AIM： To characterize the immunogenicity of a hepatitis C virus （HCV） E2 DNA vaccine alone or with a protein vaccine boost in murine and porcine animal models. METHODS： A DNA vaccine expressing a secreted form of H...AIM： To characterize the immunogenicity of a hepatitis C virus （HCV） E2 DNA vaccine alone or with a protein vaccine boost in murine and porcine animal models. METHODS： A DNA vaccine expressing a secreted form of HCV E2 protein was constructed and used to vaccinate mice and piglets with or without boosting with a recombinant E2 protein vaccine formulated with CpG ODN and 10% Emulsigen. The immunogenicity of HCV E2 vaccines was analyzed by ELISA for antibody responses, MTT assay for lymphocyte proliferation, ELISPOT for the number of interferon-γ secreting cells, and cytotoxic T lymphocyte assays. RESULTS： Intradermal injection of E2 DNA vaccine induced strong Th1-1ike immune responses in mice. In piglets, E2 DNA vaccine elicited moderate and more balanced immune responses. A DNA vaccine prime and protein boost vaccination strategy induced significantly higher E2-specific antibody levels and shifted the immune response towards Th2-1ike ones in piglets. CONCLUSION： A DNA vaccine expressing a secreted form of HCV E2 protein elicited E2-specific immune responses in mice and piglets. Recombinant E2 protein vaccination following DNA immunization significantly increased the antibody response in piglets. These HCV E2 vaccines may represent promising hepatitis C vaccine candidates for further investigations.展开更多
Background The adenovirus-based HIV-1 vaccine developed by Merck Company suffered from an unexpected failure in September 2007. This generated a big shift in the strategy of HIV vaccine development with renewed focus ...Background The adenovirus-based HIV-1 vaccine developed by Merck Company suffered from an unexpected failure in September 2007. This generated a big shift in the strategy of HIV vaccine development with renewed focus on the induction of neutralizing antibodies. A major challenge in developing an HIV-1 vaccine is to identify immunogens and adopt delivery methods that can elicit broadly neutralizing antibodies against primary isolates of different genetic subtypes. Methods Most circulating HIV-1 isolates in China are composed of clades Thai-B, CRF_BC and CRF01_AE. In order to construct DNA vaccines against these 3 HIV-1 subtypes, DNA vaccines carrying the gp120 regions from HIV-1 isolates of GX48（AE）, GX79（AE）, NX22（BC）, GS22（BC）, HN24（Thai-B） were constructed. Expression of gp120 from these DNA vaccines was detected by Western blotting in transiently transfected 293T cells. Pilot immunizations of New Zealand white rabbits were performed using the strategy of ＂DNA prime plus protein boost＂ and the neutralizing antibody response was detected in a Tzm-bl cell based assay against different HIV-1 strains. Results Response of gp120-specific antibody was relatively low after DNA primes （mean titer=10^4.72）; however, the titer of gp120-specific antibody went up with 2 protein boosts （mean titer=10^6.81）. Above all, neutralizing antibody （Nab） titers induced by this combined approach were much better than those elicited by DNA or protein used alone （P 〈0.01）. Neutralizing activities of immunized rabbit sera against several pseudoviruses and laboratorial strains were evaluated, most rabbit sera primed with monovalent vaccine were capable of neutralizing only 1 of 5 viruses, however, sera primed with the polyvalent DNA vaccines were able to neutralize at least 2 of 5 viruses. Conclusion Polyvalent DNA prime plus protein boost is an effective immunization strategy to broaden the neutralization breadth and further research should be performed on the basis of this pilot study.展开更多
Many important cash-crops suffer imbibitional chilling injury, which results in poor germination and seedling emergence, decreases seedling vigor and reduces the product of crops. The reason of the chilling injury of ...Many important cash-crops suffer imbibitional chilling injury, which results in poor germination and seedling emergence, decreases seedling vigor and reduces the product of crops. The reason of the chilling injury of plants was ascribed to a phase transition of mem-展开更多
基金Supported by the Canadian Network for Vaccines and Immuno-therapeutics
文摘AIM： To characterize the immunogenicity of a hepatitis C virus （HCV） E2 DNA vaccine alone or with a protein vaccine boost in murine and porcine animal models. METHODS： A DNA vaccine expressing a secreted form of HCV E2 protein was constructed and used to vaccinate mice and piglets with or without boosting with a recombinant E2 protein vaccine formulated with CpG ODN and 10% Emulsigen. The immunogenicity of HCV E2 vaccines was analyzed by ELISA for antibody responses, MTT assay for lymphocyte proliferation, ELISPOT for the number of interferon-γ secreting cells, and cytotoxic T lymphocyte assays. RESULTS： Intradermal injection of E2 DNA vaccine induced strong Th1-1ike immune responses in mice. In piglets, E2 DNA vaccine elicited moderate and more balanced immune responses. A DNA vaccine prime and protein boost vaccination strategy induced significantly higher E2-specific antibody levels and shifted the immune response towards Th2-1ike ones in piglets. CONCLUSION： A DNA vaccine expressing a secreted form of HCV E2 protein elicited E2-specific immune responses in mice and piglets. Recombinant E2 protein vaccination following DNA immunization significantly increased the antibody response in piglets. These HCV E2 vaccines may represent promising hepatitis C vaccine candidates for further investigations.
基金This work was supported by the grants from the China 973 Project （No. 2006CB504206） and the Natural Science Foundation of China （No. 30700706）. In addition, this work was supported by a funding from Jiangsu Provincial Key Infectious Diseases Laboratory.
文摘Background The adenovirus-based HIV-1 vaccine developed by Merck Company suffered from an unexpected failure in September 2007. This generated a big shift in the strategy of HIV vaccine development with renewed focus on the induction of neutralizing antibodies. A major challenge in developing an HIV-1 vaccine is to identify immunogens and adopt delivery methods that can elicit broadly neutralizing antibodies against primary isolates of different genetic subtypes. Methods Most circulating HIV-1 isolates in China are composed of clades Thai-B, CRF_BC and CRF01_AE. In order to construct DNA vaccines against these 3 HIV-1 subtypes, DNA vaccines carrying the gp120 regions from HIV-1 isolates of GX48（AE）, GX79（AE）, NX22（BC）, GS22（BC）, HN24（Thai-B） were constructed. Expression of gp120 from these DNA vaccines was detected by Western blotting in transiently transfected 293T cells. Pilot immunizations of New Zealand white rabbits were performed using the strategy of ＂DNA prime plus protein boost＂ and the neutralizing antibody response was detected in a Tzm-bl cell based assay against different HIV-1 strains. Results Response of gp120-specific antibody was relatively low after DNA primes （mean titer=10^4.72）; however, the titer of gp120-specific antibody went up with 2 protein boosts （mean titer=10^6.81）. Above all, neutralizing antibody （Nab） titers induced by this combined approach were much better than those elicited by DNA or protein used alone （P 〈0.01）. Neutralizing activities of immunized rabbit sera against several pseudoviruses and laboratorial strains were evaluated, most rabbit sera primed with monovalent vaccine were capable of neutralizing only 1 of 5 viruses, however, sera primed with the polyvalent DNA vaccines were able to neutralize at least 2 of 5 viruses. Conclusion Polyvalent DNA prime plus protein boost is an effective immunization strategy to broaden the neutralization breadth and further research should be performed on the basis of this pilot study.
基金Project supported by the National Natural Science Foundation of China
文摘Many important cash-crops suffer imbibitional chilling injury, which results in poor germination and seedling emergence, decreases seedling vigor and reduces the product of crops. The reason of the chilling injury of plants was ascribed to a phase transition of mem-
