EXPRESSION OF EPITHELIAL ADHESION PROTEINS AND INTEGRINS IN CHRONIC INFLAMMATION

Epithelial cell behavior in chronic inflammation is poorly characteriz ed During inflammation of tooth-supporting structures (periodontal dis ease), increased proliferation of epithelial cells into the inflamed c onnective tissue stroma is commonly seen. In some areas ulceration and degeneration take place, We studied alterations in the expression of adhesion molecules and integrins during chronic periodontal inflammati on In inflamed tissue, laminin-1 and type IV collagen were still prese nt in the basement membrane and surrounding blood vessels, but they we re also found extravascularly in inflamed connective tissue stroma. Ty pe VII collagen and laminin-5 (also known as kalinin, epiligrin, or ni cein) were poorly preserved in the basement membrane zone, but both we re found in unusual streak-like distributions in the subepithelial con nective tissue stroma in inflamed tissue. Both fibronectin and tenasci n were substantially decreased in chronically inflamed connective tiss ue, showing only punctate staining at the basement membrane zone, Inte grins of the beta 1 family showed two distinct staining patterns in ep ithelial cells during chronic inflammation;focal losses of beta 1 inte grins (alpha 2 beta 1 and alpha 3 beta 1) were found in most areas, wh ile in other areas the entire pocket epithelium was found to be strong ly positive for beta 1 integrins. No members of the alpha v, integrin family were found in any epithelia studied Expression of the alpha 6 b eta 4 integrin was high in basal cells of healthy tissue, but weak in epithelium associated with chronic inflammation. Chronic inflammation therefore involves alterations in both adhesion proteins and integrins expressed by epithelial cells, Basement membrane components found at abnormal sites in stroma in chronic inflammation might serve as new ad hesive ligands for various cell types in inflamed stroma.