N-terminally-truncated and modified amyloid-beta (A?) peptides are abundant in cerebral amyloid deposits in Alzheimer's disease (AD). Pyroglutamate A? is generated upon N-terminal truncation of A? followed by cyclization by glutaminyl cyclase to convert glutamic acid at residues 3 and 11 to pyroglutamate (A?pE3 and A?pE11). Both forms aggregate quickly, resist degradation, and are neurotoxic. It is unclear if either is present in initial A? deposition in plaques and blood vessels (i.e., acting as a seed for further deposition) or if they are modified later. However, Alzheimer's disease progression appears to correlate with the presence of A? pE peptide aggregates in brain. We hypothesize that pyroglutamate A? acts as a seed for A? deposition and accelerates inflammation, neurodegeneration and cognitive decline;therefore, targeted removal of this toxic species by immunotherapy will reduce A? deposition, inflammation and neuritic dystrophy, and protect against cognitive impairment without disturbing non-pathogenic A?. We propose 4 Specific Aims.
Aim 1 : We will determine if intrahippocampal or intraperitoneal injections of A?pE-containing mouse brain extracts enhance A? deposition, inflammation, neurodegeneration and cognitive decline in APP/PS1dE9 transgenic mice with aging in vivo.
Aim 2 : We will determine if early removal of pyroGlu A? prevents general A? plaque deposition and neuritic changes, and protects against cognitive decline by passively immunizing (i.p.) male APP/PS1dE9 tg mice with an anti-A?N3pE mAb (07/1), an anti-A?pE11 mAb, a general A? mAb (3A1), or PBS weekly from 4-12 mo of age, starting prior to plaque onset. Outcome measures: behavioral, biochemical, and neuropathological analyses.
Aim 3 : We will determine if removal of pyroGlu A? in late stage AD reduces total A? and neurodegeneration and improves cognitive deficits by passively immunizing (i.p.) female APP/PS1dE9 tg mice weekly from 12-16 mo of age, starting well after plaque onset. Antibodies and outcome measures are the same as in Aim 2.
Aim 4 : We will examine the immune response of microglia to pyroGlu A? mAbs in acute in vivo studies and in primary microglial cultures in vitro. Our collaborators at Probiodrug AG (Germany) will kindly provide us with 2 high-affinity, highly selective pyroGlu A? mAbs (anti- A? pE3 and anti-A?pE11), synthetic A?pE peptides, and brain extracts from their transgenic mouse models that accumulate pyroGlu-3 A? peptides. Our collaborators at the CND have generously provided the 3A1 general A? mAb hybridoma as a control. Importantly, my lab initiated this collaboration and has many years of experience investigating pyroGlu A? deposition, inflammation, and A? immunotherapy. The overall goal of our study is to determine whether pyroglutamate A? proteins (A?pE3 and A?pE11) are therapeutic targets for Alzheimer's disease and, whether clearance by immunotherapy specific for either pyroGlu A? species would be efficacious to prevent and/or treat AD.

Agency
National Institute of Health (NIH)
Institute
National Institute on Aging (NIA)
Type
Research Project (R01)
Project #
5R01AG040092-03
Application #
8702980
Study Section
Cell Death and Injury in Neurodegeneration Study Section (CDIN)
Program Officer
Petanceska, Suzana
Project Start
2012-09-01
Project End
2016-05-31
Budget Start
2014-08-01
Budget End
2015-05-31
Support Year
3
Fiscal Year
2014
Total Cost
Indirect Cost
Name
Brigham and Women's Hospital
Department
Type
DUNS #
City
Boston
State
MA
Country
United States
Zip Code
02115
Head, Elizabeth; Lott, Ira T; Wilcock, Donna M et al. (2016) Aging in Down Syndrome and the Development of Alzheimer's Disease Neuropathology. Curr Alzheimer Res 13:18-29
Cynis, Holger; Frost, Jeffrey L; Crehan, Helen et al. (2016) Immunotherapy targeting pyroglutamate-3 Aβ: prospects and challenges. Mol Neurodegener 11:48
Frost, Jeffrey L; Liu, Bin; Rahfeld, Jens-Ulrich et al. (2015) An anti-pyroglutamate-3 Aβ vaccine reduces plaques and improves cognition in APPswe/PS1ΔE9 mice. Neurobiol Aging 36:3187-99
Liu, Bin; Le, Kevin X; Park, Mi-Ae et al. (2015) In Vivo Detection of Age- and Disease-Related Increases in Neuroinflammation by 18F-GE180 TSPO MicroPET Imaging in Wild-Type and Alzheimer's Transgenic Mice. J Neurosci 35:15716-30
Janota, C S; Brites, D; Lemere, C A et al. (2015) Glio-vascular changes during ageing in wild-type and Alzheimer's disease-like APP/PS1 mice. Brain Res 1620:153-68
Lemere, Cynthia A (2013) Immunotherapy for Alzheimer's disease: hoops and hurdles. Mol Neurodegener 8:36
Frost, Jeffrey L; Le, Kevin X; Cynis, Holger et al. (2013) Pyroglutamate-3 amyloid-β deposition in the brains of humans, non-human primates, canines, and Alzheimer disease-like transgenic mouse models. Am J Pathol 183:369-81