Enriched stem cell and progenitor cell populations, and methods of producing and using such populations

Abstract

The present invention provides a novel method to isolate and expand pure progenitor/stem cells from a primary tissue explant, which produces a population enriched in multipotent functional progenitor/stem cells free of contaminating fibroblasts and other cell types. Cardiac progenitor/stem cells isolated by this method maintain their self-renewal and clonogenic character in vitro and differentiate into normal cells in myocardium, including cardiomyocytes, endothelial cells, and smooth muscle cells, after transplantation into ischemic hearts. The present invention also includes substantially pure populations of multipotent progenitor/stem cells, e.g., cardiac progenitor/stem cells, and their use to treat and prevent diseases and injuries, including those resulting from myocardial infarction.

1 . A method of preparing an isolated cell population enriched in stem cells or progenitor cells, comprising:
 (a) culturing a tissue sample;   (b) obtaining cells that migrate above adherent fibroblasts during said culturing;   (c) cloning one or more cells obtained in (b) to produce one or more clonogenic populations;   (d) identifying one or more clonogenic populations having a desired phenotype;   (e) isolating stem cells or progenitor cells from the one or more clonogenic populations identified in step (d) by cell sorting using one or more cell surface or internal markers of stem cells or progenitor cells; and   (f) culturing the isolated stem cells or progenitor cells in conditioned media in the absence of feeder cells;   thereby obtaining an isolated cell population enriched in stem cells or progenitor cells.   
     
     
         2 .- 34 . (canceled)