A Genetic Approach to Virulence in C. albicans

白色念珠菌毒力的遗传学方法

• 批准号: 7061717
• 负责人: SUZANNE M NOBLE
• 金额: $ 10.56万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-05-15 至 2008-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7061717
• 关键词: Candida albicans; biotechnology; candidiasis; cell adhesion; cell line; cytokine; cytotoxicity; disease /disorder model; fungal genetics; fungal proteins; gene mutation; gene targeting; genetic library; genetic screening; host organism interaction; immune response; laboratory mouse; morphology; nitric oxide; parasite infection mechanism; pathologic process; polymerase chain reaction; site directed mutagenesis; virulence

DESCRIPTION (provided by applicant): Candida albicans is the most common fungal pathogen worldwide and yet there is limited understanding of its virulence mechanisms, particularly in comparison to those of bacterial pathogens. This poverty of understanding on the academic front is associated with a dearth of safe, effective clinical diagnostic and therapeutic tools. Forward genetic screens such as signature tagged mutagenesis have been fundamental in identifying the major virulence pathways in bacteria. Such screens have not been performed in C. albicans, however, because of experimental limitations imposed by a diploid genome and the absence of a complete mating cycle. I have recently developed methods and reagents that mitigate these obstacles. The goal of this proposal is to perform the first large-scale genetic analysis of virulence in C. albicans in order to identify and study the key determinants of pathogenesis in this organism. To accomplish these goals, I have the following specific aims: (1) Construct a signature-tagged knockout library of C. albicans homozygous disruption mutants; (2) Perform a genetic screen for virulence mutants in a murine infection model of disseminated Candidiasis; (3) Characterize the virulence defects of the mutants through secondary screens of specific steps in the pathogenesis cycle; and (4) Carry out detailed cell biological, molecular biological, and biochemical analysis of selected mutants of special interest. Results from this work should enhance our understanding of fungal pathogenesis and identify novel targets for antifungal therapy.

描述（由申请人提供）：白色念珠菌是世界上最常见的真菌病原体，但对其毒力机制的了解有限，特别是与细菌病原体相比。这种对学术前沿的缺乏理解与缺乏安全、有效的临床诊断和治疗工具有关。前向基因筛选，如标记诱变，是识别细菌主要毒力途径的基础。然而，由于二倍体基因组和缺乏完整的交配周期所施加的实验限制，这种筛选尚未在白色念珠菌中进行。我最近开发了一些方法和试剂来减轻这些障碍。本研究的目的是对白色念珠菌的毒力进行首次大规模的遗传分析，以确定和研究该生物发病的关键决定因素。为了实现这些目标，我有以下具体目标：(1)构建带有特征标记的白色念珠菌纯合破坏突变体敲除文库；(2)对播散性念珠菌病小鼠感染模型进行毒力突变基因筛选；(3)通过致病周期中特定步骤的二次筛选来表征突变体的毒力缺陷；(4)对选定的特殊兴趣突变体进行详细的细胞生物学、分子生物学和生化分析。这项工作的结果将提高我们对真菌发病机制的认识，并确定抗真菌治疗的新靶点。