Detection of Peri-Synaptic Amyloid-β Pyroglutamate Aggregates in Early Stages of Alzheimer's Disease and in AβPP Transgenic Mice Using a Novel Monoclonal Antibody

Abstract

The neurodegenerative pathology in patients with Alzheimer’s disease (AD) has been associated with the progressive accumulation of aggregated and post-translationally modified amyloid-β (Aβ) species. Among them, recent studies indicate that the pyroglutamate modification of Aβ (pE(3)Aβ) catalyzed by glutaminyl cyclase might play an important role in the pathogenesis of AD. Although the effects of the pyroglutamate modification on Aβ aggregation and toxicity have been investigated, less is known about the distribution of pE(3)Aβ across the spectrum of AD and in the brains of amyloid-β protein precursor (AβPP) transgenic (tg) animals. For this purpose, we generated a novel monoclonal antibody (denominated D129) that specifically recognizes pE(3)Aβ and characterized the patterns of distribution in the postmortem brain samples from AD patients divided by disease stage (Braak stage) and in AβPP tg mice. We found that in early stages of AD and young AβPP tg mice pE(3)Aβ was found in discrete linear and granular aggregates in the neuropil that co-localized with the pre-synaptic protein synaptophysin and was in close opposition to dendrites labeled with MAP2. In later stages of AD and in older AβPP tg mice, pE(3)Aβ was abundant in diffuse and mature plaques. In conclusion, this study suggests that peri-synaptic accumulation of pE(3)Aβ might contribute to early cognitive dysfunction in AD.

Next-generation active immunization approach for synucleinopathies: implications for Parkinson’s disease clinical trials

“…The AFF 1-induced monoclonal antibody mAb-AFF1 (mouse IgG1) directed against α-syn was created by repeated immunization of BALB/c mice using AFF 1 conjugate vaccine with Alum as adjuvant as previously described [43]. Fusion of spleen cells with Ag8.531 myeloma cells and cloning of the hybridoma was performed as previously described [30].…”

A Neuroprotective Brain-penetrating Endopeptidase Fusion Protein Ameliorates Alzheimer Disease Pathology and Restores Neurogenesis

“…Alternatively, sections were immunolabeled with the mouse monoclonal antibody against the pyroglutamate modified A␤ (clone D129; Affiris AG) followed by incubation with secondary FITC-conjugated anti-mouse (24). Sections were transferred to SuperFrost slides (Fisher) and mounted under glass coverslips with anti-fading media (Vector Laboratories) (14).…”

Combinatorial Vaccine against Complement Factor C5a and Amyloid Beta: A New Therapeutic Approach in Alzheimers Disease

“…Combinatorial vaccine against C5a and Aβ by AFF1/AD02 vaccine in a mouse model of AD Short immunogenic peptides, which mimic either the C-terminal epitope of murine C5a [37] or the N-terminal epitope of Aβ [40] were selected and formulated. These vaccines where then used for an immunization therapy in human APP transgenic Tg2576 mice, a mouse model of AD-like disease.…”

“…For the detection of Aβ depositions in the brain of 15 months old Tg2576 mice the in-house generated Aβ-specific mAB 3A5 [40] was used. Both, AFF1 and AD02 vaccinated mice, revealed a statistically significant reduction of cerebral amyloid plaque area of the total coronal brain section of 0.36% (p<0.05) and 0.33% (p<0.05), compared to 0.55% in control immunized mice ( Figures 3C and 3D).…”