Sir John Walsh Research Institute Faculty of Dentistry, University of Otago, Dunedin, New Zealand.
J Periodontal Res. 2018 Aug;53(4):622-635. doi: 10.1111/jre.12552. Epub 2018 Apr 6.
T cells are known to play a pivotal role in periodontal disease; however, less is known about the T-helper subsets of regulatory T cells (Tregs) and Th17 cells. The aim of this study was to investigate the cell types expressing FoxP3 and interleukin (IL)-17A within periodontal disease tissues and to determine gene and protein expression profiles associated with periodontitis.
A total of 10 healthy/gingivitis and 10 chronic periodontitis tissues were investigated. Immunohistochemistry and immunofluorescence techniques were used to identify the FoxP3 and IL17-positive cells and to determine the cell types respectively. Gene expression was determined using semi-quantitative polymerase chain reaction array technology that allowed the analysis of 84 pathway-focused genes known to be associated with Tregs and Th17 cells. Transforming growth factor (TGF)-β1, IL10 and IL17A protein levels were determined using enzyme-linked immunosorbent assay.
Double immunofluorescence labeling revealed that all FoxP3 cells were CD4 , while IL17 cells were neither CD4 nor CD8 but were tryptase , suggestive of mast cells. More FoxP3 cells than IL17 cells were found in all the tissues examined and overall there were few IL17 cells. Statistically significant increases in gene expression were found for STAT5A, STAT3, SOCS1, TGFβ1 and IL10 in the chronic periodontitis specimens predominantly infiltrated with B cells and plasma cells when compared with healthy/gingivitis specimens predominantly infiltrated with T cells. Protein analysis demonstrated higher levels of the TGFβ1 and IL10 cytokines in periodontitis tissues and in B-cell and plasma cell predominant gingival tissues than in healthy/gingivitis tissues and T-cell predominant gingival tissues. IL17A gene and protein expression was not detected in any of the tissues.
Based on the findings of this study, we suggest that the source of low levels of IL17A in periodontal tissues is mast cells not Th17 cells and that Tregs may have a more prominent role in the pathogenesis of periodontal disease than Th17 cells.
已知 T 细胞在牙周病中发挥关键作用；然而，对于调节性 T 细胞（Tregs）和 Th17 细胞的 T 辅助亚群知之甚少。本研究旨在探讨牙周病组织中表达 FoxP3 和白细胞介素（IL）-17A 的细胞类型，并确定与牙周炎相关的基因和蛋白表达谱。
共检测了 10 例健康/牙龈炎和 10 例慢性牙周炎组织。采用免疫组织化学和免疫荧光技术分别鉴定 FoxP3 和 IL17 阳性细胞，并确定各自的细胞类型。使用半定量聚合酶链反应阵列技术确定基因表达，该技术允许分析已知与 Tregs 和 Th17 细胞相关的 84 种通路相关基因。使用酶联免疫吸附试验测定转化生长因子（TGF）-β1、IL10 和 IL17A 蛋白水平。
双重免疫荧光标记显示所有 FoxP3 细胞均为 CD4 ，而 IL17 细胞既不是 CD4 也不是 CD8 ，而是 tryptase ，提示为肥大细胞。在所有检测的组织中，FoxP3 细胞的数量均多于 IL17 细胞，且总体上 IL17 细胞数量较少。与主要浸润 T 细胞的健康/牙龈炎组织相比，主要浸润 B 细胞和浆细胞的慢性牙周炎组织中，STAT5A、STAT3、SOCS1、TGFβ1 和 IL10 的基因表达显著增加。蛋白分析表明，在牙周炎组织以及 B 细胞和浆细胞为主的牙龈组织中，TGFβ1 和 IL10 细胞因子的水平高于健康/牙龈炎组织和 T 细胞为主的牙龈组织。在任何组织中均未检测到 IL17A 基因和蛋白表达。
根据本研究的结果，我们认为牙周组织中低水平 IL17A 的来源是肥大细胞而不是 Th17 细胞，Tregs 在牙周病发病机制中的作用可能比 Th17 细胞更为突出。
