Effect in vitro of gamma interferon and interleukin-10 on generation of oxidizing species by human granulocytes

Abstract
We examined the effect of interleukin-10 (IL-10), gamma interferon (IFN-γ), phorbol ester (PDB), opsonized zymosan (OZ) and aminophylline (a cAMP phosphodiesterase inhibitor) on the reducing power and oxidizing species generation by human neutrophils, using MTT dye reduction and luminol-dependent chemiluminescence assays, respectively. Gamma interferon (IFN-γ), phorbol ester (PDB) and opsonized zymosan (OZ) were activators while interleukin-10 (IL-10) and aminophylline were inhibitors. A strong parallelism was observed between oxidizing species generation and cellular reducing power in both activation and inhibition experiments. Our results also demonstrate for the first time the effect of IL-10 on free radical generation by neutrophils. The consequence of these activating and inhibiting effects on the inflammatory process are discussed.