研究证实，较强的、持久的特异性HCV特异性T细胞免疫应答在HCV感染患者和动物模型中对HCV的清除至关重要，短暂、较弱的免疫应答易出现持续感染，导致发展为慢性丙肝。研究证实gMDSCs在HCV感染的发病中起着重要作用，但其与丙型肝炎患者抗病毒治疗（特别是DAA）临床预后的关系尚不十分清楚。我们前期研究发现，CHC初治患者gMDSCs数值明显高于抗病毒后达到SVR的患者，这与抗病毒后临床疗效密切相关。据此我们假设：：HCV感染时患者外周血gMDSC频率增高，随着DAAs治疗呈现一定的动态变化，且与机体HCV特异性CTL功能变化密切相关，可通过Arginase-1途径抑制T细胞应答。通过其与DAAs抗病毒疗效、机体HCV特异性CTL功能及PD1等抑制性受体变化的相关性分析，可作为预测CHC临床转归的免疫学指标。该研究对于发现新的预测抗病毒药物的标志物和建立新的HCV免疫治疗策略具有重要意义。

It is well know that a strong and constantly HCV specific T cell immune response was crucial for eliminating hepatitic C virus in HCV infected patients and animal models, On the contrary, a weak and transient immune response always lead to constant infection and chronic hepatitis. Lots of studies have already found that gMDSCs played an important role in the processing of HCV infection. However, the correlation between gMDSCs and the therapeutic efficiency of antiviral therapy (especially the oral antiviral drugs) in CHC patients is still unclear. In our previous study, we found that the frequency of gMDSCs in naive CHC patients were significantly higher than those antiviral treatment CHC patients who achieved SVR. So we hypothesized : the frequency of peripheral gMDSCs were significantly increased in naive HCV infected patient, then, with the different treatment efficiency of DAA, the frequency of peripheral gMDSCs showed an different dynamic changes, which closely related with HCV specific CTL and could be blocked by inhibiting Arginase-1 pathway. At last, by analysising the correlation between gMDSCs and antiviral efficacy of DAAs, state of HCV specific CTL function and the changes of PD1 inhibitory receptor, the changes of gMDSCs might be a immunology biomarker to predict the clinical outcome in CHC patients. This study will provide an important marker that could predict the outcome of antiviral therapy and establish a new treatment strategies.