miR146a impairs the IFN-induced anti-HBV immune response by downregulating STAT1 in hepatocytes
miR146a impairs the IFN-induced anti-HBV immune response by downregulating STAT1 in hepatocytes
复制标题
miR146a 通过下调肝细胞中的 STAT1 损害 IFN 诱导的抗 HBV 免疫反应
DOI：
10.1111/liv.12244
复制
发表时间：
2014-01-01
影响因子：
6.7
通讯作者：
Zhang, Jian
中科院分区：
文献类型：
--
作者：
Hou, Zhao H.;Han, Qiu J.;Zhang, Jian
背景与目的先前的研究表明，乙型肝炎病毒（HBV）通过多种途径干扰宿主的抗病毒免疫。在临床实践中，干扰素耐药性是治疗HBV感染的一个严重问题。现在，mirna已被广泛报道参与抗病毒免疫，并成为研究病毒与宿主相互作用的新工具。我们质疑mirna是否在hbv诱导的肝细胞干扰素耐药中发挥作用。方法采用qRT-PCR方法比较HepG2和HepG2.2.15细胞中smirnas的表达水平。miR146a对HBV感染的影响通过干扰miR146a水平，然后定量HBV mRNA、DNA和抗原来表征。我们采用qRT-PCR和western blot技术研究了miR146a对IFN-信号通路的影响。通过荧光素酶报告基因试验验证了miR146a启动子的活性。结果shbv感染使肝细胞内IFN-信号通路受损。MiR146a在HBV+ HepG2.2.15细胞中表达上调，与HepG2细胞相比，MiR146a在HepG2.2.15细胞中的转录活性升高。HBV感染，特别是HBx的引入，在体外诱导miR146a的表达。此外，miR146a降低了I型干扰素诱导的抗病毒因子的产生。在HBV+ HCC细胞中发现低水平的STAT1，荧光素酶报告基因检测显示STAT1在转录后被miR146a下调。此外，通过反义抑制剂沉默miR146a可增强IFN介导的抗hbv效率。结论HBV感染可促进miR146a转录，抑制STAT1，导致干扰素耐药。这些观察结果揭示了miR146a在HBV免疫发病机制中的新作用，并为IFN诱导的抗HBV作用的治疗恢复提供了潜在的靶点。
Background & AimsPrevious studies have shown that hepatitis B virus (HBV) interferes with host antiviral immunity via multiple pathways. In clinical practice, interferon resistance is a serious issue for treatment of HBV infection. Now, miRNAs have been reported to be widely involved in antiviral immunity and have become a novel tool to study virus-host interaction. We question whether miRNAs play a role in HBV-induced interferon resistance in hepatocytes.MethodsMiRNAs levels in HepG2 and HepG2.2.15 cells were compared by qRT-PCR. The effects of miR146a on HBV infection were characterized by interference miR146a level, followed by the quantification of HBV mRNA, DNA and antigens. We employed qRT-PCR and western blot to study the effects of miR146a on the IFN- signalling pathway. The miR146a promoter activity was validated by a luciferase reporter assay.ResultsHBV infection impaired IFN- signalling pathway in hepatocytes. MiR146a was upregulated in HBV+ HepG2.2.15 cells, and the transcriptional activity of miR146a in HepG2.2.15 cells was increased compared with HepG2 cells. HBV infection, especially the introduction of HBx, induced miR146a expression in vitro. Moreover, miR146a attenuated the production of type I interferon-induced antiviral factors. Low STAT1 levels were noticed in HBV+ HCC cells, and the luciferase reporter assay showed that STAT1 was post-transcriptionally downregulated by miR146a. Furthermore, the silencing of miR146a by antisense inhibitors enhanced IFN--mediated anti-HBV efficiency.ConclusionsOur findings demonstrate that HBV infection promotes miR146a transcription, which represses STAT1 and results in interferon resistance. These observations reveal a novel role for miR146a in HBV immunopathogenesis, and provide a potential target for the therapeutic recovery of IFN--induced anti-HBV effects.