Fig. 3

Effects of Il6 and Ab5 alone, or in combination on Aβ deposition. a Representative brain sections stained with pan-Aβ1–16 antibody (mAb 33.1.1) show Aβ plaque immunoreactivity in the cortex and hippocampus of 6-month-old TgCRND8 mice expressing Il6 or EGFP and immunized with mAb5 or mouse IgG. Scale bar = 150 μm. b The immunostaining was quantified from three sections from each mouse brain using Aperio imaging algorithms. Combination of Il6 overexpression and immunotherapy prevented plaque formation more, although not significantly, than each treatment individually. n = 5–7, *P < 0.05; **P < 0.01. c Representative fluorescent cortical and hippocampal sections stained with Thio-S show Aβ plaque immunoreactivity in the cortex and hippocampus of 6-month-old TgCRND8 mice expressing Il6 or EGFP and immunized with mAb5 or mouse IgG. Scale bars = 150 μm. d The number of Thio-S positive cored plaques was quantified from three sections from each mouse brain. Combination of Il6 overexpression and immunotherapy prevented plaque formation as well as Il6 overexpression alone. e Biochemical analyses of FA, SDS and RIPA extractable Aβ42 and Aβ40 levels in 6-month-old Il6-expressing TgCRND8 mice and EGFP-expressing age matched controls immunized with mAb5 or mouse IgG was performed by sandwich ELISA with anti Aβ40 and Aβ42 specific antibodies 2.13 and 13.1.1 as capture and 4G8-HRP as detection. Reduction in Aβ levels was achieved with both Il-6 overexpression and with immunotherapy, although a synergistic effect was not observed. Empty and full symbols represent male and female mice, respectively. n = 5–16, *p < 0.05, **p < 0.01, ***p < 0.001