Retinal disease models for translational photoreceptor replacement

神经视网膜或视网膜色素上皮（RPE）的疾病引起大量视力损害， 疾病，其中许多导致感光细胞的变性和死亡。一些自然 发生遗传性视网膜变性（RD）疾病已确定在狗是真正的同源 人类疾病。我们的研究团队已经证明了AAV介导的基因 在犬疾病模型中的视网膜治疗在翻译连续体中起关键作用 对治疗反应和长期结局进行快速、具有成本效益和临床相关性的评估 视网膜基因治疗然而，先前基因治疗试验的成功取决于存在可行的， 尽管是病变的靶细胞相比之下，在晚期RD中靶细胞的大量损失将需要 允许感光细胞的再生或替换以及神经细胞的恢复的治疗策略 连通性。人类视网膜疾病的狗模型可以提供所需的基础知识， 感光细胞替代疗法，以改善视功能，如AGI RFA中所规定的。我们有 组建了一个研究小组，他们在神经祖细胞和多能干细胞生物学、视网膜神经元和神经胶质细胞方面都有专业知识。 细胞分化，遗传性视网膜疾病的病理和治疗，以及实验性RD的功能分析 治疗。研究者具有评估治疗反应并制定适当治疗方案的专业知识。 评价安全性和有效性的结局指标。我们有专门的视网膜疾病研究设施， 繁殖、饲养、治疗和评估患有同源人类视网膜疾病的狗。 我们的目标是开发犬模型，在其中研究光感受器的替代， 疾病状况。狗模型将用于确定细胞移植的关键参数， 移植和分化，这将是关键的疾病特异性应用的研究再生 治疗视网膜的药物要研究的关键属性是物理移植参数， 宿主视网膜内的供体细胞，供体细胞分化和存活， 视网膜，大脑和CNS处理中视觉通路的连通性，以及 视野最初将使用来自两种良好表征的异种移植物研究移植参数。 以及标记视锥细胞和视杆细胞或仅标记视杆细胞的容易获得的人多能干细胞报道细胞系。 同时，我们将开发一个种内系统，通过产生等效的光感受器替代， 犬iPSC和视锥/视杆和仅视杆iPSC报道细胞系用于视网膜感光细胞的替换， 概括了在使用人类细胞的人类临床试验中发生的植入。一旦开发出来， 将分析犬感光前体细胞移植物在疾病中的整合和功能。 狗模型，其中可以评价分化成新的视杆细胞和视锥细胞。

Diseases of the neural retina or retinal pigment epithelium (RPE) cause a substantial number of sight-impairing disorders, many of which lead to the degeneration and death of photoreceptor cells. A number of naturally occurring inherited retinal degeneration (RD) diseases have been identified in dogs that are true homologues of human diseases. Our research team has been instrumental in demonstrating that AAV-mediated gene therapy for the retina in canine disease models plays a critical role in the translational continuum by permitting a rapid, cost-effective, and clinically relevant assessment of therapeutic responses and long-term outcomes of retinal gene therapy. However, the success of prior gene therapy trials depended on the presence of viable, albeit diseased, target cells. In contrast, the substantial loss of target cells in advanced RD will require therapeutic strategies that permit regeneration or replacement of photoreceptor cells and restoration of neural connectivity. Dog models of human retinal diseases can provide the foundational knowledge needed for photoreceptor replacement therapies to improve visual function, as specified in the AGI RFA. We have assembled a team of investigators with expertise in neural progenitor and pluripotent stem cell biology, retinal cell differentiation, inherited retinal disease pathology and therapy, and functional analysis of experimental RD treatments. The investigators have the expertise to assess therapeutic responses and to develop appropriate outcome measures to evaluate safety and efficacy. We have a dedicated retinal disease research facility to breed, maintain, treat and assess dogs with homologous human retinal disorders. Our goal is to develop canine models in which to investigate the replacement of photoreceptors under disease conditions. The dog models will be used to identify key parameters of cell transplantation, engraftment, and differentiation that will be critical for studies of disease-specific applications of regenerative medicine for the retina. Key properties to be studied are physical transplantation parameters, distribution of donor cells within the host retina, donor cell differentiation and survival, cell connectivity and functionality within the retina, connectivity to the visual pathways in the brain and CNS processing, and behavioral assays for vision. Transplantation parameters will be studied initially using xenografts derived from two well-characterized and readily available human pluripotent stem cell reporter lines that label cones and rods or only rods. Concurrently, we will develop a within-species system for photoreceptor replacement by producing equivalent canine iPSCs and cone/rod and rod-only iPSC reporter lines for replacement of retinal photoreceptor cells to recapitulate the engraftment that would occur in human clinical trials using human cells. Once developed, the canine photoreceptor precursor cell transplants will be analyzed for integration and functionality in diseased dog models in which differentiation into new rod and cone visual cells can be evaluated.