Abstract
The effects of interferon-β (IFN-β) produced by the recombinant DNA were evaluated on oxygen radical production by human neutrophils stimulated with opsonized zymosan. The oxygen radicals measured in the study were superoxide anions, hydrogen peroxide, and hydroxyl radicals. IFN-β augmented oxygen radical production that had been suppressed after neutrophils were incubated in Krebs-Ringer's solution. The potentiating effect of IFN was greatest with incubation for 3 hrs. In contrast, the function of neutrophils that had been incubated in RPMI 1640 supplemented with 10% fetal calf serum (RPMI) for 3 hrs was comparatively well preserved. Although IFN-β had almost no effect on oxygen radical production by neutrophils incubated without any inhibitor, it augmented that of neutrophils incubated with 50μM Endoxan, or 20μM colchicine. The protective role of IFN-β on neutrophil function was suggested. IFN-β elevated hydrogen peroxide production more markedly than that of superoxide anions or hydroxyl radicals. This difference may be due to induction of cellular proteins such as superoxide dismutase by IFN-β. IFN-β may be useful in the treatment of patients with malignancy whose neutrophil function was impaired by chemotherapy.
