title: Cyclosporin A and FK-506 both affect DNA binding of regulatory nuclear proteins to the human interleukin-2 promoter.
abstract: The structurally unrelated immunosuppressive drugs cyclosporin A (Sandimmun) and FK-506 both interfere with the process of T-cell proliferation by blocking the transcription of the T-cell growth factor interleukin-2 (IL-2). Here we demonstrate that the transcriptional activation of this gene requires the binding of regulatory nuclear proteins to a promoter element with sequence similarity to the consensus binding site for NF-kappa B-related transcription factors. We present evidence that the binding by regulatory nuclear proteins to the kappa B element of the IL-2 promoter is affected negatively by cyclosporin A and FK-506 at concentrations paralleling their immunosuppressive activity in vivo. The decrease in DNA-protein complex formation induced by the immunosuppressive drugs correlates with a decrease in IL-2 production. FK-506 is 10 to 100 times more potent than cyclosporin A in its ability to inhibit sequence-specific DNA binding and IL-2 production. Our findings suggest that the actions of both drugs converge at the level of DNA-protein interaction.
authors.affiliation: Preclinical Research, Sandoz Pharma Ltd., Basel, Switzerland.
authors.forename: G
authors.initials: G
authors.lastname: Baumann
authors.forename: S
authors.initials: S
authors.lastname: Geisse
authors.forename: M
authors.initials: M
authors.lastname: Sullivan
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001483:Base Sequence; D002460:Cell Line; D003524:Cyclosporins / Q000494:pharmacology*; D004247:DNA / Q000187:drug effects / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000187:drug effects* / Q000378:metabolism; D005786:Gene Expression Regulation / Q000187:drug effects; D006801:Humans; D007166:Immunosuppressive Agents / Q000494:pharmacology*; D007376:Interleukin-2 / Q000096:biosynthesis / Q000235:genetics*; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000187:drug effects / Q000378:metabolism; D011401:Promoter Regions, Genetic / Q000187:drug effects; D016559:Tacrolimus; D014158:Transcription, Genetic / Q000187:drug effects; D014162:Transfection
chemical_list: D000900:Anti-Bacterial Agents; D003524:Cyclosporins; D004268:DNA-Binding Proteins; D007166:Immunosuppressive Agents; D007376:Interleukin-2; D009687:Nuclear Proteins; D004247:DNA; D016559:Tacrolimus