Pre-clinical Modeling of Foamy Viral gene Therapy for Murine and Human SCID-X1

SCID-XL是一种由常见伽马链突变引起的灾难性免疫缺陷疾病 (YC)基因。虽然使用匹配的兄弟姐妹捐赠者进行干细胞移植可以治愈，但大多数患者缺乏 最佳捐赠者会导致较差的结果。基因置换作为一种 SCID-XL的替代治疗方法；以及使用伽玛逆转录病毒YC进行的开创性临床研究 由于病毒增强剂，交付既有显著的好处，也有意想不到的不良事件 引发了白血病的发生。这一PPG的首要假设是YC的有效性和安全性 使用基于重组泡沫病毒(FV)的载体可以显著改善基因传递。研究项目： 项目1旨在测试YC FV载体缺乏病毒增强剂(有或没有)的假设 转录盒侧的附加增强子阻断元件)将显示转基因水平 表达足以在体内进行功能挽救，同时显示出较低的遗传毒性。目标 旨在通过详细的表型、功能和分子测试这些假说 两者的分析：1)SCID-XL小动物模型和2)来源于 SCID-XL患者。我们的具体研究将包括1)EFIA-HU-YC FV的疗效和安全性评估 去髓系小鼠与非去髓系小鼠SCID-XL受体体内载体及体外替代性研究 反式激活试验：2)转导SCID-XL患者的临床前和GMP级第1代YC FV CD34*BM细胞；3)候选绝缘2

SCID-Xl is catastrophic immunodeficiency disorder caused by mutations within the common gamma chain (yc) gene. While stem cell transplantation using a matched sibling donor can be curative, most patients lack optimal donors leading to poorer outcomes. Gene replacement has many theoretical advantages as an alternative therapeutic approach for SCID-Xl; and pioneering clinical studies using gammaretroviral yc delivery lead to both significant benefit as well as unanticipated adverse events due to viral enhancer triggered leukemogenesis. The overarching hypothesis of this PPG is that both the efficacy and safety of yc gene delivery can be significantly improved using recombinant foamy virus (FV) based vectors. Studies in Project 1 are designed to test the hypotheses that yc FV vectors devoid of viral enhancers (with or without additional enhancer blocking elements flanking the transcriptional cassette) will exhibit levels of transgene expression sufficient for functional rescue in vivo while concurrently showing reduced genotoxicity. The aims of Project 1 are designed to test these hypotheses via detailed phenotypic, functional, and molecular analysis in both: 1) a small animal model of SCID-Xl and 2) hematopoietic stem cells (HSC) derived from SCID-Xl patients. Our specific studies will include efficacy and safety assessment of 1) EFIa-hu-yc FV vectors in vivo in myeloablated vs. non-myeloablated murine SCID-Xl recipients; and in alternative in vitro transactivation assays; 2) Preclinical and GMP-grade 1^' generation yc FV in transduced SCID-Xl patient CD34* BM cells; and 3) Candidate insulated 2