Revision as of 15:01, 20 October 2019

TNF-α

Tumor necrosis factor (TNF, cachexin, or cachectin; once named as tumor necrosis factor alpha or TNFα) is a cell signaling protein (cytokine) involved in systemic inflammation and is one of the cytokines that make up the acute phase reaction. It is produced chiefly by activated macrophages, although it can be produced by many other cell types such as CD4+ lymphocytes, NK cells, neutrophils, mast cells, eosinophils, and neurons.TNF is a member of the TNF superfamily, consisting of various transmembrane proteins with a homologous TNF domain. The primary role of TNF is in the regulation of immune cells. TNF, being an endogenous pyrogen, is able to induce fever, apoptotic cell death, cachexia, inflammation and to inhibit tumorigenesis and viral replication and respond to sepsis via IL1- & IL6-producing cells. Dysregulation of TNF production has been implicated in a variety of human diseases including Alzheimer's disease, cancer, major depression, psoriasis and inflammatory bowel disease (IBD). Though controversial, studies of depression and IBD are currently being linked to increased levels of TNF. Recombinant TNF is used as an immunostimulant under the INN tasonermin. TNF can be produced ectopically in the setting of malignancy and parallels parathyroid hormone both in causing secondary hypercalcemia and in the cancers with which excessive production is associated.

Usage and Biology

result

Fig. OD450 value can represent the cell number. “TNF-α” is the very group containing TNF-α theoretically. (a) Different volume of the supernatant treat the HeLa cells for 24h. (b) Different volume of the supernatant treat the HepG2 cells for 24h.

As we can see that the TNF-α is expressed after the induction, and TNF-α sample for 50% volume can kill 82.5% HepG2 cells, the TNF-α sample for 20% can kill 70.8% HeLa cells. Eventually, our system is able to induced by hypoxia and high lactic acid to secrete cytotoxic TNF-α, causing the evident death of HeLa and HepG2 cells.

References

[1] Old, L.J., Tumor necrosis factor (TNF). Science, 1985. 230(4726): p. 630-2. [2] Watanabe, N., et al., Toxic effect of tumor necrosis factor on tumor vasculature in mice. Cancer Res, 1988. 48(8): p. 2179-83. [3] Folli, S., et al., Tumor-necrosis factor can enhance radio-antibody uptake in human colon carcinoma xenografts by increasing vascular permeability. Int J Cancer, 1993. 53(5): p. 829-36.

Sequence and Features