Braun Stephen E, Lu Xiaobin V, Wong Fay Eng, Connole Michelle, Qiu Gang, Chen Ziping, Slepushkina Tatiana, Slepushkin Vladimir, Humeau Laurent M, Dropulic Boro, Johnson R Paul
Division of Immunology, New England Primate Research Center, Harvard Medical School, Southborough, MA 01772, USA.
Hum Gene Ther. 2007 Jul;18(7):653-64. doi: 10.1089/hum.2007.003.
In light of findings demonstrating that the macaque TRIM5alpha protein inhibits infection of cells by human immunodeficiency virus (HIV)-1, simian immunodeficiency virus (SIV)-based lentiviral vectors may have distinct advantages over HIV-1 vectors for the transduction of macaque hematopoietic stem cells. We evaluated the ability of an SIV vector (VRX859) encoding an antisense SIV envelope sequence and enhanced green fluorescent protein (GFP) to inhibit viral replication and to transduce rhesus CD34(+) lymphoid progenitor cells. After infection with homologous SIV strains, CD4(+) cell lines transduced with VRX859 exhibited more than 600-fold inhibition of viral replication compared with control cells. Less inhibition was observed with the divergent SIV strain SIVsmE660. Partial inhibition of a chimeric simian-human immunodeficiency virus, which contains an HIV-1 envelope in an SIV backbone, was observed, suggesting that the SIV vector also contributes to viral inhibition independent of the antisense envelope inhibitor. Transduction of rhesus CD34(+) cells with VRX859 at various multiplicities of infection resulted in transduction efficiencies comparable to those obtained with the HIV vector VRX494. However, when we evaluated transduction of rhesus T lymphocyte progenitors by examining GFP expression in CD4(+) T cells derived from transduced CD34(+) cells, we observed more efficient transduction with the SIV-based vector. GFP(+)CD4(+) T cells derived from VRX859-transduced CD34(+) cells strongly inhibited SIVmac239 replication as compared with control CD4(+) T cells. The ability of this SIV-based vector to mediate potent inhibition of SIV replication, coupled with its efficient transduction of rhesus hematopoietic progenitor cells, make it an important candidate for proof-of-principle experiments of stem cell gene therapy in the SIV-macaque model.
鉴于有研究结果表明猕猴TRIM5α蛋白可抑制人类免疫缺陷病毒（HIV）-1对细胞的感染，基于猿猴免疫缺陷病毒（SIV）的慢病毒载体在转导猕猴造血干细胞方面可能比HIV-1载体具有明显优势。我们评估了一种编码反义SIV包膜序列和增强型绿色荧光蛋白（GFP）的SIV载体（VRX859）抑制病毒复制以及转导恒河猴CD34(+)淋巴祖细胞的能力。在用同源SIV毒株感染后，与对照细胞相比，用VRX859转导的CD4(+)细胞系对病毒复制的抑制作用超过600倍。对于不同的SIV毒株SIVsmE660，观察到的抑制作用较小。观察到对一种嵌合型猿猴-人类免疫缺陷病毒（其在SIV骨架中含有HIV-1包膜）有部分抑制作用，这表明SIV载体也有助于独立于反义包膜抑制剂的病毒抑制作用。在不同感染复数下用VRX859转导恒河猴CD34(+)细胞，其转导效率与用HIV载体VRX494获得的转导效率相当。然而，当我们通过检测源自转导的CD34(+)细胞的CD4(+)T细胞中的GFP表达来评估恒河猴T淋巴细胞祖细胞的转导情况时，我们观察到基于SIV的载体转导效率更高。与对照CD4(+)T细胞相比，源自VRX859转导的CD34(+)细胞的GFP(+)CD4(+)T细胞强烈抑制SIVmac239复制。这种基于SIV的载体介导对SIV复制的有效抑制的能力，再加上其对恒河猴造血祖细胞的高效转导，使其成为SIV-猕猴模型中干细胞基因治疗原理验证实验的重要候选者。
