白细胞介素-33/ST2信号通路调控辅助T细胞/调节性T细胞免疫平衡参与慢性阻塞性肺疾病发病机制分析

Mechanism analysis of interleukin-33/ST2 signaling pathway regulating the immune balance of helper T cell/regulatory T cell in chronic obstructive pulmonary disease

目的探究基于白细胞介素-33(IL-33)/ST2信号通路激活树突状细胞(DCs)成熟,调控辅助T细胞17(Th17)/调节性T细胞(Treg)免疫平衡参与小鼠慢性阻塞性肺疾病(COPD)发病的临床机制。方法选择36只SPF级C57BL/6健康小鼠,随机选取12只作为健康对照组,其余小鼠用于制作COPD模型,采用香烟烟雾刺激和气道内注入脂多糖的方式建立COPD模型,以小鼠肺部压力-容积曲线移动或弹性程度降低为造模成功,将模型小鼠按照随机数字表法分为COPD组(n=12)和IL-33抗体干预组(n=12)。于造模开始第3周时为IL-33抗体组小鼠腹腔注射IL-33抗体,健康对照组和COPD组小鼠注射同等剂量生理盐水,于造模开始第28天在小鼠清醒状态下采集三组小鼠的内眦静脉从血液,使用PBS液冲洗三组小鼠右肺组织并收集支气管肺泡灌洗液(BALF),比较三组小鼠外周血、BALF中DCs、IL-33表达情况差异,采集肺组织甲醛固定后染色处理,光镜下观察肺组织病理变化。结果COPD组小鼠外周血、BALF中Th17/Treg比值均高于健康对照组和IL-33抗体干预组,差异有统计学意义(P<0.05);COPD组小鼠外周血、BALF中DCs成熟标志物CD80、CD86水平均高于健康对照组和IL-33抗体组,主要组织相容性复合体(MHC)-Ⅱ低于健康对照组和IL-33抗体组,差异有统计学意义(P<0.05);RT-PCR分析显示,COPD组小鼠IL-33灰度值高于健康对照组和IL-33抗体干预组,差异有统计学意义(P<0.05);三组小鼠气道炎症病理差异较大。结论调控IL-33/ST2信号通路可以激活DCs细胞成熟,恢复COPD小鼠Th17/Treg平衡,改善COPD小鼠炎症指标水平。

Objective To explore the clinical mechanism of interleukin-33(IL-33)/ST2 signaling pathway activating the maturation of dendritic cells(DCs)and regulating the immune balance of helper T cell 17(Th17)/regulatory T cell(Treg)in mice with chronic obstructive pulmonary disease(COPD).Methods A total of 36 SPF C57BL/6 healthy mice were selected,12 mice were randomly selected as the healthy control group,and the remaining mice were used to establish the COPD model.The COPD model was established by cigarette smoke stimulation and airway injection of lipopolysaccharide.The model mice were divided into COPD group(n=12)and IL-33 antibody intervention group(n=12)according to the random number table method.The mice in IL-33 antibody group were intraperitoneally injected with IL-33 antibody at the third week after modeling,and the mice in healthy control group and COPD group were injected with the same dose of normal saline.On the 28th day after modeling,the blood samples from the inner canthus vein of the three groups of mice were collected while the mice were awake.The right lung tissue of the three groups of mice was washed with PBS solution and bronchoalveolar lavage fluid(BALF)was collected.The differences in the expression of DCs and IL-33 in peripheral blood and BALF of the three groups of mice were compared.Results The Th17/Treg ratio in peripheral blood and BALF of mice in COPD group were higher than those in healthy control group and IL-33 antibody intervention group,with statistically signifcant differences(P<0.05).The levels of CD80 and CD86 in peripheral blood and BALF of mice in COPD group were higher than those in healthy control group and IL-33 antibody intervention group,and the major histocompatibility complex(MHC)-Ⅱwas lower than that in healthy control group and that in IL-33 antibody intervention group,with statistically signifcant differences(P<0.05).RT-PCR analysis showed that the gray value of IL-33 in COPD group was higher than that in healthy control group and IL-33 antibody intervention group,with statistically signifcant differences(P<0.05).The pathological differences of airway inflammation in the three groups of mice are great.Conclusion Regulating IL-33/ST2 signaling pathway can activate the maturation of DCs cells,restore Th17/Treg balance in COPD mice,and improve the level of inflammatory indicators in COPD mice.