China Animal Husbandry and Veterinary Medicine ›› 2025, Vol. 52 ›› Issue (4): 1815-1824.doi: 10.16431/j.cnki.1671-7236.2025.04.033

• Preventive Veterinary Medicine • Previous Articles     Next Articles

Construction and Biological Characteristics of Recombinant PRV in Partial Epitope Region of CSFV E2 Gene

WANG Linqing1, ZHANG Liuhui2, CHEN Ximeng2, MA Shijie2, SONG Yue1, CHEN Hongying2   

  1. 1. Molecule Biology Laboratory, Zhengzhou Normal University, Zhengzhou 450044, China;
    2. College of Veterinary Medicine, Henan Agricultural University, Zhengzhou 450046, China
  • Received:2024-07-30 Published:2025-03-29

Abstract: 【Objective】 Classical swine fever virus (CSFV) and porcine Pseudorabies virus (PRV) are two important pathogens affecting the development of current swine industry.Currently,there is no effective drug treatment,and the prevention mainly depends on vaccination.The aim of this study was to construct a recombinant PRV strain containing part of the epitope region of CSFV E2 gene and explore its biological characteristics,so as to provide reference for the development of dual vaccine against CSFV and PRV simultaneously.【Method】 Firstly,a gene segment containing the 4 epitope regions of B/C/D/A of CSFV E2 protein was inserted into the BamHⅠ site of the pG-EGFP recombinant plasmid,and the recombinant plasmid pG-E2AD-EGFP was constructed.The plasmid was then transfected into ST cells inoculated with PRV tri-gene deletion strain rPRV NY-gE/gI/TK and homologous recombination occurred in ST cells.The recombinant virus rPRV-E2AD-EGFP with green fluorescent protein was rescued by the plaque purification.The EGFP gene was knocked out using CRISPR/Cas9 knockout vector,and the non-fluorescent recombinant virus rPRV-E2AD was purified by plaque.The expression of A-D epitopes of E2 of recombinant virus rPRV-E2AD was detected by PCR amplification and Western blotting.The proliferation of the virus after treatment with different physicochemical properties was detected by 50% tissue culture infective dose (TCID50) method,and the culture and physicochemical properties of the recombinant virus were evaluated.【Result】 Recombinant virus rPRV-E2AD-EGFP expressing both CSFV E2AD antigen and EGFP was obtained through intracellular homologous recombination and viral plaque purification.EGFP gene was knocked out by CRISPR/Cas9 technique,and recombinant virus rPRV-E2AD without EGFP gene expression was obtained.Western blotting results showed that the protein size of this strain was about 27 ku,which was consistent with the CSFV E2AD antigen size.The growth characteristics of rPRV-E2AD and parent strains were basically the same in ST,IPEC-J2,PK-15 and Vero cells,both of which caused cell fusion at 12 h after infection and cell loss at 36 h after infection.Physical and chemical characteristics test results showed that the recombinant strain and the parent strain had similar culture characteristics under the same physical and chemical conditions.【Conclusion】 In this study,recombinant virus rPRV-E2AD was successfully obtained,and the foreign gene did not affect the proliferation characteristics of the parent strain.The results provided the candidate strains for the development of recombinant CSFV E2 gene live vector vaccine,and also provided the research basis for the development of PRV live vector vaccine.

Key words: Classical swine fever virus (CSFV); Pseudorabies virus (PRV); recombinant virus; E2 gene

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