title: Stability of the resistance to the thiosemicarbazone derived from 5,6-dimethoxy-1-indanone, a non-nucleoside polymerase inhibitor of bovine viral diarrhea virus.
abstract: Bovine viral diarrhea virus (BVDV) is the prototype Pestivirus. BVDV infection is distributed worldwide and causes serious problems for the livestock industry. The thiosemicarbazone of 5,6-dimethoxy-1-indanone (TSC) is a non-nucleoside polymerase inhibitor (NNI) of BVDV. All TSC-resistant BVDV variants (BVDV-TSCr T1-5) present an N264D mutation in the NS5B gene (RdRp) whereas the variant BVDV-TSCr T1 also presents an NS5B A392E mutation. In the present study, we carried out twenty passages of BVDV-TSCr T1-5 in MDBK cells in the absence of TSC to evaluate the stability of the resistance. The viral populations obtained (BVDV R1-5) remained resistant to the antiviral compound and conserved the mutations in NS5B associated with this phenotype. Along the passages, BVDV R2, R3 and R5 presented a delay in the production of cytopathic effect that correlated with a decrease in cell apoptosis and intracellular accumulation of viral RNA. The complete genome sequences that encode for NS2 to NS5B, Npro and Erns were analyzed. Additional mutations were detected in the NS5B of BVDV R1, R3 and R4. In both BVDV R2 and R3, most of the mutations found were localized in NS5A, whereas in BVDV R5, the only mutation fixed was NS5A V177A. These results suggest that mutations in NS5A could alter BVDV cytopathogenicity. In conclusion, the stability of the resistance to TSC may be due to the fixation of different compensatory mutations in each BVDV-TSCr. During their replication in a TSC-free medium, some virus populations presented a kind of interaction with the host cell that resembled a persistent infection: decreased cytopathogenicity and viral genome synthesis. This is the first report on the stability of antiviral resistance and on the evolution of NNI-resistant BVDV variants. The results obtained for BVDV-TSCr could also be applied for other NNIs.
authors.affiliation: Cátedra de Virología, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Buenos Aires, Argentina.
authors.forename: Eliana F
authors.initials: EF
authors.lastname: Castro
authors.affiliation: Cátedra de Virología, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Buenos Aires, Argentina.
authors.forename: Rodolfo H
authors.initials: RH
authors.lastname: Campos
authors.affiliation: Cátedra de Virología, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Buenos Aires, Argentina.
authors.forename: Lucía V
authors.initials: LV
authors.lastname: Cavallaro
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D001483:Base Sequence; D002417:Cattle; D002460:Cell Line; D017124:Conserved Sequence; D003588:Cytopathogenic Effect, Viral / Q000187:drug effects; D012321:DNA-Directed RNA Polymerases / Q000037:antagonists & inhibitors*; D001908:Diarrhea Viruses, Bovine Viral / Q000187:drug effects* / Q000201:enzymology* / Q000235:genetics / Q000502:physiology; D024882:Drug Resistance, Viral / Q000187:drug effects* / Q000235:genetics; D004791:Enzyme Inhibitors / Q000737:chemistry / Q000494:pharmacology; D007189:Indans / Q000737:chemistry*; D008969:Molecular Sequence Data; D009154:Mutation; D012367:RNA, Viral / Q000378:metabolism; D013882:Thiosemicarbazones / Q000737:chemistry* / Q000494:pharmacology*; D017361:Viral Nonstructural Proteins / Q000737:chemistry / Q000235:genetics; D014779:Virus Replication / Q000187:drug effects
chemical_list: C000595050:5,6-dimethoxy-1-indanone thiosemicarbazone; D004791:Enzyme Inhibitors; D007189:Indans; D012367:RNA, Viral; D013882:Thiosemicarbazones; D017361:Viral Nonstructural Proteins; D012321:DNA-Directed RNA Polymerases