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.

该提议概述了一项综合计划，以基因剖析人类的脂肪酸代谢病原体弓形虫。 T. gondii感染在美国广泛（22％的人口长期是被感染的），虽然良性通常会导致免疫抑制个体威胁生命的疾病（例如患有HIV-AID，移植受者或血液学恶性肿瘤的人）。 T.先天性传播。贡迪也是一个主要的公共卫生问题。高度毒的寄生虫菌株最近被确定为严重且反复出现的眼感染的原因最终导致失明。 T. gondii也有可能引起大量的水传播爆发，已被疾病预防控制中心列为潜在的生物恐怖病原体（附录B）。当前可用的治疗频繁且严重的不良影响，显示没有慢性感染的功效，从而允许活性感染的复发。因此，新药是迫切需要。在Apicomplexan寄生虫中发现类似叶绿体的细胞器提供了几种有希望的寄生虫特异性靶标的药物开发途径。这些途径是细菌II 脂肪酸合成途径和该途径中的酶一直是密集药的主题化学努力为抗疟疾和弓形虫病的药物开发。但是，什么是 T. gondii和相关的Apicomplexan寄生虫的这一途径尚不清楚。此外，寄生虫基因组编码可能通过合成或从宿主单元。需要对这些途径的功能和相对重要性有详细的理解指导药物开发工作达到最有希望的目标。在这个项目中，我们将使用遗传学和代谢组学以剖析三种单个途径的复杂相互作用。使用小说高效工程师有条件的T. gondii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个体途径。我们将确定特定途径损失对寄生虫脂肪的影响使用无偏代谢组分析的酸和脂质组成。定义个人之间的相互作用途径以及寄生虫及其宿主细胞之间我们使用稳定表位进行代谢通量研究跟踪。总体而言，我们预计概述的研究将产生对脂肪酸的详细机械理解合成是寄生虫代谢和代谢寄生虫相互作用的重要组成部分。突变分析将重点介绍真正必不可少的成分作为潜在的药理目标。我们还期望遗传一路上磨练的代谢组工具将被证明对解剖的许多方面非常有用寄生虫生物学以外的脂质代谢。