Abstract:
Despite the important role of tissue - resident memory T (TRM) cells in immunity and pathology of mucosal tissues, the study of tissue-resident memory T cells in periodontitis tissues is limited. Previous investigation in our laboratory identified the localization of TRM (CD103+ T cells) in periodontitis tissue. However, their function is not known. The aim of this study is to investigate the production of inflammatory mediators by CD103+ and CD103- T cells in periodontitis tissue. Human periodontal tissues were obtained from patients with severe chronic periodontitis. Intracellular cytokine staining was performed and expression of CD103, interferon gamma (IFN-γ), interleukin-17 (IL-17) and granzyme B was analyzed by 6-color flow cytometry. Majority of infiltrated T cells in periodontitis tissues were CD4+ T cells. Expression of CD103 was mainly detected on CD8+ T cells, but only minimally on CD4+ T cells. CD4+CD103+ and CD4+CD103- T cells produced IFN-γ and IL- 17 whereas CD8+CD103+ and CD8+CD103- T cells produced only IFN-γ. CD4+ and CD8+ T cells that expressed CD103 phenotype significantly produced higher proportion of IFN-γ. Granzyme B production was detected from CD103+ and CD103- T cells. We first identified the production of inflammatory mediators from CD103+ and CD103- T cells in periodontitis tissue. This suggests the possible role of resident memory T cells in periodontal inflammation and bone resorption.
