Department of Endocrinology and Metabolism, Binzhou Medical University Hospital, No. 661 Second Huanghe Road, Binzhou, 256603, China.
Department of Dermatology, Binzhou Medical University Hospital, No. 661 Second Huanghe Road, Binzhou, 256603, China.
Biol Trace Elem Res. 2023 Nov;201(11):5298-5308. doi: 10.1007/s12011-023-03598-z. Epub 2023 Feb 11.
Iodine excess may cause and aggravate autoimmune thyroiditis (AIT), which is regarded as a typical kind of autoimmune disease mainly mediated by CD4 T cells. Thus far, it is unclear whether T helper (Th) 9 cells, a novel subpopulation of CD4 T cells, play a potential role in AIT. Therefore, in the present study, changes in Th9 cells were detected in murine models of AIT induced by excess iodine intake to explore the possible immune mechanism. Female C57BL/6 mice were divided into 7 groups (n = 8) and were supplied with water containing 0.005% sodium iodide for 0, 2, 4, 6, 8, 10, and 12 weeks. With the extension of the high-iodine intake duration, the incidence of thyroiditis and the spleen index were significantly increased, and serum thyroglobulin antibody (TgAb) titers and interleukin 9 (IL-9, major cytokine from Th9 cells) concentrations were also increased. Additionally, it was revealed that the percentages of Th9 cells in spleen mononuclear cells (SMCs) and thyroid tissues were both markedly elevated and accompanied by increased mRNA and protein expression of IL-9 and key transcription factors of Th9 cells (PU.1 and IRF-4). Significantly, dynamic changes in Th9 cells were found, with a peak at 8 weeks after high iodine intake, the time point when thyroiditis was the most serious. Importantly, Th9 cells were detected in the areas of infiltrating lymphocytes in thyroid sections. In conclusion, the continuously increasing proportions of Th9 cells may play an important role in the occurrence and development of AIT induced by high iodine intake.
碘过量可导致并加重自身免疫性甲状腺炎（AIT），后者被认为是一种主要由 CD4 T 细胞介导的典型自身免疫性疾病。到目前为止，尚不清楚辅助性 T 细胞（Th）9 细胞是否在 AIT 中发挥潜在作用。因此，本研究通过检测碘过量诱导的 AIT 小鼠模型中 Th9 细胞的变化，以探讨其可能的免疫机制。将雌性 C57BL/6 小鼠分为 7 组（n = 8），分别给予含 0.005% 碘化钠的水 0、2、4、6、8、10 和 12 周。随着高碘摄入时间的延长，甲状腺炎的发病率和脾脏指数显著增加，血清甲状腺球蛋白抗体（TgAb）滴度和白细胞介素 9（IL-9，Th9 细胞的主要细胞因子）浓度也升高。此外，结果显示脾单核细胞（SMCs）和甲状腺组织中 Th9 细胞的百分比均明显升高，且 IL-9 和 Th9 细胞关键转录因子（PU.1 和 IRF-4）的 mRNA 和蛋白表达也增加。值得注意的是，Th9 细胞呈动态变化，在高碘摄入 8 周后达到高峰，此时甲状腺炎最为严重。重要的是，在甲状腺切片浸润淋巴细胞区域检测到 Th9 细胞。总之，持续增加的 Th9 细胞比例可能在碘过量诱导的 AIT 发生和发展中发挥重要作用。
