1.Generation and immunogenicity evaluation of a recombinant classical swine fever virus C-strain expressing p54 protein of African swine fever virus
Shuwen LI ; Xiaoke YANG ; Xiangyu GUAN ; Guangzhu ZHANG ; Shujian HUANG ; Yongfeng LI ; Huaji QIU
Chinese Journal of Veterinary Science 2024;44(10):2094-2100,2122
African swine fever(ASF)is a virulent,hemorrhagic disease of swine caused by African swine fever virus(ASFV),which seriously affects the healthy development of Chinese pig indus-try.The genome of ASFV is large and encodes more than 165 proteins.Among them,the p54 pro-tein is encoded by the E183L gene,which has various functions such as participating in viral as-sembly,inducing apoptosis and inducing immune response.The conventional Chinese vaccine(C-strain)is a safe and effective attenuated vaccine developed by Chinese scientists.It can efficiently protect against attacks from various genotypes of classical swine fever virus(CSFV).The aim of this study was to investigate whether C-strain can express ASFV p54 protein serve as a delivery vector for ASF genetically engineered vaccines.An infectious clone of pHCLV-p54 was constructed by homologous recombination,the recombinant virus rHCLV-p54 was rescued by transfecting it into SK6 cells by blind passaging.Its genetic stability and growth curve were determined in vitro,while rabbits were immunized to evaluate its immunity effect.The results showed that the E183L gene remained genetically stable in the recombinant virus,indicating that the E183L gene could be stably inherited in recombinant viruses,but the inserted exogenous gene affected the replication of the C-strain.The results of the rabbit immunization test showed that the recombinant virus rHCLV-p54 was able to induce ASFV-specific antibodies.The above results indicated that we have successfully constructed a recombinant C-strain that stably expresses the ASFV p54 protein.In summary,the recombinant virus rHCLV-p54 has a good immunogenicity and is warranted for fur-ther evaluation as a vaccine candidate.