title: In vitro modeling of host-parasite interactions: the 'subgingival' biofilm challenge of primary human epithelial cells.
abstract: BACKGROUND
  Microbial biofilms are known to cause an increasing number of chronic inflammatory and infectious conditions. A classical example is chronic periodontal disease, a condition initiated by the subgingival dental plaque biofilm on gingival epithelial tissues. We describe here a new model that permits the examination of interactions between the bacterial biofilm and host cells in general. We use primary human gingival epithelial cells (HGEC) and an in vitro grown biofilm, comprising nine frequently studied and representative subgingival plaque bacteria.
  
  
  RESULTS
  We describe the growth of a mature 'subgingival' in vitro biofilm, its composition during development, its ability to adapt to aerobic conditions and how we expose in vitro a HGEC monolayer to this biofilm. Challenging the host derived HGEC with the biofilm invoked apoptosis in the epithelial cells, triggered release of pro-inflammatory cytokines and in parallel induced rapid degradation of the cytokines by biofilm-generated enzymes.
  
  
  CONCLUSIONS
  We developed an experimental in vitro model to study processes taking place in the gingival crevice during the initiation of inflammation. The new model takes into account that the microbial challenge derives from a biofilm community and not from planktonically cultured bacterial strains. It will facilitate easily the introduction of additional host cells such as neutrophils for future biofilm:host cell challenge studies. Our methodology may generate particular interest, as it should be widely applicable to other biofilm-related chronic inflammatory diseases.
authors.affiliation: Institute for Oral Biology, Section for Oral Microbiology and General Immunology, University of Zürich, Plattenstrasse 11, CH-8032 Zürich, Switzerland. bernie@zzmk.uzh.ch
authors.forename: Bernhard
authors.initials: B
authors.lastname: Guggenheim
authors.forename: Rudolf
authors.initials: R
authors.lastname: Gmür
authors.forename: Johnah C
authors.initials: JC
authors.lastname: Galicia
authors.forename: Panagiota G
authors.initials: PG
authors.lastname: Stathopoulou
authors.forename: Manjunatha R
authors.initials: MR
authors.lastname: Benakanakere
authors.forename: André
authors.initials: A
authors.lastname: Meier
authors.forename: Thomas
authors.initials: T
authors.lastname: Thurnheer
authors.forename: Denis F
authors.initials: DF
authors.lastname: Kinane
mesh_terms: D017209:Apoptosis; D001419:Bacteria / Q000254:growth & development*; D001422:Bacterial Adhesion; D018441:Biofilms / Q000254:growth & development*; D002478:Cells, Cultured; D016207:Cytokines / Q000378:metabolism; D004847:Epithelial Cells / Q000378:metabolism / Q000382:microbiology*; D005881:Gingiva / Q000382:microbiology; D054884:Host-Pathogen Interactions; D006801:Humans
chemical_list: D016207:Cytokines