Genetics of fungal persistence and pathogenicity in mammalian hosts

哺乳动物宿主中真菌持久性和致病性的遗传学

• 批准号: 10874018
• 负责人: Ian Michael Ehrenreich
• 金额: $ 62.4万
• 依托单位: UNIVERSITY OF SOUTHERN CALIFORNIA
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-08-17 至 2024-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10874018
• 关键词: Adhesions; Affect; Alleles; Antifungal Therapy; Bar Codes; Blood - brain barrier anatomy; Body Temperature; Brain; CRISPR/Cas technology; Candida albicans; Candidate Disease Gene; Cells; Chromosome Mapping; Clinical; Cloning; Cre-LoxP; Data; Development; Diploidy; Dissection; Gene Expression; Genes; Genetic; Genotype; Haploidy; Health Benefit; Heritability; Heterozygote; High temperature of physical object; Human; Human body; Image; Infection; Invaded; Investigation; Kidney; Life; Liver; Mammals; Maps; Mediating; Meiosis; Microscopy; Modeling; Molecular; Morphology; Mus; Mycoses; Necrosis; Organ; Partner in relationship; Pathogenesis; Pathogenicity; Penetration; Phenotype; Physiological; Population; Protocols documentation; Role; Saccharomyces cerevisiae; Saccharomycetales; Sampling; Shapes; Societies; Source; Spleen; Surface; Testing; Tissues; Variant; Work; Yeast Model System; Yeasts; candidate identification; causal variant; clinically relevant; design; experimental study; follow-up; fungal genetics; fungus; gene cloning; genetic variant; human pathogen; insight; microbial; model organism; opportunistic pathogen; pathogenic fungus; pleiotropism; transcriptome sequencing

Project Summary Opportunistic fungal infections can be life-threatening and difficult to treat. Identifying the genetic and molecular mechanisms that enable fungi to persist in humans could have major health benefits for society, potentially even enabling the development of more effective antifungal therapies. The model organism Saccharomyces cerevisiae is itself an opportunistic human pathogen, with many strains isolated from clinical infections. The ability to infect and persist within humans is not universal among S. cerevisiae strains. Clinical S. cerevisiae isolates tend to be highly heterozygous diploids that can grow at higher temperatures and invade into surfaces. However, rigorous genetic dissection of S. cerevisiae’s persistence and pathogenicity within mammalian hosts is needed. To begin such work, we used chromosomally- encoded barcodes and lineage tracking to phenotype a panel of genotyped haploid progeny from a budding yeast cross in mice. The specific cross employed was between a haploid derivative of a clinical isolate and the reference strain. Linkage mapping identified dozens of loci influencing fungal persistence within a mammalian host, many of which lack previously identified candidate genes and show host organ-dependent effects. Following our work, major questions remain unanswered, including the genetic, molecular, and physiological mechanisms underlying yeast persistence and yeast-host interactions; how alleles at causal loci shape the phenotypes of highly heterozygous diploids resembling clinical isolates; the role of surface attachment and invasion in persistence and pathogenicity; and whether the effects of causal loci contributing to fungal pathogenicity have effects that depend on host genotype. Here, we will extend our work by (1) studying mechanisms causing yeast persistence in particular organs by cloning causal genes in yeast, as well as by using cutting-edge microscopy and RNA-seq to analyze yeast-host interactions; (2) testing how combinations of pathogenicity alleles combine in highly heterozygous diploid yeast strains; (3) analyzing how the ability to attach to and invade into surfaces influences the pathogenicity of cross progeny; and (4) examining the genetics of fungal pathogenicity across genetically distinct mouse hosts. Our proposal will utilize the untapped potential of the budding yeast model system to provide concrete insights into the genetics and molecular mechanisms underlying opportunistic fungal pathogenicity.

项目概要 机会性真菌感染可能危及生命且难以治疗。识别 使真菌能够在人类体内持续存在的遗传和分子机制可能具有重大意义 为社会带来健康益处，甚至有可能促进开发更有效的 抗真菌疗法。模式生物酿酒酵母本身就是一种机会主义生物体。 人类病原体，从临床感染中分离出许多菌株。感染能力和 在人类体内持续存在的细菌在酿酒酵母菌株中并不普遍。临床酿酒酵母 分离株往往是高度杂合的二倍体，可以在更高的温度下生长 侵入表面。然而，对酿酒酵母的持久性和严格的基因解剖 需要在哺乳动物宿主内具有致病性。为了开始这项工作，我们使用了染色体- 编码条形码和谱系追踪对一组基因型单倍体后代进行表型分析 来自小鼠中的出芽酵母杂交。所采用的具体杂交是在单倍体之间 临床分离株和参考株的衍生物。连锁图谱鉴定出数十个位点 影响哺乳动物宿主体内的真菌持久性，其中许多真菌此前缺乏识别 候选基因并显示宿主器官依赖性效应。继我们的工作之后，主要问题 仍然没有答案，包括潜在的遗传、分子和生理机制 酵母持久性和酵母-宿主相互作用；因果位点的等位基因如何塑造表型 类似于临床分离株的高度杂合的二倍体；表面附着的作用和 入侵的持久性和致病性；以及因果位点的影响是否有助于 真菌致病性的影响取决于宿主基因型。在这里，我们将扩展我们的工作 通过（1）通过克隆因果关系来研究导致酵母在特定器官中持久存在的机制 酵母中的基因，以及使用尖端显微镜和 RNA-seq 来分析酵母宿主 互动； (2) 测试致病性等位基因的组合如何高度结合 杂合二倍体酵母菌株； (3)分析附着能力和侵入能力如何 表面影响杂交后代的致病性； (4) 检查真菌的遗传学 跨遗传不同的小鼠宿主的致病性。我们的建议将利用未开发的 芽殖酵母模型系统的潜力为遗传学和 机会性真菌致病性的分子机制。