INTERLEUKIN-1

Abstract

Interleukin-1 (IL-1) is secreted by macrophages, macrophage-like cells (e.g. Langerhans cells) and by astrocytes, keratinocytes, fibroblasts or natural killer cells. IL-1 is directly involved in the activation of helper T lymphocytes. However, it has been shown that IL-1 also induces release of collagenase and prostaglandins by fibroblasts. Furthermore, injections of IL-1 into animals are followed by fever, leukocytosis, increased serum concentrations of fibrinogen, serum amyloid A and haptoglobin, and decreased levels of iron and zinc. IL-1 has been extracted from experimental granuloma and from tissues of animals with endotoxinemia. Synovial fluids from patients with osteoarthritis contain significant amounts of IL-1. All in all, IL-1 may be ultimately involved in the development of fever and fibrosis, in the destruction of joints and the activation of T lymphocytes during inflammatory processes.