Novel Azole Resistance Mechanisms in Candida albicans

描述（由申请人提供）：唑类抗真菌药物耐药性已成为包括念珠菌在内的许多真菌引起的感染管理中的一个重要问题。这个问题对免疫功能低下的患者群体，特别是那些患有艾滋病的患者群体具有重大影响。虽然使用高效抗逆转录病毒疗法（HAART）已经降低了美国艾滋病患者的OPC频率，但在不发达国家，这种疗法的有限使用，依从性差，以及与HAART相关的毒性可能会导致全球艾滋病患者中这一问题的增加。 了解唑类抗真菌药物耐药的分子基础将有助于开发治疗策略，以规避这一问题，并提高唑类抗真菌药物的效用。本提案的目的是鉴定和表征白念珠菌唑类抗真菌药物耐药的新分子机制。这一建议背后的中心假设是，特定的分子机制是负责逐步收购唑类抗真菌药耐药的C。白色念珠菌我们将使用一个综合的功能基因组和蛋白质组学的方法来表征和比较基因表达和蛋白质组谱的系列分离物内和之间的多个匹配的组唑敏感和耐药分离株的C。白色念珠菌这些研究将鉴定与唑类耐药表型相关的基因和基因产物。他们还将鉴定与已知抗性机制协调调控的基因和基因产物，从而深入了解这些机制的调控。我们还将使用反义cDNA文库筛选唑类耐药菌株的这种表型所需的基因。靶向基因破坏和过表达将用于评估候选抗性基因在这一过程中的作用。然后将检查这些突变体的体外唑类药物敏感性的变化，以及在某些情况下对唑类药物抗性基因表达和蛋白质组学谱的继发性影响。进一步的研究将检查可能在这一过程中发挥作用的点突变的关键基因的核苷酸序列。这些研究将进一步阐明唑类抗真菌药物耐药性的分子基础，并将确定新的目标，为未来的工作，对开发的化合物，既消除耐药性，提高效用的唑类抗真菌药物。

DESCRIPTION (provided by applicant): Azole antifungal resistance has emerged as a significant problem in the management of infections caused by a number of fungal species including Candida. This problem has had a significant impact in immunocompromised patient populations, particularly those suffering from AIDS. While the use of highly active antiretroviral therapy (HAART) has reduced the frequency of OPC among AIDS patients in the United States, limited access to such therapy in underdeveloped countries, poor compliance, and toxicity associated with HAART will likely contribute to an increase in this problem among AIDS patients world-wide. Understanding the molecular basis of azole resistance will facilitate the development of therapeutic strategies to circumvent this problem and improve the utility of the azole class of antifungal agents. The aim of this proposal is to identify and characterize novel molecular mechanisms of azole antifungal resistance in Candida albicans. The central hypothesis behind this proposal is that specific molecular mechanisms are responsible for the stepwise acquisition of azole antifungal resistance in C. albicans. We will use an integrated functional genomic and proteomic approach to characterize and compare the gene expression and proteomic profiles of serial isolates within and between multiple matched sets of azole-susceptible and -resistant isolates of C. albicans. These studies will identify genes and gene products that are associated with the azole resistance phenotype. They will also identify genes and gene products that are coordinately regulated with known resistance mechanisms and hence lend insight into the regulation of these mechanisms. We will also screen azole resistant isolates for genes required for this phenotype using an antisense cDNA library. Targeted gene disruption and over-expression will be used to assess the role of candidate resistance genes in this process. These mutants will then be examined for changes in in vitro azole susceptibility, and in certain cases for secondary effects on the azole resistance gene expression and proteomic profile. Additional studies will examine the nucleotide sequences of key genes for point mutations that may play a role in this process. These studies will further elucidate the molecular basis for azole antifungal resistance and will identify novel targets for future work towards the development of compounds that will both abrogate resistance and enhance the utility of the azole class of antifungal agents.