MUC1 and survivin combination tumor gene vaccine generates specific immune responses and anti-tumor effects in a murine melanoma model.

MUC1 and survivin are ideal tumor antigens. Although many cancer vaccines targeting survivin or MUC1 have entered clinical trials, no vaccine combining MUC1 and survivin have been reported. Due to tumor heterogeneity, vaccines containing a combination of antigens may have improved efficacy and coverage of a broader spectrum of cancer targets. Here, cellular responses and anti-tumor activities induced by a combination of DNA vaccine targeting MUC1 and survivin (MS) were evaluated. Results showed that CTL activity and inhibition of tumor growth were obviously enhanced in mice immunized with the combined vaccine in a protection assay. However, in order to enhance the therapeutic effect in the treatment assay, a recombinant adenovirus (rAd) vaccine expressing MUC1 and survivin (Ad-MS) was used as a booster following the DNA vaccine prime. Meanwhile, IL-2 promoting T cell proliferation was used as an immunoadjuvant for the DNA vaccine. Results showed that the CTL activity response to the DNA vaccine was enhanced nearly 200% when boosted by the rAd vaccine and was further enhanced by nearly 60% when combined with the IL-2 adjuvant. Therefore, DNA prime combined with rAd boost and IL-2 (MS/IL2/Ad-MS) adjuvant was considered as the best strategy and further evaluated. Multiple cytokines promoting cellular immune responses were shown to be greatly enhanced in mice immunized with MS/IL2/Ad-MS. Moreover, in the treatment assay, the tumor inhibition rate of MS/IL2/Ad-MS reached up to 50.1%, which may be attributed to the enhancement of immune responses and reduction of immunosuppressive factors in tumor-bearing mice. These results suggested that immunization with the combination vaccine targeting MUC1 and survivin using a DNA prime-rAd boost strategy along with IL-2 adjuvant may be an effective method for breaking through immune tolerance to tumors expressing these antigens with potential therapeutic benefits in melanoma cancer.

Zhang H ，Liu C ，Zhang F ，Geng F ，Xia Q ，Lu Z ，Xu P ，Xie Y ，Wu H ，Yu B ，Wu J ，Yu X ，Kong W ... -  《-》

DNA and adenovirus tumor vaccine expressing truncated survivin generates specific immune responses and anti-tumor effects in a murine melanoma model.

Zhang H ，Wang Y ，Liu C ，Zhang L ，Xia Q ，Zhang Y ，Wu J ，Jiang C ，Chen Y ，Wu Y ，Zha X ，Yu X ，Kong W ... -  《-》

Antitumor effect of adenoviral vector prime protein boost immunity targeting the MUC1 VNTRs.

Wang Y ，Liu C ，Xia Q ，Wang P ，Li B ，Lu Z ，Sun J ，Wu H ，Yu B ，Wu J ，Yu X ，Kong W ，Zhang H ，Cong X ... -  《-》

MUC1- and Survivin-based DNA Vaccine Combining Immunoadjuvants CpG and interleukin-2 in a Bicistronic Expression Plasmid Generates Specific Immune Responses and Antitumour Effects in a Murine Colorectal Carcinoma Model.

DNA vaccination is a promising cancer treatment due to its safety, but poor immunogenicity limits its application. However, immunoadjuvants, heterogeneous prime-boost strategies and combination with conventional treatments can be used to improve the antitumour immune effects. A CpG motif and interleukin-2 (IL-2) cytokine are often used as adjuvants. In this study, a DNA vaccine containing a CpG motif was constructed to evaluate its adjuvant effect. The results show that the cytotoxicity of the DNA vaccine was increased fivefold, and survival lifetime was prolonged twofold by the CpG motif adjuvant. To simplify the industrial production process, a bicistronic plasmid was constructed to carry the fusion genes of survivin/MUC1 (MS) and IL-2 and with a CpG motif in its backbone. The results showed that the antitumour effect of the bicistronic vaccine was the same as that of the two vaccine co-injected regime. Furthermore, the vaccine could suppress metastatic tumour foci by 69.1% in colorectal carcinoma-bearing mice. Moreover, the vaccine induced survivin- and MUC1-specific immune responses in splenocytes and induced the immune promoting factor CCL-19 and GM-CSF upregulated, while metastatic-associated factor MMP-9 and immunosuppressing factor PD-L1 downregulated in tumour tissue. When combining the vaccine with the chemotherapy drug oxaliplatin, the survival was prolonged by about 2.5-fold. In conclusion, the DNA vaccine containing a CpG motif in bicistronic form showed good effects on colorectal cancer by inhibiting both tumour growth and metastasis, and combination with oxaliplatin could improve its antitumour effects.

Liu C ，Xie Y ，Sun B ，Geng F ，Zhang F ，Guo Q ，Wu H ，Yu B ，Wu J ，Yu X ，Kong W ，Zhang H ... -  《-》

Enhancement of survivin-specific anti-tumor immunity by adenovirus prime protein-boost immunity strategy with DDA/MPL adjuvant in a murine melanoma model.

As an ideal tumor antigen, survivin has been widely used for tumor immunotherapy. Nevertheless, no effective protein vaccine targeting survivin has been reported, which may be due to its poor ability to induce cellular immunity. Thus, a suitable immunoadjuvant and optimized immunization strategy can greatly enhance the cellular immune response to this protein vaccine. DDA/MPL (monophosphoryl lipid A formulated with cationic dimethyldioctadecylammonium) has been reported to enhance the antigen uptake and presentation to T cells as an adjuvant. Meanwhile, a heterologous prime-boost strategy can enhance the cellular immunity of a protein vaccine by applying different antigen-presenting systems. Here, DDA/MPL and an adenovirus prime-protein boost strategy were applied to enhance the specific anti-tumor immunity of a truncated survivin protein vaccine. Antigen-specific IFN-γ-secreting T cells were increased by 10-fold, and cytotoxic T lympohocytes (CTLs) were induced effectively when the protein vaccine was combined with the DDA/MPL adjuvant. Meanwhile, the Th1 type cellular immune response was strongly enhanced and tumor inhibition was significantly increased by 96% with the adenovirus/protein prime-boost strategy, compared to the protein homologous prime-boost strategy. Moreover, this adjuvanted heterologous prime-boost strategy combined with oxaliplatin could significantly enhance the efficiency of tumor growth inhibition through promoting the proliferation of splenocytes. Thus, our results provide a novel vaccine strategy for cancer therapy using an adenovirus prime-protein boost strategy in a murine melanoma model, and its combination with oxaliplatin may further enhance the anti-tumor efficacy while alleviating side effects of the drug.

Wang YQ ，Zhang HH ，Liu CL ，Wu H ，Wang P ，Xia Q ，Zhang LX ，Li B ，Wu JX ，Yu B ，Gu TJ ，Yu XH ，Kong W ... -  《-》