乙型肝炎病毒及其抗原成分对干扰素信号传导途径分子和抗病毒蛋白表达的影响

The influence of HBV and its antigens on the expressions of JAK-STAT signal transduction pathway molecules and antiviral proteins of IFN alpha

目的了解HBV及其抗原成分对干扰素（IFN） α Janus激酶-信号传导和转录激活子（JAK-STAT）信号传导途径分子和抗病毒蛋白表达可能存在的影响。方法以人肝胚瘤细胞株HepG2细胞为研究对象，分别经质粒转染（以能够表达完整HBV病毒颗粒或HBsAg、HBcAg的质粒pSM2、pHBS2-S和pHBc-EGFP）、病毒感染（以HepG2．2．15细胞培养上清液感染HepG2细胞，其含有完整HBV病毒颗粒和HBV抗原）以及与HBV抗原直接接触刺激等方式处理不同组HepG2细胞，以Northern blot和RT-PCR等方法分析各处理组HepG2细胞的IFN α应答情况，如检测抗病毒蛋白【如粘病毒抵抗蛋白A（MxA）、2＇-5＇寡腺苷酸合成酶（2＇-5＇OAS）、9-27等】和JAKSTAT信号传导途径分子（如STATl）的表达。对数据进行t检验。结果转染pSM2、pHBS2-S和pHBc-GFP质粒后，HepG2细胞能够表达完整的HBV颗粒或HBV抗原，且随着转染时间的延长，HBV颗粒或抗原表达量逐步增多，转染48、96h的细胞培养上清液中HBsAg的S／CO值为0．81±0．1l和2．35±0．33（t=lO．84，P〈0．05），HBeAg的S／CO值为0．69±0．06和1．79±0．13（t=18．82，P〈0．05）。Northemblot分析提示HepG2细胞能够表达IFNα抗病毒蛋白MxA、2’，5’OAS、9-27等，但质粒转染、病毒感染和HBV抗原直接接触刺激的HepG2细胞，IFNQ抗病毒蛋白MxA、2’，5’OAS、9-27等的表达量明显减低，且随着转染时间的延长而进一步减低；此外，STATl的表达也随着HBV颗粒或HBV抗原的表达而受到抑制。结论在体外细胞模型中，HBV及其抗原成分影响IFNα JAK-STAT信号传导途径分子和抗病毒蛋白的表达；HBV具有拮抗或反作用于IFNα抗病毒活性的机制。

Objective To investigate the possible influence of HBV and its antigens on the expres- sions of JAK-STAT signal transduction pathway molecules and the antiviral proteins of IFN α. Methods The HepG2 cells were transfected with pSM2, pHBS2-S and pHBc-EGFP plasmids which express HBV whole particles or S-antigen, Pre-S antigen and core antigens. The infectious supernatant from HepG2.2.15 cells and the pured HBV proteins which contained the S, Pre-S antigens were used to treat the HepG2 cells. Northern blot and RT-PCR were applied to analyse the expresssions of the antiviral proteins MxA, 2＇ -5＇ OAS, 9-27 and the JAK-STAT signal transduction pathway molecules STAT1 in HepG2 cells responded to the IFN c~ treatment. Results The HepG2 cells transfected with pSM2, pHBS2-S and pHBc-EGFP plasmidscould express whole HBV paiticles and HBsAg, Pre-S antigen and HBcAg. The quantitation of expressed HBV particles and antigens increased significantly during the course of transfecfion. Northern blot hybridiza- tion analysis indicated that the HepG2 cells expressed IFNα antiviral proteins MxA, 2＇ -5＇ OAS and 9-27. When transfected with pHBV-dimer, pHBS2-S, pHBc-EGFP plasmids, the IFNAantiviral proteins MxA, 2＇ -5＇ OAS and 9-27 in transfected cells were reduced greatly as compared to the un-transfected HepG2 cells, and the expressed antiviral proteins decreased sharply with the development of transfection time. Furthermore, the expression of IFN α JAK-STAT signal transduction pathway molecule STAT1 was also inhibited with the expression of HBV particles and HBV antigens in transfected HepG2 cells. Conclu- sions The HBV and its antigens influence the expressions of IFN α JAK-STAT signal transduction pathway molecules and antiviral proteins in the hepatocellular models in vitro. It is idicated that HBV might possess the activity to antagonise or counteract the IFN α antiviral action.