Abstract
Granulocyte colony-stimulating factor (G-CSF) and granulocyte-macrophage colony-stimulating factor (GM-CSF) increased neutrophil C3bi-receptor expres-sion and adherènce and rapidly primed neutrophils to enhance O-2 release and membrane depolarization stimulated by chemotactic peptide, plant lectins and Ca2+ ionophore, but not by phorbol ester. Direct triggering of O-2 release in suspended neutrophils was also provoked by GM-CSF, but not by G-CSF. The biological activity was greater in non-glycosylated GM-CSF than in glycosylated GM-CSF, whereas it was identical in glycosylated and non-glycosylated G-CSFs. Direct stimulation and priming by GM-CSF were greater than those by G-CSF in all parameters tested, and the combined addition of the optimal concentrations of G-CSF and GM-CSF always resulted in the effects of GM-CSF alone.
These findings indicate that the effects of G-CSF and GM-CSF are partly similar, but qualitatively and quantitatively different from each other.
