Gene Therapy Center, Department of Pediatrics, University of Minnesota, Minneapolis, MN 55455, USA.
Gene Therapy Center, Department of Pediatrics, University of Minnesota, Minneapolis, MN 55455, USA.
Mol Ther. 2020 Jun 3;28(6):1442-1454. doi: 10.1016/j.ymthe.2020.03.018. Epub 2020 Apr 8.
Our previous study delivered zinc finger nucleases to treat mice with mucopolysaccharidosis type I (MPS I), resulting in a phase I/II clinical trial (ClinicalTrials.gov: NCT02702115). However, in the clinical trial, the efficacy needs to be improved due to the low transgene expression level. To this end, we designed a proprietary system (PS) gene editing approach with CRISPR to insert a promoterless α-l-iduronidase (IDUA) cDNA sequence into the albumin locus of hepatocytes. In this study, adeno-associated virus 8 (AAV8) vectors delivering the PS gene editing system were injected into neonatal and adult MPS I mice. IDUA enzyme activity in the brain significantly increased, while storage levels were normalized. Neurobehavioral tests showed that treated mice had better memory and learning ability. Also, histological analysis showed efficacy reflected by the absence of foam cells in the liver and vacuolation in neuronal cells. No vector-associated toxicity or increased tumorigenesis risk was observed. Moreover, no off-target effects were detected through the unbiased genome-wide unbiased identification of double-stranded breaks enabled by sequencing (GUIDE-seq) analysis. In summary, these results showed the safety and efficacy of the PS in treating MPS I and paved the way for clinical studies. Additionally, as a therapeutic platform, the PS has the potential to treat other lysosomal diseases.
我们之前的研究使用锌指核酸酶治疗黏多糖贮积症 I 型（MPS I）小鼠，这导致了一项 I/II 期临床试验（ClinicalTrials.gov：NCT02702115）。然而，在临床试验中，由于转基因表达水平低，需要提高疗效。为此，我们设计了一种专有的 CRISPR 基因编辑系统（PS）方法，将无启动子的α-L-艾杜糖苷酸酶（IDUA）cDNA 序列插入肝细胞的白蛋白基因座。在这项研究中，腺相关病毒 8（AAV8）载体将 PS 基因编辑系统递送到新生和成年 MPS I 小鼠体内。大脑中的 IDUA 酶活性显著增加，而储存水平恢复正常。神经行为学测试表明，治疗后的小鼠具有更好的记忆和学习能力。此外，组织学分析显示，肝脏中泡沫细胞的缺失和神经元细胞空泡化反映了疗效。未观察到载体相关毒性或增加肿瘤发生风险。此外，通过测序（GUIDE-seq）分析进行的无偏基因组范围内双链断裂的无偏识别表明，没有检测到脱靶效应。总之，这些结果表明 PS 在治疗 MPS I 中的安全性和疗效，并为临床研究铺平了道路。此外，作为一种治疗平台，PS 有可能治疗其他溶酶体疾病。
