Effects of Lipopolysaccharide on Antiviral Immune Response Induced by Porcine Reproductive and Respiratory Syndrome Virus

To study the effects of lipopolyscaccharide on antiviral immune response induced by porcine reproductive and respiratory syndrome virus(PRRSV),porcine alveolar macrophage(PAM)cell was prepared and cultured with PRRSV solution 100 TCID50.After inoculated 12 h,cells were treated with 100ng/mL LPS.Then collected cells and supernatants after treated 12,24,36 and 48h,respectively.The level of the virus,IFN-αand TNF-αmRNA in the PAM cells were quantitated by Realtime qPCR including lipopolysaccharide(LPS)stimulation of PRRSV infected PAM cells group,PRRSV infection control group,LPS stimulated cells control group and cell control group.The results showed that compared with unstimulated with LPS,the replication of PRRSV in PAM cells infected with PRRSV stimulated with LPS group was less than that of PRRSV infection control group from 12 to 48h.The transcription level of IFN-α mRNA improved significantly(P0.05)and the transcription level of TNF-α mRNA improved and reduced at 48 h.Compared with LPS stimulation control group,LPS stimulation of PRRSV infected PAM cells group,IFN-α mRNA transcription level improved at 12 hand reduced at 24,36 and 48h.So PRRSV infected PAM cells stimulated with LPS,the transcription of IFN-α,TNF-α mRNA was significantly improved(P0.05),thereby inhibiting the replication of PRRSV in PAM cells.