Characterization of novel virulence factors in Candida

念珠菌新型毒力因子的表征

• 批准号: 10319584
• 负责人: Michael C Lorenz
• 金额: $ 52.12万
• 依托单位: UNIVERSITY OF TEXAS HLTH SCI CTR HOUSTON
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-01-10 至 2023-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10319584
• 关键词: Adhesions; Affect; Age; Amino Acids; Animal Model; Antioxidants; Bacterial Adhesins; Binding; Biological Assay; Biology; Candida; Candida albicans; Candidiasis; Catheters; Cell Culture Techniques; Cell Wall; Cell surface; Cells; Cessation of life; Clustered Regularly Interspaced Short Palindromic Repeats; Coculture Techniques; Codon Nucleotides; Complex; Data; Defect; Diagnosis; Disseminated candidiasis; Eligibility Determination; Environment; Fungal Genes; Gastrointestinal tract structure; Gene Expression Profiling; Gene Library; Genes; Genetic; Genetic Diseases; Genetic Transcription; Goals; Human; Human Microbiome; Hydrolase; Iatrogenesis; Immune; In Vitro; Infection; Laboratories; Libraries; Life; Life Style; Lipase; Lysine; Malignant Neoplasms; Mediating; Mediator of activation protein; Metabolism; Methods; Modeling; Molecular; Morbidity - disease rate; Morphology; Mucous Membrane; Mus; Mutate; Natural Immunity; Nutritional; Open Reading Frames; Operative Surgical Procedures; Oral; Oral candidiasis; Organism; Outcome; Oxidative Stress; Oxides; Pathogenicity; Patients; Peptide Hydrolases; Peptides; Phagocytes; Phagocytosis; Phenotype; Physiological; Plant Roots; Property; Proteins; Quinones; Reactive Oxygen Species; Resistance; Risk Factors; Role; Saccharomyces cerevisiae; Series; Skin; Surface; Symbiosis; System; Testing; Trauma; United States; Vagina; Veins; Virulence; Virulence Factors; Vulvovaginal Candidiasis; amyloid formation; base; biological adaptation to stress; chemotherapy; clinically relevant; deletion library; fitness; flexibility; fungus; genetic analysis; genetic testing; genome annotation; immunological status; implantable device; in vivo; innovation; macrophage; microbiome components; microbiota; mortality; mouse model; mutant; neutrophil; novel; novel therapeutics; oral infection; oxidation; oxidative damage; pathogen; pathogenic fungus; response; success; transcriptome sequencing

Abstract Candida albicans is uniquely associated as a commensal component of the microbiota of most humans, without harm to most of us, yet it causes a range of infections from mild to life- threatening, based on the immune status of the host. The interaction between C. albicans and mammalian phagocytes is critical, and the Candida-macrophage co-culture has become a valuable model to uncover specific adaptations that promote virulence and commensalism. To further probe the novel biology of this interaction, we used transcriptional profiling to identify fungal genes induced upon phagocytosis. While some of these have recognizable functions, mostly in metabolism (a known response to phagocytosis), more than half the induced genes are uncharacterized and not widely conserved. A surprising number of these genes are quite small and missed in early annotations. Given the uniqueness of the C. albicans-human association, this set of genes is likely enriched for adaptations of C. albicans to host niches. In proof of this principle, we have mutated three of these genes and all three have host-relevant phenotypes, with one as a novel cell wall-associated microadhesin required for adhesion to biotic and abiotic surfaces and for virulence in mouse models. We propose that it clusters conventional adhesins into heterogeneous complexes on the cell surface that strengthens binding to substrates. Two others have antioxidant properties, again despite being quite small proteins (68 and 99 amino acids). These are therefore unique mediators of functions appreciated to be critical for Candida virulence (adhesion and oxidative stress resistance). We propose studies to discern the mechanistic details underlying both phenotypes. Based on the successes of our preliminary genetic analysis, we propose a larger-scale effort to generate a mutant library of all of the uncharacterized macrophage-induced genes and test them in multiple in vitro, ex vivo, and in vivo assays. The strength of this proposal is in our expertise in analyzing this critical host-pathogen interaction, our thorough genetic methods and screening protocols, and the use of multiple animal models. The innovative potential is significant given the focus on novel genes and novel biology at the host-pathogen interface. The outcome of this proposal is a deeper and broader understanding of the genetic functions that are required for commensalism and pathogenicity in fungi.

抽象的 白色念珠菌是大多数菌群的共同成分独特相关的 人类对我们大多数人没有伤害，但它会引起一系列从轻度到生命的感染 - 威胁，基于宿主的免疫地位。白色念珠菌与 哺乳动物的吞噬细胞至关重要，念珠菌巨噬细胞共培养已成为 有价值的模型，以揭示促进毒力和共同主义的特定适应性。到 进一步探讨了这种相互作用的新生物学，我们使用转录分析来识别 吞噬作用引起的真菌基因。尽管其中一些具有可识别的功能，但 主要是代谢（对吞噬作用的已知反应），超过一半的诱导基因 没有特色，并未得到广泛保守。这些基因中的一个令人惊讶的数量很大 在早期注释中很小而错过。鉴于白色念珠菌人的独特性 关联，这组基因可能会富含白色念珠菌对宿主壁ches的适应。在 这一原则的证明，我们已经突变了这三个基因，这三个基因都具有与宿主相关的 表型，一种是一种新型细胞壁相关的粘合剂，需要粘附到 生物和非生物表面以及小鼠模型中的毒力。我们建议它集群 常规粘合剂进入细胞表面的异质复合物，并增强 与底物结合。另外两个具有抗氧化特性，尽管很小 蛋白质（68和99氨基酸）。因此，这些是功能的独特调解人 认为对念珠菌毒力至关重要（粘附和氧化应激性抗性）。我们 提出研究以辨别两个表型的机械细节。基于 初步遗传分析的成功，我们提出了一项更大的努力来产生 所有未表征的巨噬细胞诱导的基因的突变库，并在多个中测试它们 体外，体内和体内测定。该建议的优势在于我们在分析方面的专业知识 这种关键的宿主 - 病原体相互作用，我们的详尽遗传方法和筛查方案， 以及使用多种动物模型。鉴于专注于 新型基因和新型生物学处于宿主 - 病原体界面。该提议的结果是 对对遗传功能的更深入，更广泛的理解 真菌中的共生和致病性。