Active immunisation with amyloid-β 1–42 severely impairs memory performance in healthy mice through TLR 2/4-dependent activation of the innate immune system

Active immunization with Aβ 1–42 was shown to prevent amyloid plaque deposition in the CNS. However, immunization with Aβ 1–42 may cause meningoencephalitis in human or an experimental autoimmune encephalomyelitis (EAE)-like disease in mice. Recently, we identified cognitive impairment and changes in psychomotor behavior in healthy C57/BL6 mice challenged with active Aβ 1–42 immunization. Immunohistochemistry and gene expression analysis revealed strong recruitment of macrophages and microglia cells in the CNS which was concomitant with severe reactive gliosis in the cerebrum and brainstem. In this study, we pri…