Cell population containing non-fetal hemangioblasts and method for producing same

Abstract

Methods are provided for expanding populations of non-fetal hemangioblasts, for example a method including (a) providing a first cell population containing non-fetal hemangioblasts; and (b) growing the enriched cell culture under conditions that promote the proliferation of the non-fetal hemangioblasts. Preferred populations include non-fetal uncommitted human hemangioblasts.

What is claimed is:  
     
         1 . A method for providing a cell population containing non-fetal hemangioblasts, said method comprising 
 a) providing a cell population containing non-fetal hemangioblasts; and    b) growing said cell population under conditions that promote the proliferation of said non-fetal hemangioblasts.    
     
     
         2 . The method of  claim 1  wherein, in step (b), said conditions are such that the number of said non-fetal hemangioblasts and their proximity to each other are sufficient to increase the proportion of non-fetal hemangioblasts in the population, compared to other cells, to provide an enriched cell culture.  
     
     
         3 . The method of  claim 1  further comprising (c) separating at least a portion of saint non-fetal hemangioblasts from other cells in said cell culture.  
     
     
         4 . The method of  claim 3  wherein said separating step (c) comprises a negative selection process.  
     
     
         5 . The method of  claim 3  wherein said separating step (c) is performed concurrently with, intermittently during, or following, said growing step (b).  
     
     
         6 . The method of  claim 3  wherein said separating step is performed more than once during growing step (b).  
     
     
         7 . The method of  claim 6  wherein said separating step is performed every 5 to 10 days.  
     
     
         8 . The method of  claim 1  wherein said growing step includes providing at least one growth factor to said cell population during cell proliferation.  
     
     
         9 . The method of  claim 8  wherein a plurality of growth factors is provided to said cell population.  
     
     
         10 . The method of  claim 9  wherein said growth factors comprise SCF, TPo and FLT-3.  
     
     
         11 . The method of  claim 8  wherein said growth factor is VEGF.  
     
     
         12 . The method of  claim 1  wherein said non-fetal hemangioblasts are human hemangioblasts.  
     
     
         13 . The method of  claim 1  wherein the non-fetal hemangioblasts provided in the providing step (a) are obtained from human cord blood.  
     
     
         14 . The method of  claim 12  wherein at least 5% of the non-fetal hemangioblasts are said human hemangioblasts.  
     
     
         15 . The method of  claim 14  wherein at least 15% of the non-fetal hemangioblasts are said human hemangioblasts.  
     
     
         16 . The method of  claim 15  wherein at least 25% of the non-fetal hemangioblasts are said human hemangioblasts.  
     
     
         17 . The method of  claim 12  wherein said human hemangioblasts are characterized as: CD2−, CD3−, CD14−, CD16−, CD19−, CD24−, CD56−, CD66b−, glycophorin A−.  
     
     
         18 . The method of  claim 17  wherein said human hemangioblasts are further characterized as: flk-1+, CD45+.  
     
     
         19 . The method of  claim 18  wherein said human hemangioblasts are further characterized as: CXCR4+, MDR+.  
     
     
         20 . The method of  claim 1  wherein at least some of the non-fetal hemangioblasts are CD 34−, Lin− cells.  
     
     
         21 . The method of  claim 20  wherein the percentage of cells that are CD 34−, Lin− is higher after the growing step (b) than in the starting cell culture.  
     
     
         22 . The method of  claim 20  wherein at least 5% of the non-fetal hemangioblasts are said CD 34−, Lin− cells.  
     
     
         23 . The method of  claim 22  wherein at least 15% of the non-fetal hemangioblasts are said CD 34−, Lin− cells.  
     
     
         24 . The method of  claim 23  wherein at least 25% of the non-fetal hemangioblasts are said CD 34−, Lin− cells.  
     
     
         25 . A cell population comprising non-fetal hemangioblasts, the cell population resulting from expansion of a starting cell sample containing fewer non-fetal hemangioblasts than the cell population.  
     
     
         26 . The cell population of  claim 25  wherein said starting cell sample contains a proportion of non-fetal hemangioblasts at least 10% lower than the cell population.  
     
     
         27 . The cell population of  claim 25  wherein the percentage of cells that are non-fetal hemangioblasts in the enriched cell culture is higher than the percentage of cells that are non-fetal hemangioblasts in the starting cell sample.  
     
     
         28 . A composition of cells in which at least 2% of the cells are non-fetal hemangioblasts.  
     
     
         29 . The composition of  claim 28  wherein at least 5% of the cells are said non-fetal hemangioblasts.  
     
     
         30 . The composition of  claim 29  wherein at least 15% of the cells are said non-fetal hemangioblasts.  
     
     
         31 . The composition of  claim 30  wherein at least 25% of the cells are said non-fetal hemangioblasts.  
     
     
         32 . The composition of  claim 28  wherein said non-fetal hemangioblasts comprise human hemangioblasts.  
     
     
         33 . The composition of  claim 28  wherein said non-fetal hemangioblasts comprise CD 34−, Lin− cells.  
     
     
         34 . The composition of  claim 32  wherein said human hemangioblasts are characterized as: CD2−, CD3−, CD14−, CD16−, CD19−, CD24−, CD56−, CD66b−, glycophorin A−.  
     
     
         35 . The composition of  claim 32  wherein said human hemangioblasts are further characterized as: flk-1+, CD45+.  
     
     
         36 . The composition of  claim 35  wherein said human hemangioblasts are further characterized as: CXCR4+, MDR+.  
     
     
         37 . A method for providing a cell population containing non-fetal uncommitted human hemangioblasts, said method comprising 
 a) providing a first cell population containing non-fetal uncommitted human hemangioblasts; and    b) growing said first cell population under conditions that promote the proliferation of said non-fetal human uncommitted hemangioblasts.