Comparative and functional genomics of C. neoformans

新型隐球菌的比较和功能基因组学

• 批准号: 10083689
• 负责人: JAMES W KRONSTAD
• 金额: $ 32.86万
• 依托单位: UNIVERSITY OF BRITISH COLUMBIA
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-08-01 至 2024-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10083689
• 关键词: Acquired Immunodeficiency Syndrome; Antifungal Agents; Binding; Cell surface; Cells; Ceruloplasmin; Cessation of life; Complex; Cryptococcosis; Cryptococcus; Cryptococcus gattii; Cryptococcus neoformans; Cysteine; Disease; Drug Compounding; Drug Targeting; Environment; Gene Expression; Genetic Screening; Goals; Growth; HIV; Heme; Heme Iron; Homeostasis; Human; Immune system; Immunocompetent; Impairment; In Vitro; Infection; Infection Control; Inhalation; Iron; Iron Chelating Agents; Knowledge; Lead; Link; Location; Mammals; Membrane; Meningoencephalitis; Mitochondria; Modeling; Molecular Analysis; Mus; Mutation; Mycoses; Nutrient; Nutritional; Nutritional Immunity; Patients; Pharmaceutical Preparations; Phenotype; Play; Polysaccharides; Process; Proliferating; Proteins; Proteomics; Regulation; Research; Role; Siderophores; Signal Transduction; Site; Structural Protein; System; Testing; Tissues; United States National Institutes of Health; Vaccines; Vacuole; Virulence; Virulence Factors; base; capsule; combat; comparative genomics; detection of nutrient; functional genomics; fungus; glutaredoxin; heme a; in vivo; mitochondrial membrane; mouse model; mutant; new therapeutic target; novel therapeutic intervention; novel therapeutics; pathogen; pathogenic fungus; permease; programs; protein complex; protein function; sensor; trafficking; transcription factor; uptake

Project Summary/Abstract. Recent estimates indicate that meningoencephalitis caused by the pathogenic fungus Cryptococcus neoformans is responsible 15% of deaths in AIDS patients. Along with other fungal pathogens, C. neoformans is therefore a major threat to the 37 million people worldwide living with HIV. A complex of related species originally designated Cryptococcus gattii has recently emerged as a primary pathogen of immunocompetent people. The long-term goal of our research program is to acquire knowledge that will lead to new strategies to combat cryptococcal infections. In particular, we are working to acquire a detailed understanding of the factors required for fungi to proliferate in vertebrate hosts. In particular, we seek to identify new targets for therapy. Our focus is on iron as an essential nutrient for pathogen proliferation and an important indicator of the host environment. Iron is especially important because mammals actively withhold iron from pathogens through a process called nutritional immunity. Pathogens must therefore be able to successfully compete for iron in order to cause disease. We have shown that iron influences the growth of C. neoformans and also the size of the polysaccharide capsule that is the major virulence factor. Our efforts have focused on characterizing the mechanisms of iron sensing and exploiting the regulatory information to identify targets required for iron acquisition. The first specific aim is to characterize the monothiol glutaredoxin Grx4 as a key sensor of iron availability. Grx4 interacts with the iron regulator Cir1 and the proteins regulate iron homeostasis and the expression of virulence factors. We seek to understand the mechanisms of iron sensing and how the iron signal influences gene expression. A second specific aim will investigate the interaction of Grx4 with a network of transcription factors. Two strong candidates have been identified (HapX and Gat201) and the interactions and regulatory influences of these proteins with Grx4 will be characterized. A final specific aim is based on highly productive genetic screens that identified components of the intracellular machinery for heme trafficking. Mutants lacking trafficking functions for heme acquisition will be constructed and tested in mouse inhalation models of cryptococcosis. Additionally, a heme sensor has been developed to detect heme availability in trafficking mutants in culture and in cryptococcal cells during proliferation in different host tissue locations. Overall, these studies will provide a comprehensive view the integration of iron sensing with the regulation of uptake strategies that are critical during cryptococcosis. !

项目摘要/摘要。最近的估计表明，脑膜脑炎是由致病菌引起的 新型隐球菌导致 15% 的艾滋病患者死亡。与其他真菌一起 因此，新型隐球菌是全球 3700 万艾滋病毒感染者的主要威胁。一个 最初指定为格特隐球菌的相关物种复合体最近已成为主要的 免疫功能正常的人的病原体。我们研究计划的长期目标是获得 这些知识将带来对抗隐球菌感染的新策略。特别是，我们正在努力 详细了解真菌在脊椎动物宿主中增殖所需的因素。在 特别是，我们寻求确定新的治疗靶点。我们的重点是铁作为人体必需的营养素 病原体增殖和宿主环境的重要指标。铁尤其重要 因为哺乳动物通过一种称为营养免疫的过程主动地阻止病原体吸收铁。 因此，病原体必须能够成功竞争铁才能引起疾病。我们有 表明铁会影响新型隐球菌的生长以及多糖胶囊的大小， 是主要的毒力因子。我们的工作重点是表征铁传感机制 利用监管信息来确定铁收购所需的目标。第一个具体目标 旨在将单硫醇谷氧还蛋白 Grx4 描述为铁可用性的关键传感器。 Grx4 相互作用 铁调节因子 Cir1 和蛋白质调节铁稳态和毒力因子的表达。 我们试图了解铁感应的机制以及铁信号如何影响基因表达。 第二个具体目标是研究 Grx4 与转录因子网络的相互作用。二 已经确定了强有力的候选者（HapX 和 Gat201）以及它们之间的相互作用和监管影响 这些带有 Grx4 的蛋白质将被表征。最终的具体目标是基于高生产力的遗传 筛选确定血红素运输细胞内机制的组成部分。突变体缺乏 将在小鼠吸入模型中构建和测试血红素获取的贩运功能 隐球菌病。此外，还开发了血红素传感器来检测贩运中血红素的可用性 培养物和隐球菌细胞在不同宿主组织位置增殖期间的突变体。全面的， 这些研究将为铁传感与吸收调节的整合提供全面的视角 在隐球菌病期间至关重要的策略。 ！