Gene Therapy for Retinitis Pigmentosa

色素性视网膜炎的基因治疗

• 批准号: 6618760
• 负责人: RAJENDRA KUMAR-SINGH
• 金额: $ 26.18万
• 依托单位: UNIVERSITY OF UTAH
• 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 2007-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6618760
• 关键词: Adenoviridae; electroretinography; gene therapy; histology; laboratory mouse; nonhuman therapy evaluation; phosphodiesterases; retinitis pigmentosa; sialate; technology /technique development; transfection /expression vector; western blottings

DESCRIPTION (provided by applicant): Retinitis Pigmentosa (RP) is one of the most frequent causes of hereditary blindness in the United States, affecting approximately 1 in every 3000 individuals. There is currently no treatment available for this disease. The broad, long term objectives of this study are to develop a therapy for RP. Some forms of RP in humans, dogs and mice (rd) are caused by mutations in the beta subunit of cGMP phosphodiesterase (bPDE). In order to deliver a normal cDNA encoding bPDE to the rd retina, we have developed a novel class of safer and less-toxic adenovirus vectors termed Encapsidated Adenovirus Minichromosomes - (EAMs or 'gutted' vectors). EAMs have a 36Kb cloning capacity, allowing insertion of large upstream regulatory elements for regulated transgene expression and/or inclusion of multiple therapeutic transgene cassettes. We have used EAMs to temporarily rescue retinal degeneration in rd1 mice by approximately 10 weeks, which would otherwise be complete by 3 weeks postnatal. Our objectives are now focused on extending this short period of rescue to one that might be more therapeutically relevant to humans. EAMs bind to their target cells by attachment of the antenna-like fiber protein to the Coxsackievirus B-adenovirus Receptor (CAR). We have determined that CAR is not significantly expressed on murine and human photoreceptors which could explain the low levels of infection by EAMs and adenovirus vectors. In order to overcome this problem, we propose to modify the structure of EAMs such that they now bind cell surface sialic acid instead of CAR. Sialic acid is abundantly present on the rod cell membrane. We also propose to test adenovirus fibers recently shown to have significantly enhanced tropism for neurons. We will use these improved EAMs to deliver bPDE to the rd10 retina. We will measure therapeutic effects on photoreceptors by PDE assays, histology, electroretinograms and western analysis. Upon completion of this study, we will have constructed and tested a vector which will have potential use in a Phase 1 clinical trial for treatment of RP in humans.

描述（由申请人提供）：色素性视网膜炎（RP）是美国遗传失明最常见的原因之一，每3000个人中约有1个。目前尚无该病的治疗方法。这项研究的广泛，长期目标是为RP开发一种疗法。人类，狗和小鼠（RD）中某些形式的RP是由CGMP磷酸二酯酶（BPDE）的β亚基突变引起的。为了将编码BPDE的正常cDNA传递到RD视网膜中，我们开发了一种新型的更安全，更毒性的腺病毒载体，称为封装的腺病毒大型腺病毒小体 - （EAMS或“ GUTTED”载体）。 EAM具有36KB的克隆能力，可以插入大型上游调节元件，以调节转基因表达和/或包含多种治疗性转基因盒。我们已经使用EAM在大约10周内暂时挽救RD1小鼠的视网膜变性，否则在产后3周就可以完成。现在，我们的目标致力于将这一短暂的营救扩展到可能在治疗上与人类更为相关的目标。 EAM通过将天线样纤维蛋白连接到Coxsackievivirus B-腺病毒受体（CAR）与其靶细胞结合。我们已经确定，在鼠和人类感光体上没有显着表达汽车，这可以解释EAMS和腺病毒载体的低水平感染。为了克服这个问题，我们建议修改EAM的结构，以便它们现在结合细胞表面唾液酸而不是CAR。在杆细胞膜上大量存在唾液酸。我们还建议测试最近证明的腺病毒纤维对神经元的乳化作用显着增强。我们将使用这些改进的EAM将BPDE运送到RD10视网膜。我们将通过PDE测定，组织学，电子图和西方分析来测量对光感受器的治疗作用。这项研究完成后，我们将构建并测试了一个载体，该向量将在1期临床试验中可能使用，以治疗人类的RP。