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.

项目概要 白色念珠菌是临床上危及生命的全身性疾病的常见原因。 这是一个高度适应的物种，能够占据人体的不同生态位，无论是作为 良性共生或作为机会病原体二倍体基因组由八个杂合子组成。 可能发生从头突变、杂合性丢失 (LOH) 或更大规模的染色体 重排，包括整个多余染色体的获得或丢失。 机制在人群中产生巨大差异，但目前了解有限 这些自然差异如何影响与宿主的相互作用。 该项目将研究种内多样性如何影响共生和 初步实验表明临床分离株表现出白色念珠菌的致病特性。 广泛的基因型差异以及在宿主传递过程中发生额外的微变异。 为了确定遗传多样性如何影响白色念珠菌生物学，我们对临床样本进行了测序 分离株将在不同的小鼠感染模型中进行条形码标记和分析。 不同的分离株将在不同的宿主生态位中表现出最佳的适应性，我们的研究将揭示这些 对每个生态位竞争过度或竞争低下的分离株 同时，SC5314 分离株的集合。 将进行条形码标记并分析表型和基因型差异 SC5314 是标准。 白色念珠菌的“实验室”分离株，但初步数据表明获得的分离株之间存在多样性 这揭示了对 SC5314 系列进行详细分析的迫切需要。 确定菌株之间的遗传变异水平以及它如何影响表型特性。 我们还将重点检查两个 C. 之间共生主义的差异。 白色念珠菌分离株 SC5314 和 529L 无法定植于小鼠胃肠道 (GI)。 在没有抗生素的情况下，而我们发现分离株 529L 可以稳定维持胃肠道定植水平 即使没有补充抗生素，为了确定造成这种差异的遗传位点，两者也进行了研究。 菌株彼此杂交并对重组后代进行基因分型。 用于数量性状基因座 (QTL) 作图，以定义构成 GI 定植特性的基因座 并了解遗传变异如何影响共生主义。 这些实验将共同使用高通量技术来研究遗传如何 白色念珠菌种群的多样性也会影响与宿主的共生和致病相互作用 作为检查胃肠道定植因素的定向方法，我们的实验将。 更好地了解白色念珠菌遗传变异在感染结果中所起的作用， 包括确定促进适应特定宿主生态位的机制。