THE ROLE OF NFATP IN CYCLOSPORINE A-SENSITIVE TUMOR-NECROSIS-FACTOR-ALPHA GENE-TRANSCRIPTION

The tumor necrosis factor-alpha (TNF alpha) gene is an immediate early gene in activated T cells, in that it is rapidly induced without a re quirement for protein synthesis. Maximal induction of TNP alpha mRNA c an be induced by treatment of T cells with calcium ionophores alone, v ia a calcineurin dependent process that is blocked by cyclosporin A. W e have previously identified a promoter element, kappa 3, that is requ ired for calcium-stimulated, cyclosporin A-sensitive induction of the TNF alpha gene in activated T cells. Here, we demonstrate that the kap pa 3 binding factor contains NFATp, a cyclosporin-sensitive DNA-bindin g protein required for interleukin-a gene transcription. NFATp binds t o two sites within the kappa 3 element, and occupancy of both sites is required for TNF alpha gene induction. Thus, although the kappa 3 ele ment has little sequence similarity to other NFATp-binding sites, it a ppears to function as a cyclosporin-sensitive promoter element in T ce lls by virtue of its ability to bind NFATp. The involvement of NFATp i n transcriptional activation of both the interleukin-2 and TNF alpha g enes suggests that this factor plays an important role in the coordina te induction of multiple cytokine genes, starting at the earliest stag es of T cell activation.