Interactions of Porphyromonas gingivalis with epithelial cells.

The invasion of gingival epithelial cells by certain pathogenic periodontal bacteria may account for their presence within diseased gingival tissue. To dissect the initial steps of a potential invasion pathway for the periodontal pathogen Porphyromonas gingivalis, laboratory and clinical bacterial isolates were tested for their interactions with a human oral epithelial cell line (KB). Several P. gingivalis strains immobilized on filters could bind oral epithelial cells. Quantitative adherence assays supported these results. The invasion of epithelial cells by P. gingivalis 33277 was measured by assay and confirmed by transmission electron microscopy. These preliminary results demonstrate that certain P. gingivalis strains are capable of internalization by human oral epithelial cells in vitro.