Modalities for the treatment of degenerative diseases of the retina

Abstract

This invention relates to methods for improved cell-based therapies for retinal degeneration and for differentiating human embryonic stem cells and human embryo-derived into retinal pigment epithelium (RPE) cells and other retinal progenitor cells.

1 . A method of treating or preventing retinal degeneration, comprising use of a cell selected from the group consisting of at least one of: RPE cells, RPE-like cells, RPE or RPE-like progenitors derived from mammalian embryonic stem cells. 
     
     
         2 . The method of  claim 1 , wherein the condition of retinal degeneration is selected from the group consisting of at least one of: retinitis pigmentosa and macular degeneration. 
     
     
         3 . The method of  claim 1 , further comprising transplantation of the cell by vitrectomy surgery into the subretinal space of the eye. 
     
     
         4 . The method of  claim 3 , wherein the cells are transplanted in a suspension, matrix, or substrate. 
     
     
         5 . The method of  claim 2 , wherein the retinitis pigmentosa is associated with an animal model. 
     
     
         6 . The method of  claim 5 , where in the animal model is selected from the group consisting of: rd mouse, RPE-65 knockout mouse, tubby-like mouse, RCS rat, Abyssinian cat, cone degeneration “cd” dog, progressive rod-cone degeneration “prcd” dog, early retinal degeneration “erd” dog, rod-cone dysplasia 1, 2 & 3 “rcd1, rcd2 and rcd3” dogs, photoreceptor dysplasia “pd” dog, and Briard “RPE-65” dog. 
     
     
         7 . The method of  claim 6 , wherein the outcome of the therapy in the animal model is evaluated using one or more of behavioral tests, fluorescent angiography, histology, and functional testing such as measuring the ability of the cells to perform phagocytosis (photoreceptor fragments), vitamin A metabolism, tight junctions conductivity, or evaluation using electron microscopy. 
     
     
         8 . A method for the spontaneous differentiation of hES cells into cells RPE, RPE-like, or RPE progenitor cells, said method comprising:
 a) allowing hES cell cultures to overgrow on MEF;   b) allowing the hES cell cultures to form a thick multilayer of cells;   c) culturing the hES cells;   d) isolation and culture of the pigmented RPE, RPE-like, and/or RPE progenitor cells from the resultant cell cultures.   
     
     
         9 . The method of  claim 8 , wherein the isolation and culture of the RPE-like cells comprises:
 a) digesting the cultured hES cells or EB's with an enzyme;   b) selectively isolating the pigmented cells;   c) plating the isolated cells on gelatin or laminin for 1-2 days to form primary cultures (P0);   d) continued culture of the primary culture for a period of up to 3 weeks; and,   e) isolation of the RPE-like cells.   
     
     
         10 . The method of  claim 9 , where in the enzyme is selected from the group consisting of one or more of trypsin, collagenase, and dispase. 
     
     
         11 . The method of  claim 8 , wherein the RPE cells are grown to establish a new RPE cell line. 
     
     
         12 . The method of  claim 11 , wherein the RPE cell line is differentiated into alternate lineages comprising treatment of the RPE cell line in culture with bFGF or FGF. 
     
     
         13 . The method of  claim 11 , wherein the new RPE cell lines varies from the already established RPE cell lines in at least one of the characteristics selected from the group consisting of: growth rate, expression of pigment, de-differentiation in culture, and re-differentiation in culture, of RPE-like cells when they are derived from different ES cell lines. 
     
     
         14 . A method for the derivation of RPE lines or precursors to RPE cells that have an increased ability to prevent neovascularization, said method comprising:
 a) aging a somatic cell from an animal such that telomerase is shortened wherein at least 10% of the normal replicative lifespan of the cell has been passed; and,   b) using the somatic cell as a nuclear transfer donor cell to create cells that overexpress angiogenesis inhibitors, wherein the angiogenesis inhibitors can be Pigment Epithelium Derived Factor (PEDF/EPC-1).   
     
     
         15 . The method of  claim 14 , wherein the somatic cells are genetically modified with exogenous genes that inhibit neovascularization. 
     
     
         16 . The method of  claim 8 , wherein the RPE-like cells are derived from a bank of ES or embryo-derived cells with homozygosity in the HLA region such that ES-derived cells have reduced complexity of their HLA antigens. 
     
     
         17 . The method of  claim 8 , wherein the ES cells are derived from a human 
     
     
         18 . (canceled)