Flavivirus sfRNA suppresses antiviral RNA interference in cultured cells and mosquitoes and directly interacts with the RNAi machinery.

In this study, we demonstrate that two flaviviruses, Dengue virus and Kunjin virus, significantly repress siRNA-mediated RNAi in infected human cells as well as during infection of the mosquito vector Culex quinquefasciatus. Arthropod-borne flaviviruses generate a small structured non-coding RNA from the viral 3' UTR referred to as sfRNA. Analysis of infections with a mutant Kunjin virus that is unable to generate appreciable amounts of the major sfRNA species indicated that RNAi suppression was associated with the generation of the non-coding sfRNA. Co-immunoprecipitation of sfRNA with RNAi mediators Dicer and Ago2 suggest a model for RNAi suppression. Collectively, these data help to establish a clear role for sfRNA in RNAi suppression and adds to the emerging impact of viral long non-coding RNAs in modulating aspects of anti-viral immune processes.
PMID: 26331679 [PubMed - as supplied by publisher]

Source: Virology - August 28, 2015 Category: Virology Authors: Moon SL, Dodd BJ, Brackney DE, Wilusz CJ, Ebel GD, Wilusz J Tags: Virology Source Type: research