Random codon re-encoding induces stable reduction of replicative fitness of Chikungunya virus in primate and mosquito cells
Autor(es): Nougairede Antoine, De Fabritus Lauriane, Aubry Fabien, Gould Ernest A, Holmes Edward C, de Lamballerie Xavier
Resumo: Large-scale codon re-encoding represents a powerful method of attenuating viruses to generate safe - cost-effective vaccines. In contrast to specific approaches of codon re-encoding which modify genome-scale properties, we evaluated the effects of r-om codon re-encoding on the re-emerging human pathogen Chikungunya virus (CHIKV), - assessed the stability of the resultant viruses during serial in cellulo passage. Using different combinations of three 1.4 kb r-omly re-encoded regions located throughout the CHIKV genome six codon re-encoded viruses were obtained. Introducing a large number of slightly deleterious synonymous mutations reduced the replicative fitness of CHIKV in both primate - arthropod cells, demonstrating the impact of synonymous mutations on fitness. Decrease of replicative fitness correlated with the extent of re-encoding, an observation that may assist in the modulation of viral attenuation. The wild-type - two re-encoded viruses were passaged 50 times either in primate or insect cells, or in each cell line alternately. These viruses were analyzed using detailed fitness assays, complete genome sequences - the analysis of intra-population genetic diversity. The response to codon re-encoding - adaptation to culture conditions occurred simultaneously, resulting in significant replicative fitness increases for both re-encoded - wild type viruses. Importantly, however, the most re-encoded virus failed to recover its replicative fitness. Evolution of these viruses in response to codon re-encoding was largely characterized by the emergence of both synonymous - non-synonymous mutations, sometimes located in genomic regions other than those involving re-encoding, - multiple convergent - compensatory mutations. However, there was a striking absence of codon reversion (<0.4%). Finally, multiple mutations were rapidly fixed in primate cells, whereas mosquito cells acted as a brake on evolution. In conclusion, r-om codon re-encoding provides important information on the evolution - genetic stability of CHIKV viruses - could be exploited to develop a safe, live attenuated CHIKV vaccine.
Imprenta: PLoS Pathogens, v. 9, n. 2, p. e1003172, 2013
Identificador do objeto digital: 10.1371/journal.ppat.1003172
Descritores: Chikungunya virus - Biosynthesis ; Chikungunya virus - Cell ; Chikungunya virus - DNA ; Chikungunya virus - Genome ; Chikungunya virus - Molecular structure ; Chikungunya virus - Pathogenesis ; Chikungunya virus - Proteins ; Chikungunya virus - RNA ; Chikungunya virus - Viral infections ; Chikungunya Virus - Virus ; Chikungunya virus - Transmission ; Chikungunya virus - Vaccine ; Chikungunya virus - Chikungunya fever ; Chikungunya virus - Public health
Data de publicação: 2013
