title: Elevated interleukin-18 protein expression in early active and progressive plaque-type psoriatic lesions.
abstract: Psoriasis is a T cell-mediated inflammatory skin disease characterized by an elevated IFN-gamma and IL-12p70 expression in skin lesions. Interleukin-18 (IL-18) synergizes with IL-12 to induce IFN-gamma production and a strong T-helper-1-mediated immune response, or to induce Th2 polarization depending on the immunological context. We have previously shown that keratinocytes in normal skin produce and store large amounts of pro-IL-18. In this study, we hypothesized that the expression of IL-18 in psoriatic lesional skin might be altered compared to normal skin. Therefore, IL-18 expression was assessed in psoriatic, stable, plaque-type lesions and early active and progressive lesions. IL-18 mRNA and protein concentrations were constitutively high, and did not differ between normal and stable, plaque-type epidermis. In active and progressive lesions an elevated expression of total IL-18 protein relative to normal and stable, plaque-type epidermis was detected using ELISA, while on Western blot, the differences in pro- or mature IL-18 were less clear. Our results indicate that the role of IL-18 in the pathogenesis of early phases of psoriasis may be more prominent than in established psoriatic lesions.
authors.affiliation: Department of Immunology, Erasmus MC, Rotterdam, The Netherlands.
authors.forename: Arjen
authors.initials: A
authors.lastname: Companjen
authors.forename: Leontine
authors.initials: L
authors.lastname: van der Wel
authors.forename: Leslie
authors.initials: L
authors.lastname: van der Fits
authors.forename: Jon
authors.initials: J
authors.lastname: Laman
authors.forename: Errol
authors.initials: E
authors.lastname: Prens
mesh_terms: D015153:Blotting, Western; D017931:DNA Primers; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D007150:Immunohistochemistry; D020382:Interleukin-18 / Q000235:genetics / Q000378:metabolism*; D011565:Psoriasis / Q000276:immunology / Q000378:metabolism* / Q000473:pathology; D012333:RNA, Messenger / Q000235:genetics; D012867:Skin / Q000378:metabolism
chemical_list: D017931:DNA Primers; D020382:Interleukin-18; D012333:RNA, Messenger