芳香烃受体及其配体VAF347在实验性自身免疫性神经炎中的作用

The role of aryl hydrocarbon receptor and its ligand VAF347 in experimental autoimmune neuritis

目的研究芳香烃受体(aryl hydrocarbon receptor,AhR)及其配体VAF347在大鼠实验性自身免疫性神经炎(experimental autoimmune neuritis,EAN)中的作用。方法运用免疫组织化学染色、流式细胞以及实时荧光定量PCR技术,检测VAF347治疗前后EAN大鼠坐骨神经AhR+、IL-17+、Foxp3+、CD3+和ED1+细胞数目的变化,脱髓鞘情况以及外周血和腹股沟淋巴结IL-17、Foxp3、IFN-γ、TGF-β1、IL-4和IL-10的表达变化。结果 VAF347明显改善EAN大鼠临床症状。VAF347激活AhR后,坐骨神经局部AhR+、IL-17+及CD3+细胞数和比例明显下降,ED1+和Foxp3+细胞数降低但其比例上升;外周血和淋巴结CD4+IL-17+细胞比例下降,而CD4+Foxp3+细胞比例明显上升。VAF347治疗使淋巴结IL-17和IFN-γ表达明显降低,TGF-β1和Foxp3表达显著增加,而IL-4和IL-10的表达在治疗前后未发生明显变化。结论 VAF347明显减轻EAN全身炎症反应,改善了临床症状,这种治疗作用可能与VAF347激活AhR后调节Foxp3+和IL-17+细胞发挥抗炎作用有关,为自身免疫性神经炎的治疗提供了新的思路。

In this study, we aim to explore the roles of aryl hydrocarbon receptor （AhR） and its water-soluble ligand VAF347 in experimental autoimmune neuritis （EAN） rats. The demyelination and accumulations of AhR＋, IL-17＋, Foxp3＋, CD3＋ and ED1＋ ceils in sciatic nerves of EAN rats with or without VAF347 treatment were observed by using immunohistochemistry. Then, the expression levels of IL-17, Foxp3, IFN-γ TGF-β1, IL-4 and IL-10 in peripheral blood and inguinal lymph nodes were investigated by flow cytometric analysis and quantitative real-time PCR. Compared with PBS-treated rats, the clinical scores and demyelination were greatly reduced in VAF347-treated rats; the accumulations and percentages of AhR＋, IL-17, CD3＋ ceils in sciatic nerves were significantly decreased by VAF347, while the ED 1 ＋ and Foxp3＋ cells presented higher percentage and lower accumulation. VAF347 suppressed CD4＋IL-17＋ cell accumulation, but improved CD4＋Foxp3＋ cell accumulation in peripheral blood and inguinal lymph nodes of EAN rats. When compared with the inguinal lymph node cells from PBS-treated rats, ceils from VAF347- treated rats secreted higher amounts of TGF-β1 and Foxp3, but lower amounts of IL-17 and IFN-γ. IL-4 or IL-10 did not demonstrated any difference before and after treatment. Those results suggested that AhR activation by VAF347 can relieved the systemic inflammation response and clinical symptoms of EAN rats, which may due to the antiinflammatory effects of Foxp3＋ and IL-17＋ cells regulated by VAF347-induced AhR activation. Thus VAF347 could be considered as a promising option in the therapy of human autoimmune-mediated neuropathies.