Cutting Edge: TLR2 is required for the innate response to Porphyromonas gingivalis: activation leads to bacterial persistence and TLR2 deficiency attenuates induced alveolar bone resorption.
Periodontitis is a chronic inflammatory disease that leads to destruction of the attachment apparatus of the teeth. The presence of particular oral bacteria and the host inflammatory response contribute to disease progression. Porphyromonas gingivalis is a Gram-negative anaerobe considered to be a major periodontal pathogen. Isolated Ags from P. gingivalis activate innate immune cells through TLR2 or TLR4. We challenged TLR2- and TLR4-deficient mice with live P. gingivalis and studied the inflammatory response and bacterial survival. Wild-type and TLR4-deficient mice produced high levels of cytokines in response to P. gingivalis challenge, whereas cytokine levels were nearly absent or delayed in TLR2-deficient mice. Surprisingly, P. gingivalis was cleared far more rapidly in TLR2-deficient mice. In addition, TLR2-deficient mice resisted bone loss following oral infection with P. gingivalis.
Burns
Elia
E
Institute of Dental Sciences, Faculty of Dental Medicine, Hadassah Medical Center, Hebrew University, Jerusalem, Israel.
Bachrach
Gilad
G
Shapira
Lior
L
Nussbaum
Gabriel
G
D016301:Alveolar Bone Loss / Q000209:etiology* / Q000276:immunology / Q000382:microbiology; D000818:Animals; D016866:Bacteroidaceae Infections; D007113:Immunity, Innate; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D050296:Microbial Viability / Q000276:immunology*; D010518:Periodontitis; D016966:Porphyromonas gingivalis / Q000276:immunology*; D051195:Toll-Like Receptor 2 / Q000172:deficiency / Q000276:immunology*; D051197:Toll-Like Receptor 4
C493486:Tlr2 protein, mouse; C493487:Tlr4 protein, mouse; D051195:Toll-Like Receptor 2; D051197:Toll-Like Receptor 4