Genetically engineered retina for improved retinal reconstruction after transplantation

ES/iPS-retinal sheet transplantation, which supplies photoreceptors as well as other retinal cells, has been shown able to restore visual function in mice with end-stage retinal degeneration. Here, by introducing a novel type of genetically engineered ES/iPS-retinal sheet with reduced numbers of secondary retinal neurons but intact photoreceptor cell layer structure, we reinforced the evidence that ES/iPS-retinal sheet transplantation can establish synaptic connections with the host, restore light responsiveness and reduce aberrant RGC spiking. Furthermore, we show that genetically engineered grafts can substantially improve the outcome of the treatment by improving neural integration. We speculate that this leads to reduced spontaneous activity in the host which in turn contributes to a better visual recovery.