New perspective of host microRNAs in the control of PRRSV infection.

Porcine reproductive and respiratory syndrome (PRRS) is one of the most important diseases in pigs, leading to significant economic losses in swine industry worldwide. PRRS virus (PRRSV) is an enveloped positive single-stranded RNA virus, which mainly infects cells of monocyte/macrophage lineage. MicroRNAs (miRNAs) are small non-coding RNAs and have emerged as important regulators of virus-host cell interactions. In the past several years, scientists have been trying to understand the interaction between host miRNAs and PRRSV infection. This review describes the mechanism of host miRNAs modulating the infection and replication of PRRSV, the approaches of delivering miRNAs into hosts, and the transcriptom of host cells during PRRSV infection. miRNAs including miR-181, miR-23, miR-30c, and miR-24-3p are reported to play important roles in PRRSV infection and replication, and in modulating host antiviral responses, while others, for example miR-204, miR-221, miR-219, need more explorations. Importantly, combining with the reverse genetic technique and current miRNAs delivery approaches such as pcDNA, recombinant lentivirus, and exosomes, we propose that miRNAs contribute to and could be used as one of potent factors in controlling PRRSV infection.