Differential effect of the cytolethal distending toxin of Actinobacillus actinomycetemcomitans on co-cultures of human oral cells.
The periodontal pathogen Actinobacillus actinomycetemcomitans expresses a cytolethal distending toxin (CDT) that typically arrests the growth of eukaryotic cells at either the G0/G1 or G2/M phase of the cell cycle. It was previously found that CDT failed to arrest the growth of human periodontal ligament fibroblasts (HPLFs) when grown in pure culture. In contrast, proliferation of an oral epithelial cell line was rapidly inhibited by the toxin. In this study, the feasibility of using mixed-cell cultures and cell-specific markers to evaluate the response of oral cells, when in heterogeneous populations, to CDT was established. Proliferation of epithelial cells was rapidly inhibited and the cells were selectively eliminated in co-culture with HPLFs or cementoblasts by 24-48 h post-intoxication. Epithelial cells and HPLFs were detected and counted in co-cultures following cell-specific immunolabelling with antibodies against simian virus 40 large T antigen and the Ab-1 surface antigen, respectively. These results demonstrated that the activities of potential virulence factors, such as CDT, from periodontal pathogens can be successfully examined in mixed-cell cultures. This approach is especially relevant to infectious diseases that affect tissues with a diverse cellular composition, such as the periodontium.
Kang
Philip
P
Departments of Periodontics1, Microbiology2 and Anatomy & Cell Biology3, School of Dental Medicine, University of Pennsylvania, 240 South 40th Street, Philadelphia, PA, USA.
Korostoff
Jonathan
J
Departments of Periodontics1, Microbiology2 and Anatomy & Cell Biology3, School of Dental Medicine, University of Pennsylvania, 240 South 40th Street, Philadelphia, PA, USA.
Volgina
Alla
A
Departments of Periodontics1, Microbiology2 and Anatomy & Cell Biology3, School of Dental Medicine, University of Pennsylvania, 240 South 40th Street, Philadelphia, PA, USA.
Grzesik
Wojciech
W
Departments of Periodontics1, Microbiology2 and Anatomy & Cell Biology3, School of Dental Medicine, University of Pennsylvania, 240 South 40th Street, Philadelphia, PA, USA.
DiRienzo
Joseph M
JM
Departments of Periodontics1, Microbiology2 and Anatomy & Cell Biology3, School of Dental Medicine, University of Pennsylvania, 240 South 40th Street, Philadelphia, PA, USA.
D016976:Aggregatibacter actinomycetemcomitans / Q000737:chemistry* / Q000502:physiology; D001427:Bacterial Toxins / Q000633:toxicity*; D002455:Cell Division / Q000187:drug effects*; D002460:Cell Line; D004847:Epithelial Cells / Q000166:cytology / Q000187:drug effects*; D005347:Fibroblasts / Q000166:cytology / Q000187:drug effects*; D005881:Gingiva / Q000166:cytology*; D006801:Humans; D010513:Periodontal Ligament / Q000166:cytology*
D001427:Bacterial Toxins; C067044:cytolethal distending toxin