Viperin is induced following dengue virus type-2 (DENV-2) infection and has anti-viral actions requiring the C-terminal end of viperin

PLoS Negl Trop Dis. 2013 Apr 18;7(4):e2178. doi: 10.1371/journal.pntd.0002178. Print 2013.

Abstract

The host protein viperin is an interferon stimulated gene (ISG) that is up-regulated during a number of viral infections. In this study we have shown that dengue virus type-2 (DENV-2) infection significantly induced viperin, co-incident with production of viral RNA and via a mechanism requiring retinoic acid-inducible gene I (RIG-I). Viperin did not inhibit DENV-2 entry but DENV-2 RNA and infectious virus release was inhibited in viperin expressing cells. Conversely, DENV-2 replicated to higher tires earlier in viperin shRNA expressing cells. The anti-DENV effect of viperin was mediated by residues within the C-terminal 17 amino acids of viperin and did not require the N-terminal residues, including the helix domain, leucine zipper and S-adenosylmethionine (SAM) motifs known to be involved in viperin intracellular membrane association. Viperin showed co-localisation with lipid droplet markers, and was co-localised and interacted with DENV-2 capsid (CA), NS3 and viral RNA. The ability of viperin to interact with DENV-2 NS3 was associated with its anti-viral activity, while co-localisation of viperin with lipid droplets was not. Thus, DENV-2 infection induces viperin which has anti-viral properties residing in the C-terminal region of the protein that act to restrict early DENV-2 RNA production/accumulation, potentially via interaction of viperin with DENV-2 NS3 and replication complexes. These anti-DENV-2 actions of viperin show both contrasts and similarities with other described anti-viral mechanisms of viperin action and highlight the diverse nature of this unique anti-viral host protein.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Blotting, Western
  • Cell Line, Tumor
  • Chlorocebus aethiops
  • Dengue / genetics
  • Dengue / metabolism*
  • Dengue / virology
  • Dengue Virus / pathogenicity*
  • Humans
  • Oxidoreductases Acting on CH-CH Group Donors
  • Proteins / genetics
  • Proteins / metabolism*
  • Reverse Transcriptase Polymerase Chain Reaction
  • Vero Cells

Substances

  • Proteins
  • Oxidoreductases Acting on CH-CH Group Donors
  • RSAD2 protein, human

Grants and funding

This work was supported by the NHMRC of Australia (MRB and KJH, ID510448, http://www.nhmrc.gov.au/); the Royal Adelaide Hospital Research Committee (http://www.rah.sa.gov.au/homepage.php#) and Flinders Medical Centre Research Foundation (http://www.fmcfoundation.com.au/)(JMC). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.