Genetic Pathways of Human Cytomegalovirus Drug Resistance

项目摘要 毒性和耐药性限制了巨细胞病毒抗病毒治疗的疗效 (CMV)免疫抑制宿主的疾病，如癌症和移植受体。 目前的治疗包括DNA聚合酶抑制剂更昔洛韦，膦甲酸和西多福韦。 末端酶抑制剂莱特莫韦最近被批准用于预防，UL 97 激酶抑制剂Maribavir已完成作为替代疗法的III期试验。临床 在实践中，CMV耐药性不能通过病毒的直接表型检测来诊断。 分离株，而是依赖于检测到的病毒突变的准确相关性 和相关的抗性表型。本研究的目的是确定 CMV耐药的遗传机制，以提高临床诊断和 开发新的抗病毒药物。许多耐药突变和多态性， CMV UL 97激酶、UL 54 DNA聚合酶和UL 56/UL 89/UL 51末端酶基因具有 已经并将继续进行表型分型，具有诊断重要性的新抗性基因座 在每一个项目期间，重组技术进展 表型分析和全基因组深度测序正在促进这一研究。在 在即将到来的项目期间，新的重点领域包括突变的表征 在药物暴露后选择已知抗病毒靶点以外的基因，并分析 基线病毒株变异对药物敏感性的影响。具体目标是（1） 研究CMV突变的进化和表型，这些突变在体外或体内发生后， 体内暴露于抗病毒化合物和组合;（2）评估表型 通过病毒全基因组深度测序确定的遗传变化的意义， 在已知的抗病毒靶基因之外，和（3）确定基线的影响 通过表征替代病毒对药物敏感性表型的病毒株 克隆和宿主细胞。

Project Summary Toxicity and drug resistance limit the efficacy of antiviral therapy for cytomegalovirus (CMV) disease in immunosuppressed hosts such as cancer and transplant recipients. Current therapy includes DNA polymerase inhibitors ganciclovir, foscarnet and cidofovir. The terminase inhibitor letermovir was recently approved for prophylaxis, and the UL97 kinase inhibitor maribavir has completed Phase 3 trial as alternative therapy. In clinical practice, CMV drug resistance cannot be diagnosed by direct phenotypic testing of viral isolates, and instead is dependent on an accurate correlation of detected viral mutations and associated resistance phenotypes. The objective of this research is to determine the genetic mechanisms of CMV drug resistance in order to improve clinical diagnosis and the development of new antivirals. Many resistance mutations and polymorphisms in the CMV UL97 kinase, UL54 DNA polymerase and UL56/UL89/UL51 terminase genes have been and continue to be phenotyped, with diagnostically important new resistance loci being identified during each project period. Technical advances in recombinant phenotyping and whole genome deep sequencing are facilitating this research. In the upcoming project period, new focus areas include the characterization of mutations selected after drug exposure in genes outside of known antiviral targets, and analysis of the effects of baseline viral strain variation on drug susceptibility. Specific aims are (1) study the evolution and phenotypes of CMV mutations that develop after in vitro or in vivo exposure to antiviral compounds and combinations; (2) evaluate the phenotypic significance of genetic changes identified by viral whole genome deep sequencing that are outside of known antiviral target genes, and (3) determine the impact of baseline viral strain on drug susceptibility phenotypes by characterization of alternative viral clones and host cells.