title: Interactions of anaerobic bacteria with dental stem cells: an in vitro study.
abstract: BACKGROUND
  In patients with periodontitis, it is highly likely that local (progenitor) cells encounter pathogenic bacteria. The purpose of this in vitro study was to elucidate how human dental follicle stem cells (hDFSC) react towards a direct challenge with anaerobic periodontal pathogens under their natural oxygen-free atmosphere. HDFSC were compared to human bone marrow mesenchymal stem cells (hBMSC) and differentiated primary human gingival fibroblasts (hGiF), as well as permanent gingival carcinoma cells (Ca9-22).
  
  
  RESULTS
  The different cell types were investigated in a co-culture system with Porphyromonas gingivalis (P. gingivalis) and Fusobacterium nucleatum (F. nucleatum). The viability of the cells and pathogens under anaerobic conditions, as well as interactions in terms of adherence and internalization, were examined. Additionally, the release of pro-inflammatory interleukin-8 (IL-8) and anti-inflammatory interleukin-10 (IL-10) was quantified via enzyme-linked immunosorbent assay. The bacteria adhered less efficiently to hDFSC compared to Ca9-22 (P. gingivalis: 0.18% adherence to hDFSC; 3.1% adherence to Ca9-22). Similar results were observed for host cell internalization (F. nucleatum: 0.002% internalization into hDFSC; 0.09% internalization into Ca9-22). Statistically significantly less IL-8 was secreted from hDFSC after stimulation with F. nucleatum and P. gingivalis in comparison with hGiF (F. nucleatum: 2080.0 pg/ml--hGiF; 19.7 pg/ml--hDFSC). The IL-10 response of the differentiated cells was found to be low in relation to their pro-inflammatory IL-8 response.
  
  
  CONCLUSIONS
  The results indicate that dental stem cells are less prone to interactions with pathogenic bacteria than differentiated cells in an anaerobic environment. Moreover, during bacterial challenge, the stem cell immune response seems to be more towards an anti-inflammatory reaction. For a potential future therapeutic use of hDFSC, these findings support the idea of a save application.
authors.affiliation: Department of Operative Dentistry and Periodontology, University of Rostock, Rostock, Germany.
authors.forename: Anne
authors.initials: A
authors.lastname: Biedermann
authors.affiliation: Department of Operative Dentistry and Periodontology, University of Rostock, Rostock, Germany.
authors.forename: Katja
authors.initials: K
authors.lastname: Kriebel
authors.affiliation: Institute of Med. Microbiology, Virology and Hygiene, University of Rostock, Rostock, Germany.
authors.forename: Bernd
authors.initials: B
authors.lastname: Kreikemeyer
authors.affiliation: Department of Operative Dentistry and Periodontology, University of Rostock, Rostock, Germany.
authors.forename: Hermann
authors.initials: H
authors.lastname: Lang
mesh_terms: D001422:Bacterial Adhesion / Q000502:physiology; D001854:Bone Marrow Cells / Q000166:cytology; D002470:Cell Survival; D002478:Cells, Cultured; D003795:Dental Sac / Q000166:cytology*; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D016753:Interleukin-10 / Q000032:analysis; D016209:Interleukin-8 / Q000032:analysis; D059630:Mesenchymal Stem Cells / Q000166:cytology / Q000378:metabolism / Q000382:microbiology; D008856:Microscopy, Fluorescence; D016966:Porphyromonas gingivalis / Q000254:growth & development / Q000502:physiology*; D013234:Stem Cells / Q000166:cytology / Q000378:metabolism / Q000382:microbiology*
chemical_list: D016209:Interleukin-8; D016753:Interleukin-10