Construction and Identification of Recombinant Fowlpox Virus Expressing GP5/GP3 of Pig Reproduction and Respiration Syndrome Virus(PRRSV) and Swine IL-18

Objective To develop a safe and effective recombinant fowlpox(FPV) as a vaccine against pig reproduction and respiration syndrome virus(PRRSV).Methods Insert the GP5/GP3 gene of Changchun strain of PRRSV downstream to the composite promoter of fowlpox virus transferring vector pUTAL-IL-18.Co-transfect chick embryo fibroblast(CEF) with the constructed recombinant plasmid pUTAL-IL-18-GP5-GP3 and FPV 282-E4 strain for homologous recombination.After 3 cycles of pressure screening in presence of 5′-bromo-deoxyuridine(BrdU),the recombinant virus was identified by PCR,RT-PCR and IFA.Results The target gene at a length of 340 bp was amplified from the genome and total RNA of recombinant fowlpox virus.The CEF transfected with recombinant fowlpox virus reacted with PRRSV specific fluorescent antibody.It indicated that the target gene was successfully expressed in recombinant fowlpox virus.Conclusion A recombinant fowlpox virus for expression of GP5/GP3 gene of PRRSV was successfully constructed.