CORNEAL EPITHELIAL-CELL ATTACHMENT WITH ENDOGENOUS LAMININ AND FIBRONECTIN

Purpose. To evaluate the role of endogenously produced laminin and fib ronectin as well as the effect of exogenous laminin and fibronectin in the attachment of human corneal epithelial cells in vitro. Methods. P rimary cultured human corneal epithelial cells labeled with H-3-thymid ine were seeded onto plates coated with laminin or fibronectin, or ont o uncoated bacteriologic plates. Attachment of cells was measured in t he presence or absence of antisera against laminin or fibronectin, by counting radioactivity. Results. Human corneal epithelial cells attach ed to plates coated with human laminin or human fibronectin in a dose- dependent manner, with 69% and 50% of cells attached to the wells coat ed with 40 mug/ml of laminin and fibronectin, respectively (P < 0.001) . The percentage of attachment to uncoated bacteriologic plates increa sed from 1.2% at 45 min of incubation to 6.7% at 90 min, 22.2% at 3 hr , and 40.1% at 6 hr of incubation. Cycloheximide, a protein synthesis inhibitor, completely inhibited cell attachment. Rabbit antiserum agai nst human fibronectin reduced cell attachment to the uncoated plates t o 67% of the control value (P < 0.01), whereas rabbit antiserum agains t human laminin decreased the attachment to 52% of the control (P < 0. 01). A combination of these two antisera reduced cell attachment to 46 % of the control (P < 0.01). Conclusions. Endogenous laminin and fibro nectin as well as exogenous laminin and fibronectin play significant r oles in the attachment of human corneal epithelial cells in culture.