title: Identification of a new dengue virus inhibitor that targets the viral NS4B protein and restricts genomic RNA replication.
abstract: Dengue virus (DENV) is an important human arthropod-borne virus with a major impact on public health. Nevertheless, a licensed vaccine or specific treatment is still lacking. We therefore screened the NIH Clinical Collection (NCC), a library of drug-like small molecules, for inhibitors of DENV replication using a cell line that contains a stably replicating DENV serotype 2 (DENV2) subgenomic replicon. The most potent DENV inhibitor in the NCC was δ opioid receptor antagonist SDM25N. This compound showed antiviral activity against wild-type DENV2 in both Hela and BHK-21 cells, but not in the C6/36 cell line derived from the mosquito Aedes albopictus. The structurally related compound naltrindole also inhibited DENV replication, albeit less potently. Using a transient subgenomic replicon, we demonstrate that SDM25N restricts genomic RNA replication rather than translation of the viral genome. We identified a single amino acid substitution (F164L) in the NS4B protein that confers resistance to SDM25N. Remarkably, an NS4B amino acid substitution (P104L), which was previously shown to confer resistance to the DENV inhibitor NITD-618, also provided resistance to SDM25N. In conclusion, we have identified a new DENV inhibitor, SDM25N, which restricts genomic RNA replication by - directly or indirectly - targeting the viral NS4B protein.
authors.affiliation: Department of Medical Microbiology, Radboud University Nijmegen Medical Centre, Nijmegen Centre for Molecular Life Sciences, Nijmegen Institute for Infection, Inflammation and Immunity, Nijmegen, The Netherlands.
authors.forename: Koen W R
authors.initials: KW
authors.lastname: van Cleef
authors.forename: Gijs J
authors.initials: GJ
authors.lastname: Overheul
authors.forename: Michael C
authors.initials: MC
authors.lastname: Thomassen
authors.forename: Suzanne J F
authors.initials: SJ
authors.lastname: Kaptein
authors.forename: Andrew D
authors.initials: AD
authors.lastname: Davidson
authors.forename: Michael
authors.initials: M
authors.lastname: Jacobs
authors.forename: Johan
authors.initials: J
authors.lastname: Neyts
authors.forename: Frank J M
authors.initials: FJ
authors.lastname: van Kuppeveld
authors.forename: Ronald P
authors.initials: RP
authors.lastname: van Rij
mesh_terms: D000330:Aedes; D019943:Amino Acid Substitution; D000818:Animals; D000998:Antiviral Agents / Q000494:pharmacology*; D002460:Cell Line; D006224:Cricetinae; D003715:Dengue / Q000188:drug therapy; D003716:Dengue Virus / Q000187:drug effects* / Q000235:genetics / Q000502:physiology; D024882:Drug Resistance, Viral / Q000235:genetics; D006367:HeLa Cells; D006801:Humans; D009154:Mutation; D009271:Naltrexone / Q000031:analogs & derivatives* / Q000494:pharmacology; D019384:Nucleic Acid Synthesis Inhibitors / Q000494:pharmacology; D012367:RNA, Viral / Q000096:biosynthesis / Q000235:genetics; D012093:Replicon / Q000187:drug effects; D054852:Small Molecule Libraries; D017361:Viral Nonstructural Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D014779:Virus Replication / Q000187:drug effects
chemical_list: D000998:Antiviral Agents; C080107:NS4B protein, flavivirus; D019384:Nucleic Acid Synthesis Inhibitors; D012367:RNA, Viral; C568302:SDM 25N; D054852:Small Molecule Libraries; D017361:Viral Nonstructural Proteins; D009271:Naltrexone; C055382:naltrindole
keywords: 50% effective concentration; Antiviral therapy; CCID50; CPE; DENV; DHF; Dengue virus; EC(50); FMDV; IFN; NCC; NGC; NIH Clinical Collection; NS4B; Naltrindole; SDM25N; cell culture infectious dose 50%; cytopathic effect; dengue hemorrhagic fever; dengue virus; foot-and-mouth disease virus; hours post-infection; hours post-transfection; hpi; hpt; interferon; strain New Guinea C