Virus-encoded Suppressors of RNA Silencing and the Role of Cellular miRNAs in Mammalian Antiviral Immune Responses
Joost Haasnoot and Ben Berkhout
from: RNA Interference and Viruses: Current Innovations and Future Trends (Edited by: Miguel Angel Martínez). Caister Academic Press, U.K. (2010)
Small RNA-directed silencing mechanisms play important roles in the regulation of eukaryotic gene expression. In plants, insects, nematodes and fungi RNA silencing mechanisms are also involved in innate antiviral defence responses. To counter antiviral RNA silencing, viruses from plants, insects and fungi encode RNA silencing suppressors (RSSs). Recent studies suggest that RNA silencing in mammals, or RNA interference (RNAi), is also involved in antiviral responses. In particular, there is increasing evidence that cellular regulatory microRNAs (miRNAs) have a function in restricting virus replication in mammalian cells. Similar to plant and insect viruses, several mammalian viruses encode RSS factors that inhibit the RNAi mechanism. Several of these suppressors are multifunctional proteins that were previously shown to block innate antiviral immune responses involving the interferon (IFN) pathway. Here we summarize the current data on mammalian virus-encoded RSS factors. In addition, different aspects of antiviral RNAi and the role of cellular miRNAs in restricting virus replication in mammalian cells are discussed read more ...