The aim of this study is to explore the immunogenicity of African swine fever virus p37 recombinant protein in mice.C57BL/6J mice were immunized subcutaneously in the abdomen using p37 recombinant protein as antigen.The second immunization was performed 21 d after the first immunization.Serum-specific antibody levels were detected by ELISA;serum cytokine levels were detected using a multifactor assay technique;mice splenic lymphocytes were isolated 7 d after sec-ondary immunization,and the number of splenic lymphocytes secreting IFN-γ after recombinant protein stimulation was detected by ELISpot;and the ratio of CD4+T cells to CD8+T cells was detected by flow cytometry.The results of indirect ELISA showed that p37 recombinant protein could stimulate mice to produce high levels of specific antibodies;ELISpot showed that p37 recom-binant protein could significantly stimulate splenic lymphocytes to produce IFN-γ(P＜0.001)and activate cellular immune responses;the results of flow cytometry showed that it could signifi-cantly stimulate the differentiation of T-lymphocytes to CD4+T-lymphocytes(P＜0.001).In ad-dition,serum levels of IL-2,IL-4,IFN-γ,and TNF-α immune-related cytokines were significantly higher after the second immunization.Immunization of mice with p37 recombinant protein induced strong humoral and cellular immune responses with good immunogenicity,providing reference for the subsequent epitope identification and functional study of p37 protein and the antigen screening of ASF mRNA vaccine.

The aim of this study is to explore the immunogenicity of African swine fever virus p37 recombinant protein in mice.C57BL/6J mice were immunized subcutaneously in the abdomen using p37 recombinant protein as antigen.The second immunization was performed 21 d after the first immunization.Serum-specific antibody levels were detected by ELISA;serum cytokine levels were detected using a multifactor assay technique;mice splenic lymphocytes were isolated 7 d after sec-ondary immunization,and the number of splenic lymphocytes secreting IFN-γ after recombinant protein stimulation was detected by ELISpot;and the ratio of CD4+T cells to CD8+T cells was detected by flow cytometry.The results of indirect ELISA showed that p37 recombinant protein could stimulate mice to produce high levels of specific antibodies;ELISpot showed that p37 recom-binant protein could significantly stimulate splenic lymphocytes to produce IFN-γ(P＜0.001)and activate cellular immune responses;the results of flow cytometry showed that it could signifi-cantly stimulate the differentiation of T-lymphocytes to CD4+T-lymphocytes(P＜0.001).In ad-dition,serum levels of IL-2,IL-4,IFN-γ,and TNF-α immune-related cytokines were significantly higher after the second immunization.Immunization of mice with p37 recombinant protein induced strong humoral and cellular immune responses with good immunogenicity,providing reference for the subsequent epitope identification and functional study of p37 protein and the antigen screening of ASF mRNA vaccine.

African swine fever(ASF)is a highly contagious disease caused by the African swine fe-ver virus(ASFV).To evaluate the immunogenicity of the pp62(CP530R)protein of ASFV,the recombinant CP530R protein was expressed in HEK 293F cells transfected with the plasmid pMAL-Fc-CP530R.Six-week-old female C57BL/6J mice were immunized with 10 μg of purified pp62 protein via subcutaneous injection,followed by a booster immunization with the same dosage at 21 days(enhanced).The humoral and cellular immune responses in the mice were then assessed using ELISA,flow cytometry,and ELISpot assays.Western blot analysis confirmed that the pp62 protein was successfully expressed,with a molecular weight of approximately 118.5 kDa.ELISA results indicated that a high level of specific antibodies was detected in the immunized mice,with antibody titers reaching up to 1∶1 638 400 at 7 days after the secondary immunization.The pro-portion of CD8+T lymphocytes in the immunized mice increased compared to the control group(P＜0.05).Results from the Q-PlexTM Mouse Cytokine Screen demonstrated that the secretion levels of IFN-γ,IL-2,IL-4,and IL-10 in serum were significantly upregulated in the immunized mice following secondary immunization(P＜0.001).In summary,these findings indicate that the pp62 protein can significantly stimulate both humoral and cellular immunity in mice,laying the groundwork for further studies on the function of the ASFV pp62 protein and the identification of novel vaccine antigens for ASF.

African swine fever(ASF)is a highly contagious disease caused by the African swine fe-ver virus(ASFV).To evaluate the immunogenicity of the pp62(CP530R)protein of ASFV,the recombinant CP530R protein was expressed in HEK 293F cells transfected with the plasmid pMAL-Fc-CP530R.Six-week-old female C57BL/6J mice were immunized with 10 μg of purified pp62 protein via subcutaneous injection,followed by a booster immunization with the same dosage at 21 days(enhanced).The humoral and cellular immune responses in the mice were then assessed using ELISA,flow cytometry,and ELISpot assays.Western blot analysis confirmed that the pp62 protein was successfully expressed,with a molecular weight of approximately 118.5 kDa.ELISA results indicated that a high level of specific antibodies was detected in the immunized mice,with antibody titers reaching up to 1∶1 638 400 at 7 days after the secondary immunization.The pro-portion of CD8+T lymphocytes in the immunized mice increased compared to the control group(P＜0.05).Results from the Q-PlexTM Mouse Cytokine Screen demonstrated that the secretion levels of IFN-γ,IL-2,IL-4,and IL-10 in serum were significantly upregulated in the immunized mice following secondary immunization(P＜0.001).In summary,these findings indicate that the pp62 protein can significantly stimulate both humoral and cellular immunity in mice,laying the groundwork for further studies on the function of the ASFV pp62 protein and the identification of novel vaccine antigens for ASF.

To explore the impact of Salmonella on Enterococcusfaecalis isolate N41 under the coexisting,the growth traits and the transcription of 26 virulence genes of N41 at various growth phases were detected.Salmonella and/or N41 were inoculated and done plate counting,then growth curves were drawn and bacterial total RNA were extracted at given time points,quantitive realtime PCR was used to analyze the RNA transcription levels of 26 virulence genes of N41.The result showed that comparison with single incubation,the bacteria concentration of N41 dropped about 3.9 times,and Salmonella dropped about 110-times.Among 26 virulence genes of N41,the RNA transcription levels of 12 virulence genes such as ebpA,ebpC,rnjB,ace,ebpR,psr and so on were promoted at the four growth phases,but the RNA transcription levels of SlyA and sprE were dropped.Except that the RNA transcription levels of CylL-S,CylL-L,efaA and AS had no significant changes at the four growth phases,the mostly rest genes increased dramatically at post-log phase.This indicated that when incubated together,N41 inhibited the growth of Salmonella significantly,and Salmonella promoted the transcription levels of virulence genes of N41 as a whole.The results lay a foundation for further research on the interaction between bacteria species and the pathogenicity mechanism of Enterococci.