INACTIVATION OF THE INTEGRIN BETA-6 SUBUNIT GENE REVEALS A ROLE OF EPITHELIAL INTEGRINS IN REGULATING INFLAMMATION IN THE LUNGS AND SKIN

The integrin alpha v beta 6 is only expressed in epithelial cells. In healthy adult epithelia, this receptor is barely detectable, but expre ssion is rapidly induced following epithelial injury. Mice homozygous for a null mutation in the gene encoding the beta 6 subunit had juveni le baldness associated with infiltration of macrophages into the skin, and accumulated activated lymphocytes around conducting airways in th e lungs. beta 6(-/-) mice also demonstrated airway hyperresponsiveness to acetylcholine, a hallmark feature of asthma. These results suggest that the epithelial integrin alpha v beta 6 participates in the modul ation of epithelial inflammation. Genetic or acquired alterations in t his integrin could thus contribute to the development of inflammatory diseases of epithelial organs, such as the lungs and skin.