Abstract:
Ex vivo gene therapy procedures targeting hematopoietic stem and progenitor cells (HSPCs) predominantly utilize lentivirus-based vectors for gene transfer. We provide the first pre-clinical evidence of the therapeutic utility of a foamy virus vector (FVV) for the genetic correction of human leukocyte adhesion deficiency type 1 (LAD-1), an inherited primary immunodeficiency resulting from mutation of the β2 integrin common chain, CD18. CD34+ HSPCs isolated from a severely affected LAD-1 patient were transduced under a current good manufacturing practice-compatible protocol with FVV harboring a therapeutic CD18 transgene. LAD-1-associated cellular chemotactic defects were ameliorated in transgene-positive, myeloid-differentiated LAD-1 cells assayed in response to a strong neutrophil chemoattractant in vitro. Xenotransplantation of vector-transduced LAD-1 HSPCs in immunodeficient (NSG) mice resulted in long-term (∼5 months) human cell engraftment within murine bone marrow. Moreover, engrafted LAD-1 myeloid cells displayed in vivo levels of transgene marking previously reported to ameliorate the LAD-1 phenotype in a large animal model of the disease. Vector insertion site analysis revealed a favorable vector integration profile with no overt evidence of genotoxicity. These results coupled with the unique biological features of wild-type foamy virus support the development of FVVs for ex vivo gene therapy of LAD-1.
摘要:
靶向造血干细胞和祖细胞(HSPC)的离体基因治疗程序主要利用基于慢病毒的载体进行基因转移。我们提供了泡沫病毒载体(FVV)用于人类白细胞粘附缺陷1型(LAD-1)遗传校正的治疗效用的第一个临床前证据,由β2整合素共同链突变引起的遗传性原发性免疫缺陷,CD18.从严重受影响的LAD-1患者分离的CD34+HSPC在当前良好的制造实践-兼容方案下与具有治疗性CD18转基因的FVV转导。LAD-1相关的细胞趋化缺陷在转基因阳性,骨髓分化的LAD-1细胞在体外检测对强嗜中性粒细胞化学引诱物的反应。在免疫缺陷(NSG)小鼠中对载体转导的LAD-1HSPCs进行异种移植导致小鼠骨髓内的长期(约5个月)人细胞移植。此外,移植的LAD-1骨髓细胞在体内显示先前报道的转基因标记水平,以改善该疾病的大型动物模型中的LAD-1表型。载体插入位点分析显示了良好的载体整合概况,没有明显的遗传毒性证据。这些结果与野生型泡沫病毒的独特生物学特征相结合,支持了FVV用于LAD-1离体基因治疗的开发。