AIDS OPPORTUNISTIC INFECTIONS--VIRULENCE OF C GLABRATA

描述(摘自申请者摘要)：在HIV阳性人群中，阴道和食道念珠菌病的第二个最常见的原因是光滑念珠菌。这在一定程度上是由于光滑念珠菌对唑类药物的相对抗药性。光滑念珠菌在ICU中也很普遍。光肩星天牛与寄主的相互作用尚不清楚。本研究的目的是分析光肩星天牛与其寄主的分子相互作用，并鉴定光肩星天牛的毒力因子。分子和基因操作在光肩星天牛中是可能的，但由于光肩星天牛是单倍体的事实，这一点变得更容易了。研究人员已经产生了随机插入突变体，并开发了一种策略，在一个池中并行筛选多达96个突变体。使用这种策略，他已经确定了EPA1基因，这是一种粘附素，介导与宿主细胞表面的碳水化合物结合。在这项提案中，他将描述这种粘附素的配体特异性、结构域结构和亚细胞定位。将使用遗传和分子方法来鉴定其他粘附素，最终目的是表征大多数与宿主-细胞相互作用有关的光肩星天牛粘附素。在分析EPA1中开发的遗传工具允许对毒力进行广泛的遗传分析。研究人员将在黏膜和系统性念珠菌病的小鼠模型中直接筛选无毒突变。许多二级筛选将识别那些与特定宿主分子离散相互作用的突变体。

DESCRIPTION (Adapted from the Applicant's Abstract): In the HIV- positive population, the second most frequent cause of vaginal and esophageal candidiasis is Candida glabrata. This is in part due to the relative resistance of C. glabrata to azole therapeutics. C. glabrata is also prevalent in ICUs. The interaction of C. glabrata with the host is not well understood. The objective of this proposal is to analyze the molecular interactions of C. glabrata with its host and to identify virulence factors in C. glabrata. Molecular and genetic manipulation is possible in C. glabrata, and is made easier by the fact that C. glabrata is haploid. The investigator has generated random insertion mutants and developed a strategy to screen up to 96 mutants in parallel in a single pool. Using this strategy, he has identified the EPA1 gene, an adhesin mediating binding to carbohydrates on the cell surface of the host. In this proposal, he will characterize this adhesin's ligand specificity, domain structure and sub-cellular localization. Genetic and molecular approaches will be used to identify other adhesins, with the eventual aim to characterize the majority of C. glabrata adhesins relevant to the host-cell interaction. The genetic tools developed in the analysis of EPA1 allow for a broad genetic analysis of virulence. The investigator will screen directly for avirulent mutants in murine models of mucosal and systemic candidiasis. A number of secondary screens will identify those mutants involved in discrete interactions with specific host molecules.