Genetic regulation of antifungal drug resistance in Candida albicans

项目总结 白色念珠菌是人类微生物区系的一种正常共生体，也能够引起 高危患者人群中的浅表和播散性感染。免疫功能受损 个人和头颈癌患者对念珠菌感染高度敏感， 常表现为口咽部念珠菌病。这些感染通常是由 生物膜的形成，这是一种具有抗性的表面附着的微生物群落，它在 口腔粘膜表面或口腔内的牙种植体上。生物膜的形成 为白色念珠菌提供独特的特性，如增加对抗真菌治疗的抵抗力 和宿主的免疫反应。生物膜中的细胞有几个数量级的情况并不少见 与自由漂浮的细胞相比，对抗菌剂的抵抗力要强得多 物种。在口腔内生物膜感染治疗后，持久存活的细胞 可能导致治疗失败，并允许该地区再次感染。我们假设抗真菌药物 生物被膜状态下白色念珠菌的耐药性由一个复杂的转录网络调节 “大师”转录调控因子及其下游靶标。这项提议旨在发现 控制白色念珠菌生物膜耐药机制的完整转录网络。在……里面 目的1.筛选纯合转录因子(Tf)缺失文库 突变体使用体外生物膜试验来鉴定在存在的情况下具有改变生长的调节剂 通常用于治疗口腔白念珠菌感染的抗真菌药物。在目标2中，我们验证我们的输入 在体大鼠义齿口腔炎生物膜模型的体外研究。在目标3中，我们将 每个转录因子之间的连接以及与下游靶基因的连接 确定控制白色念珠菌生物被膜耐药性的调控网络。这项工作将 大大扩展了我们对抗真菌耐药机制的理解，并可能导致 抗生物被膜感染的新型治疗药物的开发。

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.