THE EXPRESSION OF INTERLEUKIN-8 RECEPTOR IN UNTREATED AND TREATED PSORIASIS

The expression of IL-8 in psoriasis has been clearly shown with the us e of immunocytochemical, RT-PCR and in situ hybridization methods. The presence of its ligand, the IL-8 receptor, has been demonstrated by t he RT-PCR technique. We report here a study of;he expression of both I L-8 type A and B receptors by immunohistochemical techniques, using on e polyclonal and four monoclonal antibodies. By this technique, me fou nd that the neutrophilic granulocytes express the IL-8 type A receptor , whereas the IL-8 type B receptor was present on the keratinocytes. T he type B receptor on the keratinocytes was localized in the suprabasa l layers of the epidermis. Following therapy the expression of the IL- 8 type B receptor on the keratinocytes was reduced. This could suggest that IL-8 in psoriasis is involved in the disturbed differentiation r ather than in proliferation, probably via an autocrine loop.