Th1 responses and pathogenesis of periodontitis in mice model

Objective: To address Th1 and Th2 responses to the pathogenesis of periodontitis,experimental periodontitis was evaluated in mice to develop strong polarized Th1-based responses to the oral pathogens.Methods: Thirty six SPF KM mice were randomly divided into three groups.Periodontitis group: experimental periodontitis was induced by wrapping a 5/0 silk ligature inoculated with putative periodontopathic bacteria around the first maxillary molar.Th1-polaried group: the experimental periodontitis model was established as above,the mice were inoculated with UV-attenuated T.g at the same day.The rest was normal control group.All mice were sacrificed at the end of 1,4,8,12 weeks.The histological analysis of periodontal tissues was observed by microscope after the samples were stained with hematoxylin and eosin(HE).The concentrations of TNF-α and IL-10 in mice serum were determined by ELISA.Results: The results showed that the level of TNF-α in Th1-polaried group was significantly higher than that in periodontitis group(P 0.01).The concentrations of IL-10 in Th1-polaried group was significantly lower than that in periodontitis group(P 0.01).Subsequent infection of the periodontium with oral pathogens caused extensive inflammation and alveolar bone destruction in Th1-polaried mice.Inflammations in Th1-polaried mice were heavily infiltrated with osteoclasts.Conclusion: These results directly demonstrate that specific Th1 responses promote severe infection-stimulated alveolar bone loss.