Elucidating Leishmania strategies for parasitophorous vacuole biogenesis

阐明利什曼原虫寄生液泡生物发生的策略

• 批准号: 10672033
• 负责人: Neal Silverman
• 金额: $ 41.88万
• 依托单位: UNIV OF MASSACHUSETTS MED SCH WORCESTER
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-09-12 至 2024-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10672033
• 关键词: Address; Affect; Americas; Biogenesis; CD36 gene; CSF1R gene; Cause of Death; Cell Volumes; Cells; Central America; Cessation of life; Chemicals; Cholesterol; Complex; Cutaneous Leishmaniasis; Cytolysis; Data; Dendritic Cells; Destinations; Diffuse; Disease; Distant; Endocytic Vesicle; Future; Genes; Genetic; Goals; Health; Host Defense; Human; Hydrophobicity; Immune; Immune response; Infection; Integration Host Factors; Intracellular Space; Invaded; Knowledge; Laboratories; Leishmania; Leishmania donovani; Leishmaniasis; Lesion; Leukocytes; Lipids; Macrophage Cell Biology; Mediating; Methods; Molecular; Mucous Membrane; Mus; Mutation; Organelles; Outcome; Parasites; Parasitic Diseases; Parasitic infection; Pathogenicity; Pathology; Pathway interactions; Persons; Phagocytes; Phagosomes; Phlebotominae; Phylogenetic Analysis; Physiological; Public Health; Research; Resistance; Resources; Role; Signal Transduction; Skin; Source; South America; Sterols; Sumoylation Pathway; Symptoms; System; Vacuole; Vesicle; Virulence; Visceral; base; flexibility; human model; innovation; lipid biosynthesis; lipid transport; macrophage; member; microbicide; mouse model; neglected tropical diseases; novel; novel therapeutics; pathogen; receptor; small molecule; therapeutic development

Leishmania amazonensis is one of the main causes of cutaneous leishmaniasis in South and Central America. The burden of this pathogen on human health contrasts with the lack of fundamental knowledge about its underlying virulence and survival mechanisms. In particular, L. amazonensis is a growing public health problem because infection with this parasite often creates diffuse non-healing lesions, and more rarely, lethal visceral disease, with increasing levels of resistance to standard therapies. This broad range of outcomes indicates that these parasites are extremely flexible and adapt to different host immune responses. L. amazonensis, and other species of the L. mexicana complex, induce the formation of specialized replication niche within infected macrophages. This parasitophorous vacuole (PV) is enlarged, occupying most of intracellular space of an infected macrophage; this unique feature is essential for parasite survival and replication. However, the mechanisms involved in biogenesis of this enlarged PV are largely unknown. The long-term objective of this project is to elucidate the cellular mechanisms that drive the biogenesis of the giant PV and allow the survival and replication of amastigotes within macrophages. Our hypothesis is that amastigotes combine multiple virulence mechanisms targeting host SUMOylation, ATP6V0D2 and the receptors CD36 and CSF1R to promote PV biogenesis, subvert host defense, and orchestrate the acquisition of essential metabolites, such as lipids. Note that all Leishmania species create PVs as safe replicative niches, therefore strategies used to L. amazonensis to generate its PV could be similarly used by different Leishmania species regardless of PV size. The rationale underlying this proposal is that a systematic study of the multiple mechanisms controlling PV biogenesis will provide a better understand how L. amazonensis successfully creates its replicative niche inside generally inhospitable macrophages. This proposal is significant because the resulting deeper mechanistic understanding of the parasite-host interaction will lead to the identification of new methods to strike at this critical, but so far indestructible, replicative niche from where amastigotes trigger the outward symptoms of leishmaniasis. The proposal is innovative because will investigate 3 novel mechanisms, identified in our earlier studies, involved in the biogenesis of the L. amazonensis amastigote enlarged PV. Aim 1 will explore the role of CD36 mediated lipid transport in delivering essential lipids to or from the PV. In Aim 2, we will study how amastigote-triggered deSUMOylation induces ATP6VOD2 expression, favoring parasite physiological demands such as increased cholesterol availability. Aim 3 will focus on the study of CSF1R, which we hypothesize is hijacked by amastigotes to support the high demand for sterols by intracellular parasites and/or to control the expression of Thrombospondin1.

亚马逊利什曼原虫是南部和中部皮肤利什曼病的主要原因之一 美国。这种病原体对人类健康的负担与缺乏基础知识形成鲜明对比 关于其潜在的毒力和生存机制。特别是，L. amazonensis 是一个不断增长的公众 健康问题，因为感染这种寄生虫通常会造成弥漫性的不愈合病变，而且更罕见的是， 致命的内脏疾病，对标准疗法的抵抗力不断增加。这个广泛的范围 结果表明，这些寄生虫非常灵活，能够适应不同的宿主免疫反应。 亚马逊乳杆菌和墨西哥乳杆菌复合体的其他物种诱导专门复制的形成 受感染巨噬细胞内的生态位。这种寄生液泡（PV）增大，占据了大部分 受感染巨噬细胞的细胞内空间；这种独特的功能对于寄生虫的生存至关重要 复制。然而，这种增大的PV的生物发生机制在很大程度上尚不清楚。这 该项目的长期目标是阐明驱动巨型生物发生的细胞机制 PV 并允许巨噬细胞内无鞭毛体的存活和复制。我们的假设是 无鞭毛体结合了针对宿主 SUMOylation、ATP6V0D2 和 受体 CD36 和 CSF1R 促进 PV 生物发生、颠覆宿主防御并协调采集 必需代谢物，例如脂质。请注意，所有利什曼原虫物种都将 PV 作为安全的复制生态位， 因此，不同的利什曼原虫可以类似地使用亚马逊利什曼原虫产生 PV 的策略 与 PV 大小无关的物种。该提案的基本原理是对多重因素进行系统研究 控制PV生物发生的机制将有助于更好地了解亚马逊乳杆菌如何成功 在通常不适宜生存的巨噬细胞内创造其复制生态位。这个提议意义重大，因为 由此产生的对寄生虫与宿主相互作用的更深入的机制理解将有助于识别 新的方法来攻击这个关键的、但迄今为止坚不可摧的复制利基，从无鞭毛体触发的地方 利什曼病的外在症状。该提案具有创新性，因为将研究 3 个新颖的 我们早期研究中确定的参与 L. amazonensis 无鞭毛体生物发生的机制 放大的PV。目标 1 将探讨 CD36 介导的脂质转运在将必需脂质递送至或 来自光伏。在目标 2 中，我们将研究无鞭毛体触发的去SUMOylation 如何诱导 ATP6VOD2 表达，有利于寄生虫的生理需求，例如增加胆固醇的可用性。目标3将 重点研究 CSF1R，我们假设它被无鞭毛体劫持以支持对 通过细胞内寄生虫产生甾醇和/或控制 Thrombospondin1 的表达。