Gene Therapy for Retinitis Pigmentosa

色素性视网膜炎的基因治疗

• 批准号: 7797392
• 负责人: RAJENDRA KUMAR-SINGH
• 金额: $ 40.84万
• 依托单位: TUFTS UNIVERSITY BOSTON
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-05-01 至 2013-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7797392
• 关键词: Adenovirus Vector; Adenoviruses; Age related macular degeneration; Ally; American; Animal Model; Animals; Be++ element; Beryllium; Biochemical; Blindness; Capsid; Capsid Proteins; Cells; Cessation of life; Chromosomes, Human, Pair 12; Clinical Trials; Cloning; Complementary DNA; Cyclic GMP; Data; Defect; Dependovirus; Diabetic Retinopathy; Disease; Event; FDA approved; Fright; Gene Expression; Gene Transduction Agent; Gene Transfer; Generations; Genes; Genetic; Glaucoma; Goals; Human; Immune response; Insertional Mutagenesis; Lead; Leber' s amaurosis; Length; Liver; Malignant Neoplasms; Measures; Methods; Modeling; Modification; Molecular; Molecular Profiling; Mus; Mutation; Nucleic Acid Regulatory Sequences; Patients; Phase I Clinical Trials; Photoreceptors; Physiological; Primary carcinoma of the liver cells; Property; Proteins; Public Opinion Poll; RGD (sequence); RPE65 protein; Recombinants; Regulatory Element; Relative (related person); Retina; Retinal; Retinal Degeneration; Retinal Diseases; Retinitis Pigmentosa; Retroviral Vector; Rhodopsin; Satellite Viruses; Science; Serotyping; Somatic Gene Therapy; Structure of retinal pigment epithelium; Surface; System; Tissues; Transferrin; Transgenes; Tropism; United States; Vertebral column; Viral Genes; Virus; adeno-associated viral vector; advanced disease; gene therapy; gene transfer vector; helper-dependent adenoviral vector; in vivo; leukemia; nonhuman primate; novel; novel virus; penton base; phosphodiesterase V; phosphoric diester hydrolase; photoreceptor degeneration; promoter; public health relevance; retinal rods; success; therapy development; tool; transgene expression; vector

DESCRIPTION (provided by applicant): The long-term objective of this study is to develop a therapy for Retinitis Pigmentosa (RP), a disease that causes photoreceptor degeneration and blindness. There is currently no therapy available for this disease. RP is caused by mutations in genes expressed exclusively in the rod photoreceptors. The most common causes of recessive RP are mutations in the gene encoding the ¿ subunit of cGMP Phosphodiesterase (¿ PDE). Despite the availability of a variety of animal models with mutations in ¿ PDE, e.g. rd1, rd10, rcd etc., no evidence yet exists for long-term rescue of rod photoreceptors in these models, a prerequisite to clinical trials. This is in stark contrast to the success gene therapy approaches have had in other ocular tissues such as the retinal pigment epithelium (RPE) and specifically in animal models of Leber's congenital amaurosis. The lag in progress for rescue of rod photoreceptor diseases is due to the absence of efficacious gene transfer vectors for photoreceptors. The most commonly used vector in ocular gene therapy to date is adeno-associated virus (AAV), most serotypes of which have a limited cloning capacity of 4.8 Kb. This capacity is insufficient for the inclusion of large gene regulatory elements needed to achieve rod-specific and regulated transgene expression. Furthermore, AAV has been recently shown to cause hepatocellular carcinoma at the alarmingly high rate of 56% in animals by insertional mutagenesis. Hence, there is a need for gene therapy vectors that persist episomally. These significant deficiencies with AAV vectors and other deficiencies discussed in the proposal can be overcome through the use of helper-dependent adenovirus vectors (Hd-Ad) that have a 36K cloning capacity and persist episomally for years in non human primates. However, Hd-Ad vectors do not have a tropism for photoreceptors but instead, they target only the RPE. Recently, we have shown that adenovirus (Ad) vectors with deletions in the RGD domain of penton base or Ad vectors that display transferrin on their capsid through can very efficiently transduce photoreceptors. These modifications should readily be transferable to Hd-Ads. Hence, this proposal has 3 specific aims. Specific Aim 1: Determine whether in the context of 1st generation Ad vectors, do Ad capsids containing an RGD deletion in penton base combined with transferrin on their capsid, transduce photoreceptors more efficiently than either modification alone. Specific Aim 2: To develop a 36Kb-capacity Hd-Ad that has been modified to contain an RGD-deletion in it's penton base and transferrin on it's capsid. Examine rod specific transgene expression using very large (>10Kb) 5' upstream and downstream gene regulatory elements, including a 10Kb ¿ PDE promoter. Specific Aim 3: To examine whether the photoreceptor targeted Hd-Ad system can express ¿ PDE in the rd1 and rd10 murine retina specifically in rod photoreceptor cells using native (10Kb) ¿ PDE 5' and 3' gene regulatory elements and potentiate long term rescue of photoreceptor degeneration. PUBLIC HEALTH RELEVANCE: According to public opinion polls, blindness is second only to cancer as the most feared disease amongst Americans. The most common cause of genetic blindness is Retinitis Pigmentosa, for which there is currently no FDA-approved therapy available. This proposal aims to develop a genetic therapy for Retinitis Pigmentosa and allied disorders that cause blindness. The molecular tools developed in this study will also have application in developing therapies for diabetic retinopathy, age related macular degeneration, glaucoma etc., that are collectively the most common causes of blindness in the United States.

描述（由申请人提供）：本研究的长期目标是开发一种治疗视网膜色素变性（RP）的方法，RP是一种导致感光细胞变性和失明的疾病。目前没有治疗这种疾病的方法。RP是由只在视杆细胞感光器中表达的基因突变引起的。隐性RP的最常见原因是编码cGMP磷酸二酯酶（PDE）亚基的基因突变。尽管存在多种PDE突变的动物模型，例如rd 1、rd 10、rcd等，在这些模型中，还没有证据表明长期拯救视杆细胞光感受器，这是临床试验的先决条件。这与基因治疗方法在其他眼组织如视网膜色素上皮（RPE）中，特别是在Leber先天性黑蒙动物模型中的成功形成鲜明对比。在拯救视杆细胞疾病的进展中的滞后是由于缺乏用于光感受器的有效基因转移载体。迄今为止，眼部基因治疗中最常用的载体是腺相关病毒（AAV），其大多数血清型具有4.8Kb的有限克隆能力。这种能力不足以包含实现杆特异性和受调节的转基因表达所需的大基因调控元件。此外，最近已经显示AAV通过插入诱变以惊人的56%的高比率在动物中引起肝细胞癌。因此，需要附加型持续存在的基因治疗载体。AAV载体的这些显著缺陷和该提案中讨论的其他缺陷可以通过使用辅助依赖性腺病毒载体（Hd-Ad）来克服，所述辅助依赖性腺病毒载体具有36 K克隆能力并且在非人灵长类动物中以附加体形式持续多年。然而，Hd-Ad载体不具有对光感受器的向性，而是它们仅靶向RPE。最近，我们已经表明，在五邻体碱基的RGD结构域中具有缺失的腺病毒（Ad）载体或在其衣壳上展示转铁蛋白的Ad载体可以非常有效地抑制光感受器。这些修饰应易于转移至Hd-Ad。因此，该提案有三个具体目标。具体目标1：确定在第一代Ad载体的背景下，在五邻体碱基中含有RGD缺失的Ad衣壳与其衣壳上的转铁蛋白组合是否比单独的任一修饰更有效地抑制光感受器。具体目标二：构建一个容量为36 Kb的Hd-Ad，该Ad在其五邻体基础上缺失RGD，在其衣壳上含有转铁蛋白。使用非常大（> 10 Kb）的5'上游和下游基因调控元件（包括10 Kb <$PDE启动子）检查视杆特异性转基因表达。具体目标3：检测光感受器靶向Hd-Ad系统是否可以使用天然（10 Kb）<$PDE 5'和3'基因调控元件在rd 1和rd 10小鼠视网膜中特异性地在视杆细胞中表达<$PDE，并增强对光感受器变性的长期拯救。公共卫生相关性：根据民意调查，失明是仅次于癌症的美国人最害怕的疾病。遗传性失明最常见的原因是视网膜色素变性，目前还没有FDA批准的治疗方法。这项提案旨在开发一种遗传疗法，用于治疗视网膜色素变性和导致失明的相关疾病。本研究中开发的分子工具也将应用于开发糖尿病视网膜病变、年龄相关性黄斑变性、青光眼等的疗法，这是美国最常见的致盲原因。