DNA epitope vaccine induces strong Th2 polarized humoral immune responses specific to human Aβ.

<p>A) DNA epitope vaccine induces very strong humoral immune response in 3–4 mo old C57/Bl6 mice (n = 6). Group of non-vaccinated (n = 6) as well as group of mice (n = 6) injected with plasmid encoding MDC fused with irrelevant antigen did not generate anti-Aβ antibody. B) Anti-Aβ antibody generated in mice immunized with DNA epitope vaccine recognizes human Aβ deposits when used in immunohistochemical experiments in an AD case, and this binding is blocked by pre-absorption of sera with both Aβ₄₂ or Aβ_1–11 peptide. C) DNA epitope vaccine induces the production of anti-Aβ antibody of predominantly IgG1 isotype in wild-type (C57/Bl6) animals. D) IgG1/IgG2a^b ratio in wild-type (C57/Bl6) and 3xTg-AD mice was equal to 32.4±3.2 and 16.7±2, respectively, which is an indirect measurement of Th2-type immune response induced by DNA epitope vaccine. Of note, all experiments with C57Bl/6 mice were repeated (n = 6) with the similar results.