Lin Yea-Lih, Mettling Clement, Portales Pierre, Reynes Jacques, Clot Jacques, Corbeau Pierre
Institut de Génétique Humaine, Centre National de la Recherche Scientifique, Unité Propre de Recherche 1142, Laboratoire d'Immunologie de l'Hôpital Saint Eloi, France.
Proc Natl Acad Sci U S A. 2002 Nov 26;99(24):15590-5. doi: 10.1073/pnas.242134499. Epub 2002 Nov 14.
We have recently reported that the mean number of CCR5 coreceptors at the surface of CD4(+) T cells (CCR5 density) correlates with viral load and disease progression in HIV-1-infected persons. Here, we definitively establish that CCR5 density determines the level of virus production and identify the stages of HIV-1 replicative cycle modulated by this effect. We show, by transducing the CCR5 gene into CCR5(+) cells, that CCR5 overexpression resulted in an HIV-1 overinfectability. We sorted HOS-CD4(+)-CCR5(+) cells into two subpopulations, HOS(high) and HOS(low), the former expressing seven times more cell surface CCR5 molecules than the latter. Virus production was 30-80 times higher in HOS(high) cells than in HOS(low) cells after a single round of infection. In contrast, only twice as many viral particles entered the cytosol of HOS(high) cells as compared with the cytosol of HOS(low) cells. Yet, seven times as many early, and 24 times as many late, reverse transcription products were found in HOS(high) cells as compared with HOS(low) cells. Moreover, a 24- to 30-fold difference in the number of copies of integrated HIV-1 DNA was observed. No difference in HIV-1 LTR activation between the two cell lines was evident. Finally, we show that the higher virus production observed in HOS(high) cells is inhibited by pertussis toxin, a Galphai protein inhibitor. Thus, CCR5 density mainly modulates postentry steps of the virus life cycle, particularly the reverse transcription. These data explain why CCR5 density influences HIV-1 disease progression and underline the therapeutic interest of lowering CCR5 expression.
我们最近报道，CD4(+) T细胞表面CCR5共受体的平均数量（CCR5密度）与HIV-1感染者的病毒载量和疾病进展相关。在此，我们明确证实CCR5密度决定病毒产生水平，并确定受此效应调节的HIV-1复制周期阶段。我们通过将CCR5基因转导至CCR5(+)细胞中发现，CCR5过表达导致HIV-1超感染性。我们将HOS-CD4(+)-CCR5(+)细胞分选成两个亚群，即HOS(高)和HOS(低)，前者表达的细胞表面CCR5分子比后者多7倍。在单次感染后，HOS(高)细胞中的病毒产生量比HOS(低)细胞高30 - 80倍。相比之下，进入HOS(高)细胞胞质溶胶的病毒颗粒数量仅比进入HOS(低)细胞胞质溶胶的病毒颗粒数量多两倍。然而，与HOS(低)细胞相比，在HOS(高)细胞中发现的早期逆转录产物数量多7倍，晚期逆转录产物数量多24倍。此外，观察到整合的HIV-1 DNA拷贝数存在24至30倍的差异。两种细胞系之间HIV-1 LTR激活没有明显差异。最后，我们表明在HOS(高)细胞中观察到的较高病毒产生受到百日咳毒素（一种Galphai蛋白抑制剂）的抑制。因此，CCR5密度主要调节病毒生命周期的进入后步骤，特别是逆转录。这些数据解释了为什么CCR5密度会影响HIV-1疾病进展，并强调了降低CCR5表达的治疗意义。
