Brown A J, Cleland A
Centre for HIV Research, University of Edinburgh, UK.
AIDS. 1996 Sep;10(10):1067-73.
To determine the effect that selection for antiviral resistance in the HIV-1 pol gene has on the level of variation and pattern of evolution in the V3 region of env.
Proviral genomes obtained from two patients before, during and after the termination of zidovudine (ZDV) therapy (approximately 2 years) were amplified and sequenced in pol and env, and the evolution of the V3 hypervariable region compared with that of the reverse transcriptase domain of pol.
Gene fragments were polymerase chain reaction-amplified from patients' peripheral blood mononuclear cells. Nucleotide sequencing was carried out using T7 DNA polymerase and dye-labelled terminators on an automated DNA sequencer. Sequences were analysed using maximum likelihood phylogenetic techniques.
Both patients showed multiple resistance-associated mutations after 1 year of ZDV therapy. Sequence diversity in V3 showed no reduction during the period of treatment. Substantial change continued to occur in this region and multiple lineages were present in both patients, in contrast to the single lineage observed in the pol gene of one (patient 74), a difference confirmed by likelihood ratio tests.
There is no evidence from this study that selection due to antivirals has any significant impact on the evolution of the env gene. The independence in the evolution of these genes implies that recombination was occurring between the two genes during the study period. Such independent evolution should be allowed for in developing strategies for HIV therapy involving multiple target genes.
确定HIV-1 pol基因中抗病毒耐药性选择对env基因V3区变异水平和进化模式的影响。
从两名患者在齐多夫定（ZDV）治疗前、治疗期间及治疗终止后（约2年）获取的前病毒基因组在pol和env基因中进行扩增和测序，并将V3高变区的进化与pol基因逆转录酶结构域的进化进行比较。
从患者外周血单核细胞中通过聚合酶链反应扩增基因片段。使用T7 DNA聚合酶和染料标记的终止子在自动DNA测序仪上进行核苷酸测序。使用最大似然系统发育技术分析序列。
两名患者在接受ZDV治疗1年后均出现多个与耐药相关的突变。治疗期间V3区的序列多样性未降低。该区域持续发生显著变化，两名患者体内均存在多个谱系，这与其中一名患者（患者74）pol基因中观察到的单一谱系形成对比，似然比检验证实了这一差异。
本研究没有证据表明抗病毒药物选择对env基因的进化有任何显著影响。这些基因进化的独立性意味着在研究期间两个基因之间发生了重组。在制定涉及多个靶基因的HIV治疗策略时应考虑这种独立进化。
