Recent studies suggest that interleukin (IL)-8 exerts a direct influence on several functions such as the chemotaxis or proliferation of human keratinocytes (HK). Since the effects of IL-8 in skin are mediated through specific receptors, we have studied the characteristics of the keratinocyte IL-8 receptor. We could identify specific binding sites for IL-8 in cultured HKs by flow cytometry. Pretreatment of the cells with tumor necrosis factor (TNF)-alpha or IL-1 alpha resulted in a significant increase in IL-8 binding. IL-8 selectively induced expression of HLA-DR antigen, but had no effect on the expression of other cell surface antigens (CD11a, CD18, CD36 and CD54).