白细胞介素-10基因修饰的未成熟树突状细胞诱导自身免疫性心肌炎特异性耐受的实验研究

目的探讨白细胞介素(IL)-10基因修饰的未成熟树突状细胞(iDC)对实验性自身免疫性心肌炎的作用。方法从Lewis大鼠骨髓培养成熟树突状细胞(mDC)和iDC,pcDNA3-IL-10质粒转染iDC。分别将2×106 mDC、iDC、pcDNA3-iDC、pcDNA3-IL-10-iDC或PBS回输5天前以猪心肌肌球蛋白免疫的实验性自身免疫性心肌炎大鼠体内。3周后观察心肌炎症、超声心动图、Th1/Th2细胞因子、主要组织相容性Ⅱ(MHC-Ⅱ)类分子及共刺激分子表达。以T细胞增殖实验及过继转移实验检测pcDNA3-IL-10-iDC诱导耐受的抗原特异性。结果IL-10基因修饰的iDC显著抑制抗原特异性T细胞增殖,pcDNA3-IL-10-iDC治疗后实验性自身免疫性心肌炎大鼠心肌炎症显著减轻,心功能改善,MHC-Ⅱ、共刺激分子表达显著降低,脾细胞分泌细胞因子呈Th2型。结论IL-10基因修饰的iDC可诱导实验性自身免疫性心肌炎产生抗原特异性耐受,其机制与IL-10诱导的Th1/Th2偏离及MHC-Ⅱ、共刺激分子表达下调等有关。

IL-10 gene modification on immature dendritic cells induces antigen-specific tolerance in experimental autoimmune myocarditis

OBJECTIVE: To investigate whether IL-10 gene modification on immature dendritic cells (iDC) could induce autoimmune tolerance in rat experimental autoimmune myocarditis (EAM). METHODS: EAM was induced by cardiac myosin immunization on day 0 and day 7 in rats. A total of 2 x 10(6) mature DC (mDC), iDC, pcDNA3 transfected iDC, pcDNA3-IL-10 transfected iDC or PBS were injected intravenously at 5th immunization day. Three weeks later, echocardiography and HE staining were performed to observe the cardiac function and myocardial inflammation. Th1/Th2 cytokines were detected by ELISA and MHC-II molecules, costimulatory molecules were identified by flow cytometry. In vitro T lymphocyte proliferation assay and adoptive transfer of DCs were performed to determine the antigen specific tolerance induced by IL-10 gene modification on iDCs. RESULTS: EAM rats treated with pcDNA3-IL-10 transfected iDC showed improved cardiac function and reduced inflammatory cells infiltration into myocardium. Moreover, lower Th1 and higher Th2-type response was induced, MHC-II and costimulatory molecules down-regulated and antigen specific immunological responses towards cardiac myosin inhibited in pcDNA3-IL-10-iDC treated EAM rats. CONCLUSION: Treatment with IL-10 gene modified iDCs could ameliorates EAM by inducing Th2 polarization and down-regulation of MHC-II molecules and costimulatory molecule expressions.