Novel rhoptry effector proteins in Toxoplasma host-pathogen interaction

弓形虫宿主-病原体相互作用中的新型棒状体效应蛋白

基本信息

批准号：
8229898
负责人：
Peter John Bradley
金额：
$ 23.1万
依托单位：
UNIVERSITY OF CALIFORNIA LOS ANGELES
依托单位国家：
美国
项目类别：
财政年份：
2012
资助国家：
美国
起止时间：
2012-02-15 至 2014-01-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8229898
关键词：
Acquired Immunodeficiency Syndrome Acute Address Affinity Ala-Trp-Arg-His-Pro-Gln-Phe-Gly-Gly Blood Cell physiology Cells Central Nervous System Diseases Chronic Complex Congenital Abnormality Cytoplasm Cytoplasmic Granules Cytosol Destinations Disease Family Genes Hand Human Immune response Immunocompromised Host In Vitro Individual Infection Injection of therapeutic agent Invaded Knock-out Mammalian Cell Masks Mediating Microarray Analysis Monoclonal Antibodies Mus Names Needles Nomenclature Organelles Organism Parasites Pathway interactions Patients Penetration Phenotype Phosphotransferases Play Population Positioning Attribute Process Proteins Proteomics Role Series Shapes Signal Pathway Staging System Toxoplasma Toxoplasma gondii Virulence Work experience in vivo insight knockout gene neonate novel obligate intracellular parasite pathogen protein function response rhoptry success tissue tropism tool trafficking

项目摘要

DESCRIPTION (provided by applicant): Toxoplasma gondii is an obligate intracellular parasite that causes severe central nervous system disorders in immunocompromised individuals and birth defects in congenitally infected neonates. Intracellular survival of these organisms is dependent on the ability to invade their host cell, establish a replication-permissive niche, and avoid host cell defenses. The secretory rhoptries have emerged as a key organelle that regulates both invasion and hijacking of host cell functions. For hijacking host functions, the rhoptries inject a burst of proteins into the host cell cytoplasm that can be trafficked to distinct compartments within the infected cell and directly target host pathways. The importance of these host "effector" proteins is exemplified by a family of rhoptry kinases that are injected and play critical roles in modulating host signaling pathways and regulating parasite virulence. In addition to ROP kinases, the rhoptries inject an array of other effector proteins that are of unknown function. Most of these proteins lack homology to known proteins or identifiable domains and are unique to Toxoplasma and closely related parasites. We have identified a panel of these novel rhoptry effectors and developed gene knockouts in the biologically relevant type II strain parasites for their study. In this proposal, we will determine the role of these novel effector proteins in regulating host functions. Specifically, we will determine the host response to ?effector strains in vitro using host microarray analysis and in vivo by assessing virulence, tissue tropism, and bradyzoite formation in mice. We will additionally use exogenous expression of tandem affinity tagged effector proteins in host cells to determine their destination and identify host targets. Together, these complementary approaches promise to reveal novel mechanistic insights into how Toxoplasma uses this unique set of effector proteins to modulate its mammalian host cell. PUBLIC HEALTH RELEVANCE: Toxoplasma gondii is an intracellular parasite that infects up to a third of the world's human population and causes serious disease in immunocompromised (AIDS) patients and congenitally-infected neonates. Toxoplasma secretes an array of factors from an organelle named the rhoptries that enable it to invade and hijack its host cell. This project is focused determining the function of a novel group of rhoptry effector proteins by examining the host response to gene knockout parasites and identifying host proteins that interact with these novel effectors.

描述（由申请人提供）：弓形虫Gondii是一种强制性细胞内寄生虫，可在免疫强化的个体中引起严重的中枢神经系统疾病和先天感染的新生儿的先天缺陷。这些生物的细胞内存活取决于侵入其宿主细胞，建立复制 - 允许的生态位并避免宿主细胞防御能力的能力。分泌的躯干已成为一个关键的细胞器，可调节宿主细胞功能的侵袭和劫持。对于劫持宿主功能，rhoptries将蛋白质爆发注入宿主细胞细胞质中，这些蛋白质可以被运输到感染细胞内的不同隔室，并直接靶向宿主途径。这些宿主“效应子”蛋白的重要性被一个注射的Rhoptry激酶家族体现在调节宿主信号通路和调节寄生虫毒力中的关键作用。除了ROP激酶外，Rhoptries还注入了其他功能未知的其他效应蛋白。这些蛋白质中的大多数与已知蛋白质或可识别域缺乏同源性，并且是弓形虫和密切相关的寄生虫所独有的。我们已经确定了这些新型的Rhoptry效应子的一个小组，并在生物学相关的II型菌株寄生虫中开发了基因敲除。在此提案中，我们将确定这些新型效应蛋白在调节宿主功能中的作用。具体而言，我们将使用宿主微阵列分析和体内确定宿主对效应菌株的反应，并通过评估小鼠的毒力，组织的tropism和Bradyzoite形成。我们还将在宿主细胞中使用串联亲和标记的效应子蛋白的外源表达来确定其目的地并识别宿主靶标。这些互补的方法共同有望揭示有关弓形虫如何使用这种独特的效应蛋白来调节其哺乳动物宿主细胞的新型机械洞察。公共卫生相关性：弓形虫Gondii是一种细胞内寄生虫，可感染世界人口的三分之一，并在免疫功能低下的患者（AIDS）患者和先天感染的新生儿中引起严重的疾病。弓形虫从一个名为Rhoptries的细胞器中分泌出一系列因素，使其能够入侵并劫持其宿主细胞。该项目的重点是通过检查对基因敲除寄生虫的宿主反应并鉴定与这些新型效应子相互作用的宿主蛋白来确定一组新型的Rhoptry效应蛋白的功能。