title: Immunologic characteristics of human gingival fibroblasts in response to oral bacteria.
abstract: OBJECTIVE
  There is ample evidence that gingival fibroblasts (GFs) participate in the immune response to oral bacteria and serve as immune-regulatory cells. The objective of this study was to investigate the innate immune response of GFs to oral bacteria.
  
  
  METHODS
  Human GFs were cocultured with relatively less-pathogenic (Leptotrichia wadei, Fusobacterium nucleatum and Campylobacter gracilis) and pathogenic red-complex bacteria. The expression of mRNA for antimicrobial peptides [AMPs; namely human beta defensins (HBDs)], chemokines with antimicrobial activity [chemokine C-X-C motif (CXCL)10, CXCL11 and chemokine C-C motif ligand 20 (CCL20)] and proinflammatory mediators [interleukin (IL)6 and IL8] and the levels of CXCL11, CCL20, IL-6 and IL-8 accumulated in supernatants were analyzed using real-time PCR and ELISA, respectively. The proteolytic activities of CXCL11, CCL20, IL-6 and IL-8 produced by six species of bacteria were also determined.
  
  
  RESULTS
  The relatively less-pathogenic bacteria strongly up-regulated the expression of antimicrobial chemokines and proinflammatory mediators, whereas the red-complex bacteria stimulated low levels, or often suppressed, expression of these factors. Regarding the regulation of AMPs, the inhibition of HBD3, HBD106 and HBD107 mRNAs by Porphyromonas gingivalis was noticeable; however, differences between the two bacterial groups were not conspicuous. Differential degradation of proteins by the six bacterial species was observed: P. gingivalis and Treponema denticola degraded proteins well, whereas the other species degraded proteins to a relatively lower degree.
  
  
  CONCLUSIONS
  The invasion of red-complex bacteria into gingival connective tissue can suppress the immune response of GFs and can be a source of persistent infection in connective tissue.
authors: Department of Periodontology, Institute of Oral Health Science, Ajou University School of Medicine, Suwon, Korea.
authors: J Y
authors: JY
authors: Jang
authors: Department of Oral and Maxillofacial Surgery, Korea University Anam Hospital, Seoul, Korea.
authors: I-S
authors: IS
authors: Song
authors: Department of Oromaxillofacial Infection & Immunity, BK21 CLS, School of Dentistry and Dental Research Institute, Seoul National University, Seoul, Korea.
authors: K J
authors: KJ
authors: Baek
authors: Department of Oromaxillofacial Infection & Immunity, BK21 CLS, School of Dentistry and Dental Research Institute, Seoul National University, Seoul, Korea.
authors: Y
authors: Y
authors: Choi
authors: Department of Periodontology, Institute of Oral Health Science, Ajou University School of Medicine, Suwon, Korea.
authors: S
authors: S
authors: Ji
mesh_terms: D002167:Campylobacter / Q000276:immunology; D054418:Chemokine CCL20 / Q000378:metabolism; D054371:Chemokine CXCL11 / Q000378:metabolism; D018925:Chemokines / Q000378:metabolism; D018920:Coculture Techniques; D005347:Fibroblasts / Q000276:immunology* / Q000382:microbiology; D016967:Fusobacterium nucleatum / Q000276:immunology; D005881:Gingiva / Q000276:immunology* / Q000382:microbiology; D006801:Humans; D007113:Immunity, Innate; D015850:Interleukin-6 / Q000378:metabolism; D016209:Interleukin-8 / Q000378:metabolism; D045183:Leptotrichia / Q000276:immunology; D016966:Porphyromonas gingivalis / Q000276:immunology; D060888:Real-Time Polymerase Chain Reaction; D023083:beta-Defensins / Q000378:metabolism
chemical_list: D054418:Chemokine CCL20; D054371:Chemokine CXCL11; D018925:Chemokines; D015850:Interleukin-6; D016209:Interleukin-8; D023083:beta-Defensins
keywords: antimicrobial chemokines; human gingival fibroblasts; oral bacteria; proinflammatory mediator