Ntemgwa Michel L, Toni Thomas d'Aquin, Brenner Bluma G, Oliveira Maureen, Asahchop Eugene L, Moisi Daniela, Wainberg Mark A
McGill University AIDS Centre, Lady Davis Institute for Medical Research, Jewish General Hospital, Montreal, Quebec, Canada.
Antimicrob Agents Chemother. 2009 Feb;53(2):708-15. doi: 10.1128/AAC.01109-08. Epub 2008 Dec 8.
Recent findings suggest bidirectional antagonisms between the K65R mutation and thymidine analogue mutations in human immunodeficiency virus type 1 (HIV-1)-infected, treatment-experienced patients, yet little is known about HIV-2 in this regard. This study addressed the effects of innate polymorphisms in HIV-2 on emergent resistance to nucleoside/nucleotide analogues. Emergent drug resistance profiles in HIV-2 subtypes A (n = 3) and B (n = 1) were compared to those of HIV-1 subtypes B and C. Drug resistance was evaluated with cord blood mononuclear cells (CBMCs) and MT2 cells, using selective pressure with tenofovir (TFV), zidovudine (ZDV), stavudine (d4T), didanosine (ddI), abacavir (ABC), lamivudine (3TC), emtricitabine (FTC), or various dual-drug combinations. Resistance was evaluated using conventional and ultrasensitive sequencing approaches. In agreement with our previous findings, dual-drug combinations of TFV, ddI, ABC, d4T, ZDV, and 3TC preferentially selected for K65R in HIV-1 subtype C isolates. In HIV-1 subtype B, TFV-3TC and ZDV-3TC selected for M184I and D67N, respectively. In contrast, selections with all four HIV-2 cultures favored the development of M184I in dual-drug combinations that included either 3TC or FTC. Since HIV-2 cultures did not develop K65R, an ultrasensitive allele-specific real-time PCR assay was developed to distinguish the presence of 65R from wild-type K65 after 16 cycles with a discriminatory ability of 0.1% against a population of wild-type virus. These results underscore potential differences in emergent drug resistance pathways in HIV-1 and HIV-2 and show that polymorphisms may influence the development of the resistance pathways that are likely to emerge.
近期研究结果表明，在接受过治疗的1型人类免疫缺陷病毒（HIV-1）感染患者中，K65R突变与胸苷类似物突变之间存在双向拮抗作用，但在这方面对2型HIV（HIV-2）的了解甚少。本研究探讨了HIV-2中的先天多态性对核苷/核苷酸类似物新出现耐药性的影响。将HIV-2 A亚型（n = 3）和B亚型（n = 1）的新出现耐药谱与HIV-1 B亚型和C亚型的进行了比较。使用脐带血单个核细胞（CBMC）和MT2细胞，通过替诺福韦（TFV）、齐多夫定（ZDV）、司他夫定（d4T）、去羟肌苷（ddI）、阿巴卡韦（ABC）、拉米夫定（3TC）、恩曲他滨（FTC）或各种双药组合的选择性压力来评估耐药性。使用传统和超灵敏测序方法评估耐药性。与我们之前的研究结果一致，TFV、ddI、ABC、d4T、ZDV和3TC的双药组合在HIV-1 C亚型分离株中优先选择K65R。在HIV-1 B亚型中，TFV-3TC和ZDV-3TC分别选择M184I和D67N。相比之下，所有四种HIV-2培养物在包含3TC或FTC的双药组合中均有利于M184I的产生。由于HIV-2培养物未出现K65R，因此开发了一种超灵敏的等位基因特异性实时PCR检测方法，以在16个循环后区分65R与野生型K65的存在，对野生型病毒群体的鉴别能力为0.1%。这些结果强调了HIV-1和HIV-2新出现耐药途径的潜在差异，并表明多态性可能影响可能出现的耐药途径的发展。
