OAZI-1 enhances the immunogenicity of Melan-A vaccine in mice / 基础医学与临床

ABSTRACT

Objective To investigate whether ornithine decarboxylase antizyme inhibitor-1(OAZI-1) can enhance the immunogenicity of Melan-A and induce antitumor immune effect in the experimental animals.Methods The eukaryotic expression plasmid pcDNA3.1(-) /OAZI-1, pcDNA3.1 (-)/Melan-A and pcDNA3.1(-)/Melan-A-OAZI-1 were constructed and used to immunize BALB/c mice.The spleen lymphocytes were prepared from the immunized mice and then used to determine the lymphocyte subsets by flow cytometry assay and tumor-killing activity by LDH release assay.The blood samples were collected from the immunized mice and used to test the serum INF-γ by ELISA.Results The eukaryotic expression plasmid pcDNA3.1(-)/OAZI-1, pcDNA3.1(-)/Melan-A and pcDNA3.1(-)/Melan-A-OAZI-1 were successfully constructed.All three gene vaccines could increaseCD4+ T cell ratio (P<0.05), among of them, the ratio in the pcDNA3.1(-)/Melan-A-OAZI-1 and pcDNA3.1(-)/Melan-A immunized groups increased more significantly than other groups but no obvious differences was observed between these two groups.Similarly, all three gene vaccines could also increased CD8+T cells ratio significantly (P<0.05), but, comparing with all other groups, the highest increase was observed in the pcDNA3.1(-)/Melan-A-OAZI-1 immune group (P<0.05).The pcDNA3.1(-)/Melan-A-OAZI-1 gene vaccines significantly increased cytotoxic activity of the spleen lymphocyte in the immune mice(P<0.05).Among the three gene vaccines only pcDNA3.1(-)/Melan-A-OAZI-1 could significantly increased the INF-γ level in the mice serum (P<0.05).Conclusions OAZI-1 can improve antitumor immunity by promoting tumor antigen presentation.