INTEGRARE, Genethon, Inserm, Univ Evry, Université Paris-Saclay, 91002 Evry, France.
Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy.
Sci Transl Med. 2017 Nov 29;9(418). doi: 10.1126/scitranslmed.aam6375.
Glycogen storage disease type II or Pompe disease is a severe neuromuscular disorder caused by mutations in the lysosomal enzyme, acid α-glucosidase (GAA), which result in pathological accumulation of glycogen throughout the body. Enzyme replacement therapy is available for Pompe disease; however, it has limited efficacy, has high immunogenicity, and fails to correct pathological glycogen accumulation in nervous tissue and skeletal muscle. Using bioinformatics analysis and protein engineering, we developed transgenes encoding GAA that could be expressed and secreted by hepatocytes. Then, we used adeno-associated virus (AAV) vectors optimized for hepatic expression to deliver the transgenes to Gaa knockout (Gaa) mice, a model of Pompe disease. Therapeutic gene transfer to the liver rescued glycogen accumulation in muscle and the central nervous system, and ameliorated cardiac hypertrophy as well as muscle and respiratory dysfunction in the Gaa mice; mouse survival was also increased. Secretable GAA showed improved therapeutic efficacy and lower immunogenicity compared to nonengineered GAA. Scale-up to nonhuman primates, and modeling of expression in primary human hepatocytes using hepatotropic AAV vectors, demonstrated the therapeutic potential of AAV vector-mediated liver expression of secretable GAA for treating pathological glycogen accumulation in multiple tissues in Pompe disease.
糖原贮积病 II 型或庞贝病是一种严重的神经肌肉疾病，由溶酶体酶酸性α-葡萄糖苷酶（GAA）的突变引起，导致全身糖原病理性积累。庞贝病可采用酶替代疗法；然而，该疗法疗效有限，免疫原性高，无法纠正神经组织和骨骼肌中病理性糖原积累。我们利用生物信息学分析和蛋白质工程，开发了可在肝细胞中表达和分泌的 GAA 转基因。然后，我们使用优化用于肝表达的腺相关病毒（AAV）载体将转基因递送至 Gaa 敲除（Gaa）小鼠，即庞贝病模型。肝脏的治疗性基因转移挽救了肌肉和中枢神经系统中的糖原积累，并改善了 Gaa 小鼠的心脏肥大以及肌肉和呼吸功能障碍；还提高了小鼠的存活率。与非工程化的 GAA 相比，可分泌的 GAA 显示出更好的治疗效果和更低的免疫原性。在非人类灵长类动物中的扩大规模以及使用嗜肝 AAV 载体在原代人肝细胞中进行表达的建模，证明了 AAV 载体介导的可分泌 GAA 在肝脏中的表达治疗庞贝病中多种组织中病理性糖原积累的潜力。
