血管活性肠肽调控CD4^+CD25^+Treg/Th17平衡对实验性自身免疫性脑脊髓炎防治作用的影响

The effect of vasoactive intestinal peptide(VIP) on the regulation of CD4^+ CD25^+ Treg/Th17 balance in the prevention and treatment of experimental autoimmune cerebrospinal meningitis(EAE)

目的探讨血管活性肠肽(vocative intestinal peptide,VIP)调控CD4^+CD25^+Treg/Th17平衡对防治实验性自身免疫性脑脊髓炎(experimental autoimmune encephalomyelitis,EAE)的影响。方法 60只健康雌性wistar大鼠随机分成正常对照组、EAE对照组、VIP低剂量防治组和VIP高剂量防治组。利用髓鞘碱性蛋白(MBP)^+完全福氏佐剂(CFA)诱导建立EAE模型。自造模当日起,每隔一日分别对VIP低、高剂量防治组大鼠腹腔注射VIP 4nmol/kg(0.2 m L)、16 nmol/kg(0.8 m L),正常对照组及EAE对照组注射0.8 m L生理盐水,连续10 d。观察大鼠发病情况;HE染色观察脑组织基本病理改变;流式细胞仪检测脾组织CD4^+CD25^+Treg、Th17细胞比例;ELISA法检测脑组织中TGF-β1、IL-17A因子含量变化。结果与EAE对照组比较,VIP各剂量防治组大鼠发病潜伏期延长、进展期缩短、发病高峰期神经功能障碍评分(NDS)降低;HE染色显示正常对照组大鼠脑组织中未见炎细胞浸润,VIP各剂量防治组大鼠脑组织中炎细胞浸润程度较EAE组明显下降;与EAE对照组比较,VIP各剂量组大鼠脾组织中CD4^+CD25^+Treg细胞亚群比例升高,Th17细胞亚群比例降低,且各组间存一定的量效关系;VIP各剂量组大鼠脑组织中TGF-β1含量较EAE组明显升高,IL-17A含量较EAE组明显降低,且各组间存在一定剂量依赖关系。结论 VIP通过上调CD4^+CD25^+Treg细胞比例,促进TGF-β1因子分泌,同时下调Th17细胞比例,抑制IL-17A因子表达,从而减轻脑组织炎症细胞的浸润程度,发挥对EAE的防治作用。

Objective ： To explore the effect of vasoactive intestinal peptide（ VIP） on the regulation of CD4~＋CD25~＋Treg / Th17 balance in the prevention and treatment of experimental autoimmune cerebrospinal meningitis（ EAE）.Methods 60 healthy female Wistar rats were randomly divided into normal control group,EAE control group,VIP lowdose group and VIP high-dose group. Used of myelin basic protein（ MBP） ~＋ completely adjuvant（ CFA） to establish EAE model. Since building on,the low and high-dose VIP groups were with intraperitoneal injection of every other day respectively VIP 4 nmol / kg（ 0. 2 mL）,16 nmol / kg（ 0. 8 mL）,normal control group and EAE group with 0. 8 mL saline,10 days in a row. Record the incubation period,progression and the peak of neurological dysfunction score（ NDS） changes of rats; the pathological changes in brain at the morbidity peak of rats; the proportion of CD4~＋CD25~＋Treg / Th17 cells in spleen tissues with Flow cytometry; the cytokine levels of TGF-β1、IL-17 A in brain tissue. Results the incubation period were extended,the progression and the peak nerve dysfunction score were shortened in VIP each dose group; In normal control group,there was no inflammatory cell infiltration in the brain tissue. The degree of infiltration of inflammatory cells in the VIP control groups were significantly lower than that in the EAE group; Compared with the EAE control group,the proportion of CD4~＋CD25~＋Treg cells in the spleen tissue of VIP each dose group increased,the proportion of Th17 cells decreased,and being a dose-response relationship; The cytokine levels of TGF-β1 in brain tissue were increased and the levels of IL-17 A were reduced in VIP each dose group,being a dose-response relationship; Conclusion through upregulating of CD4~＋CD25~＋Treg cells,promoting the secretion of TGF-β1 factor and cut ting the proportion of Th17 cells,inhibiting the expression of cytokines IL-17 A,VIP reduced brain tissue inflammatory cell infiltration,and played a role in prevention and treatment of EAE.