Speck P G, Efstathiou S, Minson A C
Department of Pathology, University of Cambridge, UK.
J Gen Virol. 1996 Oct;77 ( Pt 10):2563-8. doi: 10.1099/0022-1317-77-10-2563.
The utilization of herpes simplex virus (HSV) as a vector for gene delivery to the nervous system or as a live vaccine delivery system is dependent on the construction and characterization of disabled virus mutants which are unable to cause disease. Under certain circumstances, however, replication-defective vectors may carry a potential risk if they can be efficiently complemented by a co-infecting wild-type virus. Stocks of defective vectors should, therefore, be free from replication-competent virus, and helper cell lines should be incapable of generating replication-competent virus by recombination between the vector and the complementary gene. We describe a glycoprotein H-negative (gH-) virus/helper cell line combination which generates helper-free defective virus stocks containing replication-competent virus at a frequency no higher than 1 in 10(9) p.f.u. This virus/helper cell system provides a suitable background for the construction of safe replication-defective gene delivery vectors. In vivo studies demonstrate that gH- virus is unable to initiate disease in mice and establishes latency at low efficiency compared to wild-type HSV. To determine whether gH- virus can be complemented by wild-type virus in vivo, mice were infected with a variety of mixtures of these viruses. Complementation was observed in a minority of animals infected with more than 10(6) p.f.u. of both wild-type and defective virus but the most common observation was that the presence of defective virus suppressed entry of wild-type virus into the nervous system.
单纯疱疹病毒（HSV）作为一种将基因传递至神经系统的载体或作为一种活疫苗递送系统，其应用依赖于构建和鉴定无致病能力的缺陷病毒突变体。然而，在某些情况下，如果复制缺陷型载体能够被共感染的野生型病毒有效互补，那么它们可能存在潜在风险。因此，缺陷型载体的毒株应不含具有复制能力的病毒，并且辅助细胞系应无法通过载体与互补基因之间的重组产生具有复制能力的病毒。我们描述了一种糖蛋白H阴性（gH-）病毒/辅助细胞系组合，该组合产生的无辅助缺陷型病毒毒株中，含有复制能力病毒的频率不高于10^9个噬斑形成单位（p.f.u.）中的1个。这种病毒/辅助细胞系统为构建安全的复制缺陷型基因传递载体提供了合适的背景。体内研究表明，与野生型HSV相比，gH-病毒无法在小鼠体内引发疾病，且以低效率建立潜伏感染。为了确定gH-病毒在体内是否能被野生型病毒互补，用这些病毒的多种混合物感染小鼠。在少数感染了超过10^6个p.f.u.野生型和缺陷型病毒的动物中观察到了互补现象，但最常见的情况是缺陷型病毒的存在抑制了野生型病毒进入神经系统。
