Abstract: Abstract: To investigate the immune effect of CpG DNA on DNA vaccine against somatostatin (SS), experimental mice at the age of 20 days were immunized with somatostatin eukaryotic expression plasmid pES/2SS with different adjuvant, such as the synthetic CpG- ODN, the pE-CpG plasmid, E.coli DNA and the crude liposome in the current study. The antibody against SS level and the spleen lymphocyte proliferation were detected by ELISA and MTT colorimetric assay , the concentration of GH and IGF-Ⅰwere detected by RIA assay. The results showed that the antibody against SS level , spleen lymphocyte proliferation activity and the concentrations of GH and IGF-Ⅰin the groups of CpGDNA combined the DNA vaccine was significantly increased compared with the group immunized with DNA vaccine alone. Our results suggest that the recombinant somatostatin expression plasmid can stimulate animal to produce antibody against SS, CpGDNA as adjuvant can enhance the immune effect of DNA vaccine against SS and influence the concentration of GH and IGF-Ⅰ

Key words: somatostatin gene, DNA vaccine, CpGDNA, immune effect