Pattern Recognition Receptor RIG-Ⅰ Recognizes CSFV RNA And Inhibits CSFV Replication

Innate immunity is the first line of defense against viral infection,and the retinoic acid-induced gene-like receptor(RIG-Ⅰ receptors,RLRs)are the primary receptor family for the identification of viral RNA.At present,more members of the RLRs family have retinoic acid-inducible gene I(RIG-Ⅰ),melanoma differentiation associated gene-5(MDA-5)and genetics and laboratory of genetics and physiology(LGP2).RIG-Ⅰ induces a key role in the induction of IFN during viral infection.Classical swine fever virus(CSFV)is the causative agent of classical swine fever(CSF),which poses a serious threat to the global pig industry.CSFV belongs to RNA virus,is the pathogen of CSF.Developed the research of RLRs recognize CSFV RNA,it is important to clarify the mechanism of action of innate immunity in the process of virus infection.SPF animal refers to the body does not have specific microorganisms and parasites exist in animals,is a healthy animal without infectious disease and is currently the most widely used experimental animals abroad.Therefore,SPF animals with CSFV infection experiment is more convincing to the host innate immune response.In this study,CSFV Shimen strain was selected to infect SPF pigs.Study and observe the clinical symptoms of pigs after infection with the virus.Pigs showed typical CSF clinical manifestations,elevated body temperature,loss of appetite,ataxia;the autopsy revealed a significant bleeding in the organ.We also indicated that a variety of host molecular expression changes,wherein the RIG-Ⅰ molecule is significantly altered in the host by transcriptome analysis.So we have a further exploration of RIG-Ⅰ.The RIG-Ⅰ molecule of the host was analyzed by RT-qPCR method,the results showed that the expression level of RIG-Ⅰ molecule increased first and then decreased after infection of CSFV.We validated RIG-Ⅰ to recognize viral RNA in vitro.In addition,we examined the CSFV genome copy number and structural protein E2 expression level,confirmed that overexpression of RIG-Ⅰ molecules inhibit the replication of CSFV,whereas,knowndown of RIG-Ⅰ by si RNA significantly promote the replication of CSFV in PK-15 cell.The above studies show that RIG-Ⅰ molecules play an important role in CSFV infection at the host level and the cellular level.RIG-Ⅰ molecules inhibit CSFV replication.