Tumor Necrosis Factor-α human

General description
TNFα (tumor necrosis factor α) belongs to the TNF superfamily and is mapped to human chromosome 6p21.33.[1][2] Application
Tumor Necrosis Factor-α human has been used to study the differential regulation of microRNA-146a , CFH (complement factor-H), IRAK-1 (interleukin-1 receptor associated kinase-1) and tetraspanin-12 in primary brain cell cultures in presence of TNF-α.[3] To determine the intercellular adhesion molecule-1 (ICAM1) expression using ELISA.[4] Biochem/physiol Actions
TNF-α is associated with formation, growth and destabilization of atherosclerotic plaques.[5] TNF-α is involved in the disease progression of osteoarthritis.[6] Tumor necrosis factor-α (TNF-α), also known as cachectin, is expressed as a 26 kDa membrane bound protein and is then cleaved by TNF-α converting enzyme (TACE) to release the soluble 17 kDa monomer, which forms homotrimers in circulation. TNF-α plays roles in anti-tumor activity, immune modulation, inflammation, anorexia, cachexia, septic shock, viral replication and hematopoiesis. TNF-α is cytotoxic for many transformed cells, but in normal diploid cells, it stimulates proliferation (fibroblasts), differentiation (myeloid cells) or activation (neutrophils). TNF-α also shows antiviral effects against both DNA and RNA viruses and induces production of several other cytokines.
Tumore necrosis factor-α (TNF-α), also known as cachectin, is expressed as a 26 kDa membrane bound protein and is then cleaved by TNF-α converting enzyme (TACE) to release the soluble 17 kDa monomer, which forms homotrimers in circulation. TNF-α plays roles in antitumor activity, immune modulation, inflammation, anorexia, cachexia, septic shock, viral replication and hematopoiesis. TNF-α is expressed by a great variety of cells, with numerous inductive and suppressive agents. Primarily, TNF-α is produced by macrophages in response to immunological challenges such as bacteria (lipopolysaccharides), viruses, parasites, mitogens and other cytokines. TNF-α is cytotoxic for many transformed cells (its namesake activity) but in normal diploid cells, it can stimulate proliferation (fibroblasts), differentiation (myeloid cells) or activation (neutrophils). TNF-α also shows antiviral effects against both DNA and RNA viruses and it induces production of several other cytokines. Although TNF-α is used in clinical trials as an antitumor agent, Sigma′s cytokine, growth factor and hormone products are for research only. TNF-α and the related molecule TNF-β (LT-α) share close structural homology with 28% amino acid sequence identity and both activate the same TNF receptors, TNFR1 and TNFR2. Mouse and human TNF-α share 79% amino acid sequence identity. Unlike human TNF-α, the mouse form is N-glycosylated.
Physical form
Solution in phosphate buffered saline containing 1 mg/ml bovine serum albumin.
Analysis Note
The cytolytic activity of TNF-α against WEHI 164 cells has been measured in culture using an MTT toxicity assay. The ED50 is defined as the concentration of TNF-alpha that mediates half-maximal cytotoxicity in the presence of 1 micro-g/ml actinomycin D.