HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via CrossRef Citing Articles via Google Scholar Google Scholar Articles by Kang, P. Articles by DiRienzo, J. M Search for Related Content PubMed PubMed Citation Articles by Kang, P. Articles by DiRienzo, J. M Agricola Articles by Kang, P. Articles by DiRienzo, J. M

Differential effect of the cytolethal distending toxin of Actinobacillus actinomycetemcomitans on co-cultures of human oral cells

Philip Kang¹, Jonathan Korostoff¹, Alla Volgina², Wojciech Grzesik³ and Joseph M DiRienzo²

Departments of Periodontics¹, Microbiology² and Anatomy & Cell Biology³, School of Dental Medicine, University of Pennsylvania, 240 South 40th Street, Philadelphia, PA, USA

Correspondence Joseph M. DiRienzo dirienzo{at}pobox.upenn.edu

Received March 7, 2005
Accepted April 4, 2005

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.

Abbreviations: CDT, cytolethal distending toxin; HPLF, human periodontal ligament fibroblast; PDL, periodontal ligament; SV40, simian virus 40; TD₅₀, toxic dose₅₀.