Project 1: Preclinical development of surrogate gene therapy using GALGT2

摘要 项目1将重点扩大GALGT 2基因治疗的临床用途， rAAVrh74.MCK.GALGT2. rAAVrh74.MCK.GALGT2是一种替代基因疗法， 刺激骨骼和心脏中人GALGT 2基因的过表达， 肌肉.该载体刺激肌膜糖基化的改变， 包括α肌营养不良蛋白聚糖的糖基化，使其模拟正常的糖基化 发现在神经肌肉和肌腱交界处，并增加 已知抗肌萎缩蛋白和层粘连蛋白α2替代物的突触外表达 抑制肌肉萎缩症。临床前研究表明，肌肉GALGT 2 过表达抑制Duchenne肌营养不良症小鼠模型中的疾病 (DMD)先天性肌营养不良1A（CMD 1A）和肢带肌营养不良 营养不良2D（LGMD 2D）。该载体利用AAV血清型rh74，其显示出极大的 当载体通过肌肉递送时， 血液中，而MCK启动子限制基因表达的肌肉细胞。广泛 概念验证和安全性研究已导致IND用于 DMD患者中的rAAVrh74.MCK.GALGT2。当这些临床试验开始时， 我们希望在这里进行概念验证研究，以便扩大使用 MCK.GALGT2对CMD 1A和LGMD 2D患者的免疫应答。进一步的研究 目的是扩大rAAVrh74.MCK.GALGT2基因治疗DMD的有效性 通过研究这种基因疗法是否能增加治疗效果， 外显子跳跃治疗或涉及基因过表达的治疗的有效性 卵泡抑素，一种肌肉生长抑制素抑制剂，可以生成新的肌肉质量。所有实验 这里提出的是针对快速翻译的新的治疗方法， 肌肉萎缩症，这是CORT提案的首要目标。

ABSTRACT Project 1 will focus on expanding the clinical usefulness of GALGT2 gene therapy using rAAVrh74.MCK.GALGT2. rAAVrh74.MCK.GALGT2 is a surrogate gene therapy that stimulates the overexpression of the human GALGT2 gene in skeletal and cardiac muscle. This vector stimulates changed glycosylation of the muscle membrane, including glycosylation of α dystroglycan, such that it mimics glycosylation normally found at the neuromuscular and myotendinous junctions, and increases the extrasynaptic expression of dystrophin and laminin α2 surrogates that are known to inhibit muscular dystrophy. Preclinical studies have shown that muscle GALGT2 overexpression inhibits disease in mouse models of Duchenne Musuclar Dystrophy (DMD), Congenital Muscular Dystrophy 1A (CMD1A) and Limb Girdle Muscular Dystrophy 2D (LGMD2D). This vector utilizes an AAV serotype, rh74, that shows great efficacy at delivering gene expression to muscles when the vector is delivered via the blood, while the MCK promoter confines gene expression to muscle cells. Extensive proof-of-concept and safety studies have led to an IND for the use of rAAVrh74.MCK.GALGT2 in patients with DMD. While those clinical trials are beginning, we wish here to perform proof of concept studies that would allow for the expanded use of rAAVrh74.MCK.GALGT2 to patients with CMD1A and LGMD2D. Further studies are aimed at expanded the usefulness of rAAVrh74.MCK.GALGT2 gene therapy in DMD patients by studying whether this gene therapy can increase the therapeutic effectiveness of exon skipping therapy or therapy involving gene overexpression of follistatin, a myostatin inhibitor that builds new muscle mass. All of the experiments proposed here are directed toward rapid translation of novel therapeutic approaches for muscular dystrophies, which is the overarching goal of this CORT proposal.