MicroRNA-23 inhibits PRRSV replication by directly targeting PRRSV RNA and possibly by upregulating type I interferons

Abstract

MicroRNAs (miRNAs) are small non-coding RNAs that regulate gene expression post-transcriptionally and play critical roles in intricate networks of host-pathogen interactions and innate immunity. Porcine reproductive and respiratory syndrome (PRRS) is one of the most important diseases affecting swine industry worldwide. Here, we demonstrated that miR-23, miR-378, and miR-505 were antiviral host factors against PRRS virus (PRRSV). Over-expression of the three miRNAs inhibited PRRSV infection in a dose-dependent manner, respectively. Blockage of the three endogenously expressed miRNAs significantly enhanced PRRSV replication. Different type 2 PRRSV strains harbored conserved miR-23, miR-378, and miR-505 target sites (TSs) that were sufficient to confer miRNA-mediated repression of PRRSV replication. Interestingly, miR-23 was capable of inducing type I interferon expression during PRRSV infection through IRF3/IRF7 activation, which might further lead to the inhibition of virus infection. These results suggest that miR-23, miR-378, and miR-505, especially miR-23, may have the potential to be used as antiviral therapy against PRRSV infection.

MicroRNA 373 Facilitates the Replication of Porcine Reproductive and Respiratory Syndrome Virus by Its Negative Regulation of Type I Interferon Induction

“…Previous studies have shown that some miRNAs, such as miR-125b (21), miR-26a (22), and miR-23 (42), could inhibit the replication of PRRSV, while miR-24-3p (23), upregulated by PRRSV infection in MARC-145 cells, and ssc-miR-30d-R_1 (18), downregulated by PRRSV infection in pig lungs, could promote virus replication. Notwithstanding these reports, we found that PRRSV infection upregulated the expression of (Table 1 and Fig.…”

MicroRNA-30c Modulates Type I IFN Responses To Facilitate Porcine Reproductive and Respiratory Syndrome Virus Infection by Targeting JAK1

“…Cotransfection of small RNAs with DNA constructs was conducted using Lipofectamine 2000 reagent (Invitrogen), according to the manufacturer's instructions. For quantitative real-time PCR (qRT-PCR) analysis of mRNA or miRNA expression, total RNAs were extracted, reverse transcribed, and amplified, as described previously (35). For miRNA analysis, the reverse transcription primer for miR-30 was 59-GCGAGCACAGAATTAATACG-ACTCACTATAGGTTTTTTTTTTTTVN-39.…”

“…The relative expression levels of miRNAs were normalized to U6. Previously described primers were used for mRNA analysis of porcine MX1, ISG15, PRRSV ORF7, and GAPDH (35,36). Other specific primers for qRT-PCR analysis are listed in Table II.…”

“…A mutant vector was constructed by mutating five seed nucleotides using a site-directed mutagenesis kit (Stratagene), following the manufacturer's instructions. NF-kB, ISRE, IRFs responding plasmids, and IFN-b promoter vector were constructed as described previously (35,36). A sequence containing three copies of the IFN-g-activated site (GAS) promoter element from the IRF1 gene, 59-CTGATTTCCCCGAAATGA-39, was inserted into pGL6 to construct the GAS promoter vector.…”

A brief review of microRNA and its role in PRRSV infection and replication

“…Increasing evidence indicates that miRNAs can participate in the regulation of almost every cellular activity and their abnormal expression is associated with many human diseases. Recently, several studies have demonstrated that miRNAs can regulate PRRSV infection and replication [5][6][7][8]. Here we discuss the current understanding of the role of miRNA in PRRSV infection and hypothesize that cellular miRNAs may contribute significantly to regulating PRRSV infection.…”