Gene therapy with modified GlcNAc-1-phosphotransferase for mucolipidosis

项目摘要/摘要 粘脂病是一组遗传性疾病，在这种情况下，溶酶体酶不能正确地运输到 溶酶体，由于UDP-N-乙酰氨基葡萄糖缺乏活性：溶酶体酶N-乙酰氨基葡萄糖-1- 磷酸转移酶和随后未能将甘露糖-6-磷酸残基添加到溶酶体酶中。AS 结果，溶酶体积累了各种不能被适当降解的底物，从而导致进行性 身体和神经疾病和过早死亡。同时，缺乏甘露糖的可溶性溶酶体酶- 6-磷酸，可以在血液中发现异常高的含量。目前还没有可用的治疗方法。 在这里，使用II型粘脂沉积症(也称为I-细胞病)的空白小鼠模型，我们建议研究 一种新的S1S3磷酸转移酶用于纠正这种疾病的基因治疗。我们会用一个腺体- 相关病毒载体AAV-9，具有影响全身器官和 静脉注射给小鼠的脑部。这些实验旨在解决以下问题 关于II型粘脂病对S1S3磷酸转移酶治疗的适应性：1)生物分布 包括脑在内的相关器官的磷酸转移酶表达，2)恢复甘露糖-6- 溶酶体水解酶的磷酸化，3)改善溶酶体的储存及其分布 效果，4)表型改善，包括生长和行为，以及5)没有明显的毒性，包括 死亡率，在处理的小鼠。该项目结合了糖基化和贩运 溶酶体蛋白，溶酶体疾病的治疗进展，以及粘脂病-II的特征 小鼠包括行为和病理。

PROJECT SUMMARY/ABSTRACT Mucolipidosis is a group of inherited conditions in which lysosomal enzymes do not properly traffic to the lysosomes, due to deficient activity of UDP-N-acetylglucosamine: lysosomal enzyme N-acetyl-glucosamine-1- phosphotransferase and subsequent failure to add mannose-6-phosphate residues to lysosomal enzymes. As a result, lysosomes accumulate a variety of substrates that cannot be properly degraded, causing progressive physical and neurological disease and early death. Meanwhile, soluble lysosomal enzymes, lacking mannose- 6-phosphate, can be found in the bloodstream in abnormally high amounts. There is no available treatment. Here, using a null mouse model of mucolipidosis type II (also known as “I-cell disease”), we propose to study gene therapy with a novel S1S3 phosphotransferase for correction of this disorder. We will employ an adeno- associated viral vector, AAV-9, that has the ability to effect widespread transduction of systemic organs and brain when administered intravenously to mice. The experiments are designed to address the following regarding the amenability of mucolipidosis type II to treatment with S1S3 phosphotransferase: 1) biodistribution of phosphotransferase expression to relevant organs including brain, 2) restoration of mannose-6- phosphorylation of lysosomal hydrolases, 3) improvement in lysosomal storage, and the distribution of this effect, 4) improvement in phenotype, including growth and behavior, and 5) lack of apparent toxicity, including mortality, in treated mice. The project combines complementary expertise in glycosylation and trafficking of lysosomal proteins, therapy development for lysosomal diseases, and characterization of the mucolipidosis-II mouse including behavior and pathology.