Inhibition of interleukin-4 production in CD4+ T cells by peroxisome proliferator-activated receptor-gamma (PPAR-gamma) ligands: involvement of physical association between PPAR-gamma and the nuclear factor of activated T cells transcription factor.
Peroxisome proliferator-activated receptor-gamma (PPAR-gamma) has been implicated in the regulation of multiple inflammatory processes. However, little is known of PPAR-gamma in the regulation of interleukin (IL)-4 expression in T cells. In this study, the effects of PPAR-gamma ligands on production of IL-4, a pro-inflammatory cytokine associated with the pathophysiology of allergic diseases, were investigated. 15-Deoxy-Delta12,14 prostaglandin J2 (15d-PGJ2) and ciglitazone, two representative PPAR-gamma ligands, significantly inhibited IL-4 production in both antigen-stimulated primary CD4+ T cells and the phorbol 12-myristate 13-acetate (PMA)/ionomycin-activated EL-4 T cell line. 15d-PGJ2 and ciglitazone inhibited the activation of IL-4 gene promoter in EL-4 T cells transiently transfected with IL-4 promoter/reporter constructs, and the repressive effect mapped to a region in the IL-4 promoter containing binding sites for nuclear factor of activated T cells (NF-AT). The activation of T cells by PMA/ionomycin resulted in a marked enhancement of the binding activities to the NF-AT site that was significantly inhibited by the addition of PPAR-gamma ligands. In cotransfected EL-4 T cells, PPAR-gamma also inhibited the activation of the IL-4 promoter at multiple NF-AT sites in a ligand-dependent manner. NF-ATc1 bound PPAR-gamma both in vivo and in vitro, and the interaction interfaces involved the Rel similarity domain of NF-ATc1. In cotransfections of HeLa cells, PPAR-gamma inhibited the NF-ATc1 transactivation in a ligand-dependent manner. Coexpression of p300 or AP-1 relieved the PPAR-gamma ligand-mediated inhibition of the NF-AT transactivation. From these results, we propose that PPAR-gamma ligand-mediated suppression of IL-4 production in CD4+ T cells may involve both inhibition of the NFAT-DNA interactions and competitive recruitment of transcription integrators between NF-AT and PPAR-gamma.
Chung
Su Wol
SW
College of Pharmacy and Research Institute of Drug Development, Chonnam National University, Kwangju 500-757, Republic of Korea.
Kang
Bok Yun
BY
Kim
Tae Sung
TS
D000818:Animals; D001559:Benzhydryl Compounds; D001665:Binding Sites; D015496:CD4-Positive T-Lymphocytes / Q000187:drug effects* / Q000378:metabolism; D002273:Carcinogens / Q000494:pharmacology; D002460:Cell Line; D004268:DNA-Binding Proteins / Q000378:metabolism*; D004347:Drug Interactions; D050881:E1A-Associated p300 Protein; D004852:Epoxy Compounds / Q000494:pharmacology; D015847:Interleukin-4 / Q000096:biosynthesis*; D015759:Ionomycin / Q000494:pharmacology; D008024:Ligands; D051379:Mice; D008807:Mice, Inbred BALB C; D050778:NFATC Transcription Factors; D009687:Nuclear Proteins / Q000378:metabolism; D011401:Promoter Regions, Genetic / Q000187:drug effects; D015230:Prostaglandin D2 / Q000031:analogs & derivatives* / Q000494:pharmacology*; D018160:Receptors, Cytoplasmic and Nuclear / Q000819:agonists / Q000378:metabolism*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D045162:Thiazolidinediones / Q000494:pharmacology; D015534:Trans-Activators / Q000378:metabolism; D018808:Transcription Factor AP-1 / Q000378:metabolism; D014157:Transcription Factors / Q000819:agonists / Q000378:metabolism*; D014407:Tumor Cells, Cultured; D000098826:Bisphenol A Compounds
D001559:Benzhydryl Compounds; D002273:Carcinogens; D004268:DNA-Binding Proteins; D050881:E1A-Associated p300 Protein; D004852:Epoxy Compounds; D015847:Interleukin-4; D015759:Ionomycin; D008024:Ligands; D050778:NFATC Transcription Factors; D009687:Nuclear Proteins; D015230:Prostaglandin D2; D018160:Receptors, Cytoplasmic and Nuclear; D013755:Tetradecanoylphorbol Acetate; D045162:Thiazolidinediones; D015534:Trans-Activators; D018808:Transcription Factor AP-1; D014157:Transcription Factors; C477819:15-deoxyprostaglandin J2; C494361:Ep300 protein, mouse; C019273:bisphenol A diglycidyl ether; D000098826:Bisphenol A Compounds; C039671:ciglitazone