TWEAK mediates inflammation in experimental atopic dermatitis and psoriasis

Atopic dermatitis and psoriasis are driven by alternate type 2 and type 17 immune responses, but some proteins might be critical to both diseases. We show that a deficiency of the TNF superfamily molecule TWEAK (TNFSF12) in mice results in defective maintenance of atopic dermatitis-specific Th2 and psoriasis-specific Th17 cells in the skin, and impaired expression of disease-characteristic chemokines and cytokines, such as CCL17 and TSLP in atopic dermatitis, and CCL20 and IL-19 in psoriasis. The TWEAK receptor, Fn14, is upregulated in keratinocytes and dermal fibroblasts, and TWEAK induces these cytokines and chemokines alone and in synergy with the signature T helper cytokines of either disease, IL-13 and IL-17. Furthermore, subcutaneous injection of recombinant TWEAK into naïve mice induces cutaneous inflammation with histological and molecular signs of both diseases. TWEAK is therefore a critical contributor to skin inflammation and a possible therapeutic target in atopic dermatitis and psoriasis. Overall design: Eight- to 12-week old male mice were used. TWEAK-deficient animals were bred in house on the C57BL/6 background, and Fn14-deficient animals on a BALB/c. Atopic Dermatitis-like disease was induced by epicutaneous treatment with HDM extract (10 µg/mouse and treatment) and SEB (500 ng/mouse and treatment) given in 2 cycles on days 1 and 4, and 14 and 17, on the shaved and tape-stripped back skin over a 23 day period.

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Sidler D, Wu P, Herro R, Claus M, Wolf D, Kawakami Y, Kawakami T, Burkly L, Croft M