title: Innate immune-stimulatory activity of Porphyromonas gingivalis fimbriae is eliminated by phase separation using Triton X-114.
abstract: Fimbriae are virulence factors of Porphyromonas gingivalis (P. gingivalis). In this study, the action of fimbriae on neutrophil respiratory burst and cytokine production by mononuclear cells (MNC) were investigated. Native or denatured form of purified P. gingivalis fimbriae contained endotoxin at an equivalence of 1-3μglipopolysaccharides(LPS)/mg protein. The endotoxin could be reduced to the equivalent of 1ng-LPS/mg protein by phase separation using Triton X-114. Unfractionated fimbriae caused serum-dependent priming of neutrophils for enhanced respiratory burst, but both native and denatured forms of Triton X-114-fractionated fimbriae were not active at 100μg/mL. Unfractionated fimbriae induced serum-dependent production of IL-1β by MNC. Triton X-114-fractionated fimbriae (10μg/mL)-induced production of IL-1β, IL-8 or TNF-α was much lower than that induced by unfractionated fimbriae or 10ng/mL P. gingivalis-LPS preparation. Triton X-114-fractionated fimbriae immobilized on polystyrene tubes induced adhesion-stimulated superoxide release by LPS-primed neutrophils in a β2integrin-dependent manner. P. gingivalis cells caused priming of neutrophils; however, Toll-like receptor (TLR) 4 antagonists did not affect this response. Thus, P. gingivalis fimbriae were ineffective in inducing innate immune response in leukocytes; however, they induced β2integrin-mediated response by neutrophils. Immune-stimulatory components of P. gingivalis might be recognized by receptors other than TLR4.
authors.affiliation: Section of Periodontology, Division of Oral Rehabilitation, Faculty of Dental Science, Kyushu University, Fukuoka, Japan.
authors.forename: Kohji
authors.initials: K
authors.lastname: Nozoe
authors.affiliation: Section of Periodontology, Division of Oral Rehabilitation, Faculty of Dental Science, Kyushu University, Fukuoka, Japan.
authors.forename: Terukazu
authors.initials: T
authors.lastname: Sanui
authors.affiliation: Section of Periodontology, Division of Oral Rehabilitation, Faculty of Dental Science, Kyushu University, Fukuoka, Japan.
authors.forename: Masaaki
authors.initials: M
authors.lastname: Takeshita
authors.affiliation: Section of Periodontology, Division of Oral Rehabilitation, Faculty of Dental Science, Kyushu University, Fukuoka, Japan.
authors.forename: Takao
authors.initials: T
authors.lastname: Fukuda
authors.affiliation: Division of General Dentistry, Faculty of Dental Science, Kyushu University, Fukuoka, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Haraguchi
authors.affiliation: Section of Periodontology, Division of Oral Rehabilitation, Faculty of Dental Science, Kyushu University, Fukuoka, Japan. Electronic address: yaida@dent.kyushu-u.ac.jp.
authors.forename: Yoshitomi
authors.initials: Y
authors.lastname: Aida
authors.affiliation: Section of Periodontology, Division of Oral Rehabilitation, Faculty of Dental Science, Kyushu University, Fukuoka, Japan.
authors.forename: Fusanori
authors.initials: F
authors.lastname: Nishimura
mesh_terms: D018821:CD18 Antigens / Q000276:immunology; D005591:Chemical Fractionation; D016207:Cytokines / Q000096:biosynthesis; D004731:Endotoxins / Q000276:immunology; D010861:Fimbriae, Bacterial / Q000737:chemistry* / Q000276:immunology*; D006801:Humans; D007113:Immunity, Innate; D008070:Lipopolysaccharides / Q000276:immunology; D009504:Neutrophils / Q000276:immunology*; D017830:Octoxynol; D011092:Polyethylene Glycols; D016966:Porphyromonas gingivalis / Q000276:immunology* / Q000472:pathogenicity; D016897:Respiratory Burst; D015398:Signal Transduction; D051197:Toll-Like Receptor 4 / Q000276:immunology
chemical_list: D018821:CD18 Antigens; D016207:Cytokines; D004731:Endotoxins; D008070:Lipopolysaccharides; C495345:TLR4 protein, human; D051197:Toll-Like Receptor 4; D011092:Polyethylene Glycols; D017830:Octoxynol; C010615:Nonidet P-40
keywords: Cytokine; Fimbriae; Neutrophil priming; Phase separation; Porphyromonas gingivalis; Triton X-114