Identification of the novel 3' UTR sequences of human IL-21 mRNA as potential targets of miRNAs

Sci Rep. 2017 Aug 10;7(1):7780. doi: 10.1038/s41598-017-07853-x.


Hepatitis B virus (HBV) infection is a leading cause of hepatocellular carcinoma worldwide. However, the strategy of HBV to escape from the host immune system remains largely unknown. In this study, we examined extracellular vesicles (EVs) secreted from human hepatocytes infected with HBV. EVs includeing exosomes are nano-size vesicles with proteins, mRNAs, and microRNAs (miRNAs), which can be transmitted to different cells. We found that 104 EV associated miRNAs were increased in hepatocytes more than 2-fold by HBV infection. We then selected those that were potentially implicated in immune regulation. Among them, five HBV-induced miRNAs were found to potentially target multiple sequences in the 3'UTR of IL-21, a cytokine that induces anti-viral immunity. Moreover, expression of a reporter gene with the 3' UTR of human IL-21 mRNA was suppressed by the five miRNAs individually. Finally, IL-21 expression in cloned human T cells was down-regulated by the five miRNAs. Collectively, this study identified the novel 3' UTR sequences of human IL-21 mRNA and potential binding sites of HBV-induced EV-miRNAs.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 3' Untranslated Regions*
  • Cells, Cultured
  • Extracellular Vesicles / metabolism
  • HEK293 Cells
  • Hep G2 Cells
  • Humans
  • Interleukins / genetics*
  • Interleukins / metabolism
  • MicroRNAs / genetics
  • MicroRNAs / metabolism*
  • RNA, Messenger / chemistry
  • RNA, Messenger / genetics*
  • RNA, Messenger / metabolism


  • 3' Untranslated Regions
  • Interleukins
  • MicroRNAs
  • RNA, Messenger
  • interleukin-21