title: Adenovirus delivered short hairpin RNA targeting a conserved site in the 5' non-translated region inhibits all four serotypes of dengue viruses.
abstract: BACKGROUND
  Dengue is a mosquito-borne viral disease caused by four closely related serotypes of Dengue viruses (DENVs). This disease whose symptoms range from mild fever to potentially fatal haemorrhagic fever and hypovolemic shock, threatens nearly half the global population. There is neither a preventive vaccine nor an effective antiviral therapy against dengue disease. The difference between severe and mild disease appears to be dependent on the viral load. Early diagnosis may enable timely therapeutic intervention to blunt disease severity by reducing the viral load. Harnessing the therapeutic potential of RNA interference (RNAi) to attenuate DENV replication may offer one approach to dengue therapy.
  
  
  RESULTS
  We screened the non-translated regions (NTRs) of the RNA genomes of representative members of the four DENV serotypes for putative siRNA targets mapping to known transcription/translation regulatory elements. We identified a target site in the 5' NTR that maps to the 5' upstream AUG region, a highly conserved cis-acting element essential for viral replication. We used a replication-defective human adenovirus type 5 (AdV5) vector to deliver a short-hairpin RNA (shRNA) targeting this site into cells. We show that this shRNA matures to the cognate siRNA and is able to inhibit effectively antigen secretion, viral RNA replication and infectious virus production by all four DENV serotypes.
  
  
  CONCLUSIONS
  The data demonstrate the feasibility of using AdV5-mediated delivery of shRNAs targeting conserved sites in the viral genome to achieve inhibition of all four DENV serotypes. This paves the way towards exploration of RNAi as a possible therapeutic strategy to curtail DENV infection.
authors: Recombinant Gene Products Group, International Centre for Genetic Engineering and Biotechnology, New Delhi, India.
authors: Anil Babu
authors: AB
authors: Korrapati
authors: Gokul
authors: G
authors: Swaminathan
authors: Aarti
authors: A
authors: Singh
authors: Navin
authors: N
authors: Khanna
authors: Sathyamangalam
authors: S
authors: Swaminathan
mesh_terms: D000260:Adenoviruses, Human / Q000235:genetics; D000818:Animals; D000998:Antiviral Agents / Q000008:administration & dosage* / Q000494:pharmacology*; D001688:Biological Products / Q000008:administration & dosage* / Q000494:pharmacology*; D002460:Cell Line; D003716:Dengue Virus / Q000187:drug effects* / Q000502:physiology; D004337:Drug Carriers / Q000008:administration & dosage; D005822:Genetic Vectors / Q000008:administration & dosage; D006801:Humans; D034741:RNA, Small Interfering / Q000008:administration & dosage* / Q000235:genetics / Q000494:pharmacology*; D014161:Transduction, Genetic; D014779:Virus Replication / Q000187:drug effects
chemical_list: D000998:Antiviral Agents; D001688:Biological Products; D004337:Drug Carriers; D034741:RNA, Small Interfering