Prevention of pathological change and cognitive degeneration of Tg2576 mice by inoculating Aβ_1–15 vaccine

Abstract

This study aims to discuss the effect of preventing pathological changes and cognitive degeneration of Tg2576 mice by inoculating the subunit fragment of Aβ vaccine. Thirty-two Tg2576 mice were randomly divided into four groups, each having eight mice: Group I, the control group, inoculated with adjuvants; Group II, the Aβ₄₂ group, inoculated with Aβ₄₂ vaccine; Group III, the Aβ_1–15 group, inoculated with Aβ_1–15 vaccine; and Group IV, the Aβ_36–42 group, inoculated with Aβ_36–42 vaccine. The titer of the serum antibody against Aβ₄₂ (Group II) was significantly higher than that of the control group (Group I), and a low level of antibodies could be detected in the brain homogenate in the three vaccine-inoculated groups. Morris water maze test showed that the Aβ₄₂ group, Aβ_1–15 group and Aβ_36–42 group were obviously improved compared with the control group. The cultured splenocytes sampled from each group were induced by Con A or their respective antigens, and the cell proliferation of the three vaccine-inoculated groups was significantly higher than that of the control group. In the Aβ₄₂ group, IL2 and IFN-γ were relatively low and IL4 and IL10 were relatively high. By contrast, IL4 and IL10 were much higher in the Aβ_1–15 group and IL2 and IFN-γ were much higher in the Aβ_36–42 group. The immunohistochemical test showed a large number of senile plaques in the brain cortex and hippocampus of the mice in the control group, no senile plaque in the brain of the Aβ_1–15 group and Aβ₄₂ group mice, and a small number of senile plaques in the brain of the Aβ_36–42 group mice. The results suggest that the subunit fragment of Aβ_1–15 vaccine could prevent not only cognitive and behavioral degeneration but also Aβ deposition and formation of senile plaques in Tg2576 mice.