Study On The Regulation Of Porcine Reproductive And Respiratory Syndrome Virus Replication By Galectin-1 And Galectin-3

Porcine reproductive and respiratory syndrome virus(PRRSV)is one of the most severe infectious pathogens threatening the swine industry worldwide.It is of significance to explore the interactions between viral proteins and host cellular proteins,which can help to understand the pathogenesis of PRRSV.Here,we determined the cellular proteins interacting with the nonstructural protein 11(Nsp11)or nonstructural protein 12(Nsp 12)by yeast two-hybrid screening in a cDNA library from porcine alveolar macrophage cells,then we chose Galectin-1 and Galectin-3 as research objects to analyze the significance of the interactions,in order to provide scientific evidences for further elucidating the pathogenesis of PRRSV.At first,we generated two recombinant plasmids,named Nsp11-pGBKT7 and Nsp12-pGBKT7.The Nsp1 1 and Nsp12 gene were amplified according to the sequence of the highly pathogenic vHuN4 strain.Results from toxicity and autoactivation tests showed that pGBKT7 containg the Nsp11 or Nsp 12 gene had no toxicity to the colony size of yeast and deactivated the reporter genes in Y2HGold yeast cells,so Nsp1 1-pGBKT7 and pGBKT7-Nsp12 were used as the bait to screen a cDNA library from PAMs,respectively.Sequence alignments were performed using BLAST to determine the corresponding gene,and the candidate interacting protein were identified.Co-immunoprecipitation analyses were performed to confirm the interactions between Nsp 11 and Galectin-1,Nsp12 and Galectin-3,respectively.The coding sequences of Galectin-1 and Galectin-3 were cloned into eukaryotic vector PCAGGS,respectively.Overexpression of Galectin-1 or Galectin-3 significantly inhibited the replication of of both type 1 and type 2 PRRSV strains in MARC-145 cells.Further studies found that the incubation of the prokaryotic recombinant Galectin-1 to MARC-145 cells could also lead to a significant inhibition of PRRSV replication in a dose-dependent manner.To investigate whether Galectin-1 has similar antiviral effects to other viruses,equine arteritis virus,pseudorabies virus(PRV),epidemic diarrhea virus(PEDV),swine fever virus(CSFV)and Japanese encephalitis virus(JEV)were used.The results showed that Galectin-1 displayed different degrees of restriction function to PRV,PEDV,CSFV and JEV replication,suggesting the broad-spectrum antiviral effect of Galectin-1.