INTEGRINS IN HUMAN CORNEAL EPITHELIUM

Monoclonal antibodies (Mabs) were used for immunohistochemical location of integrin beta- (beta-1,3, and 4) and alpha subunits (alpha-1-6 and alpha-v) in the epithelium of both normal and tissue-cultured human cornea. Immunoreaction for the beta-1 integrin subunit was the most intense at the membranes of the basal epithelial cells and weaker at the superficial cell membranes. Anti-beta-4 immunofluorescence appeared in the basal part of the epithelium only, apposing the basement membrane. Both anti-alpha-2 and anti-beta-3 Mabs showed an immunoreaction with distribution similar to the beta-1 integrin subunit. Immunoreaction for the alpha-6 integrin subunit resembled the distribution of the beta-4 subunit. Anti-alpha-v showed a faint immunoreaction at the basal and lateral aspects of the basal cell layer. Antisera against beta-3, alpha-1, alpha-4, and alpha-5 integrin subunits showed no specific reactions. The present results suggest that both the normal and tissue-cultured human corneal epithelium contain alpha-2-beta-1, alpha-3-beta-1, and probably also alpha-v-beta-1 and alpha-6-beta-4 integrin dimers or complexes. We discuss their role as possible receptors for some known ligands.