B型肝炎病毒聚合酶削弱干扰素-α诱导的STAŢ激活

StephenW

Hepatitis B virus polymerase impairs interferon-α–induced STA T activation through inhibition of importin-α5 and protein kinase C-䆇§
B型肝炎病毒聚合酶削弱干扰素-α诱导的STAŢ通过激活抑制的importin-α5和蛋白激酶C-䆇§
    Jieliang Chen1,2,§,
    Min Wu2,§,
    Xiaonan Zhang2,
    Wen Zhang1,2,
    Zhanqing Zhang3,
    Lixiang Chen4,
    Jing He5,
    Ye Zheng6,
    Cuncun Chen1,2,7,
    Fan Wang1,2,
    Yunwen Hu1,5,
    Xiaohui Zhou1,4,
    Cong Wang2,
    Yang Xu8,
    Mengji Lu8,
    Zhenghong Yuan1,2,7,¶,*

Article first published online: 5 FEB 2013

DOI: 10.1002/hep.26064
    1    Key Laboratory of Medical Molecular Virology, Ministry of Education and HealthShanghai Medical College of Fudan University, Shanghai, China
    2    Research UnitShanghai Medical College of Fudan University, Shanghai, China
    3    Department of Liver DiseasesShanghai Medical College of Fudan University, Shanghai, China
    4    Center of Laboratory AnimalsShanghai Medical College of Fudan University, Shanghai, China
    5    Department of Pathogen Diagnosis and BiosafetyShanghai Medical College of Fudan University, Shanghai, China
    6    Department of Pathology, Shanghai Public Health Clinical CenterShanghai Medical College of Fudan University, Shanghai, China
    7    Institutes of Medical Microbiology and Biomedical Sciences, Shanghai Medical College of Fudan University, Shanghai, China
    8    Institute of Virology, University Hospital of Essen, Essen, Germany


Abstract

Treatment with exogenous interferon (IFN)-α is not effective in the majority of patients with chronic hepatitis B virus (HBV) infection. Recent evidence suggests that HBV has evolved strategies to block the nuclear translocation of signal transducer and activator of transcription (STAT) 1 to limit IFN-α–induced cellular antiviral responses. However, it remains unclear whether STAT1 translocation is impaired in chronic hepatitis B patients and what mechanisms are involved. Here we report that the expression of HBV polymerase (Pol) in human hepatic cell lines inhibited induction of IFN-stimulated genes and resulted in a weakened antiviral activity of IFN-α. Ectopic expression of Pol suppressed IFN-α–induced STAT1 serine 727 phosphorylation and STAT1/2 nuclear accumulation, whereas STAT1 tyrosine 701 phosphorylation, and STAT1-STAT2 heterodimer formation were not affected. Further studies demonstrated that Pol interacted with the catalytic domain of protein kinase C-δ (PKC-δ) and perturbed PKC-δ phosphorylation and its association with STAT1, which resulted in the suppression of STAT1 Ser727 phosphorylation. Moreover, Pol was found to interfere with nuclear transportation of STAT1/2 by competitively binding to the region of importin-α5 required for STAT1/2 recruitment. Truncation analysis suggested that the terminal protein and RNase H domains of Pol were able to bind to PKC-δ and importin-α5, respectively, and were responsible for the inhibition of IFN-α signaling. More importantly, the inhibition of STAT1 and PKC-δ phosphorylation were confirmed in a hydrodynamic-based HBV mouse model, and the blockage of IFN-α–induced STAT1/2 nuclear translocation was observed in HBV-infected cells from liver biopsies of chronic HBV patients. Conclusions: These results demonstrate a role for Pol in HBV-mediated antagonization of IFN-α signaling and provide a possible molecular mechanism by which HBV resists the IFN therapy and maintains its persistence. (HEPATOLOGY 2013;)

StephenW

了姐俩Chen1，2，§，
    闵吴，§，
    孝南区Zhang2，
    温Zhang1，2，
    Zhanqing Zhang3，
    丽香Chen4，
    京HE5，
    叶Zheng6，
    寸寸Chen1，2,7，
    范王，2，
    马蕴雯HU1，5，
    小辉Zhou1，4，
    丛Wang2，
    杨Xu8，
    蒙冀Lu8，
    正虹媛，2,7¶，

在网上公布：2013年2月5日

DOI：10.1002/hep.26064
    1    医学分子病毒学重点实验室，教育部医学学院，上海复旦大学，中国教育和HealthShanghai
    2    研究UnitShanghai医学院，上海复旦大学，中国
    3    医学院，复旦大学，中国上海，肝DiseasesShanghai
    4    中心实验室AnimalsShanghai医学院，复旦大学，上海，中国
    5    病原诊断及部，中国复旦大学，上海医学院BiosafetyShanghai
    6    病理科，上海公共卫生临床CenterShanghai医学院，复旦大学，上海，中国
    7    医学微生物学和生物医学科学，复旦大学上海医学院，上海，中国
    8    埃森，德国埃森大学医院的病毒学研究所，



与外源性干扰素（IFN）-α治疗慢性乙型肝炎病毒（HBV）感染的患者多数是没有有效的。最近的证据表明，乙肝病毒已经发展战略，以阻止核易位限制IFN-α诱导的细胞抗病毒反应信号转导和转录激活子（STAT）1。但是，目前还不清楚是否STAT1易位受损，慢性乙型肝炎患者和涉及到什么样的机制。在这里，我们报告说，在人类肝细胞系中表达的HBV聚合酶（聚合酶）抑制诱导IFN-刺激的基因，并导致弱化的IFN-α的抗病毒活性。异位表达的波尔抑制IFN-α诱导的STAT1丝氨酸727磷酸化和STAT1 / 2核积累，而STAT1的酪氨酸701的磷酸化，STAT1，STAT2异源二聚体的形成并没有受到影响。进一步的研究表明，聚合酶的催化结构域的蛋白激酶C-δ（PKC-δ）和扰动的PKC-δ的磷酸化和其与STAT1，STAT1丝氨酸727（Ser727）磷酸化的抑制，导致互动。此外，波尔发现STAT1 / 2的核运输竞争性结合STAT1 / 2招聘要求该地区的importin-α5干扰。截断分析表明，终端蛋白质和核糖核酸酶H域的波尔能够绑定到PKC-δ的importin-α5，分别负责抑制IFN-α的信号。更重要的是，抑制STAT1和PKC-δ的磷酸化被证实在流体动力学为基础的HBV的小鼠模型，观察HBV感染的细胞和IFN-α诱导的STAT1 / 2的核转堵塞的慢性HBV的肝活检患者。结论：这些结果表明聚合酶在HBV-介导的的IFN-α的信号明显对抗的作用，并提供一个可能的分子机制，通过该机制，HBV抗IFN治疗，并保持其持久性。 （2013年肝病;)