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.

摘要 白色念珠菌是唯一相关的微生物群落的大多数 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终身的感染， 根据宿主的免疫状态，具有威胁性。C.白色念珠菌和 哺乳动物的吞噬细胞是至关重要的，而巨噬细胞-巨噬细胞共培养已经成为一种 有价值的模型，以揭示特定的适应，促进毒力和寄生虫。到 为了进一步探索这种相互作用的新生物学，我们使用转录谱来鉴定 在吞噬作用下诱导的真菌基因。虽然其中一些具有可识别的功能， 大多数在新陈代谢（一种已知的对吞噬作用的反应）中，超过一半的诱导基因 没有特征也没有被广泛保存令人惊讶的是，这些基因中有相当多的 在早期的注释中很小很小。鉴于C.人白色念珠菌 关联，这组基因可能是丰富的适应C。白色念珠菌宿主壁龛。在 为了证明这一原理，我们突变了其中三个基因，所有三个基因都具有宿主相关性。 表型，其中一种是粘附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。我们认为它聚集在 传统的粘附素进入细胞表面的异质复合物， 与底物结合。另外两种具有抗氧化特性，尽管它们很小 蛋白质（68和99个氨基酸）。因此，它们是功能的独特中介体 被认为对念珠菌毒力（粘附和氧化应激抗性）至关重要。我们 提出研究来辨别这两种表型背后的机制细节。基于 成功的初步遗传分析，我们提出了一个更大规模的努力，以产生一个 所有未表征的巨噬细胞诱导基因的突变库，并在多个 体外、离体和体内测定。这项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，我们彻底的遗传方法和筛选方案， 以及多种动物模型的使用。创新潜力巨大，因为重点是 宿主-病原体界面的新基因和新生物学。该提案的结果是 更深入和更广泛地了解遗传功能， 真菌的寄生性和致病性。