IN-VITRO CYTOKINE MODULATION OF INTERCELLULAR-ADHESION MOLECULE-1 EXPRESSION ON SYSTEMIC-SCLEROSIS NORMAL DERMAL FIBROBLASTS

Our objective was to study the regulation of intercellular adhesion mo lecule-1 (ICAM-1) expression by cytokines on cultured fibroblasts obta ined from systemic sclerosis and normal skin. ICAM-1 expression on der mal fibroblasts obtained from diffuse systemic sclerosis patients with early disease(less than or equal to 2 years) and normal dermal fibrob lasts incubated with and without cytokines was measured by radioimmuno assay and flow cytometry. Systemic sclerosis dermal fibroblasts expres sed lower basal levels of ICAM-1 than did normal dermal fibroblasts. B oth the normal and systemic sclerosis dermal fibroblasts increased the ir cell surface expression of ICAM-1 in response to interleukin-1 beta (IL 1 beta), tumor necrosis factor-alpha (TNF-alpha), and interferon- gamma(IFN-gamma) in a dose-dependent fashion. Systemic sclerosis derma l fibroblasts appeared to be hyperresponsive to IL-1 beta, TNF-alpha, and IFN-gamma. ICAM-1 expression in response to cytokine stimulation i ncreased to a greater degree on systemic sclerosis compared to normal dermal fibroblasts. The enhanced ICAM-1 expression may play a role in the retention of leukocytes involved in systemic sclerosis skin lesion s.