Involvement of CD14 on human gingival fibroblasts in Porphyromonas gingivalis lipopolysaccharide-mediated interleukin-6 secretion.
The lipopolysaccharides (LPS) of Porphyromonas gingivalis are implicated in the initiation and development of periodontal diseases. However, the mechanisms underlying P. gingivalis LPS-mediated periodontal destruction are still unknown. Here, it was found that P. gingivalis LPS activates human gingival fibroblasts (HGF) to release interleukin 6 (IL-6) via CD14. Flow-cytometric analysis showed that HGFs bind to fluorescein-isothiocyanate (FITC)-labelled LPS, and express CD14 on their surfaces. The binding of FITC LPS was competitively suppressed by unlabelled synthetic lipid A as well as by LPS. LPS-induced IL-6 production was inhibited by anti-CD14 monoclonal antibody in a dose-dependent manner. The binding of FITC LPS to HGF was abrogated by anti-CD14 monoclonal antibody. Engagement of LPS initiated the protein tyrosine phosphorylation of several intracellular proteins including extracellular signal-regulated kinase (ERK) 1 and 2, and these events were suppressed by the anti-CD14 monoclonal. These results suggest that CD14 is a cell surface binding site for LPS and is involved in the LPS-mediated activation of HGF.
Department of Pharmacology, Osaka Dental University, Hirakata, Japan. wang@cc.osaka-dent.ac.jp
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PL
Wang
K
K
Sato
M
M
Oido
T
T
Fujii
Y
Y
Kowashi
M
M
Shinohara
K
K
Ohura
H
H
Tani
Y
Y
Kuboki
D000911:Antibodies, Monoclonal; D001665:Binding Sites; D001667:Binding, Competitive; D015153:Blotting, Western; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000378:metabolism; D005347:Fibroblasts / Q000276:immunology*; D005434:Flow Cytometry; D016650:Fluorescein-5-isothiocyanate; D005456:Fluorescent Dyes; D005881:Gingiva / Q000166:cytology / Q000276:immunology*; D006801:Humans; D015850:Interleukin-6 / Q000378:metabolism*; D008050:Lipid A / Q000276:immunology; D018950:Lipopolysaccharide Receptors / Q000276:immunology*; D008070:Lipopolysaccharides / Q000276:immunology*; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases; D010766:Phosphorylation; D016966:Porphyromonas gingivalis / Q000276:immunology*; D011233:Precipitin Tests; D014443:Tyrosine / Q000378:metabolism
D000911:Antibodies, Monoclonal; D005456:Fluorescent Dyes; D015850:Interleukin-6; D008050:Lipid A; D018950:Lipopolysaccharide Receptors; D008070:Lipopolysaccharides; D014443:Tyrosine; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases; D016650:Fluorescein-5-isothiocyanate