THE INTERLEUKIN-8 RECEPTOR - A POTENTIAL TARGET FOR ANTIPSORIATIC THERAPY

Interleukin-8 is assumed to play a central role in the pathogenesis of psoriasis. Since an increased expression of the interleukin-8 recepto r has been observed both in polymorphonuclear leukocytes and in affect ed psoriatic epidermis, we were interested in whether the interleukin- 8 receptor could be a molecular target of antipsoriatic compounds. Cyc losporine, calcitriol, calcipotriol or dithranol caused a dose-depende nt decrease in interleukin-8 binding to cultured human keratinocytes, while interleukin-8 binding to granulocytes was not affected. In addit ion, the interleukin-8-induced human leukocyte antigen-DR (HLA-DR) exp ression of keratinocytes was nearly completely blocked by treatment of the cells with these substances. The inhibition of the keratinocyte i nterleukin-8 receptor and its function by antipsoriatic drugs may cont ribute to their therapeutic action.