RESUMEN
Usutu virus (USUV) and West Nile virus (WNV) are two closely related emerging mosquito-borne flaviviruses. Their natural hosts are wild birds, but they can also cause severe neurological disorders in humans. Both viruses are efficiently suppressed by type I interferon (IFN), which interferes with viral replication, dissemination, pathogenesis and transmission. Here, we show that the replication of USUV and WNV 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 flaviviruses 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 sequence 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. This study provides new insights into the strategy employed by emerging flaviviruses to overcome host defense mechanisms.
Asunto(s)
Regiones no Traducidas 3' , Flavivirus , Replicación Viral , Virus del Nilo Occidental , Regiones no Traducidas 3'/genética , Flavivirus/genética , Flavivirus/fisiología , Humanos , Animales , Replicación Viral/genética , Virus del Nilo Occidental/genética , Virus del Nilo Occidental/fisiología , Infecciones por Flavivirus/virología , Exonucleasas/metabolismo , Exonucleasas/genética , Chlorocebus aethiops , Exorribonucleasas/metabolismo , Exorribonucleasas/genética , Células HEK293 , Células Vero , Línea Celular , Interferón Tipo I/metabolismo , Genoma ViralRESUMEN
Title: L'actualité scientifique vue par les étudiants du Master Biologie-Santé de l'université de Montpellier. Abstract: L'unité d'enseignement « Immunopathologie ¼ qui propose les brèves présentées dans ce numéro est suivie par des étudiants de divers parcours du Master Biologie Santé de l'université de Montpellier. Ce Master rassemble des étudiants issus du domaine des sciences et technologies et de domaines de la santé. On y étudie les bases physiopathologiques des maladies immunologiques, les cibles thérapeutiques et les mécanismes d'échappement des microorganismes et des tumeurs Les articles présentés ont été choisis par les étudiants selon leur domaine de prédilection.