Defining the Impact of Intra-Species Diversity on C. albicans Biology

定义种内多样性对白色念珠菌生物学的影响

• 批准号: 9979250
• 负责人: Richard John Bennett
• 金额: $ 20.98万
• 依托单位: BROWN UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-03-18 至 2022-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9979250
• 关键词: Address; Adult; Affect; Aneuploidy; Antibiotics; Antifungal Agents; Attention; Bar Codes; Behavior; Benign; Biology; Candida; Candida albicans; Chromosomes; Clinic; Clinical; Collection; Data; Diploidy; Disease; Enabling Factors; Epigenetic Process; Exhibits; Gastrointestinal tract structure; Genes; Genetic; Genetic Determinism; Genetic Variation; Genome; Genomics; Genotype; Human; Human body; Immunocompromised Host; In Vitro; Individual; Infection; Knowledge; Laboratories; Lead; Life; Life Style; Loss of Heterozygosity; Modeling; Mucous Membrane; Mus; Mycoses; Oral cavity; Outcome; Pathogenicity; Phenotype; Play; Population; Property; Quantitative Trait Loci; Recombinants; Role; Sepsis; Site; Skin; Source; Supplementation; Symbiosis; Systemic disease; Systemic infection; Techniques; Testing; Variant; Yeasts; clinically relevant; comparative genomics; de novo mutation; experience; experimental study; fitness; flexibility; gastrointestinal; genetic variant; genomic locus; genomic variation; gut colonization; high throughput analysis; in vivo; interest; microbiota; mortality; mouse model; pathogen; phenomics; reproductive tract; trait

Project Summary The yeast Candida albicans is a prevalent cause of life-threatening systemic disease in the clinic. This is a highly adaptive species with the ability to occupy diverse niches in the human body, either as a benign commensal or as an opportunistic pathogen. The diploid genome consists of eight heterozygous chromosomes that can undergo de novo mutation, loss of heterozygosity (LOH), or larger scale rearrangements including the acquisition or loss of whole supernumerary chromosomes. These mechanisms generate substantial variation in the population, yet there is currently limited understanding of how these natural differences effect interactions with the host. This project will examine how intra-species diversity impacts both the commensal and pathogenic properties of C. albicans. Preliminary experiments reveal that clinical isolates exhibit extensive genotypic differences and that additional microvariation occurs during passaging in the host. To determine how genetic diversity impacts C. albicans biology, a sequenced collection of clinical isolates will be barcoded and analyzed in different murine infection models. We hypothesize that different isolates will show optimal fitness in different host niches, and our studies will reveal those isolates that are hyper- or hypo-competitive for each niche. In parallel, a collection of SC5314 isolates will be barcoded and analyzed for phenotypic and genotypic differences. SC5314 is the standard “laboratory” isolate of C. albicans and yet preliminary data indicates diversity between isolates obtained from around the world. This reveals a critical need for a detailed analysis of the SC5314 collection to determine the level of genetic variation between strains and how this is affecting phenotypic properties. We will also perform a focused examination of differences in commensalism between two C. albicans isolates, SC5314 and 529L. SC5314 is unable to colonize the murine gastrointestinal tract (GI) in the absence of antibiotics, whereas we reveal that isolate 529L stably maintains GI colonization levels even without antibiotic supplementation. To identify genetic loci responsible for this difference, the two strains have been crossed to one another and recombinant progeny genotyped. These progeny will be used for quantitative trait loci (QTL) mapping to define the loci that underlie GI colonization properties and to understand how genetic variants impact commensalism. Together, these experiments will use high-throughput techniques to examine how genetic diversity in C. albicans populations impacts commensal and pathogenic interactions with the host, as well as a directed approach to examine factors enabling colonization of the GI tract. Our experiments will provide greater understanding of the role that genetic variation in C. albicans plays in infection outcomes, including the identification of mechanisms that promote adaptation to specific host niches.

项目摘要 白色念珠菌是临床上常见的危及生命的全身性疾病。 这是一个高度适应性的物种，有能力在人体内占据不同的壁龛，无论是作为一个 良性的尿道炎或机会致病菌。二倍体基因组由八个杂合的 可能发生从头突变、杂合性丢失（洛）或更大规模的染色体 重排包括整个额外染色体的获得或丢失。这些 机制在人群中产生了很大的变化，但目前的理解有限 这些自然差异如何影响与宿主的互动。 该项目将研究物种内多样性如何影响生物多样性， 致病性C.白色念珠菌。初步实验表明，临床分离株表现出 广泛的基因型差异和在宿主传代期间发生的额外微变异。 为了确定遗传多样性如何影响C。白念珠菌生物学，临床 将分离物条形码化并在不同的鼠感染模型中分析。我们假设 不同的分离物将在不同的宿主生态位中表现出最佳适应性，我们的研究将揭示这些 对每个生态位都具有高度或低度竞争力的分离株。与此同时，一组SC5314分离株 将被条形码化并分析表型和基因型差异。SC5314是标准 实验室分离的C.但初步数据表明，获得的分离株之间存在多样性， 来自世界各地这表明迫切需要对SC5314系列进行详细分析， 确定菌株之间的遗传变异水平以及这如何影响表型特性。 我们还将对两个C. 白色念珠菌分离株SC5314和529L。SC5314不能定殖于小鼠胃肠道（GI） 在没有抗生素的情况下，而我们揭示分离物529L稳定地维持GI定殖水平， 即使没有抗生素的补充。为了确定导致这种差异的遗传位点， 已将菌株彼此杂交并对重组后代进行基因分型。这些后代将是 用于数量性状基因座（QTL）定位，以定义GI定殖特性的基因座 并了解基因变异如何影响寄生虫病。 总之，这些实验将使用高通量技术来研究基因是如何被遗传的。 C.多样性白念珠菌种群影响与宿主的寄生和致病相互作用， 作为检查使胃肠道定植的因素的直接方法。我们的实验将 提供了更好的理解的作用，遗传变异在C。白色念珠菌在感染结果中起作用， 包括确定促进适应特定宿主生态位的机制。