The biological activities of interleukin

In addition to IL-la and -1(3, a third IL-l-like protein has been identified, termed IL-1 receptor antagonist (IL-IRa). As its name suggests, this molecule appears to be capable of binding to the IL-1 receptors without triggering an intracellular response. 

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Recombinant human DL-1 receptor antagonist (Anakinra, Kineret ) blocks the biological activity of interleukin-1 by competitively inhibiting IL-1 binding to the interleukin-1 type I receptor (IL-1RI), which is expressed in a wide variety of tissues and organs. Thereby it reduces the pro-inflammatory activities of IL-1 including cartilage destiuction and bone resorption. Side effects include an increased risk of infections and neutropenia. 

Anakinra is an immunomodular that blocks the biologic activity of interleukin-1 (IL-1) by competitively inhibiting... 

The interleukin-1 (EL-1) family of proteins currently comprises IL-1 a, IL-1 (3, and the IL-1 receptor antagonist (IL-1RA). The biological activities of EL-1 are shared by IL-1 a and IL-1 (3, whereas IL-1RA is a true receptor antagonist. IL-1 is a key player in acute and chronic inflammatory diseases. Whether IL-1 has a role in normal physiology is still unresolved. IL-1 can... 

Page, C., P. Dawson, D. Woollacott, R. Thorpe, and A. Mire-Sluis (2000). Development of a lyophilization formulation that preserves the biological activity of the platelet-inducing cytokine interleukin-11 at low concentrations. J Pharm Pharmacol 52(1) 19-26. 

Anakinra blocks the biologic activity of IL-1 by competitively inhibiting IL-1 binding to the interleukin-1 type I receptor (IL-1RI), which is expressed in a wide variety of tissues and organs. 

The biological activities of several other interleukins also render them likely candidates for therapeutic application. IL-5 represents one such candidate. IL-5 is a 115 amino acid glycoprotein produced mainly by activated T lymphocytes and also by mast cells. It functions as a homodimer, exhibiting a molecular mass of 45 kDa. The individual polypeptide chains interact non-covalently and the overall dimeric structure is stabilized by two interchain disulphide linkages between cysteines 42 and 84 of each chain. Removal or alterations of the cytokine s carbohydrate side-chain does not appear to affect its biological activity. 

In vivo experiments using DBA/2 mice with Sutton lymphoma 2 (SL2), lymphosarcoma, revealed that the cytokine interleukin-2 (IL-2), which was slowly released from dex-HEMA microspheres over a period of 3-5 days, had comparable therapeutic effects as repeated injections of the free protein were administered for 5 consecutive days (37). This finding demonstrates that the biological activity of the released protein was preserved. 

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