Recombinant Human TNF

Tumor Necrosis Factor is secreted by macrophages, monocytes, neutrophils, T cells, natural killer cells following their stimulation by bacterial lipopolysaccharides although cells expressing CD8(+) secrete little or no TNF-alpha. In addition, TNF is secreted by peripheral neutrophilic granulocytes and by a number of transformed cell lines that include those of astrocytes, microglial cells, smooth muscle cells and fibroblasts. Human milk also contains this factor. The synthesis of TNF-alpha is induced by many different stimuli including interferons, IL2, GM-CSF, SP, Bradykinin, Immune complexes, inhibitors of cyclooxygenase and platelet activating factor. TNF-alpha shares approximately 30% homology with TNF-beta. Human TNF-alpha is a non-glycosylated protein of 17.6 kDa.