mardi 2 avril 2024 11:00
Labo AFMB
mardi 2 avril 2024 11:00
Labo AFMB
Usutu virus (USUV) and West Nile virus (WNV) are two closely related emerging mosquito-borne flaviviruses causing severe neurological disorders in wild birds and humans. Both viruses are efficiently suppressed by type I interferon (IFN) and are inhibited through a common set of IFN-induced genes (ISGs), with the notable exception of ISG20, which USUV is resistant to. Strikingly, USUV was the only virus among all the other tested mosquito-borne flaviriruses that demonstrated resistance to the 3′–5′ exonuclease activity of ISG20. Our findings highlight that the intrinsic resistance of the USUV genome, irrespective of the presence of cellular or viral proteins or protective post-transcriptional modifications, relies on a unique stem-loop structure present in its 3′–untranslated region. Importantly, this genomic region alone can confer ISG20 resistance to a susceptible flavivirus, without compromising its infectivity, suggesting that it could be acquired by other flaviviruses.
Publié le mars 6, 2024