Antiviral Effect Of PKR Against Capripoxvirus And Preliminary Exploration On The Relationship Of PKR And K3L

Capripoxvirus(CaPV) causes a severe and highly contagious disease in sheep or goats. The World Organization for Animal Health(OIE) classifies capripoxviruses as notifiable diseases. Capripoxvirus contains sheeppox virus(SPPV), goatpox virus(GTPV) and lumpy skin disease virus(LSDV), they are large, complex, double-stranded DNA viruses of the genus Capripoxvirus, subfamily Chordopoxvirinae,family Poxviridae.The IFN-induced double-stranded RNA-dependent protein kinase(PKR) is one of the four mammalian serine-threonine kinases(the three others are HRI, GCN2 and PERK) that phosphorylate the eIF2 a translation initiation factor, in response to stress signals, mainly as a result of viral infections.Capripox is known as a severe disease among animal pox disease. However, antiviral effect of PKR against Ca PV still has limited knowledge. In this study, we confirmed that SPPV could activate PKR by generating viral dsRNA. The antiviral effect of PKR against SPPV was evaluated by over-expression or knockdown of PKR. At the same time, we preliminary explored the relationship between SPPV K3 L and PKR.1. The effect of SPPV infection on the PKR-eIF2α signaling pathwayThis study found that SPPV infection could cause PKR and eIF2α distinct phosphorylation compared with the inactivated SPPV by UV treatment. The phosphorylation was happened in a dose-dependent manner.2. The antiviral effect of PKR when cells infected with SPPVTo determine whether PKR play a part in resisting SPPV, HeLa cells with over-expression or knockdown of PKR were infected with SPPV GL strain. The results showed that over-expression of PKR could inhibit the synthesis of viral protein and the replication of SPPV. However, the knockdown of PKR could enhance the replication of SPPV.3. PKR induced the expression of interferonTo confirm whether PKR induces IFN production when infected with SPPV, HeLa cells with knockdown of PKR were infected with SPPV GL strain and evaluated the levels of IFN-β mRNA.Compared with the negative control, the level of IFN-β mRNA in PKR knockdown cells had a significant increase. These results showed that PKR plays an important role in inducing interferon during SPPV infection.4. The preliminary inquiry of the relationship between PKR and SPPV K3 L proteinIt is be found that there are some interaction between PKR and K3 L co-express in cell nucleus. SPPV K3 L mRNA level has a lot of growth in the short term in HeLa cells when infected with SPPV GL strain.This maybe related to viral replication in cells.