HIV-1 reverse transcriptase mutations that confer decreased in vitro susceptibility to anti-RT DNA aptamer RT1t49 confer cross resistance to other anti-RT aptamers but not to standard RT inhibitors.
HIV-1 reverse transcriptase mutations that confer decreased in vitro susceptibility to anti-RT DNA aptamer RT1t49 confer cross resistance to other anti-RT aptamers but not to standard RT inhibitors.
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DOI：
10.1186/1742-6405-2-8
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发表时间：
2005-10-05
影响因子：
2.2
通讯作者：
Prasad, Vinayaka R
中科院分区：
文献类型：
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作者：
Fisher, Timothy S;Joshi, Pheroze;Prasad, Vinayaka R
针对HIV-1逆转录酶（RT）的RNA和DNA适体可以在体外抑制逆转录。RNA适体已被证明可以有效地阻断HIV-1在培养物中的复制。我们以前报道了HIV-1 RT突变体与N255 D或N265 D的取代，显示对DNA适体RT 1 t49的抗性。单独或组合携带这些突变的变异病毒在复制方面受到损害。为了解决这种适体的更广泛的适用性，测试了含有N255 D、N265 D或两者（Dbl）的HIV-1 RT变体对其他DNA/RNA适体以及其他RT抑制剂的交叉抗性程度。N265 D和Dbl RT均对测试的大多数适体具有抗性。N255 D突变体对两种DNA适体表现出轻度抗性，对三种DNA适体的敏感性变化不大，对一种DNA适体表现出超敏反应。虽然所有突变体显示野生型样核糖核酸酶H活性，但它们的活性在防止重新结合的条件下受到损害。这表明由这些突变引起的持续合成缺陷也可以影响RNase H功能，从而进一步导致突变病毒中的复制缺陷。这些结果表明，赋予抗RT适体抗性的突变体显著影响许多HIV-1 RT酶活性，这可能有助于防止体内抗性的发展。如果这样的突变在体内出现，我们的研究结果表明，变异病毒应该仍然对许多现有的抗RT抑制剂敏感。这一结果被观察到NRTI抗性突变如K65 R可以赋予对一些抗RT适体的抗性而缓和。
RNA and DNA aptamers specific for HIV-1 reverse transcriptase (RT) can inhibit reverse transcription in vitro. RNA aptamers have been shown to potently block HIV-1 replication in culture. We previously reported mutants of HIV-1 RT with substitutions N255D or N265D that display resistance to the DNA aptamer RT1t49. Variant viruses bearing these mutations singly or in combination were compromised for replication. In order to address the wider applicability of such aptamers, HIV-1 RT variants containing the N255D, N265D or both (Dbl) were tested for the extent of their cross-resistance to other DNA/RNA aptamers as well as to other RT inhibitors. Both N265D and Dbl RTs were resistant to most aptamers tested. N255D mutant displayed mild resistance to two of the DNA aptamers, little change in sensitivity to three and hypersensitivity to one. Although all mutants displayed wild type-like ribonuclease H activity, their activity was compromised under conditions that prevent re-binding. This suggests that the processivity defect caused by these mutations can also affect RNase H function thus contributing further to the replication defect in mutant viruses. These results indicate that mutants conferring resistance to anti-RT aptamers significantly affect many HIV-1 RT enzymatic activities, which could contribute to preventing the development of resistance in vivo. If such mutations were to arise in vivo, our results suggest that variant viruses should remain susceptible to many existing anti-RT inhibitors. This result was tempered by the observation that NRTI-resistance mutations such as K65R can confer resistance to some anti-RT aptamers.