RESUMO
Abstract Objective:To observe and compare the effects of immune responses of HBV DNA caccine by insertion IL-2 gene.Try to ex-Plore the efficient way to enhance the immune effect of DNA vaccines. Methods:The recombinant expression plasmid vector peDNA3.1-S/IL-2with fusion gene of HBsAg and IL-2 cloned was constructed by PCR method and DNA recombinant technique.Then, it was transfered into Cos-7 cells by cation lyposomes and was detected its transient expressing product in vitro.At last,observed and compared the cellular and humoralimmune responses to HBsAg in C57BL/6 mice by intramuscular injection.Results:The pcDNA3. 1-S/IL-2 was constructed successfully by themethod of restriction endonucleases digestion, RCR and DNA sequencing. It can increase the titers of anti-HBs antibody. The bioactivity of IL-2and lymphocyte proliferation responses to HBsAg induced by the mouse spleen immunized with psDNA3.1-S/IL-2 were improved also. Conclu-sion:These results showed the expression of HBsAg-IL-2 fused gene can enhance the immune responses and suggested the insertion of IL-2 maybe a practicable way to enhance the DNA vaccine efficacy.