Retinal disease models for translational photoreceptor replacement

神经性视网膜或视网膜色素上皮(RPE)疾病导致相当数量的视力障碍 疾病，其中许多导致光感受器细胞的退化和死亡。一些天然的 发生遗传性视网膜变性(RD)疾病的狗已被确认为真正的同源物 人类疾病。我们的研究团队帮助证明了AAV介导的基因 在犬病模型中，视网膜的治疗在翻译连续体中起着关键作用 一种快速、经济有效和临床相关的治疗反应和长期结果评估 视网膜基因疗法。然而，先前的基因治疗试验的成功取决于是否存在可行的、 尽管是有病的，目标细胞。相反，在晚期研发中目标细胞的大量损失将需要 允许光感受器细胞再生或替换以及恢复神经的治疗策略 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 光感受器替代疗法，以改善视觉功能，如AGI RFA所规定的。我们有 组建了一支在神经前体细胞和多能干细胞生物学方面具有专业知识的研究团队，视网膜 实验性视网膜脱离的细胞分化、遗传性视网膜疾病病理与治疗及功能分析 治疗。研究人员拥有评估治疗反应和制定适当的 结果评价安全性和有效性的指标。我们有专门的视网膜疾病研究设施来 培育、维护、治疗和评估患有同源人类视网膜疾病的狗。 我们的目标是发展犬模型，在此模型中研究光感受器在 疾病状况。狗模型将被用来确定细胞移植的关键参数， 嫁接和分化对于研究再生细胞在疾病中的特异性应用至关重要 治疗视网膜的药物。需要研究的关键特性是物理移植参数、分布 宿主视网膜内的供体细胞、供体细胞的分化和存活、细胞的连通性和功能 视网膜，与大脑和中枢神经系统处理的视觉通路的连接，以及行为分析 幻象。移植参数的初步研究将使用来自两个特征良好的 以及容易获得的标记视锥和视杆或仅标记视杆的人类多能干细胞报告系。 同时，我们将开发一种用于光感受器替换的物种内系统，通过生产同等的 犬ipscs和视锥/视杆及视杆细胞报告系用于替代视网膜感光细胞 重述在使用人类细胞进行的人体临床试验中将发生的植入。一旦开发出来， 犬光感受器前体细胞移植将分析疾病患者的整合和功能 可以评估分化为新的视杆细胞和视锥细胞的狗模型。

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.