Mechanisms of Antiviral Drug Resistance, Host Factors and Retroviral Replication

大多数关于核苷类和非核苷类逆转录酶（RT）抑制剂（分别为NRTI和NNRTI）的临床耐药研究分析了RT的前300个氨基酸，不包括C-末端连接子域（CN）或RNA酶H结构域（RH）。我们观察到CN和RH中的几个突变降低了RNase H活性，从而影响RNA降解和核苷酸切除之间的平衡，并增强了NRTI抗性。我们最近的研究表明，CN和RH的突变也可以增加对NNRTI的耐药性，并提出了一种平行的机制，通过这种机制可以增加对两类RT抑制剂的耐药性。已经观察到CN突变存在于药物初治患者中，我们正在探索CN突变可能在开始抗病毒治疗之前被选择的机制。在研究A3 G定位于P体的功能相关性时，我们发现P体相关蛋白Mov 10通过减少病毒产生和抑制逆转录来有效地抑制HIV-1复制。我们正在阐明Mov 10抑制HIV-1颗粒产生和逆转录的机制。在检查A3 G和A3 F对病毒DNA整合的影响时，我们观察到靶细胞而不是病毒生产细胞中的尿嘧啶DNA糖基化酶活性导致负链DNA的切口。我们将探讨这种意想不到的表型对病毒复制的意义。[对应于艾滋病毒耐药性方案2011年10月现场访问报告中的Pathak项目3]

Most studies of clinical drug resistance to nucleoside and nonnucleoside reverse transcriptase (RT) inhibitors (NRTIs and NNRTIs, respectively) analyze the first 300 amino acids of RT and do not include the C-terminal connection subdomain (CN) or the RNase H domain (RH). We observed that several mutations in the CN and RH reduce RNase H activity, thereby affecting the balance between RNA degradation and nucleotide excision, and enhancing NRTI resistance. Our recent studies have demonstrated that mutations in the CN and the RH can also increase resistance to NNRTIs, and suggest a parallel mechanism by which resistance to both classes of RT inhibitors can be increased. It has been observed that CN mutations are present in drug-naive patients, and we are exploring the mechanisms by which CN mutations may be selected prior to initiation of antiviral therapy.While investigating the functional relevance of A3G localization to P bodies, we found that P body-associated protein Mov10 potently inhibits HIV-1 replication by reducing virus production and inhibiting reverse transcription. We are elucidating the mechanisms by which Mov10 inhibits HIV-1 particle production and reverse transcription. While examining the effects of A3G and A3F on viral DNA integration, we observed that uracil DNA glycosylase activity in the target cells, not the virus producer cells, results in nicking of the minus-strand DNA. We will explore the significance of this unexpected phenotype to viral replication.[Corresponds to Pathak Project 3 in the October 2011 site visit report of the HIV Drug Resistance Program]