MOLECULAR CHARACTERIZATION OF THE NUR77 ORPHAN STEROID-RECEPTOR IN APOPTOSIS

One of the in vitro model of programmed cell death is T cell receptor (TCR)-mediated apoptosis of immature T cells and T cell hybridomas. Th is form of apoptosis requires newly gene synthesis and may relate to n egative selection during T cell development. Recently, an orphan stero id receptor Nur77 was found to be induced during TCR-mediated apoptosi s. When introduced into T cells, a dominant negative or antisense Nur7 7 construct can block the apoptosis process. Various inhibitors of TCR -mediated apoptosis, including cyclosporin A downregulate the Nur77 DN A binding activity. Thus, the Nur77 protein family may play a crucial role during T cell apoptosis.