Winters M A, Coolley K L, Girard Y A, Levee D J, Hamdan H, Shafer R W, Katzenstein D A, Merigan T C
Center for AIDS Research at Stanford, Stanford University, Stanford, California 94305-5107, USA.
J Clin Invest. 1998 Nov 15;102(10):1769-75. doi: 10.1172/JCI4948.
While many point mutations in the HIV-1 reverse transcriptase (RT) confer resistance to antiretroviral drugs, inserts or deletions in this gene have not been previously characterized. In this report, 14 RT inhibitor-treated patients were found to have HIV-1 strains possessing a 6-basepair insert between codons 69 and 70 of the RT gene. Known drug resistance mutations were also observed in these strains, with T215Y appearing in all strains. Genotypic analysis indicated that the inserts had substantial nucleotide variability that resulted in relatively restricted sets of amino acid sequences. Linkage of patients' treatment histories with longitudinal sequencing data showed that insert strains appeared during drug regimens containing ddI or ddC, with prior or concurrent AZT treatment. Drug susceptibility tests of recombinant patient isolates showed reduced susceptibility to nearly all nucleoside RT inhibitors. Site- directed mutagenesis studies confirmed the role of the inserts alone in conferring reduced susceptibility to most RT inhibitors. The addition of AZT-associated drug resistance mutations further increased the range and magnitude of resistance. These results establish that inserts, like point mutations, are selected in vivo during antiretroviral therapy and provide resistance to multiple nucleoside analogs.
虽然HIV-1逆转录酶（RT）中的许多点突变可导致对抗逆转录病毒药物产生耐药性，但此前尚未对该基因中的插入或缺失进行过特征描述。在本报告中，发现14例接受RT抑制剂治疗的患者的HIV-1毒株在RT基因的密码子69和70之间存在一个6碱基对的插入。在这些毒株中也观察到了已知的耐药突变，所有毒株中均出现了T215Y。基因分型分析表明，这些插入具有显著的核苷酸变异性，导致氨基酸序列集相对受限。将患者的治疗史与纵向测序数据相关联表明，插入毒株出现在含有去羟肌苷（ddI）或双脱氧胞苷（ddC）且同时或之前接受齐多夫定（AZT）治疗的药物治疗方案期间。对重组患者分离株进行的药敏试验表明，其对几乎所有核苷类RT抑制剂的敏感性降低。定点诱变研究证实，单独的插入在赋予对大多数RT抑制剂敏感性降低方面的作用。与AZT相关的耐药突变的添加进一步增加了耐药的范围和程度。这些结果表明，插入与点突变一样，在抗逆转录病毒治疗期间在体内被选择，并对多种核苷类似物产生耐药性。
