Genetic dissection of parasite metabolism

寄生虫代谢的基因剖析

基本信息

批准号：
7853678
负责人：
BORIS STRIEPEN
金额：
$ 35.03万
依托单位：
UNIVERSITY OF GEORGIA
依托单位国家：
美国
项目类别：
财政年份：
2010
资助国家：
美国
起止时间：
2010-03-15 至 2015-02-28
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7853678
关键词：
AIDS-Related Opportunistic Infections Ablation Acetates Acyl Carrier Protein Adverse effects Affect Anabolism Antiparasitic Agents Apicomplexa Bacterial Typing Benign Biochemical Bioinformatics Biology Bioterrorism Blindness Cataloging Catalogs Cells Centers for Disease Control and Prevention (U.S.)Chloroplasts Chronic Complex Complication Cryptosporidiosis Cryptosporidium Disease Disease Management Disease Outbreaks Dissection Drug Delivery Systems Engineering Enzymes Epitopes Essential Fatty Acids Eye Infections Fatty Acids General Practitioners Genes Genetic Growth Growth and Development function Hematologic Neoplasms Horizontal Gene Transfer Human Individual Infection Inherited Intercept Intervention Lead Life Life Cycle Stages Life Style Lipids Malaria Measures Metabolic Metabolism Modeling Modification Multi-Drug Resistance Nature Organelles Parasites Pathway interactions Pharmaceutical Chemistry Pharmaceutical Preparations Pharmacotherapy Plasmodium malariae Population Public Health Radiolabeled Recrudescences Regulation Relative (related person)Research Rest Role Route Staging System Testing Time Toxoplasma Toxoplasma gondii Toxoplasmosis Transplant Recipients Vaccines Virulent antimicrobial drug comparative genomics drug development effective therapy enzyme pathway fascinate fatty acid metabolism flexibility genome sequencing human disease immunosuppressed in vivo lipid metabolism metabolomics mutant novel novel strategies parasite genome pathogen positional cloning public health relevance radiotracer reconstruction tool transmission process uptake waterborne

项目摘要

DESCRIPTION (provided by applicant): This proposal outlines a comprehensive plan to genetically dissect the fatty acid metabolism of the human pathogen Toxoplasma gondii. T. gondii infection is widespread in the U.S. (22% of the population is chronically infected) and while usually benign can cause life-threatening disease in immunosuppressed individuals (e.g. those with HIV-AIDS, transplant recipients, or hematological malignancies). Congenital transmission of T. gondii is also a major public health concern. Highly virulent parasite strains have been recently identified as the cause of severe and recurring eye infections that ultimately lead to blindness. T. gondii also has the potential to cause significant waterborne outbreaks and has been listed by the CDC as a potential bioterrorism pathogen (appendix B). The currently available treatment has frequent and significant adverse effects and shows no efficacy in chronic infection, thus allowing for recrudescence of the active infection. Thus, new drugs are urgently needed. The discovery of a chloroplast-like organelle in apicomplexan parasites provides several promising parasite-specific target pathways for drug development. Among these pathways is a bacterial type II fatty acid synthesis pathway, and enzymes in this pathway have been the subject of intensive medicinal chemistry efforts to develop drugs against malaria and toxoplasmosis. However, what the precise function of this pathway for T. gondii and related apicomplexan parasites is remains unclear. Furthermore, the parasite genome encodes additional enzyme systems that might supply fatty acids either by synthesis or salvage from the host cell. A detailed understanding of the function and relative importance of these pathways is needed to guide the drug development effort to the most promising targets. In this project we will use genetics and metabolomics to dissect the complex interaction of three individual pathways. Using a novel and highly efficient approach to engineer conditional T. gondii mutants we will rigorously test the importance and function of each individual pathway in vivo. We will determine the impact of the loss of specific pathways on the parasite fatty acid and lipid composition using unbiased metabolomic profiling. To define the interactions between individual pathways and between the parasite and its host cell we conduct metabolic flux studies using stable epitope tracing. Overall we expect the outlined studies to produce a detailed mechanistic understanding of fatty acid synthesis as an important part of parasite metabolism and metabolic host-parasite interaction. Mutant analysis will highlight truly essential components as potential pharmacological targets. We also expect that the genetic and metabolomic tools honed along the way will prove highly useful for the dissection of many facets of parasite biology beyond lipid metabolism. PUBLIC HEALTH RELEVANCE: This project will use modern genetic and metabolomic approaches to dissect the metabolism of the human pathogen Toxoplasma gondii. The studies will provide important information to guide the development of drug treatments and will lead to a detailed understanding of host-parasite interaction at the metabolic level.

描述（由申请人提供）：该提案概述了从基因角度剖析人类病原体弓形虫脂肪酸代谢的综合计划。弓形虫感染在美国很普遍（22% 的人口为慢性感染），虽然通常是良性的，但可能会在免疫抑制个体（例如艾滋病毒/艾滋病患者、移植受者或血液恶性肿瘤患者）中引起危及生命的疾病。弓形虫的先天性传播也是一个主要的公共卫生问题。最近已确定高毒力寄生虫菌株是导致严重且反复出现的眼部感染并最终导致失明的原因。弓形虫还有可能引起严重的水传播疫情，并已被 CDC 列为潜在的生物恐怖主义病原体（附录 B）。目前可用的治疗方法具有频繁且显着的副作用，并且对慢性感染无效，从而导致活动性感染复发。因此，迫切需要新药。顶复门寄生虫中叶绿体样细胞器的发现为药物开发提供了几种有前景的寄生虫特异性靶标途径。这些途径之一是细菌 II 型脂肪酸合成途径，该途径中的酶一直是药物化学研究的重点，以开发抗疟疾和弓形虫病的药物。然而，该途径对于弓形虫和相关顶复门寄生虫的确切功能仍不清楚。此外，寄生虫基因组编码额外的酶系统，这些酶系统可以通过合成或从宿主细胞中回收来提供脂肪酸。需要详细了解这些途径的功能和相对重要性，以指导药物开发工作达到最有希望的目标。在这个项目中，我们将利用遗传学和代谢组学来剖析三个单独途径的复杂相互作用。使用新颖且高效的方法来设计条件弓形虫突变体，我们将严格测试体内每个单独途径的重要性和功能。我们将使用无偏代谢组学分析来确定特定途径的丧失对寄生虫脂肪酸和脂质组成的影响。为了定义各个途径之间以及寄生虫与其宿主细胞之间的相互作用，我们使用稳定表位追踪进行代谢流研究。总的来说，我们期望概述的研究能够对脂肪酸合成作为寄生虫代谢和代谢宿主-寄生虫相互作用的重要组成部分产生详细的机制理解。突变分析将突出真正重要的成分作为潜在的药理学目标。我们还预计，一路上磨练出来的遗传和代谢组学工具将被证明对于剖析脂质代谢以外的寄生虫生物学的许多方面非常有用。公共卫生相关性：该项目将使用现代遗传和代谢组学方法来剖析人类病原体弓形虫的代谢。这些研究将为指导药物治疗的开发提供重要信息，并将导致对代谢水平上宿主-寄生虫相互作用的详细了解。