Characterization of novel virulence factors in Candida

念珠菌新型毒力因子的表征

• 批准号: 10540739
• 负责人: Michael C Lorenz
• 金额: $ 32.1万
• 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 2024-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10540739
• 关键词: Adhesions; Affect; Age; Amaze; 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; Hospitalization; Human; Human Microbiome; Hydrolase; Iatrogenesis; Immune; In Vitro; Infection; Laboratories; Libraries; Life; Life Style; Lipase; Lysine; Macrophage; Malignant Neoplasms; Mediating; Mediator; 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; Pathogenicity; Patients; Peptide Hydrolases; Peptides; Phagocytes; Phagocytosis; Phenotype; Physiological; 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; biological adaptation to stress; chemotherapy; clinically relevant; deletion library; fitness; flexibility; fungus; gene conservation; genetic analysis; genome annotation; immunological status; implantable device; in vivo; innovation; 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 白色念珠菌作为大多数微生物群的共生成分具有独特的相关性。 人类，对我们大多数人没有伤害，但它会引起一系列感染，从轻微到致命—— 威胁，基于宿主的免疫状态。白色念珠菌之间的相互作用 哺乳动物吞噬细胞至关重要，念珠菌-巨噬细胞共培养已成为 揭示促进毒力和共生主义的特定适应的宝贵模型。到 为了进一步探讨这种相互作用的新生物学，我们使用转录分析来识别 吞噬作用诱导的真菌基因。虽然其中一些具有可识别的功能， 主要在新陈代谢（已知对吞噬作用的反应）中，超过一半的诱导基因 未表征且未广泛保存。这些基因的数量惊人 很小并且在早期注释中被遗漏。鉴于人类白色念珠菌的独特性 关联，这组基因可能因白色念珠菌适应宿主生态位而丰富。在 为了证明这一原理，我们突变了其中三个基因，并且所有三个基因都具有宿主相关性 表型，其中一种是粘附到细胞壁所需的新型细胞壁相关微粘附素 生物和非生物表面以及小鼠模型中的毒力。我们建议将其聚类 将传统的粘附素转化为细胞表面的异质复合物，从而增强 与底物结合。另外两种也具有抗氧化特性，尽管它们很小 蛋白质（68 和 99 个氨基酸）。因此，这些是功能的独特中介 被认为对念珠菌毒力（粘附和氧化应激抵抗）至关重要。我们 提出研究来辨别两种表型背后的机制细节。基于 鉴于我们初步遗传分析的成功，我们建议进行更大规模的努力来产生 所有未表征的巨噬细胞诱导基因的突变体文库，并在多个中测试它们 体外、离体和体内测定。该提案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，我们彻底的遗传方法和筛选方案， 以及多种动物模型的使用。鉴于重点关注，创新潜力巨大 宿主-病原体界面的新基因和新生物学。该提案的结果是 对所需的遗传功能有更深入和更广泛的了解 真菌中的共生现象和致病性。