线性范围:15ng/L -300ng/L.The prototype ligand of theTNFsuperfamily, TNF-α/TNFSF1A, is a pleiotropic cytokine that plays a central role in inflammation and apoptosis.TNF-α is produced by activated macrophages and other cell types including T and B cells, NK cells, LAK cells, astrocytes, endothelial cells, smooth muscle cells and some tumor cells.Rat TNF-α cDNA encodes a 235 amino acid (aa) residue type II membrane protein. The 156 aa residue soluble TNF-α is released from the C-terminus of the membrane-anchored TNF-α by TNF-α-converting enzyme (TACE), a matrix metalloprotease.The membrane-anchored form of TNF-α has been shown to have lytic activity and may also have an important role in intercellular communication. The biologically active TNF-α has been shown to exist as a trimer.TNF-α is reported to promote inflammatory cell infiltration by upregulating leukocyte adhesion molecules on endothelial cells, serve as a chemotactic agent for monocytes, and activate phagocyte killing mechanisms. Deficiencies in either TNF-α or its receptors can increase susceptibility to infection by intracellular pathogens. TNF-α may also play a role in lymphoid tissue development. Knockout mice lack splenic B cell follicles and the ability to form germinal centers. Other potential physiological roles for TNF-α and its receptors include regulating the differentiation of hematopoietic stem and progenitor cells.