THE INTERLEUKIN-8 AP-1 AND KAPPA-B-LIKE SITES ARE GENETIC END TARGETSOF FK5O6-SENSITIVE PATHWAY ACCOMPANIED BY CALCIUM MOBILIZATION

FK506, an immunosuppressant, inhibits the production of several cytoki nes in T lymphocytes. We observed that FK506 suppressed the transcript ion of a chemotactic cytokine, interleukin-8 (IL-8) in a human T cell line, Jurkat cells, activated by phorbol 12-myristate 13-acetate (PMA) and calcium (Ca2+) ionophore (ionomycin). By deleted and mutated anal ysis of the IL-8 promoters, the AP-1 and kappa B-like sites were ident ified as the responsive elements for PMA and ionomycin. FK506 suppress ed the transcriptions through the AP-1 or kappa B-like sites induced b y PMA plus Ca2+-mobilizing agents, but not those induced by Ca2+-indep endent stimuli. In gel retardation analysis, FK506 had little effect o n the binding to the AP-1 site of PMA/ionomyein-induced nuclear factor s, which were recognized with anti-JunD or c-Fos antibody. In contrast , FK506 or EGTA (Ca2+ chelator) similarly affected the formation of ka ppa B-like site binding complexes, which were not recognized by any an tibodies against the human Rel family proteins (c-Rel, p65, p50, and p 49). Furthermore, we confirmed the previous report that FK506 suppress ed the PMA/ionomycin-induced activation through authentic kappa B site of immunoglobulin (Ig) gene, to which NF-kappa B binding was also dec reased by FK506, indicating that both IL-8 kappa B-like site and Ig ka ppa B Site are FK506-sensitive in spite of the difference of binding f actors. Our results indicate that not only the reported IL-2 NF-AT and NFIL-2A sites and Ig kappa B site, but also the IL-8 AP-1 and kappa B -like sites are terminals of FK506-sensitive pathway involving Ca2+ mo bilization.