Evolved Heterogeneity Contributes to Chronic Fungal Lung Infections

项目摘要 在慢性真菌感染期间，可能会出现异质亚群。虽然这些多样化 人群可能对治疗构成重大挑战，但也提供了确定途径的机会 在体内进行选择。这项建议的重点是研究独特的口腔收集集念珠菌 （Clavispora）lusitaniae分离自患有囊性纤维化（CF）的三个个体。在每种情况下，C.卢西塔尼亚 感染取代了先前的慢性细菌感染，与高水平的气道炎症有关， 并且对治疗有抵抗力。C. Lusitaniae是一种新的念珠菌病病原体， 抗真菌药物，是耳念珠菌的近亲，耳念珠菌是一种多药耐药病原体， 导致医院相关的爆发，死亡率很高。通过基因组和表型分析， 这些慢性感染人群的可变特征，通过霍根和 在Stajich实验室，我们发现了两个基因的显著异质性：MRR 1，它编码一种转录因子， 由于其赋予对唑类、细菌毒素和宿主抗微生物肽的抗性的能力， 线粒体铁转运蛋白，影响新陈代谢和金属吸收。我们认为这些基因强烈地 影响体内宿主相互作用和真菌生理学。我们的研究表明，Mrr1控制着一个大的调节子， 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），它在糖酵解的中间体中自发形成。此外，我们发现，重复 第二个基因MRS4的功能缺失突变使细胞偏向糖酵解代谢，增加MG 生产，并增加Mrr1信号。我们认为，这些变化促进了炎症性细胞的存活， 环境具体来说，我们建议测试假设（目的1）内源性MG直接刺激 诱导型Mrr1变体，（目的2）MRS 4功能丧失突变通过 增加的糖酵解，和（目的3）增加的糖酵解减少与 活化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那样， 在包括C.耳。通过这项工作，我们的目标是 进一步加深对C. auris的表达，以及C. Lusitaniae可以用作高度易处理的， 平行系统与扩展的工具包，包括遗传，基因组学，转录组学和代谢组学资源。我们 我认为这些研究将揭示真菌适应宿主环境的新的广泛相关机制 这可以为新的治疗策略提供信息。

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.