TNFα Background Information
Tumor necrosis factor ∫ (TNF∫), also known as lymphotoxin, is a pleiotropic cytokine. TNFå, also known as cachectin, is a smaller cytokine that binds to the same receptors, producing a vast array of effects similar to those of TNF∫. TNF∫ and TNFå share 30% amino acid homology and have similar biological activities. TNF∫ is produced by activated lymphocytes, including CD4+ T helper cell type 1 lymphocytes, CD8+ lymphocytes and certain B lymphoblastoid cell lines. TNFå is produced by several different cell types, which include lymphocytes, neutrophils and macrophages. TNFå and TNF∫ can modulate many immune and inflammatory functions, while having the ability to inhibit tumor growth. Target tumor cells must express TNF receptors 1 and 2 to be killed, with the p55 receptor mediating the cytotoxic response.
