Interleukin-1 (IL-1)

Immunology?

See Also

• Toll-like receptors (TLRs)
• Interleukin-6 (IL-6)
• Cytokines?
• [Growth Factors]?

Description

IL-1 is one of the most important immune modifying interleukins. The predominant function of IL-1 is to enhance the activation of [T lymphocyte]?s in response to antigen.

Discussion

Interleukin-1 (IL-1) is a [cytokines? cytokine] that is secreted by macrophage?s, monocytes and dendritic cells. It is an important part of the inflammatory response of the body against infection. It increases the expression of adhesion factors on endothelial cells to enable transmigration of leukocytes, the cells that fight pathogens, to sites of infection. It also re-sets the hypothalamus thermoregulatory center, leading to an increased body temperature which expresses itself as fever. It is therefore called an endogenous pyrogen. The increased body temperature helps the body's immune system to fight infection.

There are a few molecules of the IL-1 family. The two most studied molecular forms of interleukin-1, are:

• IL-1α
• IL-1β

For the most part, these two forms of IL-1 bind to the same cellular receptor. This receptor is composed of two related, but non-identical, subunits that transmit intracellular signals via a pathway that is mostly shared with certain other receptors. These include the Toll family of innate immune receptors and the receptor for IL-18.

The IL-1 receptor antagonist, IL-1Ra, is an agent which binds to the same receptor on the cell surface as IL-1, and thus prevents IL-1 from sending a signal to that cell. It is used in the treatment of rheumatoid arthritis, an autoimmune disease in which IL-1 plays a key role. It is commercially produced as anakinra, which is a human recombinant form of IL-1Ra.

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