中文摘要：

目的探讨骨髓来源抑制性细胞（myeloid-derived suppressor cells,MDSCs）在CVB3诱导的病毒性心肌炎（viral myocarditis,VMC）中的保护作用。方法通过流式细胞术分选获得足量MDSCs,体外证实具有免疫抑制功能后行体内转输实验,观察疗效及免疫机制。结果与对照PBS组相比,MDSCs处理组体质量呈上升趋势,肌酸激酶（CK）活性明显降低（P〈0.001）,心脏局部炎症浸润及坏死病灶显著减少,7天生存率高达70%（P〈0.01）,而心肌病毒滴度无明显改变,却上调了CD4＋FoxP3＋调节性T细胞比例。结论 MDSCs可显著改善CVB3诱导的病毒性心肌炎,有望成为心肌炎防治的新型策略和手段。

英文摘要：

In this study, we aimed to investigate the protective effects of myeloid-derived suppressor cells （MDSCs） in CVB3-infected mice. Firstly, high purity of MDSCs was obtained by FACS sorting. Following evaluating their inhibitory effects on T cell proliferation in vitro, MDSCs were intravascularly injected into CVB3-infected mice on day 3, and the severity of viral myocarditis （VMC） in cell recipient mice were carefully detected. We found that, compared with control group, MDSCs-treated mice exhibited slight weigh body increase, dramatic decrease of serum index CK level, significant alleviation of myocardial inflammation and necrosis, and robust improve of survival rate, indicating the alleviated myocarditis. Then we further investigated the underlying mechanisms and observed that MDSCs transfer could significantly enhance the percentage of splenic CD4~Foxp3＋ regulatory T （Treg） ceils. Our study may shed some light on the protective role of MDSCs in CVB3-induced myocarditis, and may provide a possible therapeutic strategy for viral myocarditis.