Epithelial damage in the airways is a feature often observed in patients with asthma and is probably caused by the interaction of epithelial cells with leukocytes. As adhesion molecules are thought to be important in this interaction, we analyzed the expression and modulation of adhesion molecules on primary cultured human bronchial epithelial cells and the bronchial epithelial cell lines BEAS-2B and NCI-H292. E-selectin, P-selectin, and VCAM-1 were absent under basal and stimulated conditions. The adhesion molecules ICAM-1 (CD54), LFA-3 (CD58), and CD44 (H-CAM) were expressed basally on primary cultured human bronchial epithelial cells and the BEAS-2B and NCI-H292 cell lines. CD44 and LFA-3 expression did not change after stimulation with IFN-gamma or TNF-alpha. In contrast, ICAM-1 expression on human bronchial epithelial cells and BEAS-2B cells could be increased by incubation with PMA, IFN-gamma, TNF-alpha, and especially with the combination of IFN-gamma and TNF-alpha. The maximal ICAM-1 expression on both epithelial cell types was obtained with the combination of TNF-alpha and IFN-gamma after 48 h of incubation. The NCI-H292 cell line was different in that it only showed increased ICAM-1 expression after stimulation with PMA and IFN-gamma and not by the combination of IFN-gamma and TNF-alpha or with TNF-alpha alone. In conclusion, the bronchial epithelial cells tested express several adhesion molecules, but only ICAM-1 expression was influenced by inflammatory cytokines.