Research About The Molecule Adjuvant Effect Of Ailuropoda Melanoleuca IL-7to The E_1-402aa Gene Of JEV DNA Vaccine

Japanese encephalitis virus (JEV), being a member of the family Flaviviridae, is commonly regarded as a serious public health problem. The JEV genome contains a single-stranded, positive-sense RNA of approximately11kb in length. The single open reading frame contained in the genome is translated into a polyprotein which is cleaved co-and post translationally into structural and nonstructural proteins. The JEV virion contains three structural proteins:an envelope protein (E), a membrane protein M (preM), and a capsid protein (C). At least seven nonstructural proteins:NS1, NS2A, NS2B, NS3, NS4A, NS4B and NS5, can be identified in JEV infected cells.Among them, E protein can provide protection against JEV infection. IL-7which not only can promote T cell proliferation, activation through multiple links, but also can stimulate a variety of cell surface molecules expression and production of multiple cytokines such as MHC Ⅱ is widely used in the study of DNA vaccine adjutants.In this experiment, the major antigenic segment E1-402aa of JEV SA14-14-2and IL-7from Ailuropoda melanoleuca were first time cloned into eukaryotic expression vector pCI-neo to construct the recombinant plasmids pCI-E1-402aa and pCI-IL-7. And to construct the expression plasmid pCI-IL-7-E1-402aa, the IL-7gene was cloned into the eukaryotic expression vector pCI-E1-402aa through gene linker.In order to investigate the immunogenic efficiency of the DNA vaccine and IL-7, forty of JEV negative mice (4-week-old, female) were randomly divided into seven groups with eight of them each group. The blank eukaryotic expression plasmid pCI-neo and JEV vaccine were used as controls. Mice were injected with purified DNA vaccine at a dose of100ug each other. Anti-JEV antibodies were measured by ELISA, lymphocyte proliferation activity was detected by the amount of the IL-4and IFN-Y. Dates showed that the DNA vaccine can induce humoral and cellular immune responses. The rank for neutralizing antibodies titers is pCI-E]-402aa+pCI-IL-7, pCI-IL-7-E1-402aa, pCI-E1-402aa-No neutralizing antibody was found in the pCI-neo inoculation group throughout the experiment. The reactive of the IL-4and IFN-Y antibody levels of the DNA vaccine group were significantly higher than the control group. IL-4antibody levels is higher than IFN-γ antibody levels in vaccine group with IL-7. The result indicated that the IL-7can enhance the immunity of JEV DNA vaccine as cytokine adjuvant. The results provide reference data for the new generation vaccine research of JEV and immunoadjuvants of IL-7.