title: Targeted delivery of mutant tolerant anti-coxsackievirus artificial microRNAs using folate conjugated bacteriophage Phi29 pRNA.
abstract: BACKGROUND
  Myocarditis is the major heart disease in infants and young adults. It is very commonly caused by coxsackievirus B3 (CVB3) infection; however, no specific treatment or vaccine is available at present. RNA interference (RNAi)-based anti-viral therapy has shown potential to inhibit viral replication, but this strategy faces two major challenges; viral mutational escape from drug suppression and targeted delivery of the reagents to specific cell populations.
  
  
  RESULTS
  In this study, we designed artificial microRNAs (AmiRs) targeting the 3'untranslated region (3'UTR) of CVB3 genome with mismatches to the central region of their targeting sites. Antiviral evaluation showed that AmiR-1 and AmiR-2 reduced CVB3 (Kandolf and CG strains) replication approximately 100-fold in both HeLa cells and HL-1 cardiomyocytes. To achieve specific delivery, we linked AmiRs to the folate-conjugated bacterial phage packaging RNA (pRNA) and delivered the complexes into HeLa cells, a folate receptor positive cancer cells widely used as an in vitro model for CVB3 infection, via folate-mediated specific internalization. We found that our designed pRNA-AmiRs conjugates were tolerable to target mutations and have great potential to suppress viral mutational escape with little effect on triggering interferon induction.
  
  
  CONCLUSIONS
  This study provides important clues for designing AmiRs targeting the 3'UTR of viral genome. It also proves the feasibility of specific deliver of AmiRs using conjugated pRNA vehicles. These small AmiRs combined with pRNA-folate conjugates could form a promising system for antiviral drug development.
authors.affiliation: Department of Pathology and Laboratory Medicine, The Institute for Heart and Lung Health, St. Paul's Hospital, University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: Xin
authors.initials: X
authors.lastname: Ye
authors.forename: Zhen
authors.initials: Z
authors.lastname: Liu
authors.forename: Maged Gomaa
authors.initials: MG
authors.lastname: Hemida
authors.forename: Decheng
authors.initials: D
authors.lastname: Yang
mesh_terms: D020413:3' Untranslated Regions; D001483:Base Sequence; D002460:Cell Line; D004770:Enterovirus / Q000235:genetics* / Q000254:growth & development; D005492:Folic Acid / Q000737:chemistry*; D018390:Gene Targeting; D006801:Humans; D035683:MicroRNAs / Q000008:administration & dosage* / Q000235:genetics; D009690:Nucleic Acid Conformation; D012367:RNA, Viral / Q000737:chemistry / Q000235:genetics*; D010948:Viral Plaque Assay
chemical_list: D020413:3' Untranslated Regions; D035683:MicroRNAs; D012367:RNA, Viral; D005492:Folic Acid