Immunogenic response of recombinant pseudorabies virus carrying B646L and B602L genes of African swine fever virus in mice

Abstract

African swine fever (ASF) is an acute infectious disease that poses a high lethality risk to domestic pigs and wild boars, causing substantial economic losses to the global pig industry. The prevention and control of ASF remain challenging, necessitating the urgent development of a safe and effective vaccine. This study focused on the essential structural protein p72 of ASFV (encoded by the B646L gene) and its chaperone protein pB602L (encoded by the B602L gene) as the target antigenic proteins. Based on CRISPR/Cas9 gene-editing technology, we constructed a live attenuated recombinant pseudorabies virus vector expressing the p72 and pB602L proteins (designated as rPRVXJ-EGFP/B602L/B646L), and assessed its immunization effect in mice. The recombinant virus rPRVXJ-EGFP/B602L/B646L successfully proliferated and demonstrated stable expression of the p72 and pB602L proteins in BHK-21 cells. Moreover, it exhibited excellent safety when used in mice and induced specific humoral and cellular immune responses targeting p72 and pB602L. In addition, it provided complete protection (100%) against the virulent PRV strain (PRV-XJ). These results indicate that the recombinant virus rPRVXJ-EGFP/B602L/B646L possesses robust immunogenicity and safety in mice. In conclusion, PRV represents a promising viral vector for expressing ASFV gene, and our study serves as an essential reference for the development of viral vector vaccines against ASFV.