A soluble factor produced by MONOCYTES; MACROPHAGES, and other cells which activates T-lymphocytes and potentiates their response to mitogens or antigens. Interleukin-1 is a general term refers to either of the two distinct proteins, INTERLEUKIN-1ALPHA and INTERLEUKIN-1BETA. The biological effects of IL-1 include the ability to replace macrophage requirements for T-cell activation.

Interleukin-1 (endogenous pyrogen), produced primarily by monocytes, is an important pro-inflammatory cytokine that mediates the acute phase host response. The biologic activities of IL1 are properties of a protein derived from a larger precursor. Inflammation causes induction of COX2, leading to release of prostanoids, which sensitize peripheral nociceptor terminals and produce local pain hypersensitivity. Inflammation also generates sensitivity in neighboring tissue, muscle and joint pain, fever, lethargy, and anorexia. COX2 induction in regions of the CNS is mediated by IL1B. Interleukin-1-beta also stimulates bone resorption. IL1RN is a competitive inhibitor of IL1B. Mature IL1-beta levels are a sensitive and specific indicator of caspase-1 activation. (from OMIM 147720 and NCI)

(interleukin 1) Macrophage produced interleukin that induces the production of interleukin 2 by T cells that have been stimulated by antigen or mitogen; at least two types, alpha and beta, exist; interleukin 1 or a similar protein is also produced by epithelial cells and stimulates fibroblast proliferation and release of proteolytic enzymes and prostaglandins in inflammatory processes.

One of a group of related proteins made by leukocytes (white blood cells) and other cells in the body. IL-1 is made mainly by one type of white blood cell, the macrophage, and helps another type of white blood cell, the lymphocyte, fight infections. It also helps leukocytes pass through blood vessel walls to sites of infection and causes fever by affecting areas of the brain that control body temperature. There are two forms of IL-1, alpha and beta, which act the same. IL-1 made in the laboratory is used as a biological response modifier to boost the immune system in cancer therapy. IL-1 is a type of cytokine.