Role of IL-18 in the secretion of Il-1beta, sIL-1RII, and IL-1Ra by human neutrophils. 
In the present study we investigated the effect of IL- 18 on the production of IL-1beta, IL-1Ra and sIL-1RII by human neutrophils.  Our observations indicate that rhIL-18 induces IL-1beta and, to a lesser extend, IL-1Ra and sIL-1RII production by human neutrophils isolated form peripheral blood.  However, this effect was less important in comparison with LPS-stimulation.  Moreover, the results obtained suggest that IL-18 can induce priming of neutrophils for IL-1beta and, to a lesser extend, IL- Ra and sIL-1RII production by LPS-stimulated cells.  The capacity of IL-18 to serve as an effective modulator for IL-1beta and its regulatory proteins may have significance in the inflammatory and immune reactions mediated by IL-1beta.