Targeting copper homeostasis in the fungal pathogen, Cryptococcus neoformans

针对真菌病原体新型隐球菌中的铜稳态

• 批准号: 8605811
• 负责人: Richard Festa
• 金额: $ 5.39万
• 依托单位: DUKE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-09-01 至 2014-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8605811
• 关键词: Acquired Immunodeficiency Syndrome; Address; Affect; Alveolar Macrophages; Attenuated; Bioavailable; Biochemical; Biological Availability; Cancer Patient; Copper; Cryptococcal Meningitis; Cryptococcus neoformans; Data; Defense Mechanisms; Development; Drug Metabolic Detoxication; Drug Targeting; Enzymes; Equilibrium; Faculty; Fungal Meningitis; Gene Deletion; Gene Expression; Gene Expression Regulation; Gene Targeting; Genes; Genetic; Goals; Growth; HIV; Homeostasis; Human; Immunocompromised Host; In Vitro; Individual; Infection; Infection prevention; Knowledge; Laboratories; Lead; Left; Life; Mammalian Genetics; Mentors; Metabolism; Micronutrients; Modeling; Mus; Organ Transplantation; Organism; Outcome; Pathogenesis; Patients; Phagocytosis; Phagosomes; Phenotype; Play; Process; Property; Proteins; Regulation; Role; Systemic infection; Testing; Tissues; Training; Transcription Coactivator; Transplant Recipients; Virulence; Virulence Factors; Wild Type Mouse; Work; antimicrobial drug; career; cell type; chemotherapy; chromatin immunoprecipitation; fungus; in vivo; macrophage; member; mouse model; mutant; novel; pathogen; patient population; prevent; promoter; public health relevance; research study; response; tool; transcription factor

DESCRIPTION (provided by applicant): Cryptococcus neoformans is a human fungal pathogen that can progress to systemic infection in both immunocompromised and healthy individuals, leading to lethal cryptococcal meningitis. Current therapies to address C. neoformans infection are not highly effective, therefore more efficacious treatments are needed to prevent infection, particularly in vulnerable patient population such as organ transplant recipients, HIV-AIDS patients and cancer patients undergoing chemotherapy. Copper (Cu) serves as an essential co-factor for a wide variety of enzymes in fungi and humans, but excess Cu is toxic requiring organisms to maintain tight control of intracellular Cu levels. Studies suggest that the C. neoformans Cu-sensing transcription factor, Cuf1, is required for virulence in mouse infection models. While Cuf1 activates the expression of genes encoding proteins that carry out Cu import, recent work in the laboratory of my postdoctoral sponsor, Dennis J. Thiele, has demonstrated that Cuf1 activates many genes that are essential for both Cu acquisition and Cu detoxification, as well as genes encoding proteins of unknown function. Moreover, work by others suggests that activated macrophages accumulate Cu within the lumen of the phagosome as an anti-microbial agent. Since alveolar macrophages are the first line of defense against C. neoformans infection, it is important to understand how the Cuf1 Cu-sensing transcription factor, and the proteins encoded by Cuf1 target genes, play a critical role in C. neoformans virulence. In this application I outline experiments to accomplish this overall goal through three Specific Aims. In the first aim I will carry out genetic and biochemical experiments to establish whether the genes that are dependent on Cuf1 are regulated directly or indirectly by this transcription factor and to ascertain the role of these genes in Cu acquisition or detoxification. In the second aim I outline experiments to evaluate mutants in Cuf1-dependent genes to ascertain their contribution to survival to alveolar macrophage phagocytosis in vitro. In the third aim, using both wild type mice and mice created in my postdoctoral sponsor's laboratory that are specifically defective in macrophage Cu accumulation, I outline experiments to decipher what roles Cuf1-dependent genes and the host Cu homeostasis machinery play in host-pathogen interactions. The new expertise I will gain by carrying out this project at the intersection of fungal pathogenesis, Cu metalloregulation and the genetics of mammalian host Cu metabolism will contribute significantly to understanding the role of Cu in the host-pathogen axis and will provide me with cutting-edge training to launch a career as a competitive independent faculty member.

描述（由申请方提供）：新型隐球菌是一种人类真菌病原体，可在免疫功能低下和健康个体中发展为全身感染，导致致命的隐球菌脑膜炎。目前治疗C.然而，由于新生儿感染并不十分有效，因此需要更有效的治疗来预防感染，特别是在脆弱的患者群体中，例如器官移植接受者、HIV-AIDS患者和正在接受化疗的癌症患者。铜（Cu）是真菌和人类中多种酶的重要辅助因子，但过量的Cu是有毒的，需要生物体保持对细胞内Cu水平的严格控制。研究表明，C.新形式铜敏感转录因子Cuf 1是小鼠感染模型中毒力所必需的。虽然Cuf 1激活了编码进行Cu输入的蛋白质的基因的表达，但我的博士后赞助商Dennis J. Thiele的实验室最近的工作表明，Cuf 1激活了许多对Cu获得和Cu解毒至关重要的基因，以及编码未知功能蛋白质的基因。此外，其他人的工作表明，活化的巨噬细胞在吞噬体的管腔内积累Cu作为抗微生物剂。由于肺泡巨噬细胞是抵抗C.因此，了解Cuf 1铜敏感转录因子和Cuf 1靶基因编码的蛋白质如何在C.新形虫毒力在本申请中，我概述了通过三个具体目标来实现这一总体目标的实验。在第一个目标中，我将进行遗传和生化实验，以确定依赖于Cuf 1的基因是否直接或间接受该转录因子的调控，并确定这些基因在铜的获得或解毒中的作用。在第二个目标中，我概述了实验，以评估Cuf 1依赖性基因的突变体，以确定它们对肺泡巨噬细胞体外吞噬作用的存活的贡献。在第三个目标中， 野生型小鼠和小鼠在我的博士后赞助商的实验室，特别是缺陷的巨噬细胞铜积累，我概述了实验，以破译Cuf 1依赖基因和宿主铜稳态机制在宿主-病原体相互作用中发挥的作用。通过在真菌发病机理、Cu金属调节和哺乳动物宿主Cu代谢的遗传学的交叉点上开展这个项目，我将获得新的专业知识，这将大大有助于理解Cu在宿主-病原体轴中的作用，并将提供 我与尖端的培训，推出一个有竞争力的独立教师的职业生涯。