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，可能会出现异质亚群。而这些多元化 人口可能对治疗构成重大挑战，他们还提供了一个机会来识别途径 在体内选择下。该提案重点是研究独特的纵向收集的念珠菌集 （clavispora）来自三个具有囊性纤维化（CF）的个体的lusitaniae分离株。在每种情况下，C。Lusitaniae 取代先前慢性细菌感染的感染与高水平的气道炎症有关， 并且对治疗有抵抗力。 C. lusitaniae是已知会发展抗性的念珠菌病的新兴药物 抗真菌药物，是念珠菌的近亲 导致医院相关的暴发与死亡率高。通过基因组和表型分析 这些慢性感染人群中的可变特征是通过霍根和 Stajich Labs，我们发现了两个基因的引人注目的异质性：MRR1，它编码转录因子已知 因为它能够赋予对叠唑，细菌毒素和宿主抗菌肽和MRS4的耐药性 线粒体铁转运蛋白影响代谢和金属摄取。我们建议这些基因强烈 在体内影响宿主的相互作用和真菌生理。我们的研究表明，MRR1控制 抗性，代谢和金属采集基因，我们发现了MRR1的第一个内源性诱导剂， 甲基糖（Mg），它是由中间体自发形成的。此外，我们发现重复 第二个基因MRS4的功能丧失突变使细胞偏离糖酵解代谢，Mg增加了Mg 生产并增加了MRR1信号传导。我们建议这些变化促进炎症中的生存 环境。具体而言，我们建议测试（AIM 1）内源性MG直接刺激的假设 诱导MRR1变体，（AIM 2）MRS4功能丧失突变诱导MG MRR1信号传导 糖酵解的增加，（目标3）增加糖酵解可减少与 激活的中性粒细胞。正如我们在发布和初步数据中所显示的那样，所研究的途径和机制 这里是包括Auris在内的各种念珠菌病原体的广泛保守。通过这项工作，我们的目标是 进一步发展了我们对C. auris的理解，以及可以将C. lusitaniae用作高度处理的方式 具有扩展工具套件的并行系统，包括遗传，基因组，转录组和代谢组资源。我们 建议这些研究将揭示真菌适应宿主环境的新的广泛相关机制 可以为新的治疗策略提供信息。