Abstract
γδ T cells are nonclassical T lymphocytes representing the major T-cell population at epithelial barriers. In the gingiva, γδ T cells are enriched in epithelial regions adjacent to the biofilm and are considered to regulate local immunity to maintain host-biofilm homeostatic interactions. This delicate balance is often disrupted resulting in the development of periodontitis. Previous studies in mice lacking γδ T cells from birth (Tcrd-/- mice) examined the impact of these cells on ligature-induced periodontitis. Data obtained from those studies proposed either a protective effect or no impact to γδ T cells in this setting. Here, we addressed the role of γδ T cells in periodontitis using the recently developed Tcrd-GDL mice, enabling temporal ablation of γδ T cells. Specifically, the impact of γδ T cells during periodontitis was examined in 2 modalities: the ligature model and the oral infection model in which the pathogen Porphyromonas gingivalis was administrated via successive oral gavages. Ablation of γδ T cells during ligature-induced periodontitis had no impact on innate immune cell recruitment to the ligated gingiva. In addition, the number of osteoclasts and subsequent alveolar bone loss were unaffected. However, γδ T cells play a pathologic role during P. gingivalis infection, and their absence prevented alveolar bone loss. Further analysis revealed that γδ T cells were responsible for the recruitment of neutrophils and monocytes to the gingiva following the exposure to P. gingivalis. γδ T-cell ablation also downregulated osteoclastogenesis and dysregulated long-term immune responses in the gingiva. Collectively, this study demonstrates that whereas γδ T cells are dispensable to periodontitis induced by the ligature model, they play a deleterious role in the oral infection model by facilitating pathogen-induced bone-destructive immune responses. On a broader aspect, this study highlights the complex immunopathologic mechanisms involved in periodontal bone loss.
Original language | American English |
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Pages (from-to) | 428-436 |
Number of pages | 9 |
Journal | Journal of Dental Research |
Volume | 101 |
Issue number | 4 |
DOIs | |
State | Published - Apr 2022 |
Bibliographical note
Funding Information:The authors disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This work was supported by the German Israel Foundation (grant I-1432-201.11/2017) and by the program Research Cooperation Lower Saxony–Israel (project A128382) to A.H. Hovav andI. Prinz.
Funding Information:
The authors disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This work was supported by the German Israel Foundation (grant I-1432-201.11/2017) and by the program Research Cooperation Lower Saxony?Israel (project A128382) to A.H. Hovav andI. Prinz.
Publisher Copyright:
© International Association for Dental Research and American Association for Dental, Oral, and Craniofacial Research 2021.
Keywords
- Porphyromonas gingivalis
- innate immunity
- ligature
- oral mucosa
- osteoclasts
- periodontitis