Recombinase-activating gene-1 (RAG1)-deficient severe combined immunodeficiency (SCID) patients lack B and T lymphocytes due to the inability to rearrange immunoglobulin and T cell receptor genes. Gene therapy is an alternative for those RAG1-SCID patients who lack a suitable bone marrow donor. We designed lentiviral vectors with different internal promoters driving codon-optimized RAG1 to ensure optimal expression. We used Rag1 -/- mice as a preclinical model for RAG1-SCID to assess the efficacy of the various vectors. We observed that B and T cell reconstitution directly correlated with RAG1 expression. Mice with low RAG1 expression showed poor immune reconstitution; however, higher expression resulted in phenotypic and functional lymphocyte reconstitution comparable to mice receiving wild-type stem cells. No signs of genotoxicity were found. Additionally, RAG1-SCID patient CD34+ cells transduced with our clinical RAG1 vector and transplanted into NSG mice led to improved human B and T cell development. Considering this efficacy outcome, together with favorable safety data, these results substantiate the need for a clinical trial for RAG1-SCID.

中文翻译：

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重组酶激活基因1缺陷型SCID的基因治疗的临床前成功开发。

重组酶激活基因1（RAG1）缺陷的严重联合免疫缺陷症（SCID）患者由于无法重新排列免疫球蛋白和T细胞受体基因而缺乏B和T淋巴细胞。对于那些缺乏合适的骨髓供体的RAG1-SCID患者，基因疗法是另一种选择。我们设计了具有不同内部启动子的慢病毒载体，以驱动密码子优化的RAG1来确保最佳表达。我们使用Rag1-/-小鼠作为RAG1-SCID的临床前模型来评估各种载体的功效。我们观察到B和T细胞的重建与RAG1表达直接相关。RAG1表达低的小鼠表现出较差的免疫重建。然而，与接受野生型干细胞的小鼠相比，更高的表达导致表型和功能性淋巴细胞重构。没有发现遗传毒性的迹象。此外，用我们的临床RAG1载体转导并移植到NSG小鼠中的RAG1-SCID患者CD34 +细胞可改善人B和T细胞的发育。考虑到该疗效结果以及有利的安全性数据，这些结果证实了对RAG1-SCID进行临床试验的必要性。