Fig. 3.

Immune responses against Aβ₄₂ in APPswe/PS1ΔE9 mice immunized with the human Aβ₄₂ gene vaccine. A: Isotyping of anti-Aβ₄₂ antibodies after 15 immunizations with (pSP72-E3L-Aβ₄₂-ET). The sera were diluted 1:200 for detection of IgG1, IgG2a subclasses of anti-Aβ₄₂ antibodies. All vaccinated mice exhibited high levels of IgG1 antibody IgG1: t(5.00)=−6.33 p=0.001; IgG2a: t(5.02)=−1.43, p=0.212. (N=6). B and C: ELISPOT assays for IFNγ (B) and for IL4 (C). ANOVA for Fig. 3B: The average number of IFNγ cells was significantly higher in the presence versus of the absence of Aβ₄₂ peptide (32.54+6.96 versus 17.33+3.60, [F(1,10)=69.61, p<0.001]). ANOVA for Fig. 3C: The combination of group (vaccinated versus control) and Aβ₄₂ peptide (present versus absence) was significant [F(1,10)=19.76, p<0.001] with the present Aβ₄₂ peptide-vaccinated group significantly higher than the other 3 combinations. The average change in the number of IL4 T cells from Aβ₄₂ peptide present to absent changed more than 27 in the vaccinated group compared to a change in only 6.5 in the control group. In addition, the average number of IL4 T cells was significantly higher in the presence of Aβ₄₂ peptide (45.0+23.03) compared to the absence of Aβ₄₂ peptide (28.17+14.52; (F(1,10)=52.45, p<0.001).