis sabotages host SUMOylation: a novel virulence mechanism for macrophage invasion

这项建议的重点是研究一种新颖的利什曼原虫毒力策略 在哺乳动物巨噬细胞的成功感染中-蛋白质的抑制 相扑化。这种毒力机制被发现是一种基于细胞的结果 利用果蝇细胞进行全基因组RNAi筛选。击倒了几个 苏莫化因子对利什曼原虫感染的影响 在哺乳动物巨噬细胞中的进一步研究表明，L. 亚马孙原虫感染抑制宿主细胞SUMO化和相扑因子耗竭 增强的寄生虫复制。 相思修饰是一种翻译后修饰，其中小分子 泛素样修饰物蛋白(SUMO)与靶蛋白偶联。相思甲基化 调节大量的蛋白质功能或活动，以及超过6000种不同的 已经在HeLa和U2OS细胞系中发现了SUMO化蛋白。鉴于其 在细胞中普遍存在的作用，我们假设SUMO化抑制是一个重要的 日本血吸虫毒力机制的研究。 支持这一观点的是，感染相扑耗尽的巨噬细胞产生了更大的 寄生的空泡(复制的小生境)和更高的寄生虫增殖。这个 苏木糖基化参与寄生虫的生物发生和复制 将进行更详细的研究。 在更广泛的背景下，我们还将确定寄生虫如何影响SUMO化和 这种毒力策略与小鼠感染有什么关系？简而言之，我们将 确定宿主相扑机器的哪些组件是寄生虫和 确定寄生毒力因子。琥珀酰化抑制与脑缺血的相关性 利什曼病将在苏莫化因子缺陷小鼠的感染中进行评估 在关于不同利什曼原虫毒力和苏莫化的研究中 抑制能力。

This proposal is focused in the study a novel Leishmania virulence strategy involved in the successful infection of mammalian macrophages — inhibition of protein SUMOylation. This virulence mechanism was discovered has a result of a cell-based genome-wide RNAi screen using Drosophila cells. The knockdown of several SUMOylation factors affected infection by amastigotes forms of Leishmania amazonensis, and further studies in mammalian macrophages revealed that L. amazonensis infection inhibited host cell SUMOylation and depletion of SUMO factor enhanced parasite replication. SUMOylation is a post-translational modification in which a member of Small Ubiquitin-like MOdifier protein (SUMO) is conjugated to target proteins. SUMOylation regulates numerous protein functions or activities, and over six thousand different SUMOylated proteins have been cataloged in HeLa and U2OS cell lines. Given its ubiquitous role in cells, we hypothesize that SUMOylation inhibition is one important virulence mechanisms of L. amazonensis. Supporting this idea, infection of SUMO depleted macrophages produced larger parasitophorous vacuoles (the replicative niche) and higher parasite proliferation. The participation of SUMOylation in parasitophorous biogenesis and in parasite replication will be studied in more detail. In a broader context, we will also determine how parasites affect SUMOylation and what is the relevance of this virulence strategy in mouse infection. Briefly, we will determine what components of the host SUMO machinery are targeted by parasites and identify parasitic virulence factors. The relevance of SUMOylation inhibition in leishmaniasis will be evaluated in infections of mice deficient in SUMOylation factors and in studies correlating virulence of different leishmania strains and SUMOylation inhibition capacity.