ROLE OF CELL WALL INTEGRITY IN ECHINOCANDIN RESISTANCE IN C. NEOFORMANS

细胞壁完整性在新型隐球菌棘白菌素抗性中的作用

• 批准号: 9927587
• 负责人: Maureen J Donlin
• 金额: $ 38万
• 依托单位: WASHINGTON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-06-26 至 2022-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9927587
• 关键词: Africa South of the Sahara; Amphotericin B; Anabolism; Antifungal Agents; Antifungal Therapy; Antiviral Agents; Area; Biochemical; Candidate Disease Gene; Cell Communication; Cell Maintenance; Cell Wall; Cells; Cessation of life; Cryptococcosis; Cryptococcus; Cryptococcus neoformans; Cyclic AMP; Cyclic AMP-Dependent Protein Kinases; Data; Defect; Detection; Development; Disease; Drug Targeting; Fluconazole; Future; Gene Activation; Gene Deletion; Gene Proteins; Gene Targeting; Genes; Genetic; Genetic Transcription; Genomics; Glucans; Goals; HIV; HIV Seropositivity; Heat-Shock Response; Homeostasis; Human; Immunocompromised Host; Individual; Infection; Lead; Maintenance; Mammals; Measurable; Molecular; Natural Resistance; New Agents; Oxidative Stress; Pathway Analysis; Pathway interactions; Patients; Phenotype; Phosphotransferases; Play; Protein Kinase; Protein Kinase C; Proteins; Regulation; Regulatory Pathway; Relapse; Resistance; Role; Signal Pathway; Stress; Structural Protein; Toxic effect; Tuberculosis; Virulence; burden of illness; capsule; cell growth regulation; deletion library; design; echinocandin resistance; enzyme structure; fungus; genetic regulatory protein; human pathogen; inhibitor/antagonist; mortality; nitrosative stress; novel; novel therapeutics; pathogenic fungus; prevent; repaired; response; screening; synergism; transcription factor

Abstract: Cryptococcus neoformans is a pathogenic fungus that is found world-wide and causes meningioencephalitis, particularly in immunocompromised individuals. It is invariably fatal unless treated, and the current antifungals are inadequate to effectively cure this disease, due to inherent toxicities, the inability to kill the fungus and prevent relapse, or innate resistance to the class of antifungals. Recent studies have indicated that there are over 1,000,000 new cases of cryptococcosis in the world each year, which results in over 600,000 deaths. New agents to treat Cryptococcus are needed, and the fungal cell wall is an attractive target, since it is unique to fungi and absent in humans. Echinocandins are a class of antifungals that target glucan synthesis in the cell wall. Cryptococcus is naturally resistant to the echinocandins. We have shown that disruption of the cell wall integrity (CWI) signaling pathway causes Cryptococcus to become highly sensitive to echinocandins, and identified candidate transcription factors that may play a role in echinocandin resistance. This pathway is the major pathway that impacts cell wall and is dependent on protein kinase C (Pkc1). The CWI/PKC1 pathway plays a key role in response to heat shock, oxidative and nitrosative stress, and cell wall inhibitors. Our preliminary data suggests that this pathway is part of a highly connected network that controls cell wall biosynthesis, repair and remodeling. The major goal of this project is to define the mechanism(s) by which cell wall integrity is maintained in response to specific cell wall inhibitors, including echinocandins and to identify potential gene targets for antifungals with synergy to echinocandins. There are three specific aims: In the first aim, we will define the role of the cell wall integrity pathway in echinocandin resistance using genomic and network analysis approaches. In the second aim, we will identify the genes essential to cell wall integrity and that contribute to echinocandin resistance by screening large deletion sets for specific phenotypes. In the third aim, we will assess the functional interactions of the cell wall integrity components. In this highly collaborative project, we propose to use our complementary expertise to integrate genetic, phenotypic and biochemical data to identify and characterize the network of interactions governing cell wall homeostasis in C. neoformans. This will significantly advance our understanding of cell wall maintenance and remodeling in a human pathogen and will provide multiple targets for designing specific antifungal drugs that are less likely to be toxic in mammals.

抽象的： 新型隐球菌是一种在世界范围内发现的致病真菌，可引起脑膜脑炎， 特别是在免疫功能低下的个体中。除非接受治疗，否则它总是致命的，而目前的抗真菌药物 由于固有毒性、无法杀死真菌和无法有效治愈这种疾病， 防止复发或对抗真菌类药物的先天耐药性。最近的研究表明，有 全球每年新增隐球菌病病例超过 1,000,000 例，导致超过 600,000 人死亡。 需要新的治疗隐球菌的药物，而真菌细胞壁是一个有吸引力的目标，因为它是独特的 存在于真菌中，而存在于人类中。 棘白菌素是一类针对细胞壁中葡聚糖合成的抗真菌药。隐球菌是天然的 对棘白菌素耐药。我们已经证明细胞壁完整性（CWI）信号通路的破坏 导致隐球菌对棘白菌素高度敏感，并确定了候选转录 可能在棘白菌素耐药性中发挥作用的因素。该途径是影响细胞的主要途径 壁并依赖于蛋白激酶 C (Pkc1)。 CWI/PKC1 通路在响应中发挥关键作用 热休克、氧化和亚硝化应激以及细胞壁抑制剂。我们的初步数据表明，这 该通路是控制细胞壁生物合成、修复和重塑的高度连接网络的一部分。这 该项目的主要目标是确定维持细胞壁完整性的机制 特定细胞壁抑制剂，包括棘白菌素，并确定抗真菌药物的潜在基因靶标 与棘白菌素有协同作用。具体目标有以下三个： 在第一个目标中，我们将使用以下方法定义细胞壁完整性途径在棘白菌素耐药性中的作用 基因组和网络分析方法。在第二个目标中，我们将鉴定细胞壁必需的基因 完整性，并通过筛选特定的大缺失集来促进棘白菌素耐药性 表型。在第三个目标中，我们将评估细胞壁完整性成分的功能相互作用。 在这个高度合作的项目中，我们建议利用我们互补的专业知识来整合遗传、 表型和生化数据，用于识别和表征控制细胞壁的相互作用网络 新型隐球菌的体内平衡。这将显着增进我们对细胞壁维护和 人类病原体的重塑，将为设计特定的抗真菌药物提供多个靶点 对哺乳动物来说不太可能有毒。