Construction and Molecular Analysis of Gene Transfer Systems Derived from Bovine Immunodeficiency Virus

Because lentiviruses are able to infect nondividing cells, these viruses might be utilized in gene therapy applications where the target cell does not divide. However, it has been suggested that the introduction of primate lentivirus sequences, particularly those of human immunodeficiency virus, into human cells may pose a health risk for the patient. To avoid this concern, we have constructed gene transfer systems based on a nonprimate lentivirus, bovine immunodeficiency virus. A panel of vectors and packaging constructs was generated and analyzed in a transient expression system for virion production and maturation, vector expression and encapsidation, and envelope protein pseudotyping. Virion preparations were also analyzed for transduction efficiency in a panel of human and nonhuman primary cells and immortalized cell lines. The virion preparations transduced most of the target cell types, with efficiencies up to 90% and with titers of unconcentrated virus up to 5 × 10(5) infectious doses/ml. In addition, infection of nondividing human cells, including unstimulated hematopoietic stem cells and irradiated endothelial cells, was observed.

由于慢病毒（lentivirus）能够感染非分裂细胞，这类病毒可被应用于靶细胞不发生分裂的基因治疗场景。然而有研究表明，将灵长类慢病毒序列——尤其是人类免疫缺陷病毒（Human Immunodeficiency Virus, HIV）——导入人类细胞可能会对患者的健康构成风险。为规避这一隐患，我们构建了基于非灵长类慢病毒——牛免疫缺陷病毒（Bovine Immunodeficiency Virus, BIV）——的基因转移系统。
我们生成了一组载体与包装构建体，并在瞬时表达系统中对其进行了分析，检测指标涵盖病毒粒子的产生与成熟、载体的表达与衣壳包装，以及包膜蛋白的假型化。此外，我们还对病毒粒子制剂在一系列人类及非人源原代细胞与永生化细胞系中的转导效率进行了分析。
该病毒粒子制剂可转导绝大多数靶细胞类型，转导效率最高可达90%，未浓缩病毒的滴度可达5×10^5 感染剂量/毫升。此外，研究还观察到其可感染非分裂人类细胞，包括未受刺激的造血干细胞与经辐照处理的内皮细胞。