In vivo electroporation of a new gene vaccine encoding ten repeats of aβ3-10 prevents brain aβ deposition and delays cognitive impairment in Young Tg-APPswe/PSEN1dE9 Mice

Abstract

Active immunization holds great promise for the treatment of Alzheimer's disease but the infiltration of T-lymphocytes and associated meningoencephalitis observed in clinical trials needs to be overcome. To avoid this toxicity, previous studies have used synthetic truncated derivatives of Ab to promote humoral immunity. In this study, we developed a novel vaccine [p(Ab3-10)10-MT] that expresses ten repeats of Ab3-10 with melatonin (MT) as an adjuvant, and administered it intramuscularly in three-month-old Tg-APPswe/PSEN1dE9 (Tg) mice by in vivo electroporation. The p(Ab3-10)10-MT vaccine induced high titers of anti-Ab antibodies, which in turn reduced Ab deposits in the mouse brains and decreased cognitive impairment. Immunoglobulin isotyping revealed a predominantly IgG1 response, indicating a Th2 antiinflammatory response. Ex vivo cultured splenocytes exhibited a low IFN-c and high IL-4 response. Immunohistochemical analysis revealed that glial cell activation was also attenuated. These results indicate that p(Ab3- 10)10-MT may potentially be an effective vaccine to reduce accumulated Ab and attenuate cognitive deficits. © Springer Science+Business Media, LLC 2012.