Beard Brian C, Dickerson David, Beebe Kate, Gooch Christina, Fletcher James, Okbinoglu Tulin, Miller Daniel G, Jacobs Michael A, Kaul Rajinder, Kiem Hans-Peter, Trobridge Grant D
Fred Hutchinson Cancer Research Center, Seattle, Washington, USA.
Mol Ther. 2007 Jul;15(7):1356-65. doi: 10.1038/sj.mt.6300159. Epub 2007 Apr 17.
The potential for leukemia caused by retroviral vector integration has become a significant concern for hematopoietic stem cell gene therapy. We analyzed the distribution of vector integrants in pigtailed macaque and baboon repopulating cells for the two most commonly used retroviral vector systems, human immunodeficiency virus (HIV)-based lentiviral vectors and murine leukemia virus (MLV)-based gammaretroviral vectors, to help define their relative genotoxicity. All animals had polyclonal engraftment with no apparent adverse effects from transplantation with gene-modified cells. In all, 380 MLV and 235 HIV unique vector integration sites were analyzed and had distinct distribution patterns in relation to genes and CpG islands as observed in previous in vitro studies. Both vector types were found more frequently in and near proto-oncogenes in repopulating cells than in a random dataset. Analysis of functional classes of genes with integrants within 100 kilobases (kb) of their transcription start sites showed an over-representation of genes involved in growth or survival near both lentiviral and gammaretroviral integrants. Microarray analysis showed that both gammaretroviral and lentiviral vectors were found close to genes with high expression levels in primitive cells enriched for hematopoietic stem cells. These data help define the relative risk of insertional mutagenesis with MLV-, HIV-, and simian immunodeficiency virus (SIV)-based vectors in a highly relevant primate model.
逆转录病毒载体整合导致白血病的可能性已成为造血干细胞基因治疗的一个重大关注点。我们分析了两种最常用的逆转录病毒载体系统（基于人类免疫缺陷病毒（HIV）的慢病毒载体和基于鼠白血病病毒（MLV）的γ逆转录病毒载体）在猪尾猕猴和狒狒再增殖细胞中的载体整合分布情况，以帮助确定它们的相对基因毒性。所有动物均为多克隆植入，移植基因修饰细胞后未出现明显不良反应。总共分析了380个MLV和235个HIV独特的载体整合位点，其在基因和CpG岛附近的分布模式与先前的体外研究中观察到的不同。与随机数据集相比，两种载体类型在再增殖细胞的原癌基因内及附近出现的频率更高。对转录起始位点100千碱基（kb）范围内含有整合体的基因功能类别分析表明，慢病毒和γ逆转录病毒整合体附近涉及生长或存活的基因存在过度表达。微阵列分析表明，在富含造血干细胞原始细胞中，γ逆转录病毒载体和慢病毒载体均发现于高表达水平基因附近。这些数据有助于在高度相关的灵长类动物模型中确定基于MLV、HIV和猿猴免疫缺陷病毒（SIV）载体的插入诱变相对风险。
