1. The subcutaneous administration of recombinant human interleukin-1β (rhIL-1β) was found to induce an increased incidence and earlier onset of collagen-induced arthritis in mice.
2. The rhIL-1β had different effects, depending on when it was administered after collagen-immunization.
3. The effect of rhIL-1β may be due, in part, to augmentation of the immune response to type II collagen.
4. Interleukin-1-accelerated, collagen-induced arthritis will provide a useful model for investigating the role of interleukin-1 in the regulation of arthritic diseases, and the development of anti-arthritic therapeutics.