role for T cell-derived interleukin 22 in psoriatic skin inflammation

• Published in: Clinical and experimental immunology Vol. 150; no. 3; pp. 407 - 415
• Main Authors: Boniface, K, Guignouard, E, Pedretti, N, Garcia, M, Delwail, A, Bernard, F.-X, Nau, F, Guillet, G, Dagregorio, G, Yssel, H, Lecron, J.-C, Morel, F
• Format: Journal Article
• Language: English
• Published: Oxford, UK Oxford, UK : Blackwell Publishing Ltd 01.12.2007; Blackwell Publishing Ltd; Blackwell; Wiley; Blackwell Science Inc
• Subjects: Adaptive immunology; Adult; Aged; Aged, 80 and over; Analytical, structural and metabolic biochemistry; Biochemistry; Biochemistry, Molecular Biology; Biological and medical sciences; Cells, Cultured; cytokines; Dermatology; Female; Fundamental and applied biological sciences. Psychology; Gene Expression Profiling - methods; Human health and pathology; Humans; Immunology; inflammation; Inflammation Mediators - metabolism; Innate immunity; Interleukin-22; Interleukins - biosynthesis; Interleukins - genetics; Interleukins - immunology; Keratinocytes - immunology; Life Sciences; Male; Middle Aged; Molecular and cellular biology; Molecular biophysics; psoriasis; Psoriasis - immunology; Receptors, Interleukin - metabolism; Reverse Transcriptase Polymerase Chain Reaction - methods; RNA, Messenger - genetics; Skin - immunology; skin disease; T cells; T-lymphocytes; T-Lymphocytes - immunology; Translational Studies; Up-Regulation; Skin disease; Psoriasis; Cytokine; T-Lymphocyte; Interleukin 22; Biochemistry; Inflammation; Skin; cytokines; Biophysics; Molecular biology; T cells
• ISSN: 0009-9104; 1365-2249
• DOI: 10.1111/j.1365-2249.2007.03511.x

Interleukin (IL)-22 is a T cell-derived cytokine that has been reported recently to induce cutaneous inflammation in an experimental murine model of psoriasis, and to induce in vitro an inflammatory-like phenotype. In the present study, we assessed the presence of IL-22 and the IL-22 receptor 1 (IL-22R1) in skin lesions, skin-derived T cells, as well as IL-22 levels in sera from patients with psoriasis. IL-22R1 and IL-10R2 transcripts are expressed at a similar level in psoriatic and healthy skin. In contrast, IL-22 mRNA expression was up-regulated in psoriatic skin lesions compared to normal skin, whereas IL-22 mRNA levels in peripheral blood mononuclear cells from psoriatic patients and normal subjects were similar. Circulating IL-22 levels were significantly higher in psoriatic patients than in normal subjects. T cells isolated from psoriatic skin produced higher levels of IL-22 in comparison to peripheral T cells isolated from the same patients. IL-10 was expressed at similar levels in skin biopsies and peripheral blood mononuclear cells of psoriatic patients and normal subjects. Finally, we show here that supernatants of lesional psoriatic skin-infiltrating T cells induce an inflammatory response by normal human epidermal keratinocytes, resembling that observed in psoriatic lesions. Taken together, the results reported in this study indicate that IL-22 is a cytokine produced by skin-infiltrating lymphocytes that is potentially involved in initiation and/or maintenance of the pathogenesis of psoriasis.