Center for Genome Engineering, Department of Genetics Cell Biology and Development, University of Minnesota, Minneapolis, MN, USA.
Sangamo Therapeutics, Inc., 501 Canal Boulevard, Richmond, CA, USA.
Mol Ther. 2018 Apr 4;26(4):1127-1136. doi: 10.1016/j.ymthe.2018.03.002. Epub 2018 Mar 10.
Mucopolysaccharidosis type II (MPS II) is an X-linked recessive lysosomal disorder caused by deficiency of iduronate 2-sulfatase (IDS), leading to accumulation of glycosaminoglycans (GAGs) in tissues of affected individuals, progressive disease, and shortened lifespan. Currently available enzyme replacement therapy (ERT) requires lifelong infusions and does not provide neurologic benefit. We utilized a zinc finger nuclease (ZFN)-targeting system to mediate genome editing for insertion of the human IDS (hIDS) coding sequence into a "safe harbor" site, intron 1 of the albumin locus in hepatocytes of an MPS II mouse model. Three dose levels of recombinant AAV2/8 vectors encoding a pair of ZFNs and a hIDS cDNA donor were administered systemically in MPS II mice. Supraphysiological, vector dose-dependent levels of IDS enzyme were observed in the circulation and peripheral organs of ZFN+donor-treated mice. GAG contents were markedly reduced in tissues from all ZFN+donor-treated groups. Surprisingly, we also demonstrate that ZFN-mediated genome editing prevented the development of neurocognitive deficit in young MPS II mice (6-9 weeks old) treated at high vector dose levels. We conclude that this ZFN-based platform for expression of therapeutic proteins from the albumin locus is a promising approach for treatment of MPS II and other lysosomal diseases.
黏多糖贮积症 II 型（MPS II）是一种 X 连锁隐性溶酶体贮积症，由艾杜糖-2-硫酸酯酶（IDS）缺乏引起，导致受影响个体组织中糖胺聚糖（GAGs）的积累、进行性疾病和寿命缩短。目前可用的酶替代疗法（ERT）需要终身输注，并且不能提供神经益处。我们利用锌指核酸酶（ZFN）靶向系统介导基因组编辑，将人 IDS（hIDS）编码序列插入肝细胞中白蛋白基因座的“安全港”位点。在 MPS II 小鼠模型中，用编码一对 ZFN 和 hIDS cDNA 供体的重组 AAV2/8 载体以三种剂量水平进行全身给药。在 ZFN+供体处理的小鼠的循环和外周器官中观察到超生理的、载体剂量依赖性的 IDS 酶水平。所有 ZFN+供体处理组的组织中的 GAG 含量均显著降低。令人惊讶的是，我们还证明，在高载体剂量水平下治疗的年轻 MPS II 小鼠（6-9 周龄）中，ZFN 介导的基因组编辑可预防神经认知缺陷的发展。我们得出结论，这种基于 ZFN 的从白蛋白基因座表达治疗性蛋白的平台是治疗 MPS II 和其他溶酶体疾病的有前途的方法。
