RT Journal Article SR Electronic(1) A1 KATO, SATSUKI A1 NAKASHIMA, KEISUKE A1 INOUE, MAKI A1 TOMIOKA, JUN A1 NONAKA, KOJI A1 NISHIHARA, TATSUJI A1 KOWASHI, YUSUKEYR 2000 T1 Human epithelial cell death caused by Actinobacillus actinomycetemcomitans infection JF Journal of Medical Microbiology, VO 49 IS 8 SP 739 OP 745 DO https://doi.org/10.1099/0022-1317-49-8-739 PB Microbiology Society, SN 1473-5644, AB The gingival sulcus is the shallow crevice around the tooth, and its epithelium is a gateway for initial bacterial infection in periodontal disease. Recent studies have shown that Actinobacillus actinomycetemcomitans invades an epithelial cell line, KB cells, in vitro. The aim of the present study was to clarify the changes in KB cells after A. actinomycetemcomitans infection. The cytotoxic effects of A. actinomycetemcomitans on KB cells were determined at 72, 96 and 120 h after infection by an MTT assay. Nuclear morphological changes were observed by staining with Hoechst 33258. Cytoplasmic histone-associated DNA fragmentation in the infected KB cells was determined by ELISA. A. actinomycetemcomitans was cytotoxic on KB cells, and condensation and degradation of the nuclei were observed. DNA fragmentation was increased after the infection. In addition, A. actinomycetemcomitans showed similar cytotoxic effects on human gingival epithelial cells. The present study demonstrated that A. actinomycetemcomitans induces apoptotic cell death of oral epithelial cells in an in-vitro culture system. This induced apoptosis might be involved in the initiation and progression of periodontitis. , UL https://www.microbiologyresearch.org/content/journal/jmm/10.1099/0022-1317-49-8-739