A new DNA vaccine fused with the C3d-p28 induces a Th2 immune response against amyloid-beta

To enhance anti-amyloid-beta （Aβ） antibody generation and induce a Th2 immune response, we constructed a new DNA vaccine p（Aβ3-10 ）10-C3d-p28.3 encoding ten repeats of Aβ3-10 and three copies of C3d-p28 as a molecular adjuvant. In this study, we administered this adjuvant intramus-cularly to female C57BL/6J mice at 8-10 weeks of age. Enzyme linked immunosorbent assay was used to detect the titer of serum anti-Aβ antibody, isotypes, and cytokines in splenic T cel s. A 3-（4,5-cimethylthiazol-2-yl）-2,5-diphenyl tetrazolium bromide assay was used to detect the prolifera-tion rate of splenic T cel s. Brain sections from a 12-month-old APP/PS1 transgenic mouse were used for detecting the binding capacities of anti-Aβ antibodies to Aβ plaques. The p（Aβ3-10）10-C3d-p28.3 vaccine induced high titers of anti-amyloid-βantibodies, which bound to Aβplaques in APP/PS1 transgenic mouse brain tissue, demonstrating that the vaccine is effective against plaques in a mouse model of Alzheimer’s disease. Moreover, the vaccine elicited a pre-dominantly IgG1 humoral response and low levels of interferon-γ in ex vivo cultured splenocytes, indicating that the vaccine could shift the cel ular immune response towards a Th2 phenotype. This indicated that the vaccine did not elicit a detrimental immune response and had a favorable safety profile. Our results indicate that the p（Aβ3-10）10-C3d-p28.3 vaccine is a promising immunothera-peutic option for Aβvaccination in Alzheimer’s disease.

Human β-defensin-2 Enhances Anti-tumor Efficacy of Survivin-based Broad-spectrum DNA Vaccine in Mouse Tumor Model

Objective:Malignant tumors greatly endanger and affect the quality of human life.Among antitumor biotherapy strategies,DNA vaccines hold promise in part because of their unique advantages.In this study,an effective broad-spectrum antitumor DNA vaccine expressing human survivin T34A dominant-negative mutant fused with humanβ-defensin-2(HBD2)was investigated.Methods:The expression profiles of genes of interest were examined using western blotting,reverse transcription-polymerase chain reaction(RT-PCR),and enzyme-linked immunosorbent assay(ELISA)in vitro.The immune function of the fusion gene vaccine(FGV)was assessed in BALB/c mice,which included detection of serum antibody,spleen lymphocyte proliferation,interferon-gamma(IFN-γ)secretion,and lactate dehydrogenase(LDH)release.In vivo antitumor effects of FGV were examined in a mouse breast cancer(4T1)model,whereas in vitro effects were assessed using tumor cells derived from different origins.Caspase-3activity in tumor cells was also assessed after vaccine transfection.Results:The FGV triggered humoral as well as cellular immune responses against survivin.It exhibited more potent inhibition of tumor growth as well as prolonged the survival of immunized mice compared to mice immunized with only either survivin T34A or HBD2 vaccines.In addition,FGV displayed stronger cytotoxicity against tumor cells derived from different origins compared to the other vaccines and facilitated increased caspase-3 activity in transfected tumor cells.Conclusion:The novel DNA vaccine consisting of a fusion of the universal tumor antigen survivin T34A mutant with molecular adjuvant HBD2generates enhanced broad-spectrum antitumor efficacy against cancers derived from various origins.