Human Interleukin-1 RA ELISA

Features

• RUO
• calibration range 109-7000 pg/ml
• limit of detection 30 pg/ml
• intra-assay CV = 7.2%
• inter-assay CV = 7.4%

Research topic

Cytokines and chemokines and related molecules

Summary

Interleukin 1 receptor antagonist (IL-1RA) is a protein that appears to be related to the IL-1 family based on its similarities in amino acid sequence to both IL-1 beta and IL-1 alpha; similarities in gene structure; and collective gene localization. The human gene contains four exons and maps to chromosome 2q13-14. One exon in the vicinity of the two genes, encoding for the two molecular forms of IL-1. IL-1 induces the release of prostaglandins, nitric oxide and the synthesis of chemokines that promote cells of the immune system to the site of infection. IL-1RA binds to the IL-1 receptor and blocks IL-1 action through competitive inhibition. The binding of IL-1RA does not initiate such events because IL-1RA does not induce a signal on its own. The secretion of IL-1RA is apparently mediated by a classical signal sequence present at the N terminus of the protein that is encoded in the first exon of the IL-1RA gene. Neither IL-1 alpha nor IL-1 beta possess such a sequence. The lack of homology between IL-1RA and IL-1 alpha or IL-1 beta near the N terminus may provide an explanation for the biosynthetic and functional differences between IL-1RA and the two IL-1 proteins. The production of IL-1RA is stimulated by many substances including adherent IgG, other cytokines, and bacterial or viral components. Triggering IL-1 production through cytokines like IL- 13, IL-6, IL-4, IFN-γ, GM-CSF and TGF-β apparently triggers IL-1RA synthesis through elevated levels of IL-1. A number of cell types express IL-1RA, including monocytes, macrophages, neutrophils, Sertoli cells, hepatocytes, adipocytes, synovial fibroblasts, mast cells, pancreatic cells and intestinal epithelial cells. IL-1RA is an important natural anti-inflammatory protein that when missing or just available in inadequate amounts plays a key role in several pathological conditions such as rheumatoid arthritis, colitis, osteomyelitis, periostitis and pustulosis. A polymorphism of the IL-1RA gene is reported to be associated with increased risk of osteoporotic fractures and gastric cancer. In healthy tissue sufficient interleukin-1-receptor antagonist is produced to hold interleukin-1-mediated inflammation at bay. In cases of uncontrolled inflammation, there is an insufficient amount of interleukin-1-receptor antagonist to regulate the activity of interleukin-1.