Objective: To investigate whether programmed death ligand 1 (PD-L1) expressed in the periodontal tissue of chronic periodontitis and the correlativity of PD-L1 and different degrees of chronic periodontitis, provide experience for immunoregulation mechanism, clinical treatment and prognosis of chronic periodontitis.
Methods: Gingiva and periodontal tissue of healthy people and chronic periodontitis patients were collected. Based on clinical probing, periodontal tissue were classified into three groups: periodontal tissues of healthy people, periodontal tissue of mild chronic periodontitis, periodontal tissue of severe chronic periodontitis. Fluorescent quantitation polymerase chain reaction was applied to explore the expression of PD-L1 mRNA in the periodontal tissue of the different groups. Western blot and immunohistochemistry method were utilized to test the expression of PD-L1 protein in the periodontal tissue of the different groups. Combining with clinical image data, the relationship between differentially expressions of PD-L1 and different degrees of chronic periodontitis was analyzed.
Results: The relative expression quantity of PD-L1 in the periodontal tissue of the mild chronic periodontitis was significantly higher that of the severe chronic periodontitis (P<0.01). The relative expression quantity of PD-L1 in the periodontal tissue of healthy subjects and severe chronic periodontitis had no statistical significance (P>0.05).
Conclusion: The expression of PD-L1 in the periodontal tissue negativelv regulates inflammatory periodontal tissue damage.
目的: 探讨程序性死亡配体1（PD-L1）在慢性牙周炎中是否有表达，以及与不同程度慢性牙周炎的相关关系，为阐明慢性牙周炎的免疫调控机制、临床治疗和预后提供依据。
方法: 收集健康人和慢性牙周炎患者的牙龈和牙周膜组织。根据临床探测，分为正常对照组、轻度牙周炎组、重度牙周炎组。运用荧光定量聚合酶链反应（PCR）测定不同组牙周组织中PD-L1 mRNA的表达；免疫印迹（Western blot）以及免疫组织化学方法测定不同组牙周组织中PD-L1蛋白的表达。结合临床影像资料，分析PD-L1的差异表达量和不同程度慢性牙周炎的关系。
结果: 轻度牙周炎组牙周组织中PD-L1的相对表达量显著高于重度牙周炎组（P<0.01）；正常对照组牙周组织中PD-L1的相对表达量与重度牙周炎组牙周组织相比无统计学意义（P>0.05）。
结论: PD-L1在牙周组织的表达可负性调控炎症牙周组织损伤。