Interleukin-1 receptor antagonist
IL-1 receptor antagonist (IL-1ra) is a member of the IL-1 family, which acts as a natural IL-1 inhibitor. The balance between IL-1 and IL-1ra plays an important role in the course of various inflammatory diseases such as arthritis. IL-1ra is produced as different isoforms, one secreted (sIL-1ra) and three intracellular (icIL-1ra1, 2, 3), derived from the same gene. Human articular chondrocytes produce sIL-1ra in response to IL-1. This effect, which is enhanced by IL-6 and inhibited by dexamethasone, reflects increased transcription from the sIL-1ra promoter. The production of sIL-1ra by chondrocytes may have a protective effect against articular inflammatory and catabolic responses.
Swiss-Prot Accession Number: P18510
