MicroRNAs are small non-coding RNAs that modulate protein production by post-transcriptional gene regulation. They impose gene expression control by interfering with mRNA translation and stability in cell cytoplasm through a mechanism involving specific binding to mRNA based on base pair complementarity. Because of their intracellular replication cycle it is no surprise that viruses evolved in a way that allows them to use microRNAs to infect, replicate and persist in host cells. Several ways of interference between virus and host-cell microRNA machinery have been described. Most of the time, viruses drastically alter host-cell microRNA expression or synthesize their own microRNA to facilitate infection and pathogenesis. HIV and HCV are two prominent examples of this complex interplay revealing how fine-tuning of microRNA expression is crucial for controlling key host pathways that allow viral infection and replication, immune escape and persistence. In this review we delve into the mechanisms underlying cellular and viral-encoded microRNA functions in the context of HIV and HCV infections. We focus on which microRNAs are differently expressed and deregulated upon viral infection and how these alterations dictate the fate of virus and cell. Copyright © 2016 John Wiley & Sons, Ltd.
Copyright © 2016 John Wiley & Sons, Ltd.