Development of CD4⁺ memory T cells in periodontal health and disease

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Presentation Time: 03:15 PM - 04:30 PM
Poster Board Number: B178
Abstract ID: 5878

Presenting Author:
Carla Alvarez Rivas , Senior Postdoctoral Fellow at Forsyth Inst., Harvard Sch. of Dent. Med.

Abstract:

Periodontitis (PD) is a persistent biofilm-driven inflammatory disease causing teeth-supporting bone destruction. Unraveling long-term periodontal immunity is critical for understanding PD recurrence. CD4⁺ memory T cells, residing in tissues and lymphoid organs, play a key role. However, evidence on periodontal-associated CD4⁺ memory T cells is limited. Our study investigated gingival CD4⁺ memory T cell development in health and disease using a ligature-induced PD recurrence model in Foxp3eGFP-DTR mice. The model involved temporary diphtheria toxin-mediated Tregs depletion, enriching gingiva with CD4⁺ T cells for enhanced memory development. Ligature microbial composition was analyzed by 16s rRNA-seq. FTY720 was used in PD recurrence to confirm tissue-resident cells. Imaging Mass Cytometry was used to analyze CD4⁺ T memory cells and immune populations in PD patients and healthy individual gingival biopsies. Results showed early appearance and increased frequency of CD4⁺ memory T cells in gingiva pre-tooth eruption until adulthood. CD103 expression increased in TCRb⁺CD4⁺CD44⁺ T cells with age. PD recurrence accelerated bone loss (p<0.05), matching microbial biofilm composition. FTY720 didn't prevent bone loss but reduced CD45+ infiltration and increased gingival CD4⁺ memory cell frequency. Imaging Mass Cytometry in PD biopsies revealed increased CD4⁺CD45RO⁺ cells versus healthy controls, concentrated near innate cells along the subepithelial zone.