Function and regulation of tumor necrosis factor receptor type 2.

TNF is a major proinflammatory cytokine, which exerts its effects through two different receptors known as TNF-R1 and TNF-R2. Whereas TNF-R1 induced signaling pathways have been very well characterized during the past years, TNF-R2 has been much less well studied. Nevertheless, the function of TNF-R2 should not be underestimated, the more because this receptor shows a much more restricted but inducible expression. Several inflammatory diseases and cancers show upregulated levels of soluble TNF-R2 or are associated with TNF-R2 polymorphisms, implicating an important role for TNF-R2 as a therapeutic target. Here we will review the mechanisms that regulate TNF-R2 expression, as well as discuss TNF-R2 induced signal transduction and cross-talk with TNF-R1.