THE TNF RECEPTOR FAMILY MEMBER CD27 SIGNALS TO JUN N-TERMINAL KINASE VIA TRAF-2

CD27 is a lymphocyte-specific member of the TNF receptor (TNFR) family . It is a costimulatory molecule for peripheral T cells, as defined by its ability to enhance the TCR-induced proliferative response. We sho w here that CD27 augments TCR-induced Jun N-terminal kinase (JNK) acti vity in primary murine lymph node T cells. To investigate how CD27 cou ples to JNK, we performed a yeast two hybrid screen with the CD27 cyto plasmic tail. This revealed that CD27 directly associates with Traf-2. Transfection experiments using dominant negative Traf-2 indicated tha t CD27 communicates with JNK via Traf-2. These findings group CD27 tog ether with other members of the TNFR family, TNFR-1, -2, CD30 and CD40 , which have all been shown to couple to Traf proteins. Since Traf pro teins have been reported to initiate an anti-apoptotic signaling pathw ay, our data suggest that CD27 not only regulates proliferation, but a lso survival of T lymphocytes.