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Updated: Jul 10, 2026

Porphyromonas gingivalis as a Model Organism for Assessing Interaction of Anaerobic Bacteria with Host Cells
Published on: December 17, 2015
Possible requirement of intercellular adhesion molecule-1 for invasion of gingival epithelial cells by Treponema
Riyoko Tamai1, Yasuyuki Asai, Atsushi Kawabata
1Department of Oral Microbiology, Asahi University School of Dentistry, 1851-1 Hozumi, Mizuho, Gifu 501-0296, Japan.
Abstract:
Oral treponemes are members of the spirochete family of bacteria associated with periodontal diseases. In the present study, we demonstrate that intercellular adhesion molecule-1 (ICAM-1) on human gingival epithelial cells (HGEC) contributed to the invasion of Treponema medium, a medium-sized oral Treponema, into those cells. The quantity of T. medium in HGEC was found to peak at 2 h after inoculation and then decreased gradually. Immunofluorescence microscopy findings showed that the bacteria were colocalized with ICAM-1 on HGEC. Furthermore, knockdown of ICAM-1 in HGEC resulted in inhibition of T. medium invasion by RNA interference, whereas that of Toll-like receptor 2 did not. These results suggest that ICAM-1 may be required for the invasion of T. medium into HGEC, and they indicate that the molecule plays a principal role in the primary stages of the development and progression of chronic periodontitis.
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