Ex Vivo Expansion of Human Hematopoietic Stem Cells

Abstract

Methods and kits for expanding the number of hematopoietic stem cells are provided. The methods comprise incubating cells in medium comprising isolated IGFBP-2 and an angiopoietin-like protein (Angptl). Expanded HSCs are provided as well as culture media and kits for the expansion of human HSCs in a defined medium. Methods of administering expanded human HSCs to and individual are provided as well as methods of treating an individual by administering certain growth factors and cytokines.

1 - 25 . (canceled) 
     
     
         26 . A method of promoting the expansion of hematopoietic stem cells in culture, comprising culturing cells in a culture medium comprising angiopoietin 2 under conditions sufficient for expansion of the cells, wherein at least one of the cells is a hematopoietic stem cell. 
     
     
         27 . The method of  claim 26 , wherein the angiopoietin 2 is a human angiopoietin 2. 
     
     
         28 . The method of  claim 26 , wherein the cells are cultured for ten days. 
     
     
         29 . The method of  claim 26 , wherein the culture medium is serum free medium. 
     
     
         30 . The method of  claim 29 , wherein the culture medium further comprises at least one additional factor selected from the group consisting of insulin growth factor (IGF), fibroblast growth factor (FGF), thrombopoietin (TPO), and stem cell factor (SCF). 
     
     
         31 . The method of  claim 26 , wherein the cells are CD45+, Sca-1+ bone marrow cells. 
     
     
         32 . The method of  claim 26 , wherein the cells are side population cells. 
     
     
         33 . A culture medium suitable for expanding hematopoietic stem cells in vitro comprising a serum free medium and angiopoietin 2. 
     
     
         34 . The culture medium of  claim 33 , wherein the angiopoietin 2 is human angiopoietin 2. 
     
     
         35 . The culture medium of  claim 33 , wherein the culture medium further comprises at least one additional factor selected from the group consisting of insulin growth factor (IGF), fibroblast growth factor (FGF), thrombopoietin (TPO), and stem cell factor (SCF). 
     
     
         36 . The culture medium of  claim 33 , comprising at least two additional factors selected from the group consisting of insulin growth factor (IGF), fibroblast growth factor (FGF), thrombopoietin (TPO), and stem cell factor (SCF). 
     
     
         37 . The culture medium of  claim 35 , wherein the IGF is IGF-2. 
     
     
         38 . The culture medium of  claim 35 , wherein the FGF is FGF-1. 
     
     
         39 . The culture medium of  claim 35 , further comprising IGF-2, FGF-1, SCF and TPO. 
     
     
         40 . The method of  claim 30 , further comprising IGF-2, FGF-1, SCF and TPO. 
     
     
         41 . The method of  claim 26 , wherein the angiopoietin 2 has the amino acid sequence of SEQ ID NO: 1 or an amino acid sequence having at least 60% sequence identity thereto. 
     
     
         42 . The culture medium of  claim 33 , wherein the angiopoietin 2 has the amino acid sequence of SEQ ID NO: 1 or an amino acid sequence having at least 60% sequence identity thereto. 
     
     
         43 . A kit for in vitro expansion of hematopoietic stem cells comprising a) angiopoietin 2, and b) instructions for expanding hematopoietic stem cells in vitro. 
     
     
         44 . The kit of  claim 43 , wherein the angiopoietin 2 is human angiopoietin 2. 
     
     
         45 . The kit of  claim 43 , wherein the angiopoietin 2 has the amino acid sequence of SEQ ID NO: 1 or an amino acid sequence having at least 60% sequence identity thereto.