Prevention of pathological change and cognitive degeneration of Tg2576 mice by inoculating Aβ1-15 vaccine

This study aims to discuss the effect of preventing pathological changes and cognitive degeneration of Tg2576 mice by inoculating the subunit fragment of A beta 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 A beta(42) group, inoculated with A beta(42) vaccine; Group III, the A beta(1-15) group, inoculated with A beta(1-15) vaccine; and Group IV, the A beta(36-42) group, inoculated with A beta(36-42) vaccine. The titer of the serum antibody against A beta(42) (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 A beta(42) group, A beta(1-15) group and A beta(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 A beta(42) group, IL2 and IFN-gamma were relatively low and IL4 and IL10 were relatively high. By contrast, IL4 and IL10 were much higher in the A beta(1-15) group and IL2 and IFN-gamma were much higher in the A beta(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 A beta(1-15) group and A beta(42) group mice, and a small number of senile plaques in the brain of the A beta(36-42) group mice. The results suggest that the subunit fragment of A beta(1-15) vaccine could prevent not only cognitive and behavioral degeneration but also A beta deposition and formation of senile plaques in Tg2576 mice.