African swine fever(ASF)caused by African swine fever virus(ASFV)is a febrile,hem-orrhage and highly fatal infectious disease in pigs,which poses a serious threat to the global pig in-dustry.Currently,no vaccine is available for the prevention and control of ASF,and several ASF vaccines,including gene deletion attenuated live vaccines,live vector vaccines,and subunit vaccines are under the development stage in the laboratory research.As one of the most promising vaccines,live vector vaccine has the characteristic of safety and simulation of the pathogen natural infection to effectively stimulate the innate and adaptive immune responses,which becomes one of the hotspots in the research and development of novel ASF vaccines.This review focuses on the pro-gress in using modified viruses as vectors for ASF live vector vaccines,and aims to provide valua-ble information for future development of safe and effective ASF vector vaccines.

African swine fever(ASF)is an acute,febrile,and highly fatal disease caused by African swine fever virus(ASFV)in pigs.Given the current lack of commercial vaccines and the continu-ous evolution of ASFV in recent years,the emergence of moderately virulent genotype Ⅱ strains and the introduction of genotype Ⅰ attenuated strains have led to persistent and chronic infections in pigs.Therefore,the detection of specific antibodies against ASFV has become imperative.In this study,we established a competitive chemiluminescence immunoassay(p30-cCLIA)for detecting ASFV p30 antibodies using p30 monoclonal antibodies.By detecting sera with clear negative and positive backgrounds,we determined that the Cut-off value of this method was 50％,with both di-agnostic sensitivity(Dsn)and diagnostic specificity(Dsp)reaching 100％.Under optimal reaction conditions,we screened out an enzyme-labeled stabilizer suitable for p30 monoclonal antibody 16-5E7E8-HRP.Furthermore,the sensitivity of the established p30-cCLIA method was higher than that of the commercial blocking ELISA kit(1∶2 048 vs 1∶512)and exhibited good repeatability.Detection of sera positive for other porcine virus infections showed no cross-reactivity.The estab-lishment of this method provides a powerful tool for early diagnosis of ASF.

Although no cross protection was observed between different serotypes of foot-and-mouth disease virus(FMDV),there were cross-reactivity between different serotypes of antibodies produced after vaccination,the aim of this paper was to prepare the neutralizing monoclonal anti-body against Foot-and-mouth disease virus(FMDV)serotype O,and to develop the method to dis-tinguish antibody against FMDV serotype O and A based on mAb.The inactivated FMDV serotype O was used as antigen in mAb production,a series of GST fusion overlapping peptides and trun-cated peptides expressed in Escherichia coli were used to identify antigenic epitope recognized by monoclonal antibodies.In order to verify feasibility of the screened monoclonal antibodies in diag-nosis,20 positive serum of FMDV serotype O and A,20 negative serum with known background were detected by blocking ELISA.Results were as follows:five monoclonal antibodies were suc-cessfully screened.The five monoclonal antibodies showed good reactivity with FMDV serotype O,but did not react with FMDV serotype A by Western blot and IFA,these mAbs showed neutrali-zing ability to FMDV/O/MY98/GZBY/2013 by VNT.The same epitope was identified by five monoclonal antibodies,the minimum epitope was145 RGDLQVLA152,Arg145 and Gln149 were key a-mino acids of the epitope.Sequence alignment analysis revealed that the identified epitopes were conserved among most of O type FMDV strains,but Gln149 was mutated among all A,Asia 1 and SAT1-3 type FMDV strains.The mAb-8C5D3 distinguished between antibody of FMDV serotype O and FMDV serotype A by blocking ELISA.The results provided materials for development of O type FMDV antibody detection kit and evaluation of vaccine immune effect.

Although no cross protection was observed between different serotypes of foot-and-mouth disease virus(FMDV),there were cross-reactivity between different serotypes of antibodies produced after vaccination,the aim of this paper was to prepare the neutralizing monoclonal anti-body against Foot-and-mouth disease virus(FMDV)serotype O,and to develop the method to dis-tinguish antibody against FMDV serotype O and A based on mAb.The inactivated FMDV serotype O was used as antigen in mAb production,a series of GST fusion overlapping peptides and trun-cated peptides expressed in Escherichia coli were used to identify antigenic epitope recognized by monoclonal antibodies.In order to verify feasibility of the screened monoclonal antibodies in diag-nosis,20 positive serum of FMDV serotype O and A,20 negative serum with known background were detected by blocking ELISA.Results were as follows:five monoclonal antibodies were suc-cessfully screened.The five monoclonal antibodies showed good reactivity with FMDV serotype O,but did not react with FMDV serotype A by Western blot and IFA,these mAbs showed neutrali-zing ability to FMDV/O/MY98/GZBY/2013 by VNT.The same epitope was identified by five monoclonal antibodies,the minimum epitope was145 RGDLQVLA152,Arg145 and Gln149 were key a-mino acids of the epitope.Sequence alignment analysis revealed that the identified epitopes were conserved among most of O type FMDV strains,but Gln149 was mutated among all A,Asia 1 and SAT1-3 type FMDV strains.The mAb-8C5D3 distinguished between antibody of FMDV serotype O and FMDV serotype A by blocking ELISA.The results provided materials for development of O type FMDV antibody detection kit and evaluation of vaccine immune effect.

African swine fever(ASF)caused by African swine fever virus(ASFV)is a febrile,hem-orrhage and highly fatal infectious disease in pigs,which poses a serious threat to the global pig in-dustry.Currently,no vaccine is available for the prevention and control of ASF,and several ASF vaccines,including gene deletion attenuated live vaccines,live vector vaccines,and subunit vaccines are under the development stage in the laboratory research.As one of the most promising vaccines,live vector vaccine has the characteristic of safety and simulation of the pathogen natural infection to effectively stimulate the innate and adaptive immune responses,which becomes one of the hotspots in the research and development of novel ASF vaccines.This review focuses on the pro-gress in using modified viruses as vectors for ASF live vector vaccines,and aims to provide valua-ble information for future development of safe and effective ASF vector vaccines.

African swine fever(ASF)is an acute,febrile,and highly fatal disease caused by African swine fever virus(ASFV)in pigs.Given the current lack of commercial vaccines and the continu-ous evolution of ASFV in recent years,the emergence of moderately virulent genotype Ⅱ strains and the introduction of genotype Ⅰ attenuated strains have led to persistent and chronic infections in pigs.Therefore,the detection of specific antibodies against ASFV has become imperative.In this study,we established a competitive chemiluminescence immunoassay(p30-cCLIA)for detecting ASFV p30 antibodies using p30 monoclonal antibodies.By detecting sera with clear negative and positive backgrounds,we determined that the Cut-off value of this method was 50％,with both di-agnostic sensitivity(Dsn)and diagnostic specificity(Dsp)reaching 100％.Under optimal reaction conditions,we screened out an enzyme-labeled stabilizer suitable for p30 monoclonal antibody 16-5E7E8-HRP.Furthermore,the sensitivity of the established p30-cCLIA method was higher than that of the commercial blocking ELISA kit(1∶2 048 vs 1∶512)and exhibited good repeatability.Detection of sera positive for other porcine virus infections showed no cross-reactivity.The estab-lishment of this method provides a powerful tool for early diagnosis of ASF.

Objective To compare the protective effect of ischemic preconditioning(IP) and caspase inhibitor on ischemia reperfusion(IR) injury of the liver in rats,and to investigate the possible mechanism. Methods SD rats subjected to 60 or 120 minutes of 70% hepatic ischemia and 3 hours of reperfusion,respectively,then divided randomly into 6 groups: (1)Ischemia/ reperfusion group 1 (IR 1 group);(2)IR 2 group;(3)Ischemia preconditioning group 1(IP 1 group);(4)IP 2 group; (5)Caspase inhibitor treatment group1(T 1 group);(6)T 2 group.Serum levels of aspartate aminotransferase (AST) and alanine aminotransfernase (ALT),and liver Caspase-3 activity, hepatocytes apoptosis,and animal seven-day(7 d) survive rate were determined. Results Both ischemic preconditioning and Caspase inhibitor treatment could protect the liver against IR injury,and their protective effect in IP 1 group and T 1 group was equally at 3h reperfusion after 60min ischemia. At 3h reperfusion after 120min ischemia, the effect of inhibiting Caspase-3 activity and decreasing hepatocyte apoptosis in T 2 group were significantly superior to those in IP 2 group(P0.05). Conclusions Both IP and Caspase inhibitor treatment can protect the liver against IR injury in rats,and the protective effect is no significant difference between the two methods.However IP is more simple?safe and cheaper comparing with Caspase inhibitor treatment.