title: Phospholipase C, p38/MAPK, and NF-kappaB-mediated induction of MIP-3alpha/CCL20 by Porphyromonas gingivalis.
abstract: Macrophage inflammatory protein-3alpha/C-C chemokine ligand 20 (MIP-3alpha/CCL20) is an antimicrobial peptide that plays an important role in innate immunity. In addition to direct microbicidal effects, MIP-3alpha/CCL20 also exhibits cytokine-like functions that are critical during dendritic cell activation. The aim of the present study was to investigate further which signaling pathways are involved in the MIP-3alpha/CCL20 mRNA expression in response to whole-cell Porphyromonas gingivalis. Primary gingival epithelial cells (GECs) and the immortalized oral keratinocyte cell-line OKF6/TERT-2 were stimulated with whole-cell P. gingivalis. Prior to stimulation, GECs and OKF6/TERT-2 cells were pretreated with specific inhibitors for nuclear-factor-kappaB (NF-kappaB), mitogen-activated protein kinase (MAPK), phospholipase C (PLC), and phosphatidylinositol-3-kinase (PI3K). In GECs and OKF6/TERT-2 cells, activation of NF-kappaB was examined after exposure to P. gingivalis. The gene expression of MIP-3alpha/CCL20 was significantly induced in response to P. gingivalis (P <or= 0.05) compared to unstimulated control cells. This induction was specifically blocked when cells were pre-incubated with inhibitors for NF-kappaB, MAPK, and PLC (P <or= 0.05), but not for PI3K. These results demonstrate that P. gingivalis induces the MIP-3alpha/CCL20 mRNA in a NF-kappaB-, PLC-, and MAPK-dependent manner.
authors.affiliation: Department of Oral Biology, University of Washington, Seattle, Washington, USA. dommisch@uni-bonn.de
authors.forename: Henrik
authors.initials: H
authors.lastname: Dommisch
authors.forename: Whasun O
authors.initials: WO
authors.lastname: Chung
authors.forename: Søren
authors.initials: S
authors.lastname: Jepsen
authors.forename: Beth M
authors.initials: BM
authors.lastname: Hacker
authors.forename: Beverly A
authors.initials: BA
authors.lastname: Dale
mesh_terms: D054418:Chemokine CCL20 / Q000096:biosynthesis* / Q000235:genetics; D004847:Epithelial Cells / Q000502:physiology; D005881:Gingiva / Q000166:cytology; D006801:Humans; D007202:Indicators and Reagents; D015850:Interleukin-6 / Q000096:biosynthesis / Q000235:genetics; D016328:NF-kappa B / Q000502:physiology*; D050778:NFATC Transcription Factors / Q000502:physiology; D019869:Phosphatidylinositol 3-Kinases / Q000502:physiology; D016966:Porphyromonas gingivalis / Q000378:metabolism*; D012313:RNA / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D051996:Transcription Factor RelA / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology; D014162:Transfection; D010738:Type C Phospholipases / Q000502:physiology*; D048051:p38 Mitogen-Activated Protein Kinases / Q000502:physiology*
chemical_list: C108355:CCL20 protein, human; D054418:Chemokine CCL20; D007202:Indicators and Reagents; D015850:Interleukin-6; D016328:NF-kappa B; D050778:NFATC Transcription Factors; D051996:Transcription Factor RelA; D012313:RNA; D019869:Phosphatidylinositol 3-Kinases; D048051:p38 Mitogen-Activated Protein Kinases; D010738:Type C Phospholipases