Differentiation of human embryonic stem cells

Abstract

The present invention provides methods to promote the differentiation of pluripotent stem cells into insulin producing cells. In particular, the present invention provides a method to produce a population of cells, wherein greater than 85% of the cells in the population express markers characteristic of the definitive endoderm lineage.

What is claimed is: 
     
         1 . An in vitro cell culture comprising an isolated population of cells and a culture medium suitable for differentiating pluripotent stem cells,
 wherein greater than 85% of the cells are definitive endoderm cells,   wherein said population of cells is obtained by differentiating in vitro pluripotent stem cells,   wherein the culture medium lacks serum and is supplemented with BSA, 1-alanyl-1-glutamine, Activin A, Wnt-3A and a factor selected from the group consisting of insulin and from about 1 ng/ml to about 50 ng/ml of IGF-1, and   wherein said definitive endoderm cells express CXCR4 and do not express CD9.   
     
     
         2 . The in vitro culture of  claim 1 , wherein the isolated population of cells is obtained without further purifying the cells after differentiation. 
     
     
         3 . The in vitro culture of  claim 1 , wherein the medium is supplemented with BSA, 1-alanyl-1-glutamine, Activin A, Wnt-3A and from about 1 ng/ml to about 50 ng/ml of IGF-1. 
     
     
         4 . The in vitro culture of  claim 1 , wherein the medium is chemically-defined. 
     
     
         5 . The in vitro culture of  claim 1 , wherein the medium is supplemented with BSA, 1-alanyl-1-glutamine, Activin A, Wnt-3A and insulin. 
     
     
         6 . A method for generating a population of cells wherein greater than 85% of the cells in the population are definitive endoderm cells, comprising the steps of:
 a. culturing a population of pluripotent stem cells; and   b. differentiating the population of pluripotent stem cells to a population of cells wherein greater than 85% of the cells in the population are definitive endoderm cells in medium lacking serum and supplemented with BSA, Activin A, Wnt-3A and a factor selected from the group consisting of insulin and from about 1 ng/ml to about 50 ng/ml of IGF-1.   
     
     
         7 . The method of  claim 6 , wherein the population of pluripotent stem cells is differentiated in the medium lacking serum and supplemented with BSA, Activin A, Wnt-3A and a factor selected from the group consisting of insulin and from about 1 ng/ml to about 50 ng/ml of IGF-1 for a period of at least 6 days. 
     
     
         8 . The method of  claim 6 , wherein the population of pluripotent stem cells is differentiated in the medium lacking serum and supplemented with BSA, BSA, Activin A, Wnt-3A and a factor selected from the group consisting of insulin and from about 1 ng/ml to about 50 ng/ml of IGF-1 for a period of at least 7 days. 
     
     
         9 . The method of  claim 6 , wherein the step of differentiating comprises treating the pluripotent stem cells with a medium lacking serum and supplemented with BSA, Activin A, Wnt-3A and from about 1 ng/ml to about 50 ng/ml of IGF-1. 
     
     
         10 . The method  claim 6 , wherein the population of cells is obtained without further purifying the cells after differentiation. 
     
     
         11 . The method of  claim 6 , wherein the step of differentiating comprises treating the pluripotent stem cells with a medium lacking serum and supplemented with BSA, from about 5 ng/ml to about 500 ng/ml of Activin A, Wnt-3A and a factor selected from the group consisting of insulin and from about 1 ng/ml to about 50 ng/ml of IGF-1. 
     
     
         12 . The method of  claim 6 , wherein the step of differentiating comprises treating the pluripotent stem cells with a medium lacking serum and supplemented with from about 0.5 to about 2% BSA, Activin A, Wnt-3A and a factor selected from the group consisting of insulin and from about 1 ng/ml to about 50 ng/ml of IGF-1. 
     
     
         13 . The method of  claim 6 , wherein the step of differentiating comprises treating the pluripotent stem cells with a medium lacking serum and supplemented with BSA, Activin A, Wnt-3A and from about 1 ng/ml to about 100 ng/ml of insulin. 
     
     
         14 . The method of  claim 6 , wherein the step of differentiating comprises treating the pluripotent stem cells with a medium lacking serum and supplemented with about 2% BSA, Activin A, Wnt-3A and from about 1 ng/ml to about 50 ng/ml of IGF-1. 
     
     
         15 . The method of  claim 6 , wherein the medium is chemically-defined. 
     
     
         16 . An in vitro culture comprising an isolated population of cells in which greater than 85% of the cells are definitive endoderm cells and a cell culture medium,
 wherein said population of cells is obtained by differentiating pluripotent stem cells into definitive endoderm cells, and   wherein the cell culture medium lacks serum and is supplemented with BSA, 1-alanyl-1-glutamine, Activin A, Wnt-3A and either insulin or from about 1 ng/ml to about 50 ng/ml of IGF-1.   
     
     
         17 . The in vitro culture of  claim 16 , wherein the population is obtained by differentiating pluripotent stem cells into definitive endoderm cells by treating the pluripotent stem cells with the medium lacking serum and supplemented with BSA, 1-alanyl-1-glutamine, Activin A, Wnt-3A and either insulin or from about 1 ng/ml to about 50 ng/ml of IGF-1.