MicroRNAs and the immune response to respiratory virus infections.

MicroRNAs (miRNAs) are small ssRNA molecules, which are involved in gene expression regulation at the post-transcriptional level. Their biological functions include modulation of both innate and adaptive immune response. miRNAs participate in the maintenance of the airway epithelial barrier and are also implicated in the modulation of antiviral defense in epithelial cells. The immune response to respiratory viruses such as rhinovirus, influenza virus and respiratory syncytial virus is associated with an altered expression of distinct miRNAs, and the changes in the miRNA expression profile in epithelial cells may contribute to the pathogenesis of both acute and chronic airway disease. Understanding the role of these small molecules in the antiviral immune response and identification of miRNAs target genes may help to clarify the mechanisms of virus-host interaction, and in the future may lead to development of new antiviral treatments.