Anti-IL-1 Receptor Antagonist

This is an IgG preparation of whole rabbit serum purified by DEAE chromatography.  In general, this antibody also detects primate IL-1Ra in the same formats using similar dilutions, but not mouse or rabbit IL-1Ra.  The antibody does not recognize human IL-1a, IL-1b or IL-1 receptor type I and type II.  This antibody is primarily directed against the secreted form of IL-1Ra (also termed sIL-1Ra) but recognizes the native (non-denatured) as well as denatured intracellular form of IL-1Ra (also termed icIL-1Ra).  IcIL-1Ra is found in many cells as constitutively expressed protein, particularly epithelial cells and keratinocytes.  This antibody does not distinguish between sIL-1Ra and icIL-1Ra in ELISA formats or by immunohistochemistry.  When used in immunoblot analysis, it will recognize 17,000 MW IL-1Ra in supernatants released from supernatants or lysates of  2 x 106 endotoxin-stimulated human peripheral blood mononuclear cells (PBMC).  PBMC are stimulated for 24 hours with 1% (v/v) human serum plus 10 ng/mL E.coli LPS.  However, in lysates of PBMC, icIL-1Ra is also found after 48-72 hours of culture.  In monocytic cells, the initial IL-1Ra transcript is for sIL-1Ra which can be found almost exclusively intracellularly. Protein function: Inhibits the activity of interleukin-1 by binding to receptor IL1R1 and preventing its association with the coreceptor IL1RAP for signaling. Has no interleukin-1 like activity. Binds functional interleukin-1 receptor IL1R1 with greater affinity than decoy receptor IL1R2, however, the physiological relevance of the latter association is unsure. [The UniProt Consortium]