Toll-like receptors, NOD1, and NOD2 in oral epithelial cells.
Oral epithelium might be the first barrier against oral bacteria in periodontal tissue. We hypothesized that oral epithelium is endowed with innate immune receptors for bacterial components, which play roles in host defense against bacterial infection without being accompanied by excessive inflammatory responses. We found clear expression of Toll-like receptor (TLR)4 as well as TLR2, and strong expression of NOD1 and NOD2 in normal oral epithelial tissues by immunohistochemical analysis. We also showed that primary oral epithelial cells in culture expressed these molecules using PCR, flow cytometry, and immunostaining. In inflamed oral epithelium, cell-surface localizations of TLR2 and TLR4 were more clearly observed than in healthy tissue. Upon stimulation with synthetic ligands for these receptors, the expression of beta-defensin 2 was markedly up-regulated. These findings indicate that these molecules in oral epithelial cells are functional receptors that induce antibacterial responses.
Sugawara
Y
Y
Division of Oral Diagnosis, Department of Oral Medicine and Surgery, Tohoku University Graduate School of Dentistry, Sendai, Japan.
Uehara
A
A
Fujimoto
Y
Y
Kusumoto
S
S
Fukase
K
K
Shibata
K
K
Sugawara
S
S
Sasano
T
T
Takada
H
H
D048868:Adaptor Proteins, Signal Transducing / Q000276:immunology*; D000890:Anti-Infective Agents; D002478:Cells, Cultured; D004847:Epithelial Cells / Q000276:immunology; D005434:Flow Cytometry; D005455:Fluorescent Antibody Technique; D005881:Gingiva / Q000166:cytology / Q000276:immunology*; D006801:Humans; D007150:Immunohistochemistry; D047908:Intracellular Signaling Peptides and Proteins / Q000276:immunology*; D007624:KB Cells; D008024:Ligands; D053474:Nod1 Signaling Adaptor Protein; D053473:Nod2 Signaling Adaptor Protein; D010518:Periodontitis / Q000276:immunology / Q000473:pathology; D016133:Polymerase Chain Reaction; D051195:Toll-Like Receptor 2 / Q000276:immunology; D051197:Toll-Like Receptor 4 / Q000276:immunology; D051193:Toll-Like Receptors / Q000276:immunology*; D015854:Up-Regulation; D023083:beta-Defensins / Q000276:immunology / Q000378:metabolism
D048868:Adaptor Proteins, Signal Transducing; D000890:Anti-Infective Agents; C106641:DEFB4A protein, human; D047908:Intracellular Signaling Peptides and Proteins; D008024:Ligands; C119067:NOD1 protein, human; C429018:NOD2 protein, human; D053474:Nod1 Signaling Adaptor Protein; D053473:Nod2 Signaling Adaptor Protein; D051195:Toll-Like Receptor 2; D051197:Toll-Like Receptor 4; D051193:Toll-Like Receptors; D023083:beta-Defensins