Immune Responses Regulated by Key Periodontal Bacteria in Germ-Free Mice

Abstract

The immune dysregulation induced by periodontal bacteria has important roles in the development of periodontitis. However, the role of key periodontal bacteria in local and systemic immunity has not been comprehensively studied. Herein, to explore immunoregulation maps of key periodontal bacteria, a mono-colonized germ-free mice model with P. gingivalis, F. nucleatum, and T. denticola for two weeks was designed in this study. The alveolar bone loss was determined by micro-CT. A total of 14 types of innate and adaptive immune cells of the gingiva, spleen, and colon were detected by multi-color flow cytometry. P. gingivalis induced the strongest innate immune response in gingiva and mononuclear phagocytes (MNPs) changed most significantly, compared to F. nucleatum and T. denticola. Immune dysregulation of the colon was widely induced by F. nucleatum. T. denticola mainly induced immune disorder in spleen. ILC3s, Tregs, CD11B+ dendritic cells s, MNPs, macrophages, and plasmacytoid dendritic cells were the main types in response to key periodontal bacteria. However, the alveolar bone loss was not induced by key periodontal bacteria. In conclusion, the overall immunoregulation of monomicrobial stimuli to decipher the complexities of periodontitis was provided in this study. P. gingivalis, F. nucleatum, and T. denticola have different effects on local and systemic immunity in gingiva, colon, and spleen of germ-free mice.

Deciphering the interdependent labyrinth between gut microbiota and the immune system

“…Integral to host homeostasis and defence, the intestinal mucosal immune system must be balanced which has been studied in germ-free mice (Kim et al 2018;Shen et al 2022). In comparison to pathogen-free organisms, germ-free organisms produce lesser IELs (Bousbaine et al 2020), Tregs (Rogala et al 2020) and even lesser IgAsecreting plasma cells in the lamina propria (Crabbe et al 1968).…”

“…2018; Shen et al . 2022). In comparison to pathogen‐free organisms, germ‐free organisms produce lesser IELs (Bousbaine et al .…”