Integrins in Human Corneal Epithelium

Monoclonal antibodies (Mabs) were used for immunohistochemical location of integrin β- (β1.3- and 4) and a subunits (α1_6 and αv) in the epithelium of both normal and tissue-cultured human cornea. Immunoreaction for the p, integrin subunit was the most intense at the membranes of the basal epithelial cells and weaker at the superficial cell membranes. Anti-β4 immunofluorescence appeared in the basal part of the epithelium only, apposing the basement membrane. Both anti-α2 and anti-α3 Mabs showed an immunoreaction with distribution similar to the β1 integrin subunit. Immunoreaction for the α6 integrin subunit resembled the distribution of the β4 subunit. Anti-αv showed a faint immunoreaction at the basal and lateral aspects of the basal cell layer. Antisera against β3, α1, α4, and α5 integrin subunits showed no specific reactions. The present results suggest that both the normal and tissue- cultured human corneal epithelium contain α2β1, α3β1, and probably also αvβ1, and α6β4 integrin dimers or complexes. We discuss their role as possible receptors for some known ligands.