Regulated Transgene Expression in the Retina

描述(申请人提供)：本申请涉及基因组学的广泛挑战领域(区域08)，具体挑战主题为08-EY-101：复杂眼病的基因组学。影响视力的疾病已成为基因治疗的潜在候选对象。直接将病毒载体，如基于腺相关病毒(AAV)的病毒载体，注入眼睛的不同房间，可使基因转移和稳定的转基因表达进入不同类型的细胞。在视网膜下注射AAV载体后，可以实现视网膜色素上皮细胞和光感受器的高水平转导；这种方法已被用于治疗动物模型和人类的一种称为Leber先天性黑色素的先天性失明。许多其他形式的获得性和遗传性失明是基因治疗的潜在候选，尽管在许多情况下，有必要调节转基因的表达，以确保无毒性的治疗性表达。这项提议将开发一种将AAV编码的基因引入视网膜后进行药理学调节的方法，用于治疗湿性老年性黄斑变性(AMD)。该方法的基础是在可诱导启动子的控制下引入编码抗血管内皮生长因子(VEGF)抗体的基因，以及编码可被小分子激活的工程转录因子的基因，以特异性地增强转基因的表达。这种可诱导转基因表达的方法称为银染，将利用方便的报告基因在小鼠和猴子的视网膜上进行开发。将在AMD的小鼠模型中使用编码人源化VEGF抗体的载体阿瓦斯丁进行研究；这些载体也将在猴子身上进行安全性和药代动力学测试。针对AMD的银试剂系统的开发将提供一个可应用于多种视网膜疾病的基因治疗平台。这项申请的资金将创造2个新的就业机会。已确定这些职位的候选人，如《预算理由》所述。 公共卫生相关性：老年性黄斑变性(AMD)是一种日益严重的疾病：1995年有170万人患上了AMD，而预计到2030年将有630万人受到影响。这种疾病是60岁以上老年人视力残疾的主要原因，随着预期寿命的增加，这不仅是一个医学问题，而且还具有重大的社会经济影响。这项提议旨在开发一种基因疗法，这种疗法将为患者提供显著的医疗缓解，开发适用于眼睛其他适应症的技术，并将治疗干预和医疗系统的负担降至最低。

DESCRIPTION (provided by applicant): This application addresses the broad Challenge Area of Genomics (area 08) and the specific Challenge Topic is 08-EY-101: Genomics of complex eye diseases. Diseases that affect visual acuity have emerged as potential candidates for gene therapy. Direct injection of viral vectors, such as those based on adeno- associated viruses (AAV), into different compartments of the eye leads to gene transfer and stable transgene expression into various cell types. High level transduction of retinal pigmented epithelial cells and photoreceptors can be achieved following sub-retinal injection of AAV vectors; this approach has been used to treat a congenital form of blindness called Leber congenital amaurosis in animal models and humans. Many other forms of acquired and inherited blindness are potential candidates for gene therapy although in many cases it will be necessary to regulate expression of the transgene so as to assure therapeutic expression without toxicity. This proposal will develop a method for pharmacologically regulating AAV-encoded genes after introduction into the retina for the treatment of the wet form of age-related macular degeneration (AMD). The method is based on the introduction of a gene encoding an antibody to vascular endothelial growth factor (VEGF) under the control of an inducible promoter together with genes encoding an engineered transcription factor that can be activated by a small molecule to specifically enhance expression of the transgene. This method of inducible transgene expression called ARGENT will be developed in retina of mice and monkeys using convenient reporter genes. Studies will be performed with vectors encoding the humanized VEGF antibody called Avastin in mouse models of AMD; these vectors will also be tested in monkeys for safety and pharmacokinetics. Development of the ARGENT system for AMD will provide a platform of gene therapy that can be applied to a broad array of retinal diseases. Funding of this application will create 2 new jobs. Candidates have been identified for these positions as described in the Budget Justification. PUBLIC HEALTH RELEVANCE: Age-related macular degeneration (AMD) is a growing disease: 1.7 million people developed AMD in 1995 while it is projected that 6.3 million will be affected in 2030. The disease is a major cause for visual disability among persons over 60 years of age that with the increase in life expectancy is not only a medical problem but also one with a significant socio-economic impact. This proposal is designed to develop a gene therapeutic that will provide significant medical relief to patients, develop technologies applicable to other indications in the eye and minimize therapeutic interventions and the burden on the healthcare system.