Studies on defense effects of recombinant human granulocyte colony-stimulating factor (G-CSF) to infections. II. Priming effect for superoxide production by human neutrophil]

In present study, we have investigated superoxide (O2-) production from human neutrophils by recombinant human granulocyte colony-stimulating factor (G-CSF) using the microtiter plate for the purpose of being close to the inflammatory site. G-CSF by itself did not induce the release of O2- in human neutrophil on either Fetal Bovine Serum (FBS)-coated plate or plate uncoated with FBS, even if neutrophils were exposed for maximum 3 hr. However, the optimal concentration of G-CSF (50 ng/ml) was able to prime human neutrophils with enhance of O2- release stimulated by the chemotactic peptide, N-formyl-methionyl-leucyl-phenylalanine (FMLP) from 10(-6) to 10(-8) M, but not by the non chemoattractant such as phorbol myristate acetate (PMA), concanavalin A, and ionomycin. These findings indicate that G-CSF might enhance bactericidal activity of neutrophils by priming them penetrating into the inflammatory site.