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：
8416941
负责人：
Peter John Bradley
金额：
$ 19.25万
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 2015-01-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8416941
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.

描述（由申请人提供）：弓形虫是一种专性细胞内寄生虫，会导致免疫功能低下的个体严重的中枢神经系统疾病以及先天性感染的新生儿的出生缺陷。这些生物体的细胞内生存取决于侵入宿主细胞、建立允许复制的生态位以及避免宿主细胞防御的能力。分泌性棒状体已成为调节宿主细胞功能的入侵和劫持的关键细胞器。为了劫持宿主功能，菱形体将大量蛋白质注入宿主细胞的细胞质中，这些蛋白质可以被运输到受感染细胞内的不同区室并直接靶向宿主途径。这些宿主“效应”蛋白的重要性可以通过注射的菱形激酶家族来例证，这些激酶在调节宿主信号传导途径和调节寄生虫毒力方面发挥着关键作用。除了 ROP 激酶之外，菱形体还注入一系列功能未知的其他效应蛋白。大多数这些蛋白质缺乏与已知蛋白质或可识别结构域的同源性，并且是弓形虫和密切相关的寄生虫所独有的。我们已经鉴定了一组新型棒状体效应子，并在生物学相关的 II 型菌株寄生虫中开发了基因敲除技术，用于他们的研究。在本提案中，我们将确定这些新型效应蛋白在调节宿主功能中的作用。具体来说，我们将使用宿主微阵列分析确定宿主对效应菌株的体外反应，并通过评估小鼠的毒力、组织向性和缓殖子形成来确定体内宿主对效应菌株的反应。我们还将在宿主细胞中使用串联亲和标记效应蛋白的外源表达来确定它们的目的地并识别宿主靶标。总之，这些互补的方法有望揭示弓形虫如何利用这套独特的效应蛋白来调节其哺乳动物宿主细胞的新机制。