Genetic dissection of parasite metabolism

寄生虫代谢的基因剖析

基本信息

批准号：
7876328
负责人：
BORIS STRIEPEN
金额：
$ 28.74万
依托单位：
UNIVERSITY OF GEORGIA
依托单位国家：
美国
项目类别：
财政年份：
2009
资助国家：
美国
起止时间：
2009-07-18 至 2010-03-14
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7876328
关键词：
AIDS-Related Opportunistic Infections Ablation Acetates Acyl Carrier Protein Address Adverse effects Affect Anabolism Antiparasitic Agents Apicomplexa Bacterial Typing Benign Biochemical Bioinformatics Biology Bioterrorism Blindness Carbon 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 Genomics Growth Growth and Development function Hematologic Neoplasms Horizontal Gene Transfer Human Individual Infection Inherited Inorganic Phosphate Transporter Intercept Intervention Knock-out Label 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 Recombinants Recrudescences Regulation Relative (related person)Research Rest Role Route Source Staging System Testing Thioctic Acid Time Toxoplasma Toxoplasma gondii Toxoplasmosis Transplant Recipients Trioses Vaccines Virulent Yeast Model System antimicrobial drug comparative drug development effective therapy enzyme pathway fascinate fatty acid elongases fatty acid metabolism flexibility genome sequencing human disease immunosuppressed in vivo lipid metabolism metabolomics mutant novel novel strategies parasite genome pathogen positional cloning radiotracer reconstruction stable isotope tool transmission process uptake waterborne

项目摘要

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.

该提案概述了从基因角度剖析人类脂肪酸代谢的综合计划病原体弓形虫。弓形虫感染在美国很普遍（22% 的人口长期患有弓形虫感染）感染），虽然通常是良性的，但可能会在免疫抑制的个体中引起危及生命的疾病（例如，艾滋病毒/艾滋病患者、移植受者或血液恶性肿瘤患者）。先天性传播 T. 弓形虫也是一个主要的公共卫生问题。最近，高毒力寄生虫菌株已被确定为导致严重和反复出现的眼部感染，最终导致失明。弓形虫还有潜力引起严重的水传播疾病，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不良反应，并且没有显示出对慢性感染有效，从而允许活动性感染复发。因此，新药急需。顶复门寄生虫中叶绿体样细胞器的发现提供了一些证据有前途的药物开发的寄生虫特异性靶标途径。这些途径中包括 II 型细菌脂肪酸合成途径，以及该途径中的酶一直是深入医学研究的主题化学努力开发抗疟疾和弓形虫病的药物。然而，其具体功能是什么弓形虫和相关顶复门寄生虫的这条途径仍不清楚。此外，寄生虫基因组编码额外的酶系统，可以通过合成或回收来提供脂肪酸宿主细胞。需要详细了解这些途径的功能和相对重要性指导药物开发工作向最有希望的目标迈进。在这个项目中，我们将利用遗传学和代谢组学剖析三个单独途径的复杂相互作用。采用新颖高效工程条件弓形虫突变体的方法，我们将严格测试每个突变体的重要性和功能体内的个体途径。我们将确定特定途径的丧失对寄生虫脂肪的影响使用无偏代谢组学分析分析酸和脂质成分。定义个体之间的相互作用我们使用稳定表位进行代谢流研究追踪。总的来说，我们期望概述的研究能够对脂肪酸产生详细的机制理解合成是寄生虫代谢和代谢宿主-寄生虫相互作用的重要组成部分。突变分析将突出真正重要的成分作为潜在的药理学目标。我们还期望遗传一路上磨练出来的代谢组学工具将被证明对于剖析生物的许多方面非常有用。脂质代谢之外的寄生虫生物学。