Regulation of Multidrug Resistance in the Emerging Human Fungal Pathogen Candida auris

项目总结/摘要 耳念珠菌是一种迅速出现的人类真菌病原体，能够引起全身和粘膜 各种免疫功能低下个体的感染，包括器官移植受者、癌症 化疗患者和艾滋病患者。C.奥里斯已经出现在多个大陆，负责 许多医院爆发，粗死亡率高（30-70%），已被列为“紧急” 疾病控制中心（CDC）对公众健康的威胁。许多C。耳分离株对 多种类型的抗真菌剂，特别是唑类和多烯类，这是特别令人关注的，因为只有 有三种主要的药物可用于治疗念珠菌病患者。以往的研究表明，C. 耳抗真菌抗性可归因于多种遗传点突变（例如：ERG 11中的突变， 编码羊毛甾醇14α-脱甲基酶，唑类的靶点）以及某些药物的转录增加 外排泵与遗传和转录机制相反， 控制C.耳或其它人类真菌病原体。但我们的 实验室和其他人已经表明，5 ′ UTR介导翻译效率机制在 在控制形态学，生物膜形成， 白色不透明转换和相关的主要人类真菌病原体白色念珠菌的毒力。在 此外，RNA-seq分析表明，许多基因参与了各种额外的毒力， 过程，包括抗真菌药物的耐药性，在C.白色念珠菌和其他念珠菌属物种具有长的5' UTR 可能参与翻译调控的区域。使用全基因组核糖体分析，我们有 最近证明，C.白色念珠菌酵母-丝转变受到广泛的翻译控制 它并不是简单地平行于基因表达中的转录变化。几个基因与 抗真菌抗性也显示在该转变期间改变的翻译效率。重要的是，最近 多药耐药C.耳分离物已经证明， 参与蛋白质合成的基因在抗真菌治疗中表现出改变的表达。基于 根据这些观察，我们假设翻译机制在控制蛋白质表达中起着重要作用。 C.多药耐药耳。为了解决这一假设，我们将：1）确定基因组范围内的 C.的翻译谱。对氟康唑（一种常用的唑类药物）治疗的反应， 多烯药物阿替霉素B，2）鉴定和表征对促进C. 耳多药耐药最终，这项研究将提供更好的理解全球监管电路 和控制C的途径。耳多药耐药的翻译水平。此外，本研究将 确定和表征了几个关键的重要调控因子。耳用多药 耐药性，可能作为新的抗真菌策略的发展目标。

PROJECT SUMMARY/ABSTRACT Candida auris is a rapidly emerging human fungal pathogen capable of causing both systemic and mucosal infections in a wide variety of immunocompromised individuals, including organ transplant recipients, cancer patients on chemotherapy and AIDS patients. C. auris has emerged on multiple continents, is responsible for numerous hospital outbreaks and, with a high crude mortality rate (30-70%), has been classified as an “urgent” threat to public health by the Centers for Disease Control (CDC). Many C. auris isolates are highly resistant to multiple classes of antifungals, particularly azoles and polyenes, which is especially concerning given that only three major drug classes are available to treat patients with candidiasis. Previous studies have shown that C. auris antifungal resistance can be attributed to a variety of genetic point mutations (eg: mutations in ERG11, encoding lanosterol 14α-demethylase, the target of azoles) as well as increased transcription of certain drug efflux pumps. In contrast to genetic and transcriptional mechanisms, very little is known about translational mechanisms that control antifungal resistance in C. auris or other human fungal pathogens. However, our laboratory and others, have shown that 5' UTR-mediated translational efficiency mechanisms play an important role in controlling the expression of several key transcriptional regulators of morphology, biofilm formation, white-opaque switching and virulence in the related major human fungal pathogen Candida albicans. In addition, RNA-seq analyses have shown that many genes involved in a variety of additional virulence processes, including antifungal resistance, in C. albicans and other Candida species possess long 5' UTR regions that could be involved in translational regulation. Using genome-wide ribosome profiling, we have recently demonstrated that the C. albicans yeast-filament transition is under widespread translational control that does not simply parallel transcriptional changes in gene expression. Several genes associated with antifungal resistance also showed altered translational efficiency during this transition. Importantly, recent transcriptional profiling of a multidrug resistant C. auris isolate has demonstrated that a significant number of genes involved in protein synthesis show altered expression in response to antifungal treatment. Based on these observations, we hypothesize that translational mechanisms play an important role in controlling multidrug resistance in C. auris. In order to address this hypothesis, we will: 1) determine the genome-wide translational profile of C. auris in response to treatment with fluconazole, a commonly used azole, and the polyene drug amphotericin B, 2) identify and characterize translational mechanisms important for promoting C. auris multidrug resistance. Ultimately, this study will provide a better understanding of global regulatory circuits and pathways that control C. auris multidrug resistance at the translational level. In addition, this study will identify and characterize several key translationally regulated factors important for C. auris multidrug resistance that could potentially serve as targets for the development of novel antifungal strategies.