Kaye S, Comber E, Tenant-Flowers M, Loveday C
Department of Virology, University College London Medical School, U.K.
AIDS Res Hum Retroviruses. 1995 Oct;11(10):1221-5. doi: 10.1089/aid.1995.11.1221.
Point mutations in the reverse transcriptase (RT) gene of human immunodeficiency virus type-1 (HIV-1) have been associated with reduced sensitivity of the virus to inhibition by the antiretroviral drug zidovudine (ZDV). During therapy we have previously observed the accumulation of these mutations, at codons 41, 67, 70, 215, and 219 of the RT gene, in proviral DNA sequences from infected peripheral blood mononuclear cells (PBMCs) and in cell-free virus RNA. Using a quantitative point mutation assay (PMA) we have been able to quantify the proportions of mutant and wild-type sequences at these points in mixed populations of viral RNA and DNA derived from clinical samples. Thus we have confirmed that the mutations can be detected earlier in cell-free virus RNA than in PBMC proviral DNA and their accumulation in RNA precedes that in DNA. We have analyzed serial samples from 10 subjects undergoing zidovudine therapy and shown significantly higher levels of mutations in cell-free viral RNA than in PBMC proviral DNA at codons 41, 70, and 215 during the in vivo acquisition of the mutations. In the group of subjects studied the mean time delay between RNA and DNA reaching a given level of mutation was 25 days.
1型人类免疫缺陷病毒（HIV-1）逆转录酶（RT）基因中的点突变与该病毒对抗逆转录病毒药物齐多夫定（ZDV）抑制作用的敏感性降低有关。在治疗过程中，我们之前曾观察到这些突变在RT基因的第41、67、70、215和219密码子处，在来自受感染外周血单核细胞（PBMC）的前病毒DNA序列以及游离病毒RNA中积累。使用定量点突变分析（PMA），我们能够在源自临床样本的病毒RNA和DNA混合群体中的这些位点定量突变型和野生型序列的比例。因此，我们证实这些突变在游离病毒RNA中比在PBMC前病毒DNA中能更早被检测到，并且它们在RNA中的积累先于在DNA中的积累。我们分析了10名接受齐多夫定治疗的受试者的系列样本，结果显示在体内突变发生过程中，游离病毒RNA中第41、70和215密码子处的突变水平显著高于PBMC前病毒DNA中的突变水平。在所研究的受试者组中，RNA和DNA达到给定突变水平之间的平均时间延迟为25天。
