Immunologic Enhancement Of CpG ODN In DNA Vaccine

The methylation of CpG motif of Bacterial DNA has immune stimulation effect to the immune cells of mammalian cells, Whereas In mammals,the CpG motif have no immune stimulation due to it generally exists in the form of methylation. Synthetic oligodeoxynucleotides (ODN) containing unmethylated CpG motifs can mimic the immunostimulatory activity of bacterial DNA and improve the body’s immune response. Nowadays, CpG ODN is the one of the most possible vaccine adjuvants and immunotherapy.Candida albicans is a kind of conditional pathogenic bacteria. At present, It has mainly used some antifungal drugs to treat corresponding infection disease caused by Candida albicans, but the morbidity is still as high as70%. So,it is very important to develop an effective vaccine against candida albicans infection. The study found that candida albicans heat shock protein90contains three antigen epitope table B、C and H, of which C is a conservative table, can almost react with all patients serum by systemic candida albicans infection, so it can be as a vaccine candidates. The recombinant plasmid pD-HSP90C containing candida albicans heat shock protein90table C was bult by our lab, whereas it was need to join the vaccine adjuvants to enhance the immune effect due to the weak immunogenicity.It was discussed whether the CpG ODN as candida albicans nucleic acid vaccine adjuvants have significant immune enhancement effectiveness in this paper. The CpG DNA sequence was built on eukaryotic expression vector pcDNA3.1and nucleic acid vaccine pD-HSP90C, and it was formed the pD-CpG and pD-HSP90C-CpG. The pD-CpG with nucleic acid vaccine pD-HSP90C immune C57BL/6J mice, pD-HSP90C-CpG immune mice alone in this experiment. The mice were immunized with muscle injection and electrostimulation two times at two weeks interval. Two weeks after the second immunization, the blood form eye of mice was collected and applied to experimental study. Western blot to detect specific antibody in the immune C57BL/6Jmice serum; ELISA experiment detect specific antibody IgG、IgG1and IgG2b antibody titer of C57BL/6J mice serum; ELISA kit to detect IL-2、IL-4levels in the mice serum.The experimental results show that group of pD-CpG with pD-HSP90C immune mice and group of pD-HSP90C-CpG immune mice alone are generate higher specific antibody IgG、IgG2b antibody titer and IL-2levels to pD-HSP90C group,whereas IgG1antibody degrees was not increase, and IL-4content is lower.The immuneeffect was no significant difference between group of pD-CpG with pD-HSP90C immune mice and group of pD-HSP90C-CpG immune mice alone. This study showed that CpG ODN as vaccine adjuvants effectively strengthen the immune effect of nucleic acid vaccine pD-HSP90C, enhances the Thl immune response, lower the expression of Th2type cytokines and regulating Th1/Th2balance.It was laid a solid foundation for CpG ODN application in the field as vaccine adjuvants.