Huang Wei, Gamarnik Andrea, Limoli Kay, Petropoulos Christos J, Whitcomb Jeannette M
Department of Research and Development, ViroLogic, Inc., South San Francisco, California 94080, USA.
J Virol. 2003 Jan;77(2):1512-23. doi: 10.1128/jvi.77.2.1512-1523.2003.
Suboptimal treatment of human immunodeficiency virus type 1 (HIV-1) infection with nonnucleoside reverse transcriptase inhibitors (NNRTI) often results in the rapid selection of drug-resistant virus. Several amino acid substitutions at position 190 of reverse transcriptase (RT) have been associated with reduced susceptibility to the NNRTI, especially nevirapine (NVP) and efavirenz (EFV). In the present study, the effects of various 190 substitutions observed in viruses obtained from NNRTI-experienced patients were characterized with patient-derived HIV isolates and confirmed with a panel of isogenic viruses. Compared to wild-type HIV, which has a glycine at position 190 (G190), viruses with 190 substitutions (A, C, Q, S, V, E, or T, collectively referred to as G190X substitutions) were markedly less susceptible to NVP and EFV. In contrast, delavirdine (DLV) susceptibility of these G190X viruses increased from 3 to 300-fold (hypersusceptible) or was only slightly decreased. The replication capacity of viruses with certain 190 substitutions (C, Q, V, T, and E) was severely impaired and was correlated with reduced virion-associated RT activity and incomplete protease (PR) processing of the viral p55(gag) polyprotein. These defects were the result of inadequate p160(gagpol) incorporation into virions. Compensatory mutations within RT and PR improved replication capacity, p55(gag) processing, and RT activity, presumably through increased incorporation of p160(gagpol) into virions. We observe an inverse relationship between the degree of NVP and EFV resistance and the impairment of viral replication in viruses with substitutions at 190 in RT. These observations may have important implications for the future design and development of antiretroviral drugs that restrict the outgrowth of resistant variants with high replication capacity.
用非核苷类逆转录酶抑制剂（NNRTI）对1型人类免疫缺陷病毒（HIV-1）感染进行次优治疗通常会导致耐药病毒的快速产生。逆转录酶（RT）第190位的几个氨基酸替代与对NNRTI，尤其是奈韦拉平（NVP）和依非韦伦（EFV）的敏感性降低有关。在本研究中，用患者来源的HIV分离株对在接受过NNRTI治疗的患者中分离出的病毒中观察到的各种190位替代的影响进行了表征，并用一组同基因病毒进行了验证。与在第190位具有甘氨酸（G190）的野生型HIV相比，具有190位替代（A、C、Q、S、V、E或T，统称为G190X替代）的病毒对NVP和EFV的敏感性明显降低。相比之下，这些G190X病毒对地拉韦啶（DLV）的敏感性增加了3至300倍（超敏感）或仅略有降低。具有某些190位替代（C、Q、V、T和E）的病毒的复制能力严重受损，并且与病毒体相关的RT活性降低以及病毒p55（gag）多聚蛋白的蛋白酶（PR）加工不完全相关。这些缺陷是由于p160（gagpol）掺入病毒体不足所致。RT和PR内的补偿性突变改善了复制能力、p55（gag）加工和RT活性，推测是通过增加p160（gagpol）掺入病毒体实现的。我们观察到在RT第190位有替代的病毒中，NVP和EFV耐药程度与病毒复制受损之间存在反比关系。这些观察结果可能对未来抗逆转录病毒药物的设计和开发具有重要意义，这些药物可限制具有高复制能力的耐药变体的生长。
