Figure 5

Prime/boost immunization of J20 APP-tg mice with Aβ1–40/42 or dAβ1–15 leads to a reduction in hippocampal Aβ plaque burden. Following a 6-month immunization regime, the cerebral tissue was harvested, immunohistochemistry performed and computer assisted quantification completed. J20 APP-tg mice primed with an injection of Aβ1–40/42 and boosted with Aβ1–40/42 or dAβ1–15 had significantly less hippocampal area covered by Aβ immunoreactivity compared to LT(R192G) treated controls and mice boosted with Aβ1–15 peptide (A). Each group is composed of the mean of 2–6 sections from 5–7 different mice in each treatment group. Statistical significance was determined using Kruskal-Wallis nonparametric one-way ANOVA. (B) Immunostaining with the anti-Aβ rabbit polyclonal antibody, R1282, demonstrates a reduction in cerebral Aβ plaques. Vehicle control mice and mice boosted with Aβ1–15 peptide had mostly diffuse Aβ deposits with a small number of compacted plaques in the hippocampus at 10 months of age. However, in mice boosted with dAβ1–15 or Aβ1–40/42 diffuse Aβ was absent and somewhat fewer compacted Aβ plaques remained in the hippocampus, following 6 months of treatment. Scale bar = 100 μm.