摘要
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.
AIM:Both Hepatitis B virus(HBV)and Hepatitis C virus (HCV)are major causative agents of transfusion-associated and community-acquired hepatitis worldwide.Development of a HCV vaccine as wall as more effective HBV vaccines is an urgent task.DNA immunization provides a promising approach to elicit protective humoral and cellular immune responses against viral infection.The aim of this study is to achieve immune responses against both HCV and HBV by DNA immunization with fusion constructs comprising various HCV E2 gene fragments fused to HBsAg gene of HBV. METHODS:C57BL/6 mica ware immunized with plssmid DNA expressing five fragments of HCV E2 fused to the gane for HBsAg respectively.After one primary and one boosting immunizations,antibodies against HCV E2 and HBsAg ware tested and subtyped in ELISA.Splenic cytokine expression of IFN-γ and IL-10 was analyzed using an RT-PCR assay. Post-immune mouse antisera also were tested for their ability to capture HCV viruses in the serum of a hepatitis C patient in vitro. RESULTS:After immunization,antibodies against both HBsAg and HCV E2 ware detected in mouse sera,with IgG2a being the dominant immunoglobulin sub-class.High- level expression of INF-γ was detected in cultured splenic cells. Mouse antisera against three of the five fusion constructs were able to capture HCV viruses in an in vitro assay. CONCLUSION:The results indicate that these fusion constructs could efficiently elicit humoral and Thl dominant cellular immune responses against both HBV S and HCV E2 antigens in DNA-immunized mica.They thus could serve as candidates for a bivalent vaccine against HBV and HCV infection,in addition,the capacity of mouse antisera against three of the five fusion constructs to capture HCV viruses in vitro suggested that neutralizing epitopes may be pressnt in other regions of E2 besides the hypervafiable region 1.
基金
the National High-Technology Program of China,No.863-102-07-02-02
