三种免疫抑制剂对HBV质粒感染小鼠HBV复制的影响

Impact of three immunosuppressors on HBV replication in HBV plasmid transfected mice

目的应用小鼠模型评价3种临床常用的免疫抑制剂对乙型肝炎病毒(HBV)复制的影响。方法利用高压水注射法将HBV质粒p AAV/HBV1.2导入Balb/C小鼠肝内,建立小鼠HBV复制模型;将Balb/C小鼠随机分成4组,每组10只,分别给予生理盐水(Saline)、FK506、DEX和CYP处理。1w后,将供体C57BL/6小鼠皮瓣移植至上述经免疫抑制剂或生理盐水处理的Balb/C小鼠,皮肤移植后继续使用上述免疫抑制剂或生理盐水至观察期结束。采用电化学免疫发光法检测血清HBs Ag、HBs Ab和HBc Ab水平,采用Real-time PCR法检测血清病毒载量。结果FK506、地塞米松和环磷酰胺处理小鼠移植皮瓣的存活时间分别为(21.50±3.09)d、(21.50±3.09)d和(21.40±1.52)d,分别较生理盐水处理组(8.67±1.86)d明显延长[P=0.037、P=0.000和P=0.000];FK506处理组小鼠HBV复制及其抗体产生与对照组无显著性差异,地塞米松处理组在药物处理期间能维持病毒复制,但停药后病毒DNA和HBs Ag迅速下降至检测水平以下,至观察终点仍未检出HBs Ab和HBc Ab阳性,环磷酰胺能明显延长小鼠HBV复制的持续时间,即使在停药后16 w血清HBV DNA和HBs Ag均维持在较高水平,HBc Ab和HBs Ab持续阴性。结论环磷酰胺而非FK506处理可在Balb/C小鼠模型中建立HBV持续复制模型。

Objective To evaluate the effect of three commonly used immunosuppressors on HBV replica- tion in mouse model. Methods pAAV/HBV1.2,a HBV plasmid,was introduced into livers of Balb/C mice by hy- drodynamic injection to establish HBV replication model. Animals were treated with dexamethasone （DEX）, tacrolimus （FK506）,cyclophosphamide （CYP） or saline from 6 days before plasmid injection to 10 weeks after injection. HBsAg,HBsAb and HBcAb were detected by electrochemiluminescence immunoassay （ECLIA）,and HBV DNA by real-time PCR. Results The survival time of the transplanted skin grafts in DEX,FK506,and CYP treated mice were （21.50±3.09）, （21.50±3.09 ） and （21.40±1.52） days, respectively, much longer than that of grafts in saline treated mice [（8.67±1.86） d,P=0.037,P=0.000 and P=0.000,respectively];HBV replication and antibody generation in FK506 treated mice was similar to that in control group;HBV rephcation was maintained at the high level in DEX treated mice during the treatment period,however,HBV DNA and HBsAg levels dropped rapidly after the medicine withdrawal,while HBsAb and HBcAb were negative throughout the observation period; In CYP treated mice,HBV replication was prolonged and HBV DNA and HBsAg were at high levels even at week 16 after CYP withdrawal,while HBsAb and HBcAb were negative throughout the observation period. Conclusion The persistent replication of HBV in BALB/c mice can be achieved by administration of CYP rather than FK506.