Tumor necrosis factor alpha (TNF-alpha), also known as cachectin and TNFSF1A, is the prototypic ligand of the TNF superfamily. It is a pleiotropic molecule that plays a central role in inflammation, apoptosis, and immune system development. TNF-alpha is produced by a wide variety of immune and epithelial cell types. Human TNF-alpha consists of a 35 amino acid (aa) cytoplasmic domain, a 21aa transmembrane segment, and a 177aa extracellular domain (ECD). Within the ECD, human TNF-alpha shares 97% aa sequence identity with rhesus and 71%-92% with bovine, canine, cotton rat, equine, feline, mouse, porcine, and rat TNF-alpha. The 26kD type 2 transmembrane protein is assembled intracellularly to form a noncovalently linked homotrimer. Ligation of this complex induces reverse signaling that promotes lymphocyte costimulation but diminishes monocyte responsiveness. Cleavage of membrane bound TNF-alpha by TACE/ADAM17 releases a 55kD soluble trimeric form of TNF-alpha. TNF-alpha trimers bind the ubiquitous TNF RI and the hematopoietic cell-restricted TNF RII, both of which are also expressed as homotrimers. TNF-alpha regulates lymphoid tissue development through control of apoptosis. It also promotes inflammatory responses by inducing the activation of vascular endothelial cells and macrophages. TNF-alpha is a key cytokine in the development of several inflammatory disorders. It contributes to the development of type 2 diabetes through its effects on insulin resistance and fatty acid metabolism.
Sample Type:Whole cells
Intended Use:BioAssay™ ELISpot kits are highly sensitive, microplate-based assays for the detection of cytokine secreting cells. Kits are available for detection and enumeration of a single analyte or two analytes simultaneously. Complete ELISpot kits are ready-to-run and require no assay development or refinement. ELISpot Development Modules contain the basic components required to develop an ELISpot assay.
Test Principle:The analyte-specific ELISpot Development Modules contain the components for analyte detection and visualization. Each module contains enough reagents for at least five 96-well microplates.
Storage and Stability:May be stored at 4°C for short-term only. Aliquot to avoid repeated freezing and thawing. Store at -20°C for up to six months. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap. Further dilutions can be made in assay buffer.
