Elevation of PMN cytosolic free calcium and locomotion stimulated by novel peptides from IL-1-treated human synovial cell cultures.

Treatment of human synovial cell cultures with human recombinant interleukin 1 (IL-1) results in the appearance of activity in the supernatant which stimulates human polymorphonuclear neutrophils (PMNs), as assessed by increased chemokinesis and elevation of intracellular free calcium concentration. IL-1 (or related cytokines) were unable to stimulate these responses. This activity chromatographed as a single peak on C8 reversed-phase HPLC and subsequent size exclusion HPLC revealed two peaks of chemokinetic activity with apparent molecular masses of approximately equal to 13kDa and 6kDa. Fractions containing the higher molecular mass material also elevated PMN cytosolic free calcium. The local production of such factors may mediate IL-1-induced PMN accumulation in vivo.