Generation Of Recombinant Pseudorabies Viruses Eexpressing The GP2 Or GP3 Of Porcine Reproductive And Respiratory Syndrome Virus

Porcine reproductive and respiratory syndrome (PRRS) is a highly infectious viral disease. This disease causes respiratory problems and high mortality in neonatal piglets and reproductive failure in enceinte sows. Efforts to developing a safe and effective vaccine against PRRS are cotinuing. Being able to induce humoral and cellular immune responses in animals, live virus vector vaccines can provide effective protection. Pseudorabies virus (PRV), one of herpesviruses, has a large genome that contains many non-essential regions for inserting and expressing foreign genes, thus it is frequently used as live vaccine vector. In this study, a LacZ gene expression cassette containing the E. coli LacZ gene under the control of SV40 promoter was inserted into the transfer vector pBdTK-Uni previously constructed in our lab, and a 1.2 Kb fragment was ligated into the transfer vector pBdTK-Uni to prolong the homologous arm, resulting pLTK1.2-Uni, in which the lengths of upstream and downstream homologous arms all exceed 1 Kb. The GP2 and GP3 genes of PRRS virus (PRRSV) were cloned into pLTK1.2-Uni to obtain transfer vectors pLTK1.2-ORF2 and pLTK1.2-ORF3. Thereafter, the recombinant transfer vectors pLTK1.2-ORF2 or pLTK1.2-ORF3 and PRV genomic DNA were co-transfected Vero cell using Limpofectamine? 2000. Two recombinant pseudorabies viruses expressing foreign genes were generated after 5 rounds of plaque purification. The recombinant viruses offer a base for the study of the immunological function of PRRSV GP2 and GP3, and they represent potential vaccines against PRRS.