Studies on OAZI-1 protein complex in inducing specific antitumor effects in mice / 中国免疫学杂志

ABSTRACT

Objective:To analyze whether the OAZI-1 (ornithine decarboxylase antizyme inhibitor-1) protein complex isolated from tumor cells could induce specific antitumor effects in the experiment mice .Methods:OAZI-1 protein complexes were isolated from B16-F1 melanoma cells by immune magnetic beads coated with OAZI-1 antibody and used as the vaccine to immune the C 57BL/6 mice.After immunization,the mice were inoculated subcutaneously with live B 16-F1 cells and then tumor formation and growth were ob-served.ELISA was used to determine the level of cytokine IFN-γin the serum of immunized mice.Lactate dehydrogenase assay (LDH) was performed to evaluate killing effect of spleen lymphocytes on B 16-F1 cells.The mice immunized by purified OAZI-1 from prokaryotic expression and PBS were used as controls in the animal experiment .Results: Compared with the control mice ,the spleen lymphocytes ( effector cells ) from the mice inoculated with OAZI-1 protein complexes had stronger killing ability on B 16-F1 cells (target cells).At three different effectortarget ratio (101,501,1001),the killing ability of these spleen lymphocytes were 46.2%, 59.5%and 92.5% respectively,which was significantly higher than the spleen lymphocytes from the mice inoculated with purified AZIN-1 protein (36.1%,26.8% and 45.9%) or inoculated with PBS (24.6%,24.0% and 27.2%).In addition,the content of serum anti-tumor cytokine IFN-γwas also significantly higher in the mice inoculated with OAZI-1 protein complexes (538.3 pg/ml) than the mice inoculated with purified AZIN-1 ( 256.2 pg/ml ) or with PBS ( 131.0 pg/ml ) .When B16-F1 live cells were subcutaneously inoculated into the immunized mice described above ,the tumor formation rate was only 40%in the mice immunized with OAZI-1 protein complex ,but 100%in the mice immunized with PBS or purified OAZI-1.The growth of inoculated tumors in the mice immunized with OAZI-1 protein complex was also much slower than the control mice .Conclusion:The results in this study suggest that the OAZI-1 protein complex isolated from B 16-F1 tumor cells could contain some tumor antigens .When used as tumor vaccine to inoculate mice ,this complex can induce anti-tumor immune killing activity in experimental animals .