title: T cells in psoriatic lesional skin that survive conventional therapy with NB-UVB radiation display reduced IFN-gamma expression.
abstract: The type 1 T cell-derived cytokine interferon gamma (IFN-gamma) is overexpressed in psoriatic lesional skin. Recently, we have shown that a single high erythemal dose of broad-band ultraviolet B (UVB) irradiation reduces type 1 and favors type 2, i.e. interleukin-4 (IL-4), cytokine expression in normal and psoriatic skin. In this study, we wanted to see whether conventional narrow-band UVB (NB-UVB) therapy (i.e. repeated exposure to nonerythemal doses) also affects type 1/type 2 cytokine expression of T cells present in chronic plaque type psoriatic lesions. Staining of cryostat sections showed decreased expression of both IFN-gamma and IL-4 in situ after NB-UVB therapy. CD4(+) dermal T cell lines, derived from psoriatic lesional skin, displayed significantly decreased intracellular IFN-gamma expression during and after NB-UVB therapy as compared to pretreatment values. Intracellular IL-4 expression was increased in most patients after therapy. Analysis of the supernatants of these stimulated dermal T cells revealed that IFN-gamma production decreased significantly following NB-UVB therapy, whereas IL-4 expression increased in the T cell supernatants from most patients, confirming the intracellular determinations. In addition, IL-10 and transforming growth factor-beta levels in the supernatants appeared to be increased in the majority of patients following UVB therapy. Apart from the well-known killing effect of UVB on T cells, our results show that the improvement in psoriatic skin following NB-UVB therapy is also due to a reduced capacity of the surviving dermal T cells to express the proinflammatory cytokine IFN-gamma.
authors.affiliation: Department of Dermatology, Academic Medical Center, University of Amsterdam, Room L3-365, P.O. Box 22700, 1100 DE Amsterdam, The Netherlands. g.piskin@amc.uva.nl
authors.forename: Gamze
authors.initials: G
authors.lastname: Piskin
authors.forename: Regien M R
authors.initials: RM
authors.lastname: Sylva-Steenland
authors.forename: Jan D
authors.initials: JD
authors.lastname: Bos
authors.forename: Marcel B M
authors.initials: MB
authors.lastname: Teunissen
mesh_terms: D006801:Humans; D007371:Interferon-gamma / Q000096:biosynthesis*; D015847:Interleukin-4 / Q000096:biosynthesis; D011565:Psoriasis / Q000276:immunology / Q000532:radiotherapy*; D012867:Skin / Q000276:immunology / Q000528:radiation effects; D013601:T-Lymphocytes / Q000276:immunology*; D014467:Ultraviolet Therapy
chemical_list: D015847:Interleukin-4; D007371:Interferon-gamma