Exploring systemic AAV gene delivery in the dystrophic dog

摘要杜氏肌营养不良症（DMD）是最常见的致死性儿童遗传病。它是由肌营养不良蛋白基因突变引起的。在过去的十年中，DMD基因治疗取得了许多进展。据报道，在腺相关病毒（AAV）介导的微肌营养不良蛋白基因治疗的DMD小鼠模型中，令人印象深刻的全身拯救。在人体试验之前的一个重要的下一步是在犬DMD模型中证明微肌营养不良蛋白基因的治疗效果。犬的肌肉是出了名的难以转导，因为强大的细胞免疫反应。此外，DMD几乎影响到身体的每一块肌肉。只有全身性的基因转移才能真正改善这种疾病。我们最近在正常的新生犬身上开发了一种有效的全身肌肉转导方案。这是首次证明AAV系统递送可以到达大型动物的多个肌肉。为了推进DMD基因治疗研究，我们最近建立了一个柯基犬DMD模型。受影响的狗与人类患者具有相同的肌营养不良蛋白基因突变并表现出相同的临床表型。在这个翻译R21项目中，我们将把这些令人兴奋的发现应用于治疗犬R4-23/C微基因。我们将对新生儿营养不良的柯基犬进行全身AAV输送。主要目标是实现广泛的肌肉转导。我们还将使用一套全面的组织病理学终点进行初步疗效评估。本研究将为今后深入评价AAV微营养不良蛋白基因治疗犬模型奠定基础。

DESCRIPTION (provided by applicant): Abstract Duchenne muscular dystrophy (DMD) is the most prevalent lethal childhood genetic disease. It is caused by dystrophin gene mutation. Numerous progresses have been made in the last decade in developing DMD gene therapy. Impressive whole body rescue has been reported in DMD mouse models with adeno-associated virus (AAV)-mediated micro-dystrophin gene therapy. An important next step prior to human trial is to demonstrate the therapeutic efficacy of the micro-dystrophin gene in canine DMD models. Canine muscle has been notoriously difficult to transduce because of the strong cellular immune response. Furthermore, DMD affects nearly every muscle in the body. Only systemic gene transfer can truly ameliorate the disease. We recently developed an efficient whole body muscle transduction protocol in normal neonatal dogs. This is the first demonstration that systemic AAV delivery can reach multiple muscles in a large animal. To advance DMD gene therapy studies, we have recently established a Corgi dog model for DMD. The affected dogs share the same dystrophin gene mutation and display the same clinical phenotype as human patients. In this translational R21 project, we will apply these exciting findings to the therapeutic canine R4-23/C microgene. We will perform systemic AAV delivery in neonatal dystrophic Corgi dogs. The primary goal is to achieve wide spread muscle transduction. We will also perform preliminary efficacy evaluation using a comprehensive set of histopathology endpoints. Our study will set up a foundation to thoroughly evaluate AAV micro-dystrophin gene therapy in dog models in the future. PUBLIC HEALTH RELEVANCE: Project Narrative Duchenne muscular dystrophy (DMD) is caused by dystrophin gene mutation. Currently, there is no cure. Adeno-associated virus-mediated gene therapy has shown a great promise to ameliorate this disease. In this study we will develop novel techniques to achieve whole body gene transfer in newborn DMD dogs. The majority of DMD patients can be diagnosed through neonatal screening. Our study will open the door for neonatal gene therapy in human patients in the future.