Abstract
Background: Alzheimer's disease (AD) is the most well-known and most common type of age-related dementia. Amyloid deposition and hyperphosphorylation of tau protein are both pathological hallmarks of AD. Using a triple-transgenic mouse model (3xTg-AD) that develops plaques and tangles in the brain similar to human AD, we provide evidence that active full-length DNA amyloid-β peptide 1-42 (Aβ42) trimer immunization leads to reduction of both amyloid and tau aggregation and accumulation. Methods: Immune responses were monitored by enzyme-linked immunosorbent assay (ELISA) (antibody production) and enzyme-linked immunospot (cellular activation, cytokine production). Brains from 20-month-old 3x Tg-AD mice that had received DNA Aβ42 immunotherapy were compared with brains from age- and gender-matched transgenic Aβ42 peptide-immunized and control mice by histology, Western blot analysis, and ELISA. Protein kinase activation and kinase levels were studied in Western blots from mouse hemibrain lysates. Results: Quantitative ELISA showed a 40% reduction of Aβ42 peptide and a 25-50% reduction of total tau and different phosphorylated tau molecules in the DNA Aβ42 trimer-immunized 3xTg-AD mice compared with nonimmunized 3xTg-AD control animals. Plaque and Aβ peptide reductions in the brain were due to the anti-Aβ antibodies generated following the immunizations. Reductions of tau were likely due to indirect actions such as less Aβ in the brain resulting in less tau kinase activation. Conclusions: The significance of these findings is that DNA Aβ42 trimer immunotherapy targets two major pathologies in AD - amyloid plaques and neurofibrillary tangles - in one vaccine without inducing inflammatory T-cell responses, which carry the danger of autoimmune inflammation, as found in a clinical trial using active Aβ42 peptide immunization in patients with AD (AN1792).
Original language | English (US) |
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Article number | 115 |
Journal | Alzheimer's Research and Therapy |
Volume | 10 |
Issue number | 1 |
DOIs | |
State | Published - Nov 20 2018 |
Keywords
- Alzheimer's disease
- Amyloid-β
- Aβ oligomer
- DNA vaccination
- Immunotherapy
- Tau
- Tau kinases
ASJC Scopus subject areas
- Neurology
- Clinical Neurology
- Cognitive Neuroscience