Bruggemans Anne, Vansant Gerlinde, Van de Velde Paulien, Debyser Zeger
Molecular Virology and Gene Therapy, KU Leuven, Leuven, Flanders, Belgium.
J Virus Erad. 2023 Aug 29;9(3):100343. doi: 10.1016/j.jve.2023.100343. eCollection 2023 Sep.
A better understanding of HIV-1 latency is a research priority in HIV cure research. Conversely, little is known about the latency characteristics of HIV-2, the closely related human lentivirus. Though both viruses cause AIDS, HIV-2 infection progresses more slowly with significantly lower viral loads, even when corrected for CD4 T cell counts. Hence a direct comparison of latency characteristics between HIV-1 and HIV-2 could provide important clues towards a functional cure. Transduction of SupT1 cells with single-round HIV-1 and HIV-2 viruses with an enhanced green fluorescent protein (eGFP) reporter showed higher levels of eGFP expression for HIV-2 than HIV-1, while HIV-1 expression appeared more cytotoxic. To compare HIV-1 and HIV-2 gene expression, latency and reactivation in more detail, we have generated HIV-2 OGH, a replication deficient, near full- length, double reporter virus that discriminates latently and productively infected cells in cell culture. This construct is based on HIV-1 OGH, and to our knowledge, first of its kind for HIV-2. Using this construct we have observed a higher eGFP expression for HIV-2, but higher losses of HIV-1 transduced cells in SupT1 and Jurkat cells and a reduced sensitivity of HIV-2 for reactivation with TNF-α. In addition, we have analysed HIV-2 integration sites and their epigenetic environment. HIV-1 and HIV-2 share a preference for actively transcribed genes in gene-dense regions and favor active chromatin marks while disfavoring methylation markers associated with heterochromatin. In conclusion the HIV-2 OGH construct provides an interesting tool for studying HIV-2 expression, latency and reactivation. As simian immunodeficiency virus (SIV) and HIV-2 have been proposed to model a functional HIV cure, a better understanding of the mechanisms governing HIV-2 and SIV latency will be important to move forward. Further research is needed to investigate if HIV-2 uses similar mechanisms as HIV-1 to achieve its integration site selectivity.
更好地理解HIV-1潜伏是HIV治愈研究中的一个研究重点。相反，对于密切相关的人类慢病毒HIV-2的潜伏特征却知之甚少。尽管两种病毒都会导致艾滋病，但HIV-2感染进展更为缓慢，病毒载量显著更低，即便校正了CD4 T细胞计数也是如此。因此，直接比较HIV-1和HIV-2之间的潜伏特征可能为功能性治愈提供重要线索。用带有增强型绿色荧光蛋白（eGFP）报告基因的单轮HIV-1和HIV-2病毒转导SupT1细胞，结果显示HIV-2的eGFP表达水平高于HIV-1，而HIV-1的表达似乎更具细胞毒性。为了更详细地比较HIV-1和HIV-2的基因表达、潜伏和再激活情况，我们构建了HIV-2 OGH，这是一种复制缺陷型、近乎全长的双报告病毒，可在细胞培养中区分潜伏感染和活跃感染的细胞。该构建体基于HIV-1 OGH，据我们所知，这是首个针对HIV-2的此类构建体。使用该构建体，我们观察到HIV-2的eGFP表达更高，但在SupT1和Jurkat细胞中，HIV-1转导细胞的损失更多，且HIV-2对TNF-α再激活的敏感性降低。此外，我们分析了HIV-2的整合位点及其表观遗传环境。HIV-1和HIV-2都倾向于整合到基因密集区域中活跃转录的基因上，且偏好活跃染色质标记，同时不喜欢与异染色质相关的甲基化标记。总之，HIV-2 OGH构建体为研究HIV-2的表达、潜伏和再激活提供了一个有趣的工具。由于有人提出猴免疫缺陷病毒（SIV）和HIV-2可作为功能性HIV治愈的模型，更好地理解控制HIV-2和SIV潜伏的机制对于取得进展至关重要。需要进一步研究来调查HIV-2是否使用与HIV-1类似的机制来实现其整合位点选择性。
