Modulation of neutrophil functions by a beta-interferon of human origin

The effects of a beta interferon (beta-IFN) of human origin on different parameters of human neutrophil functioning were evaluated in vitro. In the concentration range 10(2)-10(4) IU/ml beta-IFN enhanced superoxide anion (O2-) production evoked by the peptide N-formylmethionyl-leucylphenylalanine (FMLP), 10(-7) M, when O2- production elicited by FMLP in the absence of beta-IFN treatment was 2.43 +/- 0.32 nmol cytochrome C reduced/10(6) cells/min. The enhancement afforded by 10(3) and 10(4) IU/ml beta-IFN was statistically significant. When FMLP-induced O2- generation was 4.55 +/- 0.3 nmol cytochrome C reduced/10(6) cells/min, no increase was detected after beta-IFN treatment. Phagocytosis was enhanced by beta-IFN in one case, with no effect in four others. Chemotaxis was not affected by exposure to beta-IFN. These results indicated that beta-IFN could exert modulating effects on some neutrophil functions that varied according to the extent of cell response to the stimuli.