Pugach Pavel, Marozsan Andre J, Ketas Thomas J, Landes Elissa L, Moore John P, Kuhmann Shawn E
Department of Microbiology and Immunology, Weill Medical College of Cornell University, 1300 York Avenue, Box 62, New York, NY 10021, USA.
Virology. 2007 Apr 25;361(1):212-28. doi: 10.1016/j.virol.2006.11.004. Epub 2006 Dec 12.
Human immunodeficiency virus type 1 (HIV-1) infection can be inhibited by small molecules that target the CCR5 coreceptor. Here, we describe some properties of clonal viruses resistant to one such inhibitor, SCH-D, using both chimeric, infectious molecular clones and Env-pseudotypes. Studies using combinations of CCR5 ligands, including small molecule inhibitors, monoclonal antibodies (MAbs) and chemokine derivatives such as PSC-RANTES, show that the fully SCH-D-resistant viruses enter target cells by using the SCH-D-bound form of CCR5. However, the way resistance to SCH-D and other small molecule CCR5 inhibitors is manifested depends on the target cell and the nature of the assay (single- vs. multi-cycle). In multi-cycle assays using primary lymphocytes, SCH-D does not inhibit resistant molecular clones, and it can even enhance their infectivity modestly. In contrast, the same viruses (as Env-pseudotypes) are significantly inhibited by SCH-D in single-cycle entry assays using U87-CD4/CCR5 cells, resistance being manifested by incomplete inhibition at high SCH-D concentrations. When a single-cycle, Env-pseudotype entry assay was performed using either U87-CD4/CCR5 cells or PBMC under comparable conditions, entry was inhibited by up to 88% in the former cells but by only 28% in the PBMC. Hence, there are both cell- and assay-dependent influences on how resistance is manifested. We also take this opportunity to correct our previous report that SCH-D-resistant isolates are also substantially cross-resistant to PSC-RANTES [Marozsan, A.J., Kuhmann, S.E., Morgan, T., Herrera, C., Rivera-Troche, E., Xu, S., Baroudy, B.M., Strizki, J., Moore, J.P., 2005. Generation and properties of a human immunodeficiency virus type 1 isolate resistant to the small molecule CCR5 inhibitor, SCH-417690 (SCH-D). Virology 338 (1), 182-199]. A substantial element of this resistance was attributable to the unappreciated carry-over of SCH-D from the selection cultures into analytical assays.
1型人类免疫缺陷病毒（HIV-1）感染可被靶向CCR5共受体的小分子抑制。在此，我们使用嵌合感染性分子克隆和Env假型，描述了对一种此类抑制剂SCH-D耐药的克隆病毒的一些特性。使用包括小分子抑制剂、单克隆抗体（MAb）和趋化因子衍生物（如PSC-RANTES）在内的CCR5配体组合进行的研究表明，完全对SCH-D耐药的病毒通过使用与SCH-D结合形式的CCR5进入靶细胞。然而，对SCH-D和其他小分子CCR5抑制剂耐药性的表现方式取决于靶细胞和检测方法的性质（单循环与多循环）。在使用原代淋巴细胞的多循环检测中，SCH-D不抑制耐药分子克隆，甚至还能适度增强它们的感染性。相比之下，在使用U87-CD4/CCR5细胞的单循环进入检测中，相同的病毒（作为Env假型）被SCH-D显著抑制，在高SCH-D浓度下耐药表现为不完全抑制。当在可比条件下使用U87-CD4/CCR5细胞或PBMC进行单循环Env假型进入检测时，前者细胞中的进入被抑制高达88%，而在PBMC中仅被抑制28%。因此，耐药性的表现存在细胞和检测方法依赖性影响。我们还借此机会纠正我们之前的报告，即对SCH-D耐药的分离株对PSC-RANTES也存在显著的交叉耐药性[Marozsan, A.J., Kuhmann, S.E., Morgan, T., Herrera, C., Rivera-Troche, E., Xu, S., Baroudy, B.M., Strizki, J., Moore, J.P., 2005. 对小分子CCR5抑制剂SCH-417690（SCH-D）耐药的1型人类免疫缺陷病毒分离株的产生及特性。病毒学338 (1), 182 - 199]。这种耐药性的一个重要因素可归因于从选择培养物中未被认识到的SCH-D残留到分析检测中。
