Division of Microbiology and Immunology, Department of Oral Biology and Tissue Engineering, Meikai University School of Dentistry, Sakado, Japan.
Research Institute of Odontology (M-RIO), Meikai University School of Dentistry, Sakado, Japan.
J Med Microbiol. 2022 Dec;71(12). doi: 10.1099/jmm.0.001627.
A diverse microbiota including fungi exists in the subgingival sites of patients with chronic periodontitis. The cell wall of , the most abundant fungal species, contains β-glucan. Dectin-1 binds β-glucan and participates in fungal recognition. Human periodontal ligament fibroblasts (PDLFs) are present in the periodontal ligament and synthesize immunomodulatory cytokines that influence the local response to infections. However, the expression and role of Dectin-1 in PDLFs have not been explored. This study aimed to determine if PDLFs express Dectin-1 and induce innate immune responses through Dectin-1 and the signalling molecule Syk. The expression of Dectin-1 in PDLFs was determined by flow cytometry, western blotting and confocal microscopy. Real-time PCR and Western blotting were used to determine the immune response of PDLFs stimulated with β-glucan-rich zymosan and . Dectin-1 was constitutively expressed in PDLFs. Zymosan induced the expression of cytokines, including , and , and the chemokine . Zymosan also induced the expression of the antimicrobial peptide β-defensin-1 (). Further, the phosphorylation of Syk and NF-κB occurred upon Dectin-1 activation. Notably, heat-killed induced the expression of , , and , and this activation was suppressed by the Syk inhibitor, R406. These findings indicate that the Dectin-1/Syk pathway induces an innate immune response of PDLFs, which may facilitate the control of oral infections such as candidiasis and periodontitis.
慢性牙周炎患者的龈下部位存在着多样化的微生物群落，其中包括真菌。真菌的细胞壁含有β-葡聚糖，而这种葡聚糖是最丰富的真菌物种。Dectin-1 可与β-葡聚糖结合，并参与真菌识别。人牙周韧带成纤维细胞（PDLFs）存在于牙周韧带中，并合成影响局部感染反应的免疫调节细胞因子。然而，Dectin-1 在 PDLFs 中的表达和作用尚未得到探索。本研究旨在确定 PDLFs 是否表达 Dectin-1，并通过 Dectin-1 和信号分子 Syk 诱导固有免疫反应。通过流式细胞术、Western blot 和共聚焦显微镜确定 PDLFs 中 Dectin-1 的表达。通过实时 PCR 和 Western blot 确定 PDLFs 对富含β-葡聚糖的酵母聚糖和 的免疫反应。Dectin-1 在 PDLFs 中持续表达。酵母聚糖诱导细胞因子（包括 、 和 ）和趋化因子 的表达。酵母聚糖还诱导抗菌肽 β-防御素-1 () 的表达。此外，Dectin-1 激活后 Syk 和 NF-κB 发生磷酸化。值得注意的是，热灭活 的诱导 、 、 和 的表达，而这种激活被 Syk 抑制剂 R406 抑制。这些发现表明，Dectin-1/Syk 途径诱导 PDLFs 发生固有免疫反应，这可能有助于控制口腔感染，如念珠菌病和牙周炎。
