Utilisation of ISA Reverse Genetics and Large-Scale Random Codon Re-Encoding to Produce Attenuated Strains of Tick-Borne Encephalitis Virus within Days

Lauriane De Fabritus (1) , Antoine Nougairède (1, 2) , Fabien Aubry (1) , Ernest A. Gould (1) , Xavier De Lamballerie (1, 2)

1 EPV - Emergence des Pathologies Virales
2 IHU Marseille - Institut Hospitalier Universitaire Méditerranée Infection

Large-scale codon re-encoding is a new method of attenuating RNA viruses. However, the use of infectious clones to generate attenuated viruses has inherent technical problems. We previously developed a bacterium-free reverse genetics protocol, designated ISA, and now combined it with large-scale random codon-re-encoding method to produce attenuated tick-borne encephalitis virus (TBEV), a pathogenic flavivirus which causes febrile illness and encephalitis in humans. We produced wild-type (WT) and two re-encoded TBEVs, containing 273 or 273+284 synonymous mutations in the NS5 and NS5+NS3 coding regions respectively. Both re-encoded viruses were attenuated when compared with WT virus using a laboratory mouse model and the relative level of attenuation increased with the degree of re-encoding. Moreover, all infected animals produced neutralizing antibodies. This novel, rapid and efficient approach to engineering attenuated viruses could potentially expedite the development of safe and effective new-generation live attenuated vaccines.

Keywords: Antibodies; Mouse models; Tick-borne encephalitis virus; Enzyme-linked immunoassays; RNA viruses; Japanese encephalitis virus; Viral pathogens; Dengue virus

Domains: Vaccinology; Virology

Lauriane De Fabritus, Antoine Nougairède, Fabien Aubry, Ernest A. Gould, Xavier De Lamballerie. Utilisation of ISA Reverse Genetics and Large-Scale Random Codon Re-Encoding to Produce Attenuated Strains of Tick-Borne Encephalitis Virus within Days. PLoS ONE, 2016, 11 (8), pp.e0159564. ⟨10.1371/journal.pone.0159564⟩. ⟨hal-01785361⟩