Construction of the recombinant plasmid containing the NS1 gene of dengue 3 virus and observation of its immunogenicity

Objective:To construct a recombinant plasmid DNA containing NS1 gene of dengue 3 virus and observe its immunogenicity in order to lay a foundation for studying a novel dengue vaccine.Methods:Genomic RNA of dengue 3 virus was isolated from murine brain infected with virus. NS1 gene fragment was obtained with RT_PCR, and then cloned into an eukaryotic expressing vector. The recombinant plasmid was transfected into COS7 cells by electroporation and its expression was detected by immuno_fluorescence assay(IFA). Subsequently, the recombinant plasmid DNA was used to immunize BALB/c mice to observe its immunogenicity. Results:With restriction analysis and sequencing, it was confirmed that NS1 fragment of dengue 3 virus was inserted into the vector. The expressed protein could be detected in the cytoplasm of COS7 cells with IFA. The mice immunized with the recombinant plasmid DNA could induce cellular immune response to dengue 3 virus.Conclusion:The recombinant plasmid DNA containing NS1 gene of dengue 3 virus can be expressed in COS7 cells. This kind of recombinant plasmid DNA can induce a specific cellular immune response to dengue 3 virus in mice.