INDUCTION OF PSORIASIFORM INFLAMMATION BY A BACTERIAL SUPERANTIGEN INTHE SCID-HU XENOGENEIC TRANSPLANTATION MODEL

Psoriasis is a chronic skin disease affecting about 2% of the Caucasia n population, characterized by co-existing inflammation and epidermal hyperproliferation. A T-Iymphocyte-mediated autoimmune reaction induce d by bacterial superantigens might be central in its pathogenesis. To model psoriasiform inflammation, we transplanted clinically uninvolved skin from psoriatic patients onto SCID mice. Repetitive intradermal i njections with a bacterial superantigen and simultaneous intraperitone al injections with the patients' superantigen-stimulated peripheral mo nonuclear blood cells resulted in an inflammatory reaction exhibiting some of the hallmarks of psoriasis, e.g. epidermal hyperproliferation, papillomatosis, focal neo-expression of ICAM-1, and an exocytotic T-l ymphocytic infiltrate characterized by the expression of the cutaneous lymphocyte-associated antigen. These observations document the potent ial of superantigens to trigger psoriasiform dermatitis and provide a model to study lymphocyte homing. (C) Munksgaard 1997.