Culture and characterization of human junctional epithelial cells

This study was undertaken to establish a culture of junctional epithelial cells derived from gingival tissue attached to the tooth surface and to characterize these cells immunocytochemically and ultrastructurally. Primary cultures of cells were obtained from the junctional tissue explanted on type I collagen-coated dishes and immersed in Dulbecco's modified Eagle's medium containing 10% fetal bovine serum (FBS). Cells were subcultured with conditioned serum-free keratinocyte medium (keratinocyte-SFM + 5% FBS) on dishes coated with solubilized extract of the basement membrane. After 24 hours, the medium was changed to keratinocyte-SFM (0.09 mM Ca2+). The cell-doubling time was 40.5 hours. As a control, cells from gingival tissue were cultured by the same method. Cells from junctional tissue and gingival tissue were compared immunocytochemically using monoclonal antibodies to keratin, vimentin, and desmoplakins I and II and using Dolichos biflorus agglutinin (DBA). The keratin AE1 and AE3 was expressed by all of culture cells. The vimentin (specific for the intermediate filament of mesenchymal cells) was also expressed by all cells. The expression pattern of keratin 19 was observed not only by cells from junctional tissue but also by cells from gingival tissue. All keratin peptides were expressed in both cells. However, DBA reacted only with cells from the junctional tissue. Anti-desmoplakin I and II reacted with both cells, however, the staining patterns differed. DBA-positive cultured epithelial cells from the junctional tissue showed poor tonofilament bundles and were rich in cytoplasmic organelles. These findings suggest that junctional epithelial cells can be isolated from junctional tissue and cultured under improved conditions.