AIM: Both Hepatitis B virus (HBV) and Hepatitis C virus(HCV) are major causative agents of transfusion-associatedand community-acquired hepatitis worldwide. Developmentof a HCV vaccine as well as more effective HBV va...AIM: Both Hepatitis B virus (HBV) and Hepatitis C virus(HCV) are major causative agents of transfusion-associatedand community-acquired hepatitis worldwide. Developmentof a HCV vaccine as well as more effective HBV vaccines isan urgent task. DNA immunization provides a promisingapproach to elicit protective humoral and cellular immuneresponses against viral infection. The aim of this study is toachieve immune responses against both HCV and HBV by DNAimmunization with fusion constructs comprising various HCVE2 gene fragments fused to HBsAg gane of HBV.METHODS: C57BL/6 mice were immunized with plasmid DNAexpressing five fragments of HCV E2 fused to the gene forHBsAg respectively. After one primary and one boostingimmunizations, antibodies against HCV E2 and HBsAg weretested and subtyped in ELISA. Splenic cytokine expressionof IFN-γ and IL-10 was analyzed using an RT-PCR assay.Post-immune mouse antisera also were tested for theirability to capture HCV viruses in the serum of a hepatitis Cpatient in vitro.RESUTLTS: After immunization, antibodies against bothHBsAg and HCV E2 were detected in mouse sera, withIgG2a being the dominant immunoglobulin sub-class. High-level expression of INF-γ was deuetected in cultured splenic cells.Mouse antisera against three of the five fusion constructs wereable to capture HCV viruses in an in vitro assay.CONCLUSION: The results indicate that these fusionconstructs could efficiently elicit humoral and Th1 dominantcellular immune responses against both HBV S and HCV E2antigens in DNA-immunized mice. They thus could serve ascandidates for a bivalent vaccine against HBV and HCVinfection. In addition, the capacity of mouse antisera againstthree of the five fusion constnucts to capture HCV virusses invitro suggested that neutralizing epitopes may be present inother regions of E2 besides the hypervariable region 1.展开更多
Foot-and-mouth disease virus （FMDV） is highly contagious and responsible for huge outbreaks among cloven hoofed animals. The aim of the present study is to evaluate a plasmid DNA immunization system that expresses t...Foot-and-mouth disease virus （FMDV） is highly contagious and responsible for huge outbreaks among cloven hoofed animals. The aim of the present study is to evaluate a plasmid DNA immunization system that expresses the FMDV/OflRN/2007 VP1 gene and compare it with the conventional inactivated vaccine in an animal model. The VP1 gene was sub-cloned into the unique Kpn I and BamH I cloning sites of the peDNA3.1＋ and pEGFP-N1 vectors to construct the VPI gene cassettes. The transfected BHKT7 cells with sub-cloned pEGFP-N1-VP1 vector expressed GFP-VP1 fusion protein and displayed more green fluorescence spots than the transfected BHKT7 cells with pEGFP-N1 vector, which solely expressed the GFP protein. Six mice groups were respectively immunized by the sub-cloned pcDNA3.1＋-VP1 gene cassette as the DNA vaccine, DNA vaccine and PCMV-SPORT-GMCSF vector （as molecular adjuvant） together, conventional vaccine, PBS （as negative control）, pcDNA3.1＋ vector （as control group） and PCMV-SPORT vector that contained the GMCSF gene （as control group）. Significant neutralizing antibody responses were induced in the mice which were immunized using plasmid vectors expressing the VP1 and GMCSF genes together, the DNA vaccine alone and the conventional inactivated vaccine （P〈0.05）. Co-administration of DNA vaccine and GMCSF gene improved neutralizing antibody response in comparison with administration of the DNA vaccine alone, but this response was the most for the conventional vaccine group. However, induction of humeral immunity response in the conventional vaccine group was more protective than for the DNA vaccine, but T-cell proliferation and IFN-？ concentration were the most in DNA vaccine with the GMCSF gene. Therefore the group that was vaccinated by DNA vaccine with the GMCSF gene, showed protective neutralizing antibody response and the most Thl cellular immunity.展开更多
AIM： To construct a recombinant live attenuated Salmonella typhimurium DNA vaccine encoding H pylori ureB gene and mouse IL-2 gene and to detect its immunogenicity in vitro and in vivo. METHODS： Hpylori ureB and mou...AIM： To construct a recombinant live attenuated Salmonella typhimurium DNA vaccine encoding H pylori ureB gene and mouse IL-2 gene and to detect its immunogenicity in vitro and in vivo. METHODS： Hpylori ureB and mouse IL-2 gene fragments were amplified by polymerase chain reaction （PCR） and cloned into pUCmT vector. DNA sequence of the amplified ureB and IL-2 genes was assayed, then cloned into the eukaryotic expression vector pIRES through enzyme digestion and ligation reactions resulting in pIRES-ureB and pIRES-ureB-IL-2. The recombinant plasmids were used to transform competent E. co/i DH5α, and the positive clones were screened by PCR and restriction enzyme digestion. Then, the recombinant pIRES-ureB and pIRES-ureB-IL-2 were used to transform LB5000 and the recombinant plasmids extracted from LB5000 were finally introduced into the final host SL7207. After that, recombinant strains were grown in vitro repeatedly. In order to detect the immunogenicib/of the vaccine in vitro, pIRES-ureB and pIRES-ureB-IL-2 were transfected to COS-7 cells using LipofectamineTM2000, the immunogenicity of expressed UreB and IL-2 proteins was assayed with SDS-PAGE and Western blot. C57BL/6 mice were orally immunized with 1 × 10^8 recombinant attenuated Salmonella typhimurium DNA vaccine. Four weeks after vaccination, mice were challenged with 1 × 10^7 CFU of live Hpylori SS1. Mice were sacrificed and the stomach was isolated for examination of H pylon 4 wk post-challenge. RESULTS： The 1700 base pair ureB gene fragment amplified from the genomic DNA was consistent with the sequence of H pylori ureB by sequence analysis. The amplified 510 base pair fragment was consistent with the sequence of mouse IL-2 in gene bank. It was confirmed by PCR and restriction enzyme digestion that H pylori ureB and mouse IL-2 genes were inserted into the eukaryotic expression vector pIRES. The experiments in vitro showed that stable recombinant live attenuated Salmonella typhimurium DNA vaccine carrying ureB and IL-2 genes was successfully constructed and the specific strips of UreB and IL-2 expressed by recombinant plasmids were detected through Western blot. Study in vivo showed that the positive rate of rapid urease test of the immunized group including ureB and ureB-IL-2 was 37.5% and 12.5% respectively, and was significantly lower than that （100%） in the control group （P 〈 0.01）. CONCLUSION： Recombinant attenuated Salmonella typhimurium DNA vaccine expressing UreB protein and IL-2 protein with immunogenicity can be constructed. It can protect mice against H pylori infection, which may help the development of a human-use H pylori DNA vaccine.展开更多
Objective: To directionally clone the ompl gene fromChlamydia trachomatis (Ct) F genotype onto a plasmid vectorfor constructing a rudimentary DNA vaccine. Methods: The complete ompl gene from genomic DNA of CtF genoty...Objective: To directionally clone the ompl gene fromChlamydia trachomatis (Ct) F genotype onto a plasmid vectorfor constructing a rudimentary DNA vaccine. Methods: The complete ompl gene from genomic DNA of CtF genotype wild species was amplified with primers designedby computer. The recombinant gene was obtained byrestriction enzyme cutting, linking the gene with the plasmidvector in vitro, transforming the recombinant gene intobacteria, and extracting the DNA from the bacteria. Results: DNA extracted from the bacteria was composed ofthe ompl gene and plasmid, which is identified by threemethods of singular restrictive enzyme cutting, doublerestrictive enzyme cutting and PCR. Conclusion: Cloning of the ompl gene from the Ct Fgenotype means that a rudimentary DNA vaccine wassuccessfully constructed.展开更多
基金the National High-Technology Program of China,No.863-102-07-02-02
文摘AIM: Both Hepatitis B virus (HBV) and Hepatitis C virus(HCV) are major causative agents of transfusion-associatedand community-acquired hepatitis worldwide. Developmentof a HCV vaccine as well as more effective HBV vaccines isan urgent task. DNA immunization provides a promisingapproach to elicit protective humoral and cellular immuneresponses against viral infection. The aim of this study is toachieve immune responses against both HCV and HBV by DNAimmunization with fusion constructs comprising various HCVE2 gene fragments fused to HBsAg gane of HBV.METHODS: C57BL/6 mice were immunized with plasmid DNAexpressing five fragments of HCV E2 fused to the gene forHBsAg respectively. After one primary and one boostingimmunizations, antibodies against HCV E2 and HBsAg weretested and subtyped in ELISA. Splenic cytokine expressionof IFN-γ and IL-10 was analyzed using an RT-PCR assay.Post-immune mouse antisera also were tested for theirability to capture HCV viruses in the serum of a hepatitis Cpatient in vitro.RESUTLTS: After immunization, antibodies against bothHBsAg and HCV E2 were detected in mouse sera, withIgG2a being the dominant immunoglobulin sub-class. High-level expression of INF-γ was deuetected in cultured splenic cells.Mouse antisera against three of the five fusion constructs wereable to capture HCV viruses in an in vitro assay.CONCLUSION: The results indicate that these fusionconstructs could efficiently elicit humoral and Th1 dominantcellular immune responses against both HBV S and HCV E2antigens in DNA-immunized mice. They thus could serve ascandidates for a bivalent vaccine against HBV and HCVinfection. In addition, the capacity of mouse antisera againstthree of the five fusion constnucts to capture HCV virusses invitro suggested that neutralizing epitopes may be present inother regions of E2 besides the hypervariable region 1.
文摘Foot-and-mouth disease virus （FMDV） is highly contagious and responsible for huge outbreaks among cloven hoofed animals. The aim of the present study is to evaluate a plasmid DNA immunization system that expresses the FMDV/OflRN/2007 VP1 gene and compare it with the conventional inactivated vaccine in an animal model. The VP1 gene was sub-cloned into the unique Kpn I and BamH I cloning sites of the peDNA3.1＋ and pEGFP-N1 vectors to construct the VPI gene cassettes. The transfected BHKT7 cells with sub-cloned pEGFP-N1-VP1 vector expressed GFP-VP1 fusion protein and displayed more green fluorescence spots than the transfected BHKT7 cells with pEGFP-N1 vector, which solely expressed the GFP protein. Six mice groups were respectively immunized by the sub-cloned pcDNA3.1＋-VP1 gene cassette as the DNA vaccine, DNA vaccine and PCMV-SPORT-GMCSF vector （as molecular adjuvant） together, conventional vaccine, PBS （as negative control）, pcDNA3.1＋ vector （as control group） and PCMV-SPORT vector that contained the GMCSF gene （as control group）. Significant neutralizing antibody responses were induced in the mice which were immunized using plasmid vectors expressing the VP1 and GMCSF genes together, the DNA vaccine alone and the conventional inactivated vaccine （P〈0.05）. Co-administration of DNA vaccine and GMCSF gene improved neutralizing antibody response in comparison with administration of the DNA vaccine alone, but this response was the most for the conventional vaccine group. However, induction of humeral immunity response in the conventional vaccine group was more protective than for the DNA vaccine, but T-cell proliferation and IFN-？ concentration were the most in DNA vaccine with the GMCSF gene. Therefore the group that was vaccinated by DNA vaccine with the GMCSF gene, showed protective neutralizing antibody response and the most Thl cellular immunity.
基金the National Natural Science Foundation of China, No. 30170427
文摘AIM： To construct a recombinant live attenuated Salmonella typhimurium DNA vaccine encoding H pylori ureB gene and mouse IL-2 gene and to detect its immunogenicity in vitro and in vivo. METHODS： Hpylori ureB and mouse IL-2 gene fragments were amplified by polymerase chain reaction （PCR） and cloned into pUCmT vector. DNA sequence of the amplified ureB and IL-2 genes was assayed, then cloned into the eukaryotic expression vector pIRES through enzyme digestion and ligation reactions resulting in pIRES-ureB and pIRES-ureB-IL-2. The recombinant plasmids were used to transform competent E. co/i DH5α, and the positive clones were screened by PCR and restriction enzyme digestion. Then, the recombinant pIRES-ureB and pIRES-ureB-IL-2 were used to transform LB5000 and the recombinant plasmids extracted from LB5000 were finally introduced into the final host SL7207. After that, recombinant strains were grown in vitro repeatedly. In order to detect the immunogenicib/of the vaccine in vitro, pIRES-ureB and pIRES-ureB-IL-2 were transfected to COS-7 cells using LipofectamineTM2000, the immunogenicity of expressed UreB and IL-2 proteins was assayed with SDS-PAGE and Western blot. C57BL/6 mice were orally immunized with 1 × 10^8 recombinant attenuated Salmonella typhimurium DNA vaccine. Four weeks after vaccination, mice were challenged with 1 × 10^7 CFU of live Hpylori SS1. Mice were sacrificed and the stomach was isolated for examination of H pylon 4 wk post-challenge. RESULTS： The 1700 base pair ureB gene fragment amplified from the genomic DNA was consistent with the sequence of H pylori ureB by sequence analysis. The amplified 510 base pair fragment was consistent with the sequence of mouse IL-2 in gene bank. It was confirmed by PCR and restriction enzyme digestion that H pylori ureB and mouse IL-2 genes were inserted into the eukaryotic expression vector pIRES. The experiments in vitro showed that stable recombinant live attenuated Salmonella typhimurium DNA vaccine carrying ureB and IL-2 genes was successfully constructed and the specific strips of UreB and IL-2 expressed by recombinant plasmids were detected through Western blot. Study in vivo showed that the positive rate of rapid urease test of the immunized group including ureB and ureB-IL-2 was 37.5% and 12.5% respectively, and was significantly lower than that （100%） in the control group （P 〈 0.01）. CONCLUSION： Recombinant attenuated Salmonella typhimurium DNA vaccine expressing UreB protein and IL-2 protein with immunogenicity can be constructed. It can protect mice against H pylori infection, which may help the development of a human-use H pylori DNA vaccine.
文摘Objective: To directionally clone the ompl gene fromChlamydia trachomatis (Ct) F genotype onto a plasmid vectorfor constructing a rudimentary DNA vaccine. Methods: The complete ompl gene from genomic DNA of CtF genotype wild species was amplified with primers designedby computer. The recombinant gene was obtained byrestriction enzyme cutting, linking the gene with the plasmidvector in vitro, transforming the recombinant gene intobacteria, and extracting the DNA from the bacteria. Results: DNA extracted from the bacteria was composed ofthe ompl gene and plasmid, which is identified by threemethods of singular restrictive enzyme cutting, doublerestrictive enzyme cutting and PCR. Conclusion: Cloning of the ompl gene from the Ct Fgenotype means that a rudimentary DNA vaccine wassuccessfully constructed.
