Recombinant human IL-1β and TNF-α stimulate production of IL-1α and IL-1β by vascular smooth muscle cells and IL-1α by vascular endothelial cells

Vascular endothelial cells(EC) produced IL-1α but not IL-1β into extracellular fluids. Vascular smooth muscle cells(SMC), on the other hand, produced both IL-1α, and IL-1β , and IL-1β produced was much higher than IL-α. The addition of recombinant human IL-1β or recombinant human TNF-α significantly enhanced IL-1α production in EC, and IL-1α and IL-1β production in SMC. IL-1β release was not observed even when EC were stimulated with TNF-α. These results suggest that the species of released form of IL-1 are different in different cell types and that cytokines enhance IL-1α and IL-1β production in SMC and IL-1α production in EC.