Szojka Zsófia Ilona, Kunkli Balázs, Kiarie Irene Wanjiru, Linkner Tamás Richárd, Al-Muffti Aya Shamal, Ahmad Hala, Benkő Szilvia, Jansson Marianne, Tőzsér József, Mahdi Mohamed
Laboratory of Retroviral Biochemistry, Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Debrecen, 4032 Debrecen, Hungary.
Division of Medical Microbiology, Department of Laboratory Medicine, Lund University, Box 188, SE-221 00 Lund, Sweden.
Int J Mol Sci. 2025 Apr 8;26(8):3460. doi: 10.3390/ijms26083460.
Viral protein X (Vpx) is a unique accessory protein encoded by the genome of the human immunodeficiency virus type 2 (HIV-2) and lineages of the simian immunodeficiency virus of sooty mangabeys. So far, counteracting the cellular restriction factor SAMHD1 and mediating the efficient translocation of viral pre-integration complex have been recognized as key functions of Vpx; however, a thorough exploration of its effects on the cellular transcriptome and cytokine milieu has not yet been undertaken. In this study, we carried out the transcriptomic analysis of THP-1 cells and determined differential gene expressions induced by HIV-2 Vpx, utilizing vectors coding for the wild-type and K68-R70 functionally restricted proteins. Significantly altered genes were then validated and quantified through real-time quantitative PCR (qPCR); additionally, replication-competent virions were also used to confirm the findings. Moreover, we analyzed the effect of Vpx expression on the secretion of key cytokines in the medium of transfected cells. Our findings revealed that wild-type HIV-2 Vpx can significantly alter the expression of genes coding for helicases, zinc finger proteins, chaperons, transcription factors and proteins involved in DNA methylation. Differentially altered genes were involved in negative regulation of viral processes, the type I interferon-signaling pathway, DNA-template transcription, elongation, the positive regulation of interferon beta production and the negative regulation of innate immune response. Importantly, Vpx was also found to decrease the expression of HIV-1 Tat, possibly through the downregulation of a crucial splicing factor, required for the maturation of Tat. Additionally, studies on cellular cytokine milieu showed that this accessory protein induced key proinflammatory cytokines. Our study provides important information about the complex role played by HIV-2 Vpx in priming and taming the cellular environment to allow for the establishment of the infection.
病毒蛋白X（Vpx）是由人类免疫缺陷病毒2型（HIV-2）基因组以及乌黑白眉猴猿猴免疫缺陷病毒谱系编码的一种独特辅助蛋白。到目前为止，对抗细胞限制因子SAMHD1以及介导病毒整合前复合物的有效易位已被公认为Vpx的关键功能；然而，尚未对其对细胞转录组和细胞因子环境的影响进行全面探索。在本研究中，我们利用编码野生型和功能受限的K68-R70蛋白的载体，对THP-1细胞进行了转录组分析，并确定了HIV-2 Vpx诱导的差异基因表达。然后通过实时定量PCR（qPCR）对显著改变的基因进行验证和定量；此外，还使用具有复制能力的病毒粒子来证实这些发现。此外，我们分析了Vpx表达对转染细胞培养基中关键细胞因子分泌的影响。我们的研究结果表明，野生型HIV-2 Vpx可显著改变编码解旋酶、锌指蛋白、伴侣蛋白、转录因子以及参与DNA甲基化的蛋白质的基因表达。差异改变的基因参与病毒过程的负调控、I型干扰素信号通路、DNA模板转录、延伸、干扰素β产生的正调控以及先天免疫反应的负调控。重要的是，还发现Vpx可能通过下调Tat成熟所需的关键剪接因子来降低HIV-1 Tat的表达。此外，对细胞因子环境的研究表明，这种辅助蛋白可诱导关键促炎细胞因子。我们的研究提供了关于HIV-2 Vpx在启动和调节细胞环境以允许感染建立过程中所起复杂作用的重要信息。
