阻断程序性死亡蛋白-1及其配体信号通路增强慢性乙型肝炎病毒感染小鼠的抗病毒免疫

目的 建立慢性HBV感染的小鼠模型,体内阻断PD-1/PD-L1信号通路,增强模型小鼠的抗病毒免疫,探寻慢性乙型肝炎治疗的新方法.方法 以流体动力学法给C57BL/6小鼠尾静脉注射pAAV/HBV1.2-GFP,不同时间点检测血清和组织中各种HBV标志物的表达.给模型小鼠腹腔注射抗PD-L1的单克隆抗体,检测小鼠血清ALT和HBV DNA载量的变化.两计量资料比较采用t检验.结果 成功建立慢性HBV感染小鼠模型,建模90 d后仍能检测到血清HBsAg的表达及高载量的HBV DNA.体内阻断PD-1/PD-L1信号通路后,小鼠血清ALT水平明显上升(t=5.436,P＜0.01),同时,血清HBV DNA载量显著下降,t=4.919,P＜0.01,差异有统计学意义.结论 慢性HBV感染小鼠模型是研究HBV感染免疫耐受机制及治疗方法较好的工具;体内阻断PD-1/PD-L1信号通路,能增强慢性HBV感染小鼠的抗病毒免疫,可能成为慢性乙型肝炎治疗的新策略.

Enhancement of antiviral immunity in HBV mouse model by blocking PD-1/PD-L1 signaling pathway

Objective To establish a mouse model for human chronic HBV infection,and to investigate the role ofPD-1/PD-L1 signaling pathway in antiviral immunity.Methods A mouse model was established by hydrodynamic injection of the plasmid pAAV/HBV 1.2-GFP into the tail vein of C57BL/6 mice,HBV markers were assayed at different time points after injection.After intraperitoneal injection of anti-PD-L1 monoclonal antibody,the serum ALT,and HBV DNA in the serum,liver and kidney were assayed.Results The chronic HBV infection mouse model were established successfully,serum HBsAg and high load of HBV DNA were detectable 90 days after plasmid injection.After blocking of the PD-1/PD-L1 pathway,the sernm ALT level of mice were significantly increased(P＜0.01),and the HBV DNA load in serum(P＜0.01),liver(P＜0.05)and kidney(P＜0.05)were decreased significantly.Conclusion Blocking the PD-1/PD-L1 signaling pathway Can enhance antiviral response in mice with chronic HBV infection.