Arora Sunil K, Gupta Sachin, Toor Jaideep S, Singla Anuj
Department of Immunopathology, Postgraduate Institute of Medical Education and Research, Chandigarh, India.
AIDS Res Hum Retroviruses. 2008 Feb;24(2):125-30. doi: 10.1089/aid.2007.0156.
ABSTRACT We genotyped the RT and PI regions of the pol gene of HIV-1 from treatment-naive infected individuals in North India and evaluated their possible physiological relevance and association with drug resistance. Plasma samples from 52 newly diagnosed HIV-1-infected drug-naive individuals were subjected to CD4(+) cell count and plasma viral load. For genotyping, the protease and RT regions of the pol gene were amplified from cDNA reverse transcribed from plasma viral RNA by single or nested polymerase chain reaction (PCR). Sequences of amplified products were analyzed for mutations using the Stanford DR and REGA database. Two out of 49 amplicons showed mutations at known "major" subtype B drug resistance positions (one each in protease and RT). In the protease region it showed a major drug resistance mutation at M46I as well as "minor" positions F53L and T74P. In the RT gene, one patient showed a mutation at major NNRTI position G190V. Forty-nine percent had mutations in the hinge (M36I, R41K, H69K) and alpha-helix (L89M) regions of the C-virus protease, which has been linked to increased catalytic activity. Our study indicates that a number of major mutations associated with resistance to PIs, NNRTIs, and NRTIs do exist, though at a low frequency, among HIV-1 isolates from treatment-naive individuals in North India. Many minor or accessory mutations related to resistance to PIs and NRTIs are also present as the variants. These results point to the greater biochemical fitness of subtype C protease and faster decrease in drug sensitivity.
我们对印度北部初治感染个体的HIV-1 pol基因的RT和PI区域进行了基因分型，并评估了它们可能的生理相关性以及与耐药性的关联。对52例新诊断的HIV-1感染初治个体的血浆样本进行了CD4(+)细胞计数和血浆病毒载量检测。为了进行基因分型，通过单重或巢式聚合酶链反应（PCR）从血浆病毒RNA逆转录得到的cDNA中扩增pol基因的蛋白酶和RT区域。使用斯坦福耐药性（DR）和REGA数据库分析扩增产物的序列以检测突变。49个扩增子中有2个在已知的B亚型“主要”耐药位点出现突变（蛋白酶和RT区域各1个）。在蛋白酶区域，它在M46I以及“次要”位点F53L和T74P处显示出主要耐药突变。在RT基因中，1例患者在主要非核苷类逆转录酶抑制剂（NNRTI）位点G190V处出现突变。49%的个体在C型病毒蛋白酶的铰链区（M36I、R41K、H69K）和α-螺旋区（L89M）存在突变，这与催化活性增加有关。我们的研究表明，在印度北部初治个体的HIV-1分离株中，确实存在一些与对蛋白酶抑制剂（PIs）、非核苷类逆转录酶抑制剂（NNRTIs）和核苷类逆转录酶抑制剂（NRTIs）耐药相关的主要突变，尽管频率较低。许多与对PIs和NRTIs耐药相关的次要或辅助突变也以变体形式存在。这些结果表明C型蛋白酶具有更高的生化适应性以及更快的药物敏感性下降。
