IN-VITRO T-CELL RESPONSE TO STAPHYLOCOCCAL-ENTEROTOXIN-B SUPERANTIGENIN CHRONIC PLAQUE TYPE PSORIASIS

Recent studies have demonstrated the important role of CD4+ T cells in the pathophysiology of psoriasis, One of the current hypotheses is th at triggering of the psoriatic inflammatory process could be secondary to CD4+ T cell activation by bacterial superantigens in the skin, In this study, IL-2-derived T cell lines were recovered from the blood an d the skin of 4 patients with chronic plaque type psoriasis and of 2 p atients with allergic contact dermatitis (ACD). Blood and skin T cell lines were tested for their ability to proliferate in vitro to staphyl ococcal enterotoxin B (SEE) presented by MHC class Ii expressing antig en-presenting cells, The results showed a significantly higher SEE-ind uced T cell proliferation in skin T cell lines as compared to blood T cell lines in 3 out of 4 psoriatic patients and in one of the 2 ACD pa tients, No difference between the skin and blood T cells for their res ponse to phytohemagglutinin was observed, Furthermore the blood T cell lines from both patients and control individuals responded equally we ll to SEE. Thus psoriatic skin T cell lines were characterized by an e nrichment in SEE-responding T cells. Since similar enhancement of SEE- responsive T cells was occasionally found in ACD patients, we propose that SEE could be an environmental factor associated with rather than responsible for psoriatic inflammation.