Mechanisms of Antiviral Drug Resistance, Host Factors and Retroviral Replication

大多数临床耐药研究对核苷类和非核苷类逆转录酶(RT)抑制剂(分别为NRTI和NNRTI)分析RT的前300个氨基酸，不包括C末端连接亚域(CN)或RNase H域(RH)。我们观察到CN和RH的几个突变降低了RNase H的活性，从而影响了RNA降解和核苷酸切除之间的平衡，并增强了NRTI的耐药性。我们最近的研究表明，CN和RH的突变也可以增加对NNRTIs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这两种RT抑制剂的耐药性。已经观察到在药物初治的患者中存在CN突变，我们正在探索在开始抗病毒治疗之前选择CN突变的机制。在研究A3G定位与P小体的功能相关性时，我们发现P小体相关蛋白Mov10通过减少病毒产生和抑制逆转录来有效地抑制HIV-1的复制。我们正在阐明Mov10抑制HIV-1颗粒产生和逆转录的机制。在检测A3G和A3F对病毒DNA整合的影响时，我们观察到靶细胞中的尿嘧啶DNA糖基酶活性，而不是病毒产生细胞中的尿嘧啶DNA糖基酶活性，导致了负链DNA的缺口。我们将探索这种意想不到的表型对病毒复制的意义。

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]