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 GAA 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 GAA 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.

II型糖原贮积病或Pompe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）突变引起，这种突变导致糖原在整个人体中的病理性积累。庞贝氏病可使用酶替代疗法。但是，它的功效有限，免疫原性高，并且不能纠正病理性糖原在神经组织和骨骼肌中的蓄积。使用生物信息学分析和蛋白质工程，我们开发了编码GAA的转基因，该基因可以由肝细胞表达和分泌。然后，我们使用针对肝表达优化的腺相关病毒（AAV）载体将GAA转基因递送至Gaa基因敲除（Gaa ^-/-）小鼠，庞贝病的模型。治疗性基因转移到肝脏可以挽救肌肉和中枢神经系统中的糖原积累，并减轻Gaa ^-/-小鼠的心脏肥大以及肌肉和呼吸功能障碍；小鼠的存活率也增加了。与非工程GAA相比，可分泌GAA表现出更高的治疗功效和更低的免疫原性。规模扩大到非人类灵长类动物，并使用肝细胞AAV载体模拟人类原代肝细胞中GAA表达，证明了AAV载体介导的可分泌GAA肝表达在庞培病多个组织中的病理性糖原积累的治疗潜力。