Combined DNA Immunization Of HBV Envelope And HCV Core

DNA immunization has recently been proven to induce both humoral and cellular immune responses against a range of viruses, so it shows a promising approach to prevention and cure of persistent viral infection. HCV core is highly conserved among HCV genotypes, and its immunogenicity can clear viruses from HCV patients. Although the DNA immunization of HCV core can only induces very weak immune responses, it can be improved by the secretable signal peptide, transmembrane protein and cytokines.In this study, bicistronic vector pcDNA3.0BA was constructed . HCV core and HBV preS2S gene or GM-CSF gene were inserted into this vector,and the resulted plasmids were used for transient expression in COS-7 cells in vitro and immunizing mice in vivo.The immune responses to both HBs and HCV,as well as the modulating effects resulting from the co-expression of GM-CSF, were studied.1. Construction of pcDNA3.0BA bicistrinicBicistronic plasmid vector pcDNA3.0BA containing two CMV promoters and two different MCS was constructed from pcDNA3.0. This bicistronic vector can co-express two kinds of genes,with the first gene serving as immunogen and the second gene serving as additional immunogen or as modulator for the immune responses.2. Secreted signal peptide and transmembrane protein enhance the DNA immunization to HCV core.HBV preC was fused with HCV C69,C154 and C191 respectively ,and pc69 was further fused with TM from transmembrane protein of influenza virus. A series of eukaryotic expressing plasmids with these chimeric genes were constructed. The results of transient expression in Cos-7 cells labed by 35S Met and immunoprecipation indicated that preC signal peptide can lead C69 and C154 secret into supernatant, but has little effect on C191 ,and pc69TM protein was primarily...