Effect of interferon-alpha on production of reactive oxygen species by human neutrophils

In order to examine that the effects of interferon alpha (IFN-alpha) on the production of reactive oxygen species from human neutrophils, we investigated in vitro effects of IFN-alpha on neutrophil chemiluminescence responses. Human neutrophils were incubated with 0-1 x 10(5) IU/mL IFN-alpha for 10-60 min just before stimulation with opsonized zymosan and phorbol 12-myristate 13-acetate. Luminol-dependent (LmCL) and lucigenin-dependent (LgCL) chemiluminescence responses were measured using a Lumi Box H-1000. The LmCL response was inhibited by pre-incubation with high concentrations of IFN-alpha (more than 1 x 10(4) IU/mL). In contrast, LgCL response was increased when neutrophils were pre-incubated with high concentration of IFN-alpha. Effects of pre-incubation of IFN-alpha were similar between CL responses stimulated with OZ and PMA. The increase of LgCL might be due to the inhibitory effect of IFN-alpha on myeloperoxidase degranulation, in view of the decreased LmCL responses.