TNF-α is an important cytokine produced by numerous cell types including neutrophils, activated lymphoctyes, macrophages and NK cells. It plays a critical role in inflammatory responses and in apoptosis. The two receptors for TNF-α, TNF-R1 and TNF-R2 can mediate distinct cellular responses. In most cases cytotoxicity elicited by TNF has been reported to act throught TNF-R1. In contrast, TNF-R2 appears to be important in T cell signaling and responses to infection. TNF-R2 to distinct members of the TRAF family leading to the activation of NF-κB. Soluble forms of both receptors have also been characterized which can bind TNF-α and may play an important role in immune disorders.
