Gene Vaccine Induced Immune Responses Prolonged The Survival Of Multiple Myeloma Mice

Objective To observe the therapeutic effect of gene vaccine induced immunization on Multiple Myeloma -bearing mice. Methods In vitro, multiple myeloma cells were transfected with plasmid pcDNA3.1-2VNTR/myc-hisB of Lipofectamine2000.The above Mouse myeloma cells were inoculated subcutaneously with female BALB/c mice to establish animal models of tumor.These female BALB/c mice were immunized with pcDNA-2VNTR/myc-hisB or pcDNA/myc-his B. Serum levels of anti-VNTR antibody were detected dynamically by ELISA after immunization. The Cytotoxic T lymphocyte (CTL) activity was tested by the method of LDH and spleen lymphocyte proliferation activity was surveyed by CCK-8 method. Sizes of tumors were measured and the inhibition of tumor growth as well as the survival of tumor-bearing mice was observed. Results After immunization for 25 days, serum antigen-specific antibodies of MUC1-2VNTR were detected. Mass of tumor in the immunized group was significantly lighter than that of the empty plasmid control group and the physiological saline group (P<0.01). CTL and NK cell activity of recombinant plasmid group was also markedly higher than that of other two groups. When the ratio of effector cells to target cells reached 80:1, specific CTL response was strongly detected in immunized mice. Compared with those immunized with empty vector, the spleen lymphocytes, which immunized with recombinant plasmid pcDNA3.1-2VNTR/myc-his B, proliferated obviously (P< 0.01). Conclusions This study showed that MUC1-2VNTR DNA immunization could induce both humoral and cellular tumor specific immune response in MM mice model, and may inhibit the multiple myeloma tumor cell growth in this model. Most importantly, the results firstly demonstrated that this immunization prolonged the survival of tumor-bearing mice, which could be used as a possible clinical trial for the vaccine treatment of multiple myeloma, even cured, in the future.