Sustained delivery of therapeutics to the visual system using genetically modified autologous mesenchymal stem cells to treat blinding diseases

项目总结 这项拟议研究的目的是评估一种新的分娩方法的安全性和有效性。 中枢神经系统(CNS)和视网膜的治疗方法治疗与视觉相关的疾病 减损。测试的假设是自体基因修饰的间充质干细胞 (MSCs)可以作为有效的载体，将治疗药物持续输送到大脑和大脑的视觉中心 用于治疗由视觉的一个或多个部分的病理引起的致盲疾病 系统。概念验证研究将使用经过充分表征和验证的犬类模型进行 CLN2型神经性蜡样脂褐素沉积症，是一种以广泛传播为特征的儿科疾病 由于视网膜和视觉的退化而导致的进行性视力丧失的神经变性 大脑的处理中心，认知和运动能力下降，以及癫痫发作。CLN2病由以下原因引起 TPP1基因突变，导致可溶性溶酶体酶三肽基多肽酶-1(TPP1)缺失。 假设通过植入自体骨髓间充质干细胞向中枢神经系统提供TPP1 生产和分泌这种蛋白质的基因改造将改善犬的疾病相关视力损失 模特。为了验证这一假设，产生TPP1的MSCs将被注射到眼睛的玻璃体和玻璃体内 受CLN2病影响的犬的脑脊液。根据先前的研究，大量转移 预计将分别从这些位置植入视网膜和大脑的细胞中获得TPP1。功能性 在接受治疗的狗身上，将使用一种基于iPad平板电脑的新型测试来评估视力，该测试需要在 显示稳定灰色的屏幕和显示黑白条纹/栅格图案的屏幕。视网膜功能 将通过视网膜电描记术进行评估，视网膜-中枢神经系统的相互作用将通过定量评估 小学生计量学。还将使用已建立的疾病进展生物标记物对狗进行监测，以确定是否 移植产生TPP1的骨髓间充质干细胞不直接改善神经系统疾病体征 与视力相关，保留认知功能，抑制脑萎缩，延长健康寿命 与对照犬相比。此外，还将评估 移植的MSCs及其通过组织病理学和免疫组织化学产生的TPP1酶 中枢神经系统组织的分析。这些目标的成功实现将为测试这一点奠定基础 CLN2病和类似溶酶体储存障碍儿童的治疗方法。会的 也是采用这种方法治疗许多其他影响中枢神经系统的疾病的原型 视网膜。

PROJECT SUMMARY The objective of the proposed research is to evaluate the safety and efficacy of a novel method of delivering therapeutics to the central nervous system (CNS) and the retina to treat diseases associated with visual impairment. The hypothesis tested will be that autologous genetically modified mesenchymal stem cells (MSCs) can serve as effective vehicles for sustained delivery of therapeutics to visual centers in the brain and to the retina for the treatment of blinding diseases that result from pathology in one or more parts of the visual system. Proof of concept studies will be performed using a well-characterized and validated canine model of CLN2 neuronal ceroid lipofuscinosis, a disease with pediatric onset characterized by widespread neurodegeneration resulting in progressive loss of vision due to degeneration of both the retina and visual processing centers in the brain, cognitive and motor decline, and seizures. CLN2 disease is caused by mutations in TPP1, which result in deficiencies of the soluble lysosomal enzyme tripeptidyl peptidase-1 (TPP1). It is hypothesized that providing TPP1 to the CNS using implantation of autologous MSCs that have been genetically modified to produce and secrete the protein will ameliorate disease-related vision loss in the canine model. To test this hypothesis, TPP1-producing MSCs will be injected into the vitreous of the eye and into the cerebrospinal fluid (CSF) of dogs affected by CLN2 disease. Based on previous studies, significant transfer of TPP1 from cells implanted in these locations to the retina and brain are anticipated, respectively. Functional vision will be evaluated in treated dogs using a novel iPad tablet based test that requires a choice between a screen displaying solid grey and a screen displaying a black and white stripe / grating pattern. Retinal function will be assessed with electroretinography, and retina-CNS interactions will be assessed with quantitative pupillometry. Dogs will also be monitored with established biomarkers of disease progression to determine if implantation of TPP1-producing MSCs results in amelioration of the neurological disease signs not directly associated with vision, preserves cognitive function, inhibits brain atrophy, and extends healthy lifespan when compared with control dogs. In addition, assessed will be the safety, persistence, and distribution of the implanted MSCs and the TPP1 enzyme they produce through histopathologic and immunohistochemical analysis of CNS tissues. Successful accomplishment of these aims will set the groundwork for testing this approach to therapy in children suffering from CLN2 disease and similar lysosomal storage disorders. It will also serve as the prototype for adopting this approach to treat many other diseases affecting the CNS and retina.