[Characteristics of the immune status in aged mice with experimental periodontitis]

To establish mice model with periodontitis by oral infection with Porphyromonas gingivalis, simulating human periodontal disease. The immune status of youth and aged mice were compared, and the cytokines expression of regulatory T cells and Th17 cells in this model were analyzed.

Entity microscope was used to evaluate the extent of periodontal bone resorption. H-E staining was used to observe infiltration of inflammatory cells in periodontal lesions. TRAP staining was used to observe osteoclastes in alveolar bone. The expression levels of TGF-β1, IL-10, IL-17A and RANKL mRNA in periodontal tissues were detected by real-time quantitative PCR. SPSS 17.0 software package was used for statistical analysis.

At 4-week after infection, the distance of cemento-enamel junction to the alveolar crest was significantly increased in the periodontal disease group compared with the normal control group (P<0.01); In the aged mice, the cemento-enamel junction to the alveolar crest distance significantly increased compared with youth mice (P<0.01). Periodontal tissues had inflammatory cell infiltration, and deep periodontal pockets. Moreover, the expression levels of TGF-β1 and IL-10 mRNA were significantly decreased (P<0.01) and the expression levels of IL-17A, RANKL mRNA qsignificantly increased (P<0.01).

The expression of inflammation mediator is abnormal in aged mice with more serious periodontal lesions than youth mice. It is suggested that the inflammatory status of periodontitis not only has a relationship with the decreased expression of inhibitory cytokines, but also relates to aging.