title: Sequence-Specific Modifications Enhance the Broad-Spectrum Antiviral Response Activated by RIG-I Agonists.
abstract: The cytosolic RIG-I (retinoic acid-inducible gene I) receptor plays a pivotal role in the initiation of the immune response against RNA virus infection by recognizing short 5'-triphosphate (5'ppp)-containing viral RNA and activating the host antiviral innate response. In the present study, we generated novel 5'ppp RIG-I agonists of varieous lengths, structures, and sequences and evaluated the generation of the antiviral and inflammatory responses in human epithelial A549 cells, human innate immune primary cells, and murine models of influenza and chikungunya viral pathogenesis. A 99-nucleotide, uridine-rich hairpin 5'pppRNA termed M8 stimulated an extensive and robust interferon response compared to other modified 5'pppRNA structures, RIG-I aptamers, or poly(I·C). Interestingly, manipulation of the primary RNA sequence alone was sufficient to modulate antiviral activity and inflammatory response, in a manner dependent exclusively on RIG-I and independent of MDA5 and TLR3. Both prophylactic and therapeutic administration of M8 effectively inhibited influenza virus and dengue virus replication in vitro. Furthermore, multiple strains of influenza virus that were resistant to oseltamivir, an FDA-approved therapeutic treatment for influenza, were highly sensitive to inhibition by M8. Finally, prophylactic M8 treatment in vivo prolonged survival and reduced lung viral titers of mice challenged with influenza virus, as well as reducing chikungunya virus-associated foot swelling and viral load. Altogether, these results demonstrate that 5'pppRNA can be rationally designed to achieve a maximal RIG-I-mediated protective antiviral response against human-pathogenic RNA viruses.
  
  
  OBJECTIVE
  The development of novel therapeutics to treat human-pathogenic RNA viral infections is an important goal to reduce spread of infection and to improve human health and safety. This study investigated the design of an RNA agonist with enhanced antiviral and inflammatory properties against influenza, dengue, and chikungunya viruses. A novel, sequence-dependent, uridine-rich RIG-I agonist generated a protective antiviral response in vitro and in vivo and was effective at concentrations 100-fold lower than prototype sequences or other RNA agonists, highlighting the robust activity and potential clinical use of the 5'pppRNA against RNA virus infection. Altogether, the results identify a novel, sequence-specific RIG-I agonist as an attractive therapeutic candidate for the treatment of a broad range of RNA viruses, a pressing issue in which a need for new and more effective options persists.
authors.affiliation: Vaccine & Gene Therapy Institute of Florida, Port St. Lucie, Florida, USA.
authors.forename: Cindy
authors.initials: C
authors.lastname: Chiang
authors.affiliation: Vaccine & Gene Therapy Institute of Florida, Port St. Lucie, Florida, USA.
authors.forename: Vladimir
authors.initials: V
authors.lastname: Beljanski
authors.affiliation: Vaccine & Gene Therapy Institute of Florida, Port St. Lucie, Florida, USA.
authors.forename: Kevin
authors.initials: K
authors.lastname: Yin
authors.affiliation: Vaccine & Gene Therapy Institute of Florida, Port St. Lucie, Florida, USA Lady Davis Institute-Jewish General Hospital, McGill University, Montreal, Canada.
authors.forename: David
authors.initials: D
authors.lastname: Olagnier
authors.affiliation: Lady Davis Institute-Jewish General Hospital, McGill University, Montreal, Canada.
authors.forename: Fethia
authors.initials: F
authors.lastname: Ben Yebdri
authors.affiliation: Vaccine & Gene Therapy Institute of Florida, Port St. Lucie, Florida, USA.
authors.forename: Courtney
authors.initials: C
authors.lastname: Steel
authors.affiliation: Lady Davis Institute-Jewish General Hospital, McGill University, Montreal, Canada.
authors.forename: Marie-Line
authors.initials: ML
authors.lastname: Goulet
authors.affiliation: Vaccine & Gene Therapy Institute-Oregon Health and Science University, Beaverton, Oregon, USA.
authors.forename: Victor R
authors.initials: VR
authors.lastname: DeFilippis
authors.affiliation: Vaccine & Gene Therapy Institute-Oregon Health and Science University, Beaverton, Oregon, USA.
authors.forename: Daniel N
authors.initials: DN
authors.lastname: Streblow
authors.affiliation: Vaccine & Gene Therapy Institute of Florida, Port St. Lucie, Florida, USA.
authors.forename: Elias K
authors.initials: EK
authors.lastname: Haddad
authors.affiliation: Vaccine & Gene Therapy Institute of Florida, Port St. Lucie, Florida, USA.
authors.forename: Lydie
authors.initials: L
authors.lastname: Trautmann
authors.affiliation: Vaccine & Gene Therapy Institute of Florida, Port St. Lucie, Florida, USA.
authors.forename: Ted
authors.initials: T
authors.lastname: Ross
authors.affiliation: Lady Davis Institute-Jewish General Hospital, McGill University, Montreal, Canada.
authors.forename: Rongtuan
authors.initials: R
authors.lastname: Lin
authors.affiliation: Vaccine & Gene Therapy Institute of Florida, Port St. Lucie, Florida, USA jhiscott@vgtifl.org.
authors.forename: John
authors.initials: J
authors.lastname: Hiscott
mesh_terms: D000818:Animals; D002460:Cell Line; D002646:Chikungunya virus / Q000737:chemistry / Q000235:genetics / Q000276:immunology*; D000071457:DEAD Box Protein 58; D053487:DEAD-box RNA Helicases / Q000235:genetics / Q000276:immunology*; D003716:Dengue Virus / Q000737:chemistry / Q000235:genetics / Q000276:immunology*; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype / Q000737:chemistry / Q000235:genetics / Q000276:immunology*; D051379:Mice; D008807:Mice, Inbred BALB C; D009690:Nucleic Acid Conformation; D012367:RNA, Viral / Q000819:agonists* / Q000235:genetics / Q000276:immunology*; D011971:Receptors, Immunologic; D014777:Virus Diseases / Q000235:genetics / Q000276:immunology* / Q000821:virology
chemical_list: D012367:RNA, Viral; D011971:Receptors, Immunologic; C452820:RIGI protein, human; D000071457:DEAD Box Protein 58; D053487:DEAD-box RNA Helicases