Department of Respiratory Medicine, The Second Hospital of Shandong University, Jinan, Shandong, China.
Department of Pediatrics, Qilu Children's Hospital of Shandong University, Jinan, Shandong, China.
Immun Inflamm Dis. 2023 Jun;11(6):e903. doi: 10.1002/iid3.903.
The aryl hydrocarbon receptor (AhR) is a critical regulator of the pathogenesis of autoimmune disorders. We aimed to investigate the therapeutic effect of the AhR agonist tapinarof during the development of systemic lupus erythematosus (SLE).
MRL/lpr mice were intraperitoneally injected with 1 or 5 mg/kg tapinarof for 6 weeks. Kidney histopathology was evaluated using hematoxylin and eosin (H&E) and Periodic-Acid-Schiff (PAS) staining. Immunofluorescence microscopy was performed to detect immune complex renal depositions. Flow cytometry (FCM) analysis was carried out to determine the proportions of T and B cell subsets. Realtime qPCR was used to quantify the expression of Tfh cell-associated genes. We conducted an in vitro polarization experiment to observe the effect of tapinarof on Tfh differentiation. Western blotting was used to detect the expression of target proteins.
We found that tapinarof treatment ameliorated lupus phenotypes, including splenomegaly, lymph node enlargement, kidney damages, immune complex deposition, and excessive secretion of antibodies. Additionally, we showed that Treg subpopulation frequencies significantly increased in MRL/lpr mice treated with tapinarof, while the proportion of Th1/Th2 cells was reduced after tapinarof administration. Moreover, tapinarof suppressed Tfh cell differentiation and germinal center (GC) reaction in vivo. The inhibitory effect of tapinarof on Tfh cells was further verified in the in vitro Tfh cell polarization experiment. Realtime qPCR revealed that tapinarof repressed the expression of Tfh signature genes. Mechanistically, tapinarof significantly inhibited the phosphorylation levels of JAK2 and STAT3. The capacity for Tfh differentiation was partially rescued by the STAT3 activator Colivelin TFA. Furthermore, our in vitro Tfh polarization experiments indicated that tapinarof suppressed Tfh cell development in SLE.
Our data demonstrated that tapinarof modulated the JAK2-STAT3 pathway to suppress Tfh cell differentiation for the treatment of lupus symptoms in MRL/lpr mice.
芳香烃受体（AhR）是自身免疫性疾病发病机制的关键调节因子。我们旨在研究 AhR 激动剂 tapinarof 在系统性红斑狼疮（SLE）发展过程中的治疗作用。
MRL/lpr 小鼠经腹腔注射 1 或 5mg/kg tapinarof 治疗 6 周。采用苏木精和伊红（H&E）及过碘酸雪夫（PAS）染色评估肾脏组织病理学变化。免疫荧光显微镜检测免疫复合物在肾脏中的沉积。流式细胞术（FCM）分析确定 T 和 B 细胞亚群的比例。实时 qPCR 用于定量检测滤泡辅助性 T 细胞（Tfh）相关基因的表达。我们进行了体外极化实验，观察 tapinarof 对 Tfh 分化的影响。Western blot 检测靶蛋白的表达。
我们发现 tapinarof 治疗改善了狼疮表型，包括脾肿大、淋巴结肿大、肾脏损伤、免疫复合物沉积和抗体过度分泌。此外，我们发现 tapinarof 治疗后 MRL/lpr 小鼠中 Treg 亚群频率显著增加，而 tapinarof 给药后 Th1/Th2 细胞比例降低。此外，tapinarof 抑制体内 Tfh 细胞分化和生发中心（GC）反应。体外 Tfh 细胞极化实验进一步验证了 tapinarof 对 Tfh 细胞的抑制作用。实时 qPCR 显示 tapinarof 抑制 Tfh 特征基因的表达。机制上，tapinarof 显著抑制 JAK2 和 STAT3 的磷酸化水平。STAT3 激活剂 Colivelin TFA 部分挽救了 Tfh 细胞的分化能力。此外，我们的体外 Tfh 极化实验表明，tapinarof 抑制了 SLE 中 Tfh 细胞的发育。
我们的数据表明，tapinarof 通过调节 JAK2-STAT3 通路抑制 Tfh 细胞分化，从而治疗 MRL/lpr 小鼠的狼疮症状。
