CD70 is a ligand of CD27 and is a TNF related transmembrane protein induced upon activation on T and B cells []. The CD27/CD70 interaction plays a key role in T dependent B cell responses and is responsible for plasma cell differentiation []. The CD27/CD70 pathway has been shown to contribute to the pathophysiology of autoimmunity [].
Tumor necrosis factor receptor superfamily member 7 (TNFRSF7), also known as CD27, T14, S152, Tp55, S152 or LPFS2, has a key role in the generation of immunological memory via effects on T-cell expansion and survival, and B cell development [, ]. It binds to ligand CD70, and plays a key role in regulating B-cell activation and immunoglobulin synthesis. CD27 transduces signals that lead to the activation of NF-kappaB and MAPK8/JNK, and mediates the signaling process through adaptor proteins TRAF2 and TRAF5. CD27-binding protein (SIVA), a pro-apoptotic protein, can bind to CD27 and may play an important role in the apoptosis induced by this receptor []. The potential role of the CD27/CD70 pathway in the course of inflammatory diseases, such as arthritis, and inflammatory bowel disease, suggests that CD70 may be a target for immune intervention. The expression of CD27 and CD44 molecules correlates with the differentiation stage of B cell precursors and has been shown to have a biological significance in acute lymphoblastic leukemia [].This entry represents the N-terminal domain of TNFRSF7. TNF-receptors are modular proteins. The N-terminal extracellular part contains a cysteine-rich region responsible for ligand-binding. This region is composed of small modules of about 40 residues containing 6 conserved cysteines; the number and type of modules can vary in different members of the family [, , ].
