Effects of various recombinant human hemopoietic growth factors (rhEpo, rhG-CSF, rhGM-CSF, rhIl-3) on the growth of peripheral blood progenitor cells (BFU-E, CFU-GM).

The effects of rhEpo 1, rhG-CSF, rhGM-CSF and rhI1-3 on the growth of both CFU-GM and BFU-E from normal human adult peripheral blood have been studied in plasma clot cultures. Using optimal concentrations of all growth factors, alone and in combination with all other factors, rhI1-3 showed the highest activity in regard to growth of both CFU-GM and BFU-E, whereas rhGM-CSF treatment resulted only in half-maximal colony growth compared to rhI1-3. No synergism or additive effect was seen with the combination of rhI1-3 and rhGM-CSF. Treatment with rh-G-CSF had no additional effect with optimal concentrations of rhI1-3 and/or rhGM-CSF. When suboptimal concentrations of rhGM-CSF and rhI1-3 were applied, however, they showed a marked synergism on both BFU-E and CFU-GM. RhG-CSF, added to a suboptimal concentration of rhGM-CSF, resulted in a marked growth increase of CFU-GM but had no effect on BFU-E.