title: Ectopic expression of microRNA-155 enhances innate antiviral immunity against HBV infection in human hepatoma cells.
abstract: BACKGROUND
  Host innate antiviral immunity is the first line of defense against viral infection, and is precisely regulated by thousands of genes at various stages, including microRNAs. MicroRNA-155 (miR-155) was found to be up-regualted during viral infection, and influence the host immune response. Besides, the expression of miR-155, or its functional orthologs, may also contribute to viral oncogenesis. HBV is known to cause hepatocellular carcinoma, and there is evidence that attenuated intracellular immune response is the main reason for HBV latency. Thus, we assume miR-155 may affect the immune response during HBV infection in human hepatoma cells.
  
  
  RESULTS
  We found that ectopic expression of miR-155 upregulated the expression of several IFN-inducible antiviral genes in human hepatoma cells. And over-expression of miR-155 suppressed suppressor of cytokine signaling 1 (SOCS1) expression and subsequently enhanced signal transducers and activators of transcription1 (STAT1) and signal transducers and activators of transcription3 (STAT3) phosphorylation. We further demonstrate that ectopic expression of miR-155 inhibits HBV X gene expression to some extent in vitro.
  
  
  CONCLUSIONS
  MiR-155 enhances innate antiviral immunity through promoting JAK/STAT signaling pathway by targeting SOCS1, and mildly inhibits HBV infection in human hepatoma cells.
authors.affiliation: School of Pharmaceutical Sciences, Shandong University, Jinan 250012, China.
authors.forename: Chenhe
authors.initials: C
authors.lastname: Su
authors.forename: Zhaohua
authors.initials: Z
authors.lastname: Hou
authors.forename: Cai
authors.initials: C
authors.lastname: Zhang
authors.forename: Zhigang
authors.initials: Z
authors.lastname: Tian
authors.forename: Jian
authors.initials: J
authors.lastname: Zhang
mesh_terms: D015870:Gene Expression; D006515:Hepatitis B virus / Q000276:immunology*; D022781:Hepatocytes / Q000276:immunology* / Q000821:virology*; D006801:Humans; D007372:Interferons / Q000276:immunology; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction; D000071222:Suppressor of Cytokine Signaling 1 Protein; D050826:Suppressor of Cytokine Signaling Proteins / Q000378:metabolism
chemical_list: C524942:MIRN155 microRNA, human; D035683:MicroRNAs; C108944:SOCS1 protein, human; D000071222:Suppressor of Cytokine Signaling 1 Protein; D050826:Suppressor of Cytokine Signaling Proteins; D007372:Interferons