Development of gene editing, optogenetic therapy and robotic eye surgery in large animal models

遗传性眼病包括视网膜色素变性、老年性黄斑变性(AMD)和视神经疾病。加在一起，他们占了全球不可逆转的视力损失的大部分。在牛津大学，我们正在开发一系列开创性的视网膜基因疗法，其中几种已经进入高级临床试验，通过解决潜在的遗传原因来治疗这些致盲疾病。在这个项目中，我们的目标是在进入临床试验之前，通过在非人类灵长类动物(NHP)中研究这些疗法，弥合小动物模型和人类研究之间的重要差距。在视网膜色素变性和AMD中，称为光感受器的光检测细胞丢失，但其他视网膜细胞，如向大脑传递脉冲的神经节细胞保持完好。在LHON中，线粒体基因的突变首先影响神经节细胞，因此来自视网膜的信号无法发送到大脑。为这些疾病开发基因治疗方法的研究已经取得了重大进展，我们现在有一种被批准的基因治疗方法，Luxturna，用于治疗一种由特定基因突变引起的疾病。基因治疗的目标是用健康的拷贝来取代突变的基因。然而，对于许多患者来说，突变是未知的，对于那些出现较晚的患者来说，那里的光感受器已经丢失，基因替换可能是不可能的。在这些患者中，光遗传疗法是一种非常有希望的策略，在包括神经节细胞在内的视网膜存活细胞中表达光敏蛋白，使它们能够探测光线并恢复视力。然而，到目前为止，通过基因疗法有效地靶向这些细胞还没有实现。此外，由于神经节细胞中的线粒体在LHON中受到影响，如果我们能够将健康的基因输送到这些细胞，特别是线粒体，那么就有可能减缓神经节细胞的退化和相关的视力丧失。在这个项目中，我们的目标是开发一种使用机器人的手术程序，以更有效地向视网膜神经节细胞输送基因治疗。该程序将包括在动物模型中由机器人辅助直接向视神经输注，这目前不可能在患者身上手动进行。在实现这一目标之后，我们的目标是在未来的人类临床试验中开发这项技术的应用，包括光遗传学应用和视神经疾病的治疗。此外，该项目旨在开发一种名为CRISPR/CAS的基因编辑系统，以敲除或编辑与AMD有关的人类视网膜疾病相关基因。最后，我们的目标是评估眼部基因编辑的有效性和安全性，以及对这些新治疗方法的免疫反应。这些方法有可能导致治疗范围更广的致盲疾病。光遗传疗法可以成为一种普遍的治疗方法，可以在任何晚期视网膜退化中恢复视力，而不考虑遗传原因。改善对视网膜神经节细胞的靶向可能导致LHON和其他视神经疾病的潜在治疗，包括青光眼，这是全球最常见的不可逆性失明原因。此外，改进的线粒体靶向可能对其他遗传性线粒体疾病的治疗产生影响，这些疾病会导致全身疾病，并涉及眼睛以外的器官。总之，该项目将在英国建立第一个眼科NHP设施，开展与美国和欧洲同行学术机构同等的视网膜基因治疗工作，并促进许多新兴的眼部基因治疗方法的翻译。这一独特的平台将促成广泛的高影响力研究项目，在英国国内和国际上开展合作，并加强英国在基因治疗开发方面的领先地位。

Genetic eye diseases include retinitis pigmentosa, age-related macular degeneration (AMD) and optic neuropathies. Together, they account for the majority of irreversible sight loss worldwide. At Oxford, we are developing a range of pioneering retinal gene therapies, several of which have reached advanced clinical trials, to treat these blinding diseases by addressing the underlying genetic causes. In this project, we aim to bridge the vital gap between studies in small animal models and humans by investigating these therapies in non-human primates (NHPs), before moving into clinical trials.In retinitis pigmentosa and AMD, light detecting cells called photoreceptors are lost, but other retinal cells such as ganglion cells that transmit impulses to the brain remain intact. In LHON, mutations in mitochondrial genes affect the ganglion cells first, so the signal from the retina cannot be sent to the brain. Significant advances have been made in research to develop genetic treatments for these diseases, and we now have an approved gene therapy treatment, Luxturna, for one form of the disease caused by mutations in a specific gene. Gene therapy treatments aim to replace the mutated genes by healthy copies. However, for many patients, mutations are not known and for those who present late, where the photoreceptors have already been loss, gene replacement may not be possible. In these patients, optogenetic therapy is a very promising strategy where light sensitive proteins are expressed in surviving cells of the retina, including ganglion cells, to make them able to detect light and restore vision. However, efficient targeting of these cells with genetic therapies has not been achieved to date. Moreover, as the mitochondria in ganglion cells are affected in LHON, if we can deliver healthy genes to these cells, and in particular to the mitochondria, then there is potential to slow down ganglion cell degeneration and associated loss of vision.In this project we aim to develop a surgical procedure using a robot to more effectively deliver genetic therapies to retinal ganglion cells. The procedure will involve robot-assisted direct infusion into the optic nerve in an animal model, which is currently not possible to perform manually in patients. Having achieved this, we then aim to develop applications for this technique including optogenetic applications and for the treatment of optic neuropathies in future human clinical trials. In addition, the project aims to develop a gene editing system called CRISPR/Cas to knockout or edit human retinal disease-associated genes implicated in AMD. Lastly we aim to assess the efficacy and safety of gene editing in the eye and the immune responses to these new treatments. The approaches have potential to lead to the treatment of a much broader range of blinding diseases. Optogenetic therapy could become a universal treatment and restore vision in any late stage retinal degeneration irrespective of genetic cause. Improved targeting of retinal ganglion cells could lead to potential treatments of LHON and other optic neuropathies including glaucoma, the most common cause of irreversible blindness worldwide. In addition, improved mitochondrial targeting may have implications for treatment of other inherited mitochondrial disease that lead to systemic diseases and involve organs other than the eye.In summary, project will establish the first in UK ocular NHP facility to carry out retinal gene therapy work on par with US and European counterpart academic institutions and facilitate translation of many emerging ocular genetic therapies. This unique platform will enable a wide range of high impact research projects, collaborations both within the UK and internationally, and strengthening the UK's leading role in gene therapy development.