Overcoming Emerging Aspergillus fumigatus Azole Resistance Via Protease Inhibition

通过蛋白酶抑制克服新出现的烟曲霉唑抗性

• 批准号: 10320260
• 负责人: Robert Andrew Cramer
• 金额: $ 44.46万
• 依托单位: DARTMOUTH COLLEGE
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-02-01 至 2024-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10320260
• 关键词: Address; Animal Model; Antifungal Agents; Aspergillosis; Aspergillus fumigatus; Azole resistance; Biological Assay; Cells; Chemicals; Chemistry; Clinical; Complex; Data; Disease; Disease Progression; Drug Kinetics; Drug resistance; Environment; Fostering; Fungal Drug Resistance; Genetic; Genomics; Goals; Growth; Human; Hypoxia; Impairment; In Vitro; Infection; Laboratories; Lead; Libraries; Ligase; Link; Measures; Modeling; Molds; Molecular Target; Morbidity - disease rate; Mus; Mycoses; Organism; Outcome; Oxygen; Pathway interactions; Peptide Hydrolases; Pharmaceutical Preparations; Pharmacology; Pharmacology and Toxicology; Pharmacotherapy; Phase; Phenotype; Physiological; Predisposition; Property; Reporter; Resistance; Series; Serine Protease; Signal Pathway; Site; Specificity; Therapeutic; Toxic effect; Transcriptional Activation; Treatment outcome; Triazoles; Validation; Virulence; acute toxicity; analog; base; candidate identification; cytotoxicity; druggable target; fitness; fungus; improved; in vivo; in vivo evaluation; inhibitor/antagonist; mortality; mouse model; mutant; novel; pathogenic fungus; pre-clinical; resistant strain; response; scaffold; small molecule; small molecule libraries; therapeutic candidate; ubiquitin-protein ligase

PROJECT SUMMARY. Infections caused by the filamentous fungus Aspergillus fumigatus and related species are associated with significant morbidity and mortality despite contemporary antifungal drug therapies. Many factors contribute to poor treatment outcomes including the physiological state of the fungus at the site of infection and the global emergence of triazole drug resistant strains. One major regulatory mechanism used by the fungus to progress disease and resist triazole drug activity is proteolytic activation of the transcriptional regulator, SrbA. Activation of SrbA in vivo is absolutely required for fungal virulence and intrinsic triazole drug resistance, as null mutants of SrbA regulatory factors such as the fungal specific activating serine protease RbdB and E3 ubiquitin ligases (DSCs) are avirulent in animal models of invasive aspergillosis (IA) and have significant increases in triazole susceptibility. The objective of this proposal in response to RFA-AI-17-036 is to identify small molecules that inhibit SrbA activation and develop them into advanced therapeutic candidates with broad-spectrum activity against triazole resistant filamentous fungi. Potent inhibitors of the SrbA- dependent signaling pathway will be developed for clinical use as an adjunctive therapy in combination with a triazole antifungal agent that is used to treat IA. The adjunctive therapy is expected to provide several advantages over triazole monotherapy, including growth inhibition in hypoxic conditions and increased antifungal activity of the triazole drug in both drug susceptible and drug resistant infections. As the SrbA pathway is conserved among most human fungal pathogens, some of which are inherently azole resistant, we anticipate broad spectrum clinical utility beyond infections caused by A. fumigatus. Our approach leverages the availability of well characterized protease and ligase inhibitor chemical libraries, both known druggable targets in many disease settings, with the expertise of Microbiotix Inc. and the Cramer Laboratory at Dartmouth. The R21 phase of this application will utilize high-throughput cell based screens of defined targeted small molecule libraries to identify and confirm SrbA regulatory protease and/or ligase inhibitors and validate their antifungal activity, pathway specificity, and mammalian toxicity of early hits and leads. In the R33 phase, validated hits will be chemically optimized, validated, defined pharmacologically, determine mechanism of action, and finally proceed to in vivo pharmacologic and toxicology profiling and antifungal efficacy in established murine models of invasive aspergillosis.

项目摘要。由丝状真菌曲霉引起的感染和相关物种 尽管当代抗真菌药物疗法，仍与明显的发病率和死亡率有关。许多 因素导致治疗结果不良，包括在该部位的真菌的生理状态 感染和抗三唑药物抗性菌株的全球出现。一种主要的监管机制 进行疾病和抗三唑药物的真菌是转录的蛋白水解激活 监管机构，SRBA。真菌毒力和内在的三唑药物绝对需要SRBA在体内的激活 抗性，作为SRBA调节因子的无效突变体，例如真菌特异性激活丝氨酸蛋白酶 RBDB和E3泛素连接酶（DSC）在浸润性曲霉病（IA）的动物模型中是无毒的，并且具有 三唑敏感性的显着增加。该提案以响应RFA-AI-17-036的目的是 识别抑制SRBA激活并将其发展为晚期治疗候选者的小分子 具有抗三唑耐丝状真菌的广谱活性。 SRBA的有效抑制剂 将开发依赖的信号通路作为临床用作作为辅助治疗，并结合使用 用于治疗IA的三唑抗真菌剂。预计辅助疗法将提供几种 优于三唑单一疗法的优势，包括低氧条件下的生长抑制和增加 三唑药在药物易感和耐药感染中的抗真菌活性。作为srba 大多数人类真菌病原体中的途径是保守的，其中一些固有地是抗唑的，我们 预期广泛的临床实用性超出了烟曲霉引起的感染。我们的方法利用了 蛋白酶和连接酶抑制剂化学库的可用性，这两个可用性靶标 在许多疾病环境中，Microbiotix Inc.和Dartmouth的Cramer实验室的专业知识。这 该应用的R21相将利用定义的针对小分子的高通量细胞屏幕 识别和确认SRBA调节蛋白酶和/或连接酶抑制剂的库并验证其抗真菌 早期流行和铅的活动，途径特异性和哺乳动物毒性。在R33阶段，已验证的命中 将通过化学优化，经过验证，在药理学上定义，确定作用机理，最后 继续进行体内药理学和毒理学分析和抗真菌疗效 侵入性曲霉病。