Genethon, 1bis Rue de l'Internationale, 91020 Evry, France.
Institute of Experimental Hematology, Hannover Medical School, Carl-Neuberg-Str.1, D-30625 Hannover, Germany.
Genes (Basel). 2014 May 16;5(2):415-29. doi: 10.3390/genes5020415.
Gene transfer vectors derived from gamma-retroviruses or lentiviruses are currently used for the gene therapy of genetic or acquired diseases. Retroviral vectors display a non-random integration pattern in the human genome, targeting either regulatory regions (gamma-retroviruses) or the transcribed portion of expressed genes (lentiviruses), and have the potential to deregulate gene expression at the transcriptional or post-transcriptional level. A recently developed alternative vector system derives from the avian sarcoma-leukosis alpha-retrovirus (ASLV) and shows favorable safety features compared to both gamma-retroviral and lentiviral vectors in preclinical models. We performed a high-throughput analysis of the integration pattern of self-inactivating (SIN) alpha-retroviral vectors in human CD34+ hematopoietic stem/progenitor cells (HSPCs) and compared it to previously reported gamma-retroviral and lentiviral vectors integration profiles obtained in the same experimental setting. Compared to gamma-retroviral and lentiviral vectors, the SIN-ASLV vector maintains a preference for open chromatin regions, but shows no bias for transcriptional regulatory elements or transcription units, as defined by genomic annotations and epigenetic markers (H3K4me1 and H3K4me3 histone modifications). Importantly, SIN-ASLV integrations do not cluster in hot spots and target potentially dangerous genomic loci, such as the EVI2A/B, RUNX1 and LMO2 proto-oncogenes at a virtually random frequency. These characteristics predict a safer profile for ASLV-derived vectors for clinical applications.
目前，源自γ-逆转录病毒或慢病毒的基因转移载体被用于遗传或获得性疾病的基因治疗。逆转录病毒载体在人类基因组中显示出非随机的整合模式，靶向调节区域（γ-逆转录病毒）或表达基因的转录部分（慢病毒），并有可能在转录或转录后水平下调基因表达。最近开发的替代载体系统源自禽肉瘤白血病α-逆转录病毒（ASLV），与临床前模型中的γ-逆转录病毒和慢病毒载体相比，具有更好的安全性特征。我们对自我失活（SIN）α-逆转录病毒载体在人 CD34+造血干/祖细胞（HSPCs）中的整合模式进行了高通量分析，并将其与在相同实验条件下获得的先前报道的γ-逆转录病毒和慢病毒载体整合谱进行了比较。与γ-逆转录病毒和慢病毒载体相比，SIN-ASLV 载体仍然优先选择开放染色质区域，但没有偏向于转录调节元件或转录单位，如基因组注释和表观遗传标记（H3K4me1 和 H3K4me3 组蛋白修饰）所定义的。重要的是，SIN-ASLV 整合不会在热点处聚集，并以几乎随机的频率靶向潜在危险的基因组位点，如 EVI2A/B、RUNX1 和 LMO2 原癌基因。这些特征预测 ASLV 衍生载体在临床应用中具有更安全的特性。
