Gallo Daniela, Piantanida Eliana, Bombelli Raffaella, Lepanto Silvia, Bruno Antonino, Gallazzi Matteo, Bilato Giorgia, Borgese Marina, Baci Denisa, Mortara Lorenzo, Tanda Maria Laura
Endocrine Unit, Department of Medicine and Surgery, University of Insubria, ASST Dei Sette Laghi, 21100 Varese, Italy.
Immunology and General Pathology Laboratory, Department of Biotechnology and Life Sciences, University of Insubria, 21100 Varese, Italy.
Int J Mol Sci. 2025 Jan 24;26(3):977. doi: 10.3390/ijms26030977.
Graves' disease (GD) is an autoimmune disorder, driven by the appearance of circulating autoantibodies (Ab) against the thyroid stimulating hormone (TSH) receptor, thus causing hyperthyroidism. While antithyroid drugs, the only available treatment for GD, carry a significant risk of relapse, advances in immunology could pave the way for more effective therapies. Natural killer (NK) cells, divided into cytotoxic CD56 and cytokine-secreting CD56 subsets, regulate immune responses through cytokine production and cell lysis and may play a role in the pathogenesis of GD. To investigate their involvement, we conducted flow cytometry on peripheral blood samples from 131 GD patients at various stages (disease onset, on antithyroid drugs, and in remission) and 97 age- and sex-matched healthy controls (HC). We analyzed NK cell subsets, activating (CD16, CD69, NKG2D, NKp30) and inhibitory receptors (CD161, NKG2A), degranulation (CD107a), and intracellular cytokines expression (interferon γ, tumor necrosis factor α). Statistical comparisons were made between GD patients and HC and across disease stages. GD patients had a higher frequency of total NK cells ( < 0.028) and CD56 NK cells ( < 0.01) but a lower frequency of CD56 NK cells ( = 0.005) compared to HC. NK cells in GD patients expressed activating receptors more frequently, except for NKG2D, but had decreased cytokine expression and degranulation ability. At GD onset, patients had higher frequencies of total NK cells, CD56 NK cells, and NK cells expressing activating receptors compared to patients receiving ATD treatment and those in remission. CD161 NK cells were lower at GD onset and returned to levels of HC following treatment. Correlation analysis revealed that free thyroxine (FT4) levels were inversely correlated with CD107a NK cells ( < 0.05) and positively correlated with CD69 NK cells ( < 0.01). These findings suggest that hyperthyroidism impairs NK cell degranulation, with the increased frequency of NK cells potentially compensating for their reduced function. This dysfunction may contribute to the unregulated immune response in GD, highlighting NK cells as a potential target for novel therapeutic strategies.
格雷夫斯病（GD）是一种自身免疫性疾病，由针对促甲状腺激素（TSH）受体的循环自身抗体（Ab）出现所驱动，从而导致甲状腺功能亢进。虽然抗甲状腺药物是GD唯一可用的治疗方法，但复发风险很高，而免疫学的进展可能为更有效的治疗铺平道路。自然杀伤（NK）细胞分为细胞毒性CD56和分泌细胞因子的CD56亚群，通过细胞因子产生和细胞裂解来调节免疫反应，可能在GD的发病机制中起作用。为了研究它们的参与情况，我们对131例处于不同阶段（疾病发作、服用抗甲状腺药物和缓解期）的GD患者以及97例年龄和性别匹配的健康对照（HC）的外周血样本进行了流式细胞术检测。我们分析了NK细胞亚群、激活受体（CD16、CD69、NKG2D、NKp30）和抑制性受体（CD161、NKG2A）、脱颗粒（CD107a）以及细胞内细胞因子表达（干扰素γ、肿瘤坏死因子α）。在GD患者和HC之间以及不同疾病阶段进行了统计学比较。与HC相比，GD患者的总NK细胞频率更高（<0.028），CD56⁺NK细胞频率更高（<0.01），但CD56⁻NK细胞频率更低（=0.005）。GD患者的NK细胞更频繁地表达激活受体，NKG2D除外，但细胞因子表达和脱颗粒能力降低。在GD发作时，与接受抗甲状腺药物治疗的患者和缓解期患者相比，患者的总NK细胞、CD56⁺NK细胞以及表达激活受体的NK细胞频率更高。CD161⁺NK细胞在GD发作时较低，治疗后恢复到HC水平。相关性分析显示，游离甲状腺素（FT4）水平与CD107a⁺NK细胞呈负相关（<0.05），与CD69⁺NK细胞呈正相关（<0.01）。这些发现表明，甲状腺功能亢进会损害NK细胞脱颗粒，NK细胞频率增加可能会补偿其功能降低。这种功能障碍可能导致GD中不受控制的免疫反应，突出了NK细胞作为新型治疗策略潜在靶点的地位。
