Expressed anti-HBV primary microRNA shuttles inhibit viral replication efficiently in vitro and in vivo

Mol Ther. 2008 Jun;16(6):1105-12. doi: 10.1038/mt.2008.82. Epub 2008 Apr 22.


The use of RNA interference (RNAi) to inhibit gene expression is potentially applicable in the treatment of viral infections such as hepatitis B virus (HBV) persistence. Although efficient HBV gene silencing by short hairpin RNA (shRNA) expressed from RNA polymerase (Pol) III promoters has been reported, constitutive high-level transcription may cause harmful side effects. Here, we report an approach that allows the use of a Pol II promoter to improve transcription regulation of expressed RNAi effecters. Pol II [cytomegalovirus (CMV)] or Pol III (U6) promoter cassettes that transcribe anti-HBV primary microRNA (pri-miR)-122 and pri-miR-31 shuttles were generated. In cultured cells both types of pri-miR-like sequences effected knockdown of markers of viral replication (>80%) and were processed to form intended 21-nucleotide guides. The concentration of CMV-expressed miRs was approximately 85-fold lower than the U6 shRNA-derived guide RNA. When cells were co-transfected with pri-miR expression cassettes, attenuation of independent RNAi-mediated gene silencing was not observed, which is in contrast to the action of U6 shRNA expression cassettes. The efficacy of the anti-HBV pri-miR shuttles in vivo was verified using the murine hydrodynamic injection model. Employing Pol II-expressed pri-miR mimics may be useful in the treatment of HBV infection, and potentially also for generic application in RNAi-based therapy.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Line
  • Cells, Cultured
  • Cytomegalovirus / genetics
  • Gene Silencing
  • Genetic Therapy / methods*
  • Hepatitis B virus / genetics*
  • Humans
  • In Vitro Techniques
  • Mice
  • MicroRNAs*
  • Models, Genetic
  • Plasmids / metabolism
  • RNA Interference
  • Transfection
  • Virus Replication*


  • MicroRNAs