干扰素-γ基因敲除小鼠慢性乙型肝炎病毒复制模型的建立

An IFN-γ knockout mouse model of HBV persistence

目的:建立干扰素-(interferon-,IFN-)基因敲除小鼠慢性乙型肝炎病毒(hepatitis B virus,HBV)复制模型.方法:IFN-基因敲除(IFN--/-)小鼠繁育并抽提组织DNA进行聚合酶链反应(PCR)及凝胶电泳鉴定基因型.IFN--/-小鼠纯合子9只与野生型C57BL/6小鼠9只同时高压水注射pAAV/HBV1.2质粒,按既定时间点采血检测乙型肝炎表面抗原(hepatitis B virus surface antigen,HBsAg)、乙型肝炎e抗原(hepatitis B virus e antigen,HBeAg)和HBV DNA.血清HBsAg和HBeAg表达水平由电化学发光法进行定量检测.经抽提血清总DNA后,血清HBV DNA由定量PCR进行检测.结果:本实验室繁殖的IFN--/-小鼠均为纯合子基因型.IFN--/-小鼠和野生型C57BL/6小鼠血清中HBsAg、HBeAg和HBV DNA持续存在,转染后第40天仍阳性.但是,IFN--/-小鼠血清HBsAg表达水平高于C57BL/6野生小鼠(40天时,P=0.042);IFN--/-小鼠血清HBV DNA持续高水平复制,明显高于C57BL/6野生小鼠(第25天时,P=0.012;第40天时,P=0.039).两组小鼠血清HBeAg表达水平无差异.结论:IFN--/-小鼠慢性HBV复制模型成功建立,并揭示了IFN-在慢性HBV感染中可抑制HBV复制.

AIM： To develop an interferonq （IFN-γ） knock- out mouse model of HBV persistence. METHODS： Nine IFN-T knock-out （IFN-γ/） mice were injected hydrodynamically with 10 micrograms of pAAV/HBV1.2 DNA via the tail vein. Nine wild-type C57BL/6 mice were used as controls. After injection, blood samples were regularly taken to monitor serum levels of HB-sAg, HBeAg and HBV DNA. HBsAg and HBeAg were determined by electrochemiluminescence immunoassay （ECLIA） on an E170 analyzer. To- tal DNA was extracted from serum samples and used for detection of HBV DNA by real-time PCR. RESULTS： Serum HBsAg, HBeAg and HBV DNA in IFN-γ/ mice were continuously posi- tive until 40 d after the injection of the pAAV/ HBV1.2 DNA. The levels and duration of serum HBsAg, HBeAg and HBV DNA in IFN-γ,-/- mice were similar to those in control mice. Serum HBsAg levels in IFN-γ-/- mice were higher than those in wild-type C57BL/6 mice on day 40 post injection （P = 0.042）. Serum HBV DNA levels in IFN-γ,/ mice were persistently higher than those in wild-type C57BL/6 mice （P = 0.012, on day 25; P = 0.039, on day 40）. No significant difference was observed in serum HBeAg levels between IFN-γ/ mice and control mice. CONCLUSION： We have successfully developed an IFN-γ/ mouse model of HBV persistence. Our data suggest that IFN-7 could suppress HBV replication during chronic HBV infection.