title: IL-18 enhances IFN-gamma-induced production of CXCL9, CXCL10, and CXCL11 in human keratinocytes.
abstract: IL-18 is involved in the pathogenesis of atopic dermatitis, psoriasis, and allergic contact dermatitis. CXCL9, CXCL10, and CXCL11 recruit type 1 T cells, and the production of these chemokines by keratinocytes is enhanced in these dermatoses. We examined the in vitro effects of IL-18 on IFN-gamma-induced CXCL9, CXCL10, and CXCL11 production in human keratinocytes. IL-18 enhanced the IFN-gamma-induced secretion and mRNA expression of CXCL9, CXCL10, and CXCL11 in parallel to the activation of NF-kappaB, STAT1, and IFN-regulatory factor (IRF)-1. Antisense oligonucleotides against NF-kappaB p50, p65, or STAT1 suppressed CXCL9, CXCL10, and CXCL11 production, and antisense IRF-1 suppressed CXCL11 production. Inhibitors of PI3 K, p38 MAPK, and MEK suppressed IL-18 plus IFN-gamma-induced CXCL9, CXCL10, and CXCL11 production and NF-kappaB, STAT1, and IRF-1 activities. IL-18 induced phosphorylation of ERK and Akt, while IFN-gamma induced phosphorylation of p38 MAPK. These results suggest that IL-18 may potentiate IFN-gamma-induced CXCL9, CXCL10, and CXCL11 production in keratinocytes by activating NF-kappaB, STAT1, or IRF-1 through PI3 K/Akt and MEK/ERK pathways. These effects of IL-18 may promote the infiltration of type 1 T cells into lesions with inflammatory dermatoses and amplify the skin inflammation. IL-18 may act as a pro-inflammatory cytokine in these dermatoses and thus is a candidate therapeutic target.
authors.affiliation: Department of Dermatology, Teikyo University School of Medicine, Tokyo, Japan. nmk@med.teikyo-u.ac.jp
authors.forename: Naoko
authors.initials: N
authors.lastname: Kanda
authors.forename: Teruo
authors.initials: T
authors.lastname: Shimizu
authors.forename: Yayoi
authors.initials: Y
authors.lastname: Tada
authors.forename: Shinichi
authors.initials: S
authors.lastname: Watanabe
mesh_terms: D002478:Cells, Cultured; D054357:Chemokine CXCL10; D054371:Chemokine CXCL11; D054370:Chemokine CXCL9; D019743:Chemokines, CXC / Q000276:immunology / Q000378:metabolism*; D004797:Enzyme-Linked Immunosorbent Assay; D005434:Flow Cytometry; D015870:Gene Expression; D006801:Humans; D050856:Interferon Regulatory Factor-1 / Q000276:immunology / Q000378:metabolism; D007371:Interferon-gamma / Q000276:immunology / Q000378:metabolism*; D020382:Interleukin-18 / Q000276:immunology / Q000378:metabolism*; D015603:Keratinocytes / Q000276:immunology / Q000378:metabolism*; D016328:NF-kappa B / Q000276:immunology / Q000378:metabolism; D012333:RNA, Messenger / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D050794:STAT1 Transcription Factor / Q000276:immunology / Q000378:metabolism; D015398:Signal Transduction / Q000276:immunology; D014162:Transfection; D015854:Up-Regulation
chemical_list: C515202:CXCL11 protein, human; C080810:CXCL9 protein, human; D054357:Chemokine CXCL10; D054371:Chemokine CXCL11; D054370:Chemokine CXCL9; D019743:Chemokines, CXC; C494257:IRF1 protein, human; D050856:Interferon Regulatory Factor-1; D020382:Interleukin-18; D016328:NF-kappa B; D012333:RNA, Messenger; D050794:STAT1 Transcription Factor; C494079:STAT1 protein, human; D007371:Interferon-gamma