Action of bacterial extracts from Aggregatibacter actinomycetemcomitans in the production of IL-6 and IL-8 by human gingival fibroblasts
Abstract number: P730
Gonzalez O., Roa N., Valdivieso C., Gamboa F.
Objective: Periodontal disease is refers to a pathological response that cause inflammation and loss of supporting structures of the teeth. Aggregatibacter actinomycetemcomitans is a Gram-negative bacillus associated to aggressive forms of periodontitis. This microorganism express a cytolethal distending toxin (Cdt), which induces cell cycle arrest and modulates cytokine synthesis. The aim of this study was to evaluate the action of two bacterial extracts from A. actinomycetemcomitans (Cdt mutant and wild-type strains) in the production of IL-6 and IL-8 by human gingival fibroblasts (HGF).
Methods: The supernatants from HGF primary cell cultures were exposed to either wild type A. actinomycetemcomitans or Cdt mutant strain bacterial extracts. The IL-6 and IL-8 production was determined by using a cytometric bead array human inflammation kit (Becton-Dickinson).
Results: There were not significant differences in IL-6 and IL-8 levels produced by HGF challenged with wild type or Cdt mutant bacterial extracts. However, when response to lipopolysaccharide was not controlled by preincubation of HGF with antibodies anti-CD14 and anti-TLR4 before bacterial challenge, IL-8 production was significantly reduced in HGF stimulated with Cdt mutant but not with A. actinomycetemcomitans wild type strain.
Conclusion: These results suggest that Cdt does no affect directly the IL-6 and IL-8 production by HGF in vitro. Nevertheless, a potential indirect immunostimulatory role of Cdt in HGF may be associated with other A. actinomycetemcomitans bacterial components such as lipopolysaccharide, which has to be studied.
|Session name:||19th European Congress of Clinical Microbiology and Infectious Diseases|
|Location:||Helsinki, Finland, 16 - 19 May 2009|
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