Hepatitis C virus non-structural 3/4A protein interferes with intrahepatic interferon-γ production
Hepatitis C virus non-structural 3/4A protein interferes with intrahepatic interferon-γ production
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DOI：
10.1136/gut.2010.232116
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发表时间：
2012-04-01
期刊：
影响因子：
24.5
通讯作者：
Sallberg, Matti
中科院分区：
文献类型：
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作者：
Brenndorfer, Erwin Daniel;Brass, Anette;Sallberg, Matti
已知丙型肝炎病毒的非结构（NS）3/4A蛋白酶/解旋酶通过切割CARD衔接子诱导IFN β（Cardif）、T细胞蛋白酪氨酸磷酸酶（TC-PTP）和含TIR结构域的衔接子诱导IFN β（TRIF）来调节感染肝细胞中的信号传导途径，目的通过分析小鼠肝内炎症反应，研究NS 3/4A对肝细胞内和细胞间信号传导的影响，方法采用Western blot、ELISA、实时荧光定量PCR、流式细胞术和生存监测等方法，检测LPS/D-半乳糖胺（D-galN）或TNF α/D-galN处理的NS 3/4A转基因（Tg）小鼠肝内免疫功能的变化。进行细胞因子或针对信号传导组分的抗体的注射，以分析相应途径与所研究问题的相关性。结果LPS/D-galN或TNF α/D-galN处理后，NS 3/4A-Tg小鼠肝脏信号转导子和转录激活子1和2的激活受到抑制。肝干扰素-g（IFN-γ）的减少证实了这一点。IFN γ的重建恢复了NS 3/4A-Tg小鼠对LPS/TNF α的抗性。随后，体内阻断IFNg使得野生型小鼠对LPS/TNF α治疗具有抗性。表达失活的NS 3/4A蛋白酶的新Tg小鼠在肝脏IFN γ水平和对LPS/D-galN的敏感性方面具有与野生型小鼠相同的表型。最后，在NS 3/4A-Tg小鼠的趋化因子的配置文件被改变，朝着抗炎状态，这有助于解释改变免疫细胞亚群和减少肝脏IFN γ production.Conclusions我们的数据表明，NS 3/4A蛋白酶减少肝内生产的IFN Ω和改变TNF α介导的影响，从而损害肝脏炎症反应。这可能有助于病毒的持久性。
Background The non-structural (NS) 3/4A protease/helicase of the hepatitis C virus is known to modulate signalling pathways in the infected hepatocyte by cleaving CARD adaptor inducing IFN beta (Cardif), T-cell protein tyrosine phosphatase (TC-PTP) and TIR domain-containing adaptor inducing IFN beta (TRIF), but the effects of NS3/4A in vivo still remain unclear.Aim To investigate the influence of NS3/4A on intracellular and intercellular signalling in vivo by analysing the intrahepatic inflammatory response of naive, lipopolysaccharide (LPS)/D-galactosamine (D-galN) or tumour necrosis factor-alpha (TNF alpha)/D-galN-treated NS3/4A-transgenic (Tg) mice.Methods The intrahepatic immunity of naive and LPS/D-galN-or TNF alpha/D-galN-treated NS3/4A-Tg mice was determined using western blot, ELISA, real-time PCR, flow cytometry and survival monitoring. The injection of cytokines or antibodies against signalling components was performed to analyse the relevance of the respective pathways for the investigated issues. A Tg mouse lineage expressing an inactivated NS3/4A protease (NS3/4A(Ile1073Ala)-Tgs) was generated to examine if protective effects were NS3/4A protease dependent.Results The activation of hepatic signal transducer and activator of transcription 1 and 2 was impaired in NS3/4A-Tg mice after treatment with LPS/D-galN or TNF alpha/D-galN. This was paralleled by a reduction in hepatic interferon-g (IFN gamma). Reconstitution of IFN gamma reverted the resistance to LPS/TNF alpha in NS3/4A-Tg mice. Subsequently, blocking IFNg in vivo rendered wild-type mice resistant against treatment with LPS/TNF alpha. A new Tg mouse expressing an inactivated NS3/4A protease had the same phenotype as wild-type mice with respect to hepatic IFN gamma levels and sensitivity to LPS/D-galN. Finally, the chemokine profile was altered in the NS3/4A-Tg mice towards an anti-inflammatory state, which helps to explain the altered immune cell subsets and reduction in hepatic IFN gamma production.Conclusions Our data demonstrate that the NS3/4A protease reduces the intrahepatic production of IFN Omega and alters TNF alpha-mediated effects, thereby impairing the hepatic inflammatory response. This may contribute to viral persistence.