[Role of adhesion molecules in bronchial inflammation and bronchial hyperreactivity]

Adhesion molecules are glycoproteins situated in the cell membrane. These molecules permit cells to integrate specifically with the specific cellular receptors or ligands and with the extracellular matrix during intra-tissular migration. Structurally, 4 large families can be distinguished: the immunoglobulin family, the integrins, the selectines, and finally the cadherines. The results of preliminary studies in man seem to confirm those obtained in vivo and in vitro in animals. The in vitro studies have shown that overall the inflammatory cells, such as the eosinophils as well as the endothelial and epithelial cells have many adhesion molecules, the regulation of which is dependent on many cytokinetic mediators, such as interleukin 1 beta (IA-1 beta), tumour necrosis factor (TNF alpha) and interleukin 4 (IL4). In man, it has been observed that there is a significant increase in TNF alpha in the bronchial mucosae of asthmatics. Together, the experimental studies have shown the crucial role of adhesion molecules in specific recruitment and their regulation by cytokines in the physiopathology of bronchial inflammation and hyper-reactivity that are characteristic of asthmatic disease.