Characterization of Mast cell in inflamed gingiva in mouse model.

Mast cells (MCs) are a key cell type of the hematopoietic lineage that the evolutionarily conserved functions in pathogen surveillance. At the earliest stages of infection, mast cells are important for communicating the presence of a pathogen to many cell types located nearby in the site of infection and distally in draining lymph nodes. We already reported that our established murine periodontal disease model shows significant inductions of IL-17 expressing CD4⁺ T cells in inflamed gingiva with dramatically inductions of inflammatory cytokines were detected of mice orally infected with Porphyromonas gingivalis (Pg.). In this study, we elucidate the mechanism of interactions between MCs and effector T cell in inflamed gingiva. A murine periodontal disease model was dissect and isolated mononuclear cells from inflamed gingiva for determined the frequencies of MCs (FceRIa⁺/c-Kit⁺) by flow cytometer. Three days after the initial P.g-infection, significant induction of MCs was detected in inflamed gingiva. Those expressions were maintained during the infection period. Further, these MCs significantly express CD63, as a maker of MCs activation, at same P.g-infection period. Taken together, these results indicated that MCs in inflamed gingiva might key role for initiate inflammation for periodontal disease in early stage. This work was supported by Grant-in-aid for Young Scientist (B) (no. 25861781).