title: Site-Specific Neutrophil Migration and CXCL2 Expression in Periodontal Tissue.
abstract: The oral microbial community is the best-characterized bacterial ecosystem in the human host. It has been shown in the mouse that oral commensal bacteria significantly contribute to clinically healthy periodontal homeostasis by influencing the number of neutrophils that migrate from the vasculature to the junctional epithelium. Furthermore, in clinically healthy tissue, the neutrophil response to oral commensal bacteria is associated with the select expression of the neutrophil chemokine CXCL2 but not CXCL1. This preliminary study examined the contribution of commensal bacteria on neutrophil location across the tooth/gingival interface. Tissue sections from the root associated mesial (anterior) of the second molar to the root associated distal (posterior) of the second molar were examined for neutrophils and the expression of the neutrophil chemokine ligands CXCL1 and CXCL2. It was found that both the number of neutrophils as well as the expression of CXCL2 but not CXCL1 was significantly increased in tissue sections close to the interdental region, consistent with the notion of select tissue expression patterns for neutrophil chemokine expression and subsequent neutrophil location. Furthermore, mice gavaged with either oral Streptococcus or Lactobacillus sp. bacteria induced a location pattern of neutrophils and CXCL2 expression similar to the normal oral flora. These data indicate for the first time select neutrophil location and chemokine expression patterns associated with clinically healthy tissue. The results reveal an increased inflammatory load upon approaching the interproximal region, which is consistent with the observation that the interproximal region often reveals early clinical signs of periodontal disease.
authors.affiliation: Department of Periodontics, School of Dentistry, University of Washington, Seattle, WA, USA.
authors.forename: A
authors.initials: A
authors.lastname: Greer
authors.affiliation: Department of Preventive Dentistry, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Irie
authors.affiliation: Centre for Immunology and Infectious Disease, Blizard Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London, UK.
authors.forename: A
authors.initials: A
authors.lastname: Hashim
authors.affiliation: Department of Oral Health Sciences, School of Dentistry, University of Washington, Seattle, WA, USA.
authors.forename: B G
authors.initials: BG
authors.lastname: Leroux
authors.affiliation: Department of Periodontics, School of Dentistry, University of Washington, Seattle, WA, USA.
authors.forename: A M
authors.initials: AM
authors.lastname: Chang
authors.affiliation: Centre for Immunology and Infectious Disease, Blizard Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London, UK.
authors.forename: M A
authors.initials: MA
authors.lastname: Curtis
authors.affiliation: Department of Periodontics, School of Dentistry, University of Washington, Seattle, WA, USA rdarveau@u.washington.edu.
authors.forename: R P
authors.initials: RP
authors.lastname: Darveau
mesh_terms: D000818:Animals; D002465:Cell Movement / Q000502:physiology; D054426:Chemokine CXCL2 / Q000502:physiology*; D051379:Mice; D008809:Mice, Inbred C3H; D009504:Neutrophils / Q000502:physiology*; D010519:Periodontium / Q000378:metabolism / Q000382:microbiology / Q000502:physiology*; D013291:Streptococcus / Q000378:metabolism
chemical_list: D054426:Chemokine CXCL2; C404915:Cxcl2 protein, mouse
keywords: bacteria; cell signaling; chemokines; epithelia; gingiva; histochemistry