Genetic regulation of antifungal drug resistance in Candida albicans

项目摘要 白色念珠菌是人类微生物群的正常分支，也能够引起 高危患者人群中的浅表和播散性感染。免疫受损 个体和患有头颈癌的人对念珠菌感染高度敏感， 其经常表现为口咽念珠菌病。这些感染通常是由 生物膜的形成，一种抗性，表面粘附的微生物群落， 口腔的粘膜表面或口腔内的牙植入物上。形成生物膜 提供了C.具有独特特性的白色念珠菌，例如对抗真菌治疗的耐药性增加 和宿主的免疫反应生物膜中的细胞是几个数量级的细胞并不罕见。 与相同的自由漂浮细胞相比， 物种在治疗口腔中基于生物膜的感染后， 可能导致治疗失败并使该区域再次感染。我们假设抗真菌药物 C.抗性生物膜状态下的白念珠菌受一个复杂的转录网络调控， “主”转录调节因子及其下游靶点。该提案旨在发现 控制C.白色念珠菌生物膜在 目的1、筛选一个完整的纯合转录因子（TF）缺失文库 使用体外生物膜测定法鉴定在存在下生长改变的调节剂的突变体 通常用于治疗口腔C.白色念珠菌感染在目标2中，我们验证了 使用体内大鼠义齿性口炎生物膜模型的体外研究结果。在目标3中，我们映射 每个转录因子彼此之间以及与下游靶基因的连接， 确定了控制C.白色念珠菌生物膜这项工作将 显著扩大了我们对抗真菌药物耐药机制的理解，并可能导致 开发针对生物膜感染的新疗法。

PROJECT SUMMARY Candida albicans is a normal commensal of the human microbiota that is also capable of causing superficial and disseminated infections in at-risk patient populations. Immunocompromised individuals and those with head and neck cancers are highly susceptible to Candida infections, which frequently manifest as oropharyngeal candidiasis. These infections are typically caused by the formation of a biofilm, a resistant, surface-adhered microbial community that develops on mucosal surfaces of the mouth or on dental implants within the oral cavity. Formation of a biofilm provides C. albicans with unique properties, such as increased resistance to antifungal treatments and the host immune response. It is not uncommon for cells in a biofilm to be several orders of magnitude more resistant to an antimicrobial agent compared to free-floating cells of the same species. After treatment of a biofilm-based infection in the oral cavity, persistent surviving cells can cause treatment failures and permit reinfection of the area. We hypothesize that the antifungal resistance of C. albicans in the biofilm state is regulated by a complex transcriptional network of “master” transcriptional regulators and their downstream targets. This proposal aims to discover the complete transcriptional network controlling resistance mechanisms in C. albicans biofilms. In Aim 1, we screen a comprehensive library of homozygous transcription factor (TF) deletion mutants using in vitro biofilm assays to identify regulators with altered growth in the presence of antifungals commonly prescribed to treat oral C. albicans infections. In Aim 2, we validate our in vitro findings using an in vivo rat biofilm model of denture stomatitis. In Aim 3, we map the connections of each transcription factor to one another as well as to downstream target genes to determine the regulatory network controlling resistance in C. albicans biofilms. This work will significantly expand our understanding of antifungal resistance mechanisms and may lead to the development of novel therapeutics against biofilm infections.