Escape of Tick-Borne Flavivirus from 2'-C-Methylated Nucleoside Antivirals Is Mediated by a Single Conservative Mutation in NS5 That Has a Dramatic Effect on Viral Fitness

0482878 - BC 2018 RIV US eng J - Článek v odborném periodiku
Eyer, Luděk - Kondo, H. - Zouharová, D. - Hirano, M. - Valdés, James J. - Muto, M. - Kastl, T. - Kobayashi, S. - Haviernik, J. - Igarashi, K. - Kariwa, H. - Vaculovicova, M. - Černý, Jiří - Kizek, R. - Kroeger, A. - Lienenklaus, S. - Dejmek, Milan - Nencka, Radim - Palus, Martin - Salát, J. - De Clercq, E. - Yoshii, K. - Růžek, Daniel
Escape of Tick-Borne Flavivirus from 2'-C-Methylated Nucleoside Antivirals Is Mediated by a Single Conservative Mutation in NS5 That Has a Dramatic Effect on Viral Fitness.
Journal of Virology. Roč. 91, č. 21 (2017), č. článku e01028-17. ISSN 0022-538X. E-ISSN 1098-5514
Grant CEP: GA MZd(CZ) NV16-34238A
Institucionální podpora: RVO:60077344 ; RVO:61388963
Klíčová slova: antiviral agents * antiviral therapy * escape mutant * tick-borne * encephalitis virus * tick-borne pathogens
Obor OECD: Virology
Impakt faktor: 4.368, rok: 2017

Tick-borne encephalitis virus (TBEV) causes a severe and potentially fatal neuroinfection in humans. Despite its high medical relevance, no specific antiviral therapy is currently available. Here we demonstrate that treatment with a nucleoside analog, 7-deaza-2'-C-methyladenosine (7-deaza-2'-CMA), substantially improved disease outcomes, increased survival, and reduced signs of neuroinfection and viral titers in the brains of mice infected with a lethal dose of TBEV. To investigate the mechanism of action of 7-deaza-2'-CMA, two drug-resistant TBEV clones were generated and characterized. The two clones shared a signature amino acid substitution, S603T, in the viral NS5 RNA-dependent RNA polymerase (RdRp) domain. This mutation conferred resistance to various 2'-C-methylated nucleoside derivatives, but no cross-resistance was seen with other nucleoside analogs, such as 4'-C-azidocytidine and 2'-deoxy-2'-beta-hydroxy-4'-azidocytidine (RO-9187). All-atom molecular dynamics simulations revealed that the S603T RdRp mutant repels a water molecule that coordinates the position of a metal ion cofactor as 2'-C-methylated nucleoside analogs approach the active site. To investigate its phenotype, the S603T mutation was introduced into a recombinant TBEV strain (Oshima-IC) generated from an infectious cDNA clone and into a TBEV replicon that expresses a reporter luciferase gene (Oshima-REP- luc2A). The mutants were replication impaired, showing reduced growth and a small plaque size in mammalian cell culture and reduced levels of neuroinvasiveness and neurovirulence in rodent models. These results indicate that TBEV resistance to 2'-C-methylated nucleoside inhibitors is conferred by a single conservative mutation that causes a subtle atomic effect within the active site of the viral NS5 RdRp and is associated with strong attenuation of the virus.
Trvalý link: http://hdl.handle.net/11104/0278276