Eukaryotic Expressing and the DNA Immunization of E Protein Gene ofDengue virus 2

The gene encoding a strategically truncated E glycoprotein，approximately 80％ of the N·terminal sequence was cloned into the eukaryotic expressing plasmid pCXN2 to get the recombinant plasmid pCXN2一E．Indirect immune fluorescence assay showed that the recombinant plas mid pCXN2·E Can be expressed in COS一7 cells．Th e specific an tibody against DV2 E was detected by ELISA at 2 weeks after the last inoculation，an d maintained to 1 5 weeks；Plague red uction neutralization test (PRNT)was performed on sera obtained at 2 weeks post inoculation．Th e sera had high PRNT50 titer which was overl"640；Th e percentage of CD4+T—lymphocyte subtype cells in immune mice increased compared with the control group．Th e percentage of CD8 T—lymphocyte subtype cells in the group of pCXN2一E was significantly higher than that of pCXN2 group (p0．01)；Mice protection against challenge showed that 60％ mi ce survived．In conclusion：pCXN2一E Can induce humoral an d celIuar immune response．Especially,the raise of CD8 CTL is importan t to clear virus．