阿奇霉素对肺移植术后闭塞性细支气管炎小鼠Th17/Treg平衡的影响

摘要

目的 探讨阿奇霉素对肺移植术后闭塞性细支气管炎的影响及对辅助性T(Th)17细胞/调节性T细胞(Treg)平衡的作用.方法 无特定病原体(SPF)级C57BL/6小鼠24只、Balb/c小鼠48只.以C57BL/6小鼠为供体,Balb/c小鼠为受体,将Balb/c小鼠随机分成4组,每组12只,分别为实验对照组(C组)、阿奇霉素对照组(Cazm组)、移植组(T组)、移植治疗组(Tazm组).T组和Tazm组建立气管异位移植模型模拟肺移植术后闭塞性细支气管炎.于移植后1 d起,给予Cazm组和Tazm组小鼠阿奇霉素30 mg/kg每周灌胃3次,分别于移植后14 d和28 d取出移植气管,收集外周血.取出移植气管行苏木素-伊红(HE)染色观察病理学变化,采用逆转录聚合酶链反应(RT-PCR)法检测外周血细胞ROR-γt和Foxp3信使核糖核酸(mRNA)的表达,采用酶链免疫吸附试验(ELISA)法检测血浆Th17、Treg相关细胞因子的水平变化.结果 气管异位移植后,与C组气管相比,T组和Tazm组移植气管出现闭塞并有炎症浸润,Tazm组程度要轻于T组.与T组相比,Tazm组ROR-γt mRNA表达水平降低(P<0.05),两者Foxp3 mRNA表达差异无统计学意义(P>0.05).与T组相比,Tazm组细胞因子白细胞介素(IL)-6、IL-17水平降低(均为P<0.05).结论 阿奇霉素持续治疗可延缓移植后闭塞性细支气管炎的进展,可能与抑制Th17细胞分化及其介导的炎症作用相关.%Objective To evaluate the effect of azitromycin upon the bronchiolitis obliterans and T helper (Th)17/regulatory T cell (Treg) balance after lung transplantation. Methods Twenty-four specific pathogen free(SPF) C57BL/6 mice were used as the donors and 48 Balb/c mice were utilized as the recipients. The Balb/c mice were randomly divided into the control (C group), azitromycin control (Cazm group), transplantation (T group) and transplantation + azitromycin groups (Tazm group), 12 mice in each group. In the T and Tazm groups, heterotopic tracheal transplantation models were established to simulate bronchiolitis obliterans after lung transplantation. From 1 d post-transplantation, intragastric administration of azitromycin was given at a dose of 30 mg/kg three times per week in the Cazm and Tazm groups. At 14 and 28 d after transplantation, the transplanted trachea was removed and peripheral blood was collected. The tracheal sample was prepared for hematoxylin-eosin (HE) staining for pathological observation. The expression levels of ROR-γt and Foxp3 messenger ribonucleic acid (mRNA) in the peripheral blood were quantitatively measured by reverse transcription polymerase chain reaction (RT-PCR). The variation in the related cytokines levels of Th17 cells and Treg in the plasma was detected by enzyme linked immunosorbent assay (ELISA). Results After heterotopic tracheal transplantation, compared with the C group, thetracheal occlusion accompanied with inflammatory infiltration was observed in the T and Tazm groups. The severity of relevant symptoms in the Tazm group was slighter than that in the T group. Compared with the T group, the expression level of ROR-γt mRNA in the Tazm group was significantly down-regulated (P<0.05). No statistical significance was identified in the expression of Foxp3 mRNA between two groups (P>0.05). Compared with the T group, the levels of interleukin (IL)-6 and IL-17 cytokines in the Tazm group were significantly down-regulated (all P<0.05). Conclusions Persistent therapy of azitromycin can delay the progression of bronchiolitis obliterans after transplantation, which is probably associated with inhibiting Th17 cell differentiation and inflammation.