Primitive human HPCs are better maintained and expanded in vitro at 1 percent oxygen than at 20 percent

When cultured at 1-percent O(2) for 7 days in presence of IL-3 and SCF, the CD34+ cells present in apheresis components underwent more cell divisions and better maintained their primitive progenitor cell potential. As suggested by previous results in mice, our data on human cells emphasize the potential interest of cultures at low O(2) tension (1%) for cell therapy protocols aimed at expanding primitive HPCs in autografts.