EPITHELIAL-CELLS AS REGULATORS OF AIRWAY INFLAMMATION

The past decade has seen major advances in our understanding of the me tabolic and biochemical functions of the epithelial cell. As a result, the traditional view of the epithelium as a relatively passive physic al barrier to the external environment has been superseded by the conc ept that the epithelial cell plays a key role in regulating airway inf lammation, The epithelial cell exerts this modulatory effect in severa l ways, Epithelial cells can function to maintain mucosal integrity an d to modulate local immune responses. They can also limit inflammatory processes by degrading, or inhibiting, proinflammatory mediators and proteins. However, the epithelium also responds to a range of stimuli by producing biologically active mediators that can influence airway i nflammation. These include, but are not limited to, a broad range of c ytokines and chemokines that can exert profound effects on inflammator y cells, as well as lipid and peptide mediators. This review will high light some of these aspects of the role of the epithelium in regulatin g airway inflammation.