PD-1/PD-L1 pathway: A double-edged sword in periodontitis

Area of Science:

• Immunology
• Periodontology
• Microbiology

Background:

• Periodontitis is an infectious and immunologic disease causing periodontal tissue destruction.
• Programmed death protein 1 (PD-1) and its ligand (PD-L1) are immune checkpoints regulating T cell activity.
• Elevated PD-1/PD-L1 expression is observed in periodontitis patients compared to healthy individuals.

Purpose of the Study:

• To review the dual role of the PD-1/PD-L1 pathway in periodontitis development and progression.
• To explore the mechanism of PD-1/PD-L1 in periodontitis-associated systemic disorders.
• To identify the PD-1/PD-L1 pathway as a potential therapeutic target.

Main Methods:

• Literature review of studies on PD-1/PD-L1 in periodontitis.
• Analysis of the impact of Porphyromonas gingivalis on PD-1/PD-L1 expression.
• Examination of the association between PD-1/PD-L1 and systemic diseases.

Main Results:

• Porphyromonas gingivalis is implicated in driving PD-1/PD-L1 upregulation in periodontitis.
• High PD-1/PD-L1 expression can suppress inflammation but promote P. gingivalis immune evasion.
• The PD-1/PD-L1 pathway is linked to systemic conditions like cancer and Alzheimer's disease.

Conclusions:

• The PD-1/PD-L1 pathway acts as a 'double-edged sword' in periodontitis.
• Dysregulation of PD-1/PD-L1 influences both local periodontal and systemic health.
• Modulating the PD-1/PD-L1 pathway offers a novel therapeutic strategy for periodontitis and related disorders.