Intravitreal gene therapy for inherited retinal disease

项目概要/摘要 遗传性视网膜疾病（IRD）是全球失明的主要原因。这些疾病通常 导致感光细胞退化的单基因疾病。从历史上看， 根据临床表型和电生理结果进行分类，然后分组为各种 疾病实体。在过去的三十年中，许多形式的遗传性视网膜疾病的遗传基础已经被发现。 这一发现导致了超过270种视网膜疾病基因的鉴定。重要的是， 医学和视觉科学已经导致了FDA批准的用于IRD相关的病毒介导的基因疗法。 RPE 65基因突变患有这种疾病的儿童用携带RPE 65的AAV治疗， 在玻璃体切除术时视网膜下腔中的黄斑。许多其他影响视网膜的单基因疾病 目前正在各种临床试验中成为目标，主要是通过类似的策略将病毒输送到 通过视网膜下途径进入黄斑。以这种方式施用的病毒介导的基因疗法受到以下限制： 仅治疗黄斑区。此外，它需要眼内手术，分离黄斑， 从视网膜色素上皮，并进行视力威胁手术并发症的风险。最近 研究已经证明，在视网膜下泡的位置处的进行性黄斑萎缩（视网膜细胞死亡 ~15%的患者在治疗后第一年内接受这种基因治疗，这表明视网膜下基因 治疗最终可能弊大于利。经由玻璃体内途径的治疗性施用是 侵入性小得多，发生在临床环境中，并且可以潜在地重复以实现最大的 治疗效果然而，玻璃体内病毒介导的基因治疗可能与增加的 炎症此外，天然的AAV不会穿透视网膜层来破坏光感受器， 有效地在这项研究中，我们将利用PDE 6C突变的非人类灵长类动物，这是一个关键的基因突变。 光传导的组成部分，导致电沉默锥光感受器。一个被证明有效的 在现有的治疗性AAV-PR 1.7-PDE 6C载体中，我们将比较通过腺病毒载体递送的AAV的功效。 视网膜下与玻璃体内途径挽救视锥细胞功能。此外，我们将比较炎症反应 在这些背景之间，确定免疫系统的活性成分，并定义前 宿主动物中存在的抗AAV抗体。我们将衡量交付路线和 炎症影响生理性抢救。这一建议将推进玻璃体内基因治疗领域， 遗传性视网膜疾病本提案的目的是确定玻璃体内注射与 视网膜下基因治疗，宿主中预先存在的循环抗体的作用，可能会减轻疗效 以及眼部炎症对视力恢复的影响程度。共同努力， 这项研究将促进对玻璃体内基因治疗及其与眼部炎症关系的理解 和治疗效果。

Project Summary/Abstract Inherited retinal diseases (IRDs) are a major source of blindness worldwide. These diseases are typically single-gene disorders that result in the degeneration of photoreceptor cells. Historically they have been classified based on the clinical phenotype and electrophysiological results, and then grouped into various disease entities. In the past three decades the genetic basis of many forms of inherited retinal diseases have been discovered leading to the identification of over 270 retinal disease genes. Importantly, the field of medicine and vision science has resulted in an FDA-approved viral mediated gene therapy for IRD associated with mutations in RPE65. Children with this condition are treated with AAV carrying RPE65 delivered to the macula in the subretinal space at the time of vitrectomy. Many other single gene disorders affecting the retina are currently being targeted in various clinical trials, mostly through similar strategies to deliver virus to the macula through the subretinal route. Viral mediated gene therapy administered in this fashion is limited by treatment of only the macular area. Furthermore, it requires intraocular surgery, detachment of the macula from the retinal pigmented epithelium, and carries the risk of sight-threatening surgical complications. Recent studies have demonstrated progressive macular atrophy (retinal cell death) at the site of the subretinal bleb in ~15% of patients receiving this gene therapy within the first year after treatment, suggesting subretinal gene therapy may ultimately cause more harm than good. Therapeutic administration via the intravitreal route is much less invasive, takes place in a clinical setting, and can potentially be repeated to achieve maximal therapeutic effect. However, intravitreal viral mediated gene therapy can be associated with increased inflammation. In addition, native AAVs do not penetrate the retinal layers to transduce photoreceptors efficiently. In this study, we will take advantage of non-human primates with a mutation in PDE6C, a key component of phototransduction, causing electrically silent cone photoreceptors. With a proven effective therapeutic AAV-PR1.7-PDE6C vector in hand, we will compare the efficacy of AAV delivered via the subretinal vs intravitreal route to rescue cone function. Furthermore, we will compare inflammatory reaction between these contexts, determine the active components of the immune system, and define the role of pre- existing anti-AAV antibodies in host animals. We will measure the degree to which the route of delivery and inflammation affects the physiologic rescue. This proposal will advance the field of intravitreal gene therapy for inherited retinal diseases. The aims of this proposal will determine the efficacy of intravitreal compared to subretinal gene therapy, the role of pre-existing circulating antibodies in the host that may mitigate the efficacy of treatment, and the degree to which ocular inflammation affects the visual rescue. Together, the aims of this study will advance the understanding of intravitreal gene therapy and its relationship with ocular inflammation and treatment efficacy.