Evolved Heterogeneity Contributes to Chronic Fungal Lung Infections

进化的异质性导致慢性肺部真菌感染

• 批准号: 10413233
• 负责人: DEBORAH A HOGAN
• 金额: $ 45.46万
• 依托单位: DARTMOUTH COLLEGE
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-07-19 至 2026-06-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10413233
• 关键词: Affect; Antibiotic Resistance; Antifungal Agents; Azole resistance; Bacterial Infections; Bacterial Toxins; Biology; Candida; Candida auris; Candidiasis; Cells; Chronic; Coculture Techniques; Collaborations; Complex; DNA Binding; Data; Development; Disease Outbreaks; Drug resistance; Environment; Event; Evolution; Fermentation; Frequencies; Fungal Drug Resistance; Genes; Genetic; Genomics; Glycolysis; Growth; Heterogeneity; Hospitals; Hydrogen Peroxide; Induced Mutation; Infection; Inflammation; Iron; Lung infections; Metabolic; Metabolism; Metals; Mitochondria; Modeling; Modification; Multi-Drug Resistance; Mutation; Mycoses; Oxidative Stress; Pathway interactions; Phenotype; Phylogenetic Analysis; Physiology; Population; Production; Proteins; Publishing; Pyruvaldehyde; Regulon; Reporting; Resistance; Resistance development; Respiration; Signal Transduction; Stress; Surface; System; Testing; Time; Treatment Failure; Variant; Work; active control; airway inflammation; antimicrobial peptide; chronic infection; cystic fibrosis patients; fitness; fungus; health care settings; in vivo; inflammatory milieu; loss of function mutation; metabolomics resource; mortality; multi-drug resistant pathogen; neutrophil; pathogen; pathogenic fungus; programs; response; tool; trait; transcription factor; transcriptomics; treatment strategy; uptake

Project Summary During chronic fungal infections, heterogeneous subpopulations can arise. While these diversified populations can pose significant challenges for treatment, they also provide an opportunity to identify pathways under selection in vivo. This proposal focuses on the study of unique longitudinally-collected sets of Candida (Clavispora) lusitaniae isolates from three individuals with cystic fibrosis (CF). In each case, the C. lusitaniae infections replaced prior chronic bacterial infections, were associated with high levels of airway inflammation, and were resistant to treatment. C. lusitaniae is an emerging agent of candidiasis known to develop resistance to antifungal drugs and is a close relative of Candida auris, a multidrug resistant pathogen that has repeatedly caused hospital associated outbreaks with high mortality. Through the genomic and phenotypic analysis of variable traits in these chronic infection populations, via a productive collaboration between the Hogan and Stajich Labs, we found striking heterogeneity in two genes: MRR1, which encodes a transcription factor known for its ability to confer resistance to azoles, bacterial toxins, and host antimicrobial peptides, and MRS4, a mitochondrial iron transporter that affects metabolism and metal uptake. We propose that these genes strongly impact host interactions and fungal physiology in vivo. Our studies revealed that Mrr1 controls a large regulon of resistance, metabolic and metal acquisition genes, and we discovered the first endogenous inducer of Mrr1, methylglyoxal (MG), which spontaneously forms from intermediates in glycolysis. Further, we found that repeated loss-of-function mutations in a second gene, MRS4, biases cells towards a glycolytic metabolism, increased MG production, and increased Mrr1 signaling. We propose that these changes promote survival in an inflammatory environment. Specifically, we propose to test the hypotheses that (Aim 1) endogenous MG directly stimulates inducible Mrr1 variants, (Aim 2) that MRS4 loss-of-function mutations induce MG Mrr1 signaling through increased glycolysis, and (Aim 3) that increased glycolysis decreases ROS accumulation in co-culture with activated neutrophils. As we show in published and preliminary data, the pathways and mechanisms studied here are conserved broadly across diverse Candida pathogens including C. auris. Through this work, we aim to further develop our understanding of C. auris, and ways in which C. lusitaniae can be used as a highly tractable, parallel system with an expanded tool kit including genetic, genomic, transcriptomic, and metabolomic resources. We propose that the studies will reveal new broadly relevant mechanisms by which fungi adapt to the host environment which can inform new treatment strategies.

项目摘要 在慢性真菌感染期间，可能会出现不同的亚群。虽然这些产品多样化 人口可能对治疗构成重大挑战，它们也提供了确定治疗途径的机会 在体内进行选择。这项建议侧重于对独特的纵向收集的念珠菌集合的研究 (Clavispora)lusitaniae分离自三个囊性纤维化(CF)患者。在每一种情况下，卢西坦氏杆菌 感染取代了以前的慢性细菌感染，与高水平的呼吸道炎症有关， 并且对治疗有抵抗力。卢氏假丝酵母菌是一种新出现的可产生耐药性的念珠菌病病原体。 对抗真菌药物敏感，是金黄色念珠菌的近亲，金黄色念珠菌是一种耐多药的病原体，曾多次 导致医院相关疫情，死亡率高。通过基因组和表型分析 通过Hogan和Hogan之间的富有成效的合作，这些慢性感染人群中的可变特征 我们在两个基因中发现了惊人的异质性：MRR1，它编码一种已知的转录因子 由于其对氮唑、细菌毒素和宿主抗菌肽的抗药性，以及MRS4，A 影响新陈代谢和金属摄取的线粒体铁转运体。我们认为这些基因强烈地 影响寄主相互作用和体内真菌生理学。我们的研究表明，mrr1控制着大量的 抗性、代谢和金属获得基因，我们发现了MRr1的第一个内源性诱导物， 甲基乙二醛(MG)，由糖酵解的中间产物自发形成。此外，我们发现重复了这一点 第二个基因MRS4的功能丧失突变使细胞偏向糖酵解代谢，增加MG 产量，并增加了mrr1信号。我们认为这些变化促进了炎症性疾病的存活率。 环境。具体地说，我们建议检验(目标1)内源性MG直接刺激的假设 可诱导的MRr1变异体，(目标2)MRS4功能缺失突变通过 增加糖酵解，以及(目标3)增加糖酵解减少与 激活的中性粒细胞。正如我们在已发表的和初步的数据中所显示的，所研究的途径和机制 在各种念珠菌中广泛保守，包括金黄色念珠菌。通过这项工作，我们的目标是 进一步发展我们对金黄色葡萄球菌的理解，以及如何将金黄色葡萄球菌用作高度易驯化的 具有扩展工具包的并行系统，包括遗传、基因组、转录和代谢组学资源。我们 提出这些研究将揭示真菌适应宿主环境的新的广泛相关的机制 这可以为新的治疗策略提供信息。