Generation of retinal pigment epithelium and retinal organoids from universal human pluripotent stem cells

Subretinal transplantation of RPE (retinal pigment epithelium) differentiated from human pluripotent stem cells (hPSCs) including human induced pluripotent stem cells (hiPSCs) and human embryonic stem cells (hESCs) into patients are a promising stem cell therapy for treatment of dry AMD (age-related macular degeneration) and Stargardt’s macular dystrophy. If we can prepare universal hiPSCs and universal hiPSC-derived RPE and RPE organoids, which do not show immunoresponsive when the cells are contacted with allogenic immune cells such as natural killer (NK) cells, macrophages and cytotoxic CD8+ cells, we will have off-the-shelf universal hiPSC-derived RPE and RPE organoids, which can be used for the treatment of any patients of dry AMD and Stargardt’s macular dystrophy without use of immunosuppressive medicine. We will develop universal hiPSCs without gene editing, which do not show human leukocyte antigen (HLA) class I and class II where universal hiPSCs and their differentiated cells do not show immune rejection when these cells are transplanted into any patients having different HLA class I and class II types. Our innovative universal hiPSCs are prepared by mixing amniotic fluids obtained from multi donors where no immune rejection of the stem cells (universal amniotic fluid stem cells) can be survived during the mixing of allogenic amniotic fluids from multi donors (Key technology of this project, under submission into US patent (A. Higuchi)), whereas conventional universal hiPSCs are prepared using gene editing such as Crispr/Cas9 technology, which are difficult to be approved in clinical application because of their gene editing. Universal hiPSCs are differentiated into retinal pigment epithelium (RPE) and RPE organoids using severalinhibitors to speed up their differentiation. We will develop optimal differentiation protocol and optimal cell culture materials for differentiation of universal hiPSCs into RPE and RPE organoids with high efficiency and high purity. Universal hiPSCs and universal hiPSC-derived RPE and RPE organoids will be delivered to Dr Chou’s group (Sub project 2) and they will characterize universal hiPSCs and transplant universal hiPSC-derived RPE and RPE organoids into Royal College of Surgeons (RCS) rats and nude rats subretinally, where RCS rats are an animal model of dry AMD disease. We will evaluate immune response of RPE and RPE organoids derived from universal hiPSCs as well as conventional hiPSCs and hESCs using allogenic mononuclear cells containing NK cells, macrophages and cytotoxic CD8+ cells. From collaboration with Dr Chou’s group (Sub project 2), We will find the effect of universal hiPSC-derived RPE and RPE organoids from pigmentation (RPE survival) on rats’ eyes compared to conventional hESC-derived RPE. We will discuss advantages of usage of universal hiPSC-derived RPE and RPE organoids transplantation in the animal model of dry AMD disease for future clinical application of transplantation of universal hiPSC-derived RPE into patients with dry AMD and Stargardt’s macular dystrophy. Our final goal of this project is to develop off-the-shelf universal hiPSC-derived RPE and RPE organoids for treatment of any patients with dry AMD and Stargardt’s macular dystrophy without usage of immunosuppressive medicine.