ELISA kit for the detection of sTNFR (60 kDa) in the research laboratory

Tumor Necrosis Factor (TNF) was originally discovered as a serum protein with necrotizing effects on certain transplantable mouse tumors in vivo and cytotoxic effects against some transformed cells in vitro. The TNF family consists of two proteins designated TNF alpha, also called cachectin, and TNF beta, also called lymphotoxin, which are  pleiotropic cytokines that can mediate a wide variety of biological effects. TNF beta is produced by activated lymphocytes, whereas TNF alpha is mostly produced by activated macrophages. Soluble TNF beta is a T-cell derived glycoprotein of 25 kDa encoded by a gene within the MHC. The molecule consists of a 17.5 to 18 kDa polypeptide core and 7kDa of N-linked carbohydrate. TNF beta is 28% structurally homologous with the macrophage produced non-glycoprotein TNF beta. The genes for TNF alpha and TNF beta are closely linked, and the proteins share biological  activities. TNF has been shown to interact with a cell through specific high affinity receptors with a few hundred up to more than 20,000 copies per cell. In a variety of cell lines, two different TNF receptor proteins have been identified and the cDNAs cloned. Recently, an ELISA has been established by Adolf and Apfler which provides a simple, rapid, and highly sensitive method for the determination of soluble TNFR (60 kDa) levels in body fluids or cell culture supernatants.