Department of Microbiology and Immunology, University of Rochester Medical Center, 601 Elmwood Avenue, Rochester, NY 14642, USA.
Virology. 2010 Oct 25;406(2):253-60. doi: 10.1016/j.virol.2010.07.028. Epub 2010 Aug 10.
We recently reported that the M184I 3TC resistant mutation reduces RT binding affinity to dNTP substrates. First, the HIV-1 M184I mutant vector displays reduced transduction efficiency compared to wild type (WT) RT vector, which could be rescued by both elevating the cellular dNTP concentration and incorporating WT RT molecules into the M184I vector particles. Second, the central polypurine tract (cPPT) mutation and M184I mutation additively reduced the vector transduction to almost undetectable levels, particularly in nondividing cells. Third, the M184I (-) cPPT vector became significantly more sensitive to 3TC than the M184I (+) cPPT vector, but not to AZT or Nevirapine in the dividing cells. Finally, this 3TC sensitizing effect of the cPPT inactivation of the M184I vector was reversed by elevating the dCTP level, but not by the other three dNTPs. These data support a mechanistic interaction between cPPT and M184I RT with respect to viral replication and sensitivity to 3TC.
我们最近报道了 M184I 3TC 耐药突变降低了 RT 对 dNTP 底物的结合亲和力。首先，与野生型（WT）RT 载体相比，HIV-1 M184I 突变载体的转导效率降低，这可以通过提高细胞内 dNTP 浓度和将 WT RT 分子掺入 M184I 载体颗粒来挽救。其次，中央多嘧啶序列（cPPT）突变和 M184I 突变使载体转导降低到几乎无法检测的水平，特别是在非分裂细胞中。第三，M184I（-）cPPT 载体比 M184I（+）cPPT 载体对 3TC 的敏感性显著增加，但在分裂细胞中对 AZT 或奈韦拉平不敏感。最后，通过提高 dCTP 水平可以逆转 cPPT 失活 M184I 载体对 3TC 的敏感性，但其他三种 dNTP 则不行。这些数据支持 cPPT 和 M184I RT 之间在病毒复制和对 3TC 敏感性方面的机制相互作用。
