biostudies-literatureSaavedra FMNIDCR NIH HHSNational Institute of Allergy and Infectious Diseases Division of Intramural ResearchNational Institute of Dental and Craniofacial Research620-630https://www.ebi.ac.uk/biostudies/studies/S-EPMC12372767biostudies-literatureUnknown18(3)Emerging evidence indicates that gingival-resident helper CD4⁺ T cells are major drivers of periodontal inflammation in response to commensal and pathogenic oral microorganisms. Whether tissue-resident memory CD8⁺ T cells (T_RM), which principally safeguard against viruses and cancer but also drive certain autoimmune and inflammatory conditions, impact periodontitis progression and severity remain unknown. We asked whether local reactivation of oral CD8⁺ T_RM of a defined antigen specificity could exacerbate ligature-induced periodontitis (LIP), a well-established model of periodontal disease in mice. Topical application of virus-mimicking peptides to the oral mucosa concurrent with LIP 1) intensified alveolar bone loss, 2) amplified gingival and cervical lymph node inflammation, and 3) stimulated gingival transcriptional changes in genes related to innate immune sensing and cell-mediated cytotoxicity. Therapeutic depletion of CD103-expressing oral CD8⁺ T_RM in advance of LIP prevented exacerbation of disease. These observations provide evidence that oral CD103⁺ CD8⁺ T_RM have the potential to participate in gingival inflammation, alveolar bone loss, and periodontitis.Mucosal immunologyTriggering mouth-resident antiviral CD8<sup>+</sup> T cells potentiates experimental periodontitis.PMC12372767K99 DE031014R00 DE031014Joag VStolley JMBrotto DBSaavedra FMMatson CAVezys VNesmiyanov PPHerzberg MCMasopust DfalseTriggering mouth-resident antiviral CD8<sup>+</sup> T cells potentiates experimental periodontitis.Emerging evidence indicates that gingival-resident helper CD4⁺ T cells are major drivers of periodontal inflammation in response to commensal and pathogenic oral microorganisms. Whether tissue-resident memory CD8⁺ T cells (T_RM), which principally safeguard against viruses and cancer but also drive certain autoimmune and inflammatory conditions, impact periodontitis progression and severity remain unknown. We asked whether local reactivation of oral CD8⁺ T_RM of a defined antigen specificity could exacerbate ligature-induced periodontitis (LIP), a well-established model of periodontal disease in mice. Topical application of virus-mimicking peptides to the oral mucosa concurrent with LIP 1) intensified alveolar bone loss, 2) amplified gingival and cervical lymph node inflammation, and 3) stimulated gingival transcriptional changes in genes related to innate immune sensing and cell-mediated cytotoxicity. Therapeutic depletion of CD103-expressing oral CD8⁺ T_RM in advance of LIP prevented exacerbation of disease. These observations provide evidence that oral CD103⁺ CD8⁺ T_RM have the potential to participate in gingival inflammation, alveolar bone loss, and periodontitis.2025-01-01T00:00:00Z2025 Jun2026-05-03T03:06:57.976Z2026-05-03T03:05:47.017ZS-EPMC123727673998820310.1016/j.mucimm.2025.02.003