Novel Azole Resistance Mechanisms in Candida albicans

白色念珠菌的新唑耐药机制

• 批准号: 7235410
• 负责人: P. David Rogers
• 金额: $ 32.17万
• 依托单位: UNIVERSITY OF TENNESSEE HEALTH SCI CTR
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-06-01 至 2009-05-21
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7235410
• 关键词: ABCB1 gene; Acquired Immunodeficiency Syndrome; Address; Antifungal Agents; Azole resistance; Azoles; Base Sequence; CDR1 gene; Candida; Candida albicans; Candidate Disease Gene; Class; Clinical; Country; Development; Disruption; Frequencies; Fungal Drug Resistance; Future; Gene Expression; Gene Proteins; Gene Targeting; Genes; Highly Active Antiretroviral Therapy; Immune; Immunocompromised Host; In Vitro; Infection; Mediating; Molecular; Numbers; Patients; Phenotype; Phosphatidylinositol Transfer Protein; Play; Point Mutation; Population; Predisposition; Process; Protein Overexpression; Proteins; Proteomics; Regulation; Resistance; Role; Sequence Analysis; Stream; Synthetic Genes; Therapeutic; Therapeutic Index; Toxic effect; Transcriptional Regulation; United States; Work; base; cDNA Library; efflux pump; functional genomics; improved; insight; mutant; novel; protein expression; resistance mechanism; transcription factor

DESCRIPTION (provided by the 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 immune-compromised 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 genes in addition to CDR1, CDR2, MDR1, ERG11 and PDR16 are required 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 transcriptional 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. 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.

描述（由申请人提供）：唑抗真菌耐药性已成为治疗由包括念珠菌在内的多种真菌物种引起的感染的一个重大问题。这个问题对免疫功能低下的患者群体，特别是艾滋病患者产生了重大影响。虽然高效抗逆转录病毒疗法 (HAART) 的使用降低了美国 AIDS 患者中 OPC 的发生率，但在不发达国家，获得此类疗法的机会有限、依从性差以及与 HAART 相关的毒性可能会导致这种情况的增加。全世界艾滋病患者面临的问题。了解唑类耐药性的分子基础将有助于制定治疗策略来规避这一问题并提高唑类抗真菌药物的实用性。该提案的目的是鉴定和表征白色念珠菌中唑类抗真菌耐药性的新分子机制。该提议背后的中心假设是，除了 CDR1、CDR2、MDR1、ERG11 和 PDR16 之外，白色念珠菌逐步获得唑类抗真菌耐药性还需要其他基因。我们将使用集成的功能基因组和蛋白质组学方法来表征和比较白色念珠菌的唑敏感和耐药分离株的多个匹配组内和之间的系列分离株的基因表达和蛋白质组谱。这些研究将鉴定与唑类抗性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节的基因和基因产物，从而深入了解这些机制的转录调节。我们还将使用反义 cDNA 文库筛选唑类抗性分离株以获得该表型所需的基因。靶向基因破坏和过度表达将用于评估候选抗性基因在此过程中的作用。然后将检查这些突变体的体外唑类敏感性的变化。其他研究将检查可能在此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，并将确定未来开发化合物的新靶点，从而消除耐药性并增强唑类抗真菌药物的效用。