Mechanisms of Cell-to-Cell and Cell-to-Substrate Adhesion of Human Epithelial, Chang Conjunctiva Cells

The adhesive property was studied of Chang conjunctiva cells of human epithelial line. Cells dissociated with only EDTA aggregated in Ca2+-free and Mg2+-free conditions, whereas cells dissociated by trypsin did not aggregate under the same conditions. Cells dissociated with trypsin solution containing Ca2+ aggregated in the presence of Ca2+ and/or Mg2+. Cells dis-sociated by trypsin without Ca2+ showed less aggregation in the presence of divalent cations. In cases of cell adhesion to non-cellular substrates, the particular method of cell dissociation did not produce different results. Only a small fraction of inoculated cells attached onto plastic coated with bovine serum albumin or gelation. Many inoculated cells attached rapidly and spread onto plastic coated with collagen, when Mg2+ was present in the medium. These results were discussed with the hypothesis that Ca2+ and Mg2+ act differently in cell adhesion.