Quantification and localization of HLA-DR and intercellular adhesion molecule-1 (ICAM-1) molecules on bronchial epithelial cells of asthmatics using confocal microscopy.

An increased expression of HLA-DR and ICAM-1 molecules on bronchial epithelial cells has been observed in asthmatic patients. The aim of this study was to evaluate the localization and to quantify the spontaneous expression of HLA-DR and ICAM-1 on bronchial epithelial cells recovered by bronchial brushing of nine asthmatics and nine controls. Epithelial cells constituted over 95% of cells recovered as shown using an anti-cytokeratin MoAb. Expression of HLA-DR and ICAM-1 was studied using indirect immunofluorescence and confocal microscopy. The intensity of fluorescence of epithelial cells expressing HLA-DR and ICAM-1 was significantly (P < 0.003) increased in asthmatics. In asthmatics, but not in controls, the expression of both molecules was localized in the cytoplasm on the apicolateral portions of the cells. This study shows an up-regulation in the expression of HLA-DR and ICAM-1 molecules by bronchial epithelial cells from asthmatics and a localization of these molecules within the cell.