title: Expression of interferon-gamma receptors in normal and psoriatic skin.
abstract: Psoriatic keratinocytes have a reduced antiproliferative response to interferon (IFN)-gamma, and HLA-DR expression is usually not observed on keratinocytes in psoriatic plaques despite the presence of activated T cells. We have therefore compared the expression of IFN-gamma receptors in psoriatic skin with that of normal human skin. Using mouse monoclonal antibodies and immunoperoxidase staining on cryostat cut sections, we detected IFN-gamma receptors on keratinocytes throughout the epidermal layers except stratum corneum in normal skin (n = 11). Biopsy specimens from involved psoriatic skin (n = 17) consistently showed a staining pattern that differed from that of normal skin in that only the lower part of epidermis reacted with the antibodies to IFN-gamma receptors, whereas the upper layers showed no or minimal staining. Expression of IFN-gamma receptors in uninvolved psoriatic skin (n = 16) did not differ from that of healthy controls. Forty-five percent of the biopsies from lesional psoriatic skin displayed ICAM-1 positive keratinocytes, and only two specimens had a limited expression of HLA-DR reactive keratinocytes. The decreased binding of antibodies against the IFN-gamma receptors in the upper part of psoriatic epidermis might be secondary to abnormal maturation of psoriatic keratinocytes or a primary defect involving abnormal modulation of IFN-gamma receptors.
authors.affiliation: Department of Clinical Immunology, Karolinska Hospital, Stockholm, Sweden.
authors.forename: A
authors.initials: A
authors.lastname: Scheynius
authors.forename: J
authors.initials: J
authors.lastname: Fransson
authors.forename: C
authors.initials: C
authors.lastname: Johansson
authors.forename: H
authors.initials: H
authors.lastname: Hammar
authors.forename: B
authors.initials: B
authors.lastname: Baker
authors.forename: L
authors.initials: L
authors.lastname: Fry
authors.forename: H
authors.initials: H
authors.lastname: Valdimarsson
mesh_terms: D000328:Adult; D001706:Biopsy; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011565:Psoriasis / Q000473:pathology*; D011971:Receptors, Immunologic / Q000502:physiology*; D017471:Receptors, Interferon; D012867:Skin / Q000648:ultrastructure*
chemical_list: D011971:Receptors, Immunologic; D017471:Receptors, Interferon