Downregulation of miR-296-3p by highly pathogenic porcine reproductive and respiratory syndrome virus activates the IRF1/TNF- α signaling axis in porcine alveolar macrophages

In this study, we used a highly pathogenic PRRSV-2 (speciesBetaarterivirus suid 2) strain to show that PRRSV infection robustly downregulates the expression of miR-296-3p in porcine alveolar macrophages (PAMs). Furthermore, we demonstrated that overexpression of miR-296-3p increases the replication of highly pathogenic (HP)-PRRSV in PAMs. Notably, the overexpression of miR-296-3p inhibited the induction of TNF- α, even with increased viral replication, compared with that in the HP-PRRSV-infected control group. We also demonstrated that miR-296-3p targets IRF1-facilitated viral infection and modulates the expression of TNF-α in PAMs during HP-PRRSV infection and that IRF1 regulates the expression of TNF-α by activating theTNF promoter via IRF1 response elements. In summary, these findings show that HP-PRRSV infection activates the IRF1/TNF- α signaling axis in PAMs by downregulating host miR-296-3p. This extends our understanding of the inflammatory response induced by HP-PRRSV infection.
Source: Archives of Virology - Category: Virology Source Type: research