UP-REGULATION OF ICAM-1 EXPRESSION ON HUMAN DERMAL FIBROBLASTS BY IFN-BETA IN THE PRESENCE OF TNF-ALPHA

Unstimulated human fibroblasts show low or undetectable ICAM-1 express ion. Interferon-beta (IFN-beta) at concentrations of 10, 100, and 1000 IU/ml in the presence of tumor necrosis factor-alpha (TNF-alpha) sign ificantly increased the ICAM-1 expression of fibroblasts in a dose-dep endent manner. Treatment with IFN-beta alone, however, did not up-regu late the ICAM-1 expression. Furthermore the attachment of peripheral b lood mononuclear cells (PBMCs) to cytokine-treated fibroblasts was inc reased. This augmented attachment was partly inhibited by anti-ICAM-1 antibody. These results suggest that IFN-beta and TNF-alpha may cooper atively modulate the attachment of PBMCs in the dermis.