Enya Blessing, Skowronski Jacek
Department of Molecular Biology and Microbiology, Case Western Reserve School of Medicine, 10900 Euclid Ave., Cleveland, OH 44106, USA.
Viruses. 2025 Jul 7;17(7):958. doi: 10.3390/v17070958.
Vpr, a virion-associated accessory virulence factor of HIV-1, promotes virus replication in both T cells and macrophages. Although Vpr's early activity-antagonism of preintegration silencing and host restriction factors-has been documented, the relative contribution of virion-associated versus de novo expressed Vpr to HIV-1 replication fitness remains unclear. Here, we developed a T cell-based system that genetically separates early and late Vpr functions by combining tetracycline-inducible Vpr expression in CEM.SS T cells with vpr-deficient HIV-1 constructs and Gag p6 mutations that block Vpr packaging. CEM.SS T cells have been shown to recapitulate the positive effect of Vpr on HIV-1 replication observed in activated primary T cells. Using pairwise replication fitness assays under spreading infection conditions, we demonstrate that de novo synthesized Vpr exerts the dominant effect on HIV-1 replication in T cells, while virion-associated Vpr plays a lesser role. Somewhat unexpectedly, our findings reveal that antagonism of preintegration HIV-1 silencing by virion-associated Vpr is unlikely to be the major driver of enhanced HIV-1 replication in proliferating T cells. Instead, this function may play a more prominent role in the infection of non-dividing T cells and/or other cell types.
Vpr是HIV-1的一种与病毒体相关的辅助毒力因子，可促进病毒在T细胞和巨噬细胞中复制。尽管Vpr的早期活性——对整合前沉默和宿主限制因子的拮抗作用——已有文献记载，但与病毒体相关的Vpr和从头表达的Vpr对HIV-1复制适应性的相对贡献仍不清楚。在此，我们开发了一种基于T细胞的系统，通过将CEM.SS T细胞中四环素诱导的Vpr表达与vpr缺陷的HIV-1构建体以及阻断Vpr包装的Gag p6突变相结合，从基因上分离Vpr的早期和晚期功能。已证明CEM.SS T细胞能够重现Vpr对活化的原代T细胞中HIV-1复制的积极作用。在扩散感染条件下使用成对复制适应性测定，我们证明从头合成的Vpr对T细胞中HIV-1复制发挥主要作用，而与病毒体相关的Vpr作用较小。有点出乎意料的是，我们的研究结果表明，与病毒体相关的Vpr对整合前HIV-1沉默的拮抗作用不太可能是增殖T细胞中HIV-1复制增强的主要驱动因素。相反，该功能可能在非分裂T细胞和/或其他细胞类型的感染中发挥更突出的作用。
