Tumor necrosis factors (TNF family) refer to a group of cytokines which are mainly secreted by macrophages and can induce cell death of certain tumor cell lines. The first two members of the family to be identified were: Tumor Necrosis Factor Alpha (TNF Alpha) and Tumor necrosis factor-beta (TNF-β), also known as Lymphotoxin-alpha, a cytokine that is inhibited by interleukin 10.
Tumor necrosis factor alpha (TNF-alpha), also known as TNF, TNFA or TNFSF2, is the prototypic cytokine of the TNF superfamily, and is a multifunctional molecule involved in the regulation of a wide spectrum of biological processes including cell proliferation, differentiation, apoptosis, lipid metabolism, and coagulation. Two TNF-alpha receptors, TNF-R1 (TNF receptor type 1; CD120a; p55/60) and TNF-R2 (TNF receptor type 2; CD120b; p75/80), bind to TNF-alpha. TNF-alpha protein is produced mainly by macrophages, and large amounts of this cytokine are released in response to lipopolysaccharide, other bacterial products, and Interleukin-1 (IL-1). TNF-alpha is involved in fighting against the tumorigenesis, thus, is regarded as a molecular insight in cancer treatment.
|Trimeric structure of TNF alpha, produced by Mus musculus, based on PDB structure 2TNF (1.4 Å Resolution). Baeyens, KJ et al. (1999).|
The 1.4 A resolution structure of recombinant mouse tumour-necrosis factor alpha (mTNF) at 100 K has been determined. The crystals are triclinic, space group P1, with unit-cell parameters a = 48.06, b = 48.18, c = 51.01 A, alpha = 114.8, beta = 103.6, gamma = 91.1 degrees. The structure was refined to a final crystallographic R value of 19.7% (Rfree = 23.3%), including 3477 protein atoms, one 2-propanol molecule, one Tris molecule and 240 water molecules. Throughout the crystal lattice, the trimers are differently packed compared with human TNF, which was crystallized in the tetragonal space group P41212 and refined to 2.6 A resolution. The structures of mTNF and human TNF are very similar, diverging mainly in regions that are either flexible and/or involved in crystal packing. Some loops in mTNF which contain residues important for receptor binding are better resolved than in human TNF, such as the surface-exposed loops 30-34 and 144-147, which are also important for receptor specificity. Compared with human TNFs, the channel formed by the three monomers in mTNF is narrower. One 2-propanol molecule trapped in the trimeric channel could be a lead compound for the design of TNF inhibitors.
From Entrez Gene: This gene encodes a multifunctional proinflammatory cytokine that belongs to the tumor necrosis factor (TNF) superfamily. This cytokine is mainly secreted by macrophages. It can bind to, and thus functions through its receptors TNFRSF1A/TNFR1 and TNFRSF1B/TNFBR. This cytokine is involved in the regulation of a wide spectrum of biological processes including cell proliferation, differentiation, apoptosis, lipid metabolism, and coagulation. This cytokine has been implicated in a variety of diseases, including autoimmune diseases, insulin resistance, and cancer. Knockout studies in mice also suggested the neuroprotective function of this cytokine. [provided by RefSeq, Jul 2008]
From UniProt: Cytokine that binds to TNFRSF1A/TNFR1 and TNFRSF1B/TNFBR. It is mainly secreted by macrophages and can induce cell death of certain tumor cell lines. It is potent pyrogen causing fever by direct action or by stimulation of interleukin-1 secretion and is implicated in the induction of cachexia, Under certain conditions it can stimulate cell proliferation and induce cell differentiation.The TNF intracellular domain (ICD) form induces IL12 production in dendritic cells.