Martinez I, Dornburg R
Graduate Program in Microbiology and Molecular Genetics, Rutgers University, New Brunswick, NJ 08903, USA.
Hum Gene Ther. 1996 Apr 10;7(6):705-12. doi: 10.1089/hum.1996.7.6-705.
Contamination of retroviral vector preparations with replication-competent retroviruses is a major safety concern in human gene therapy. These can arise by recombination between retroviral vectors and packaging cell sequences. Recently, we constructed new packaging lines, derived from spleen necrosis virus (SNV) that do not contain overlapping regions of homology between these two components (DSH134G and DSH29B cells). These cell lines were tested for the presence of recombination products and replication-competent viruses in comparison to a similar packaging line (DSN) that contains a partial overlap between vector and viral protein coding regions. No recombination products were detected in DSH cells. However, we found that recombination had occurred in DSN cells, partially reconstituting a provirus-like structure that was capable of being spread, although inefficiently, through an infected cell culture. Our data indicate that even small regions of sequence homology eventually allow homologous recombination between vector and helper cell genomes.
逆转录病毒载体制剂被具有复制能力的逆转录病毒污染是人类基因治疗中的一个主要安全问题。这些具有复制能力的逆转录病毒可通过逆转录病毒载体与包装细胞序列之间的重组产生。最近，我们构建了源自脾坏死病毒（SNV）的新包装细胞系，这两个组件（DSH134G和DSH29B细胞）之间不包含同源重叠区域。与包含载体和病毒蛋白编码区域之间部分重叠的类似包装细胞系（DSN）相比，对这些细胞系进行了重组产物和具有复制能力的病毒的检测。在DSH细胞中未检测到重组产物。然而，我们发现DSN细胞中发生了重组，部分重构了一种类似前病毒的结构，这种结构能够在受感染的细胞培养物中传播，尽管效率不高。我们的数据表明，即使是很小的序列同源区域最终也会允许载体与辅助细胞基因组之间发生同源重组。
