Interleukin 1, but not interleukin 1 inhibitor, is released from human monocytes by immune complexes

Immune complexes (IC) are believed to play a role in the pathogenesis of some autoimmune diseases in which interleukin 1 (IL-1) and probably other cytokines also take part. This investigation shows that tetanus toxoid-human anti-tetanus toxoid IC induce human monocytes to release IL-1. The activity was identified as being mainly IL-1 beta by molecular size chromatography, isoelectric focusing, and anti-IL-1 beta affinity chromatography. Endotoxins were eliminated by repetitive washing of the IC suspension and by preincubation of IC with polymyxin B. The IL-1-inducing effect of IC was destroyed by heating at 80 degrees C, and it was not blocked by the cytoskeleton inhibitor cytochalasin B. IL-1 inhibitors were not detected in the supernatants.