Generation and Partial Characterization of Rabbit Monoclonal Antibody to Pyroglutamate Amyloid-β3-42 (pE3-Aβ)

Area of Science:

• Neuroscience
• Immunology
• Biochemistry

Background:

• N-terminally truncated pyroglutamate amyloid-β (pE3-Aβ) is a major component of amyloid plaques in Alzheimer's disease (AD) and Down syndrome (DS) brains.
• Previous studies indicated pE3-Aβ as a potential therapeutic target, but eliciting a strong immune response in mice is challenging.
• Rabbits are known to generate favorable immune responses to small peptides, making them suitable for antibody generation.

Purpose of the Study:

• To generate and characterize a rabbit monoclonal antibody (RabmAb) specific for pE3-Aβ.
• To assess the antibody's utility in detecting pE3-Aβ in biological samples and its potential for AD and DS research and therapeutics.

Main Methods:

• Generation and characterization of a rabbit monoclonal antibody (RabmAb) against pE3-Aβ.
• Specificity testing using Enzyme-Linked Immunosorbent Assay (ELISA) with various Aβ peptides.
• Affinity determination (KD), epitope mapping, and sensitivity assessments (dot blotting, sandwich ELISA).
• Detection of pE3-Aβ in human AD and DS brain extracts using ELISA, immunoblotting, and immunohistology.

Main Results:

• A specific IgG class RabmAb was successfully generated, showing no cross-reactivity with other Aβ forms.
• The antibody exhibited high affinity (KD = 1 nM) and detected pE3-Aβ down to 2 fmol (dot blot) and 10 pg/ml (sandwich ELISA).
• pE3-Aβ was detected in AD and DS brain extracts, with immunolabeling of plaques and blood vessels in AD and DS brains.

Conclusions:

• The developed RabmAb is highly specific and sensitive for pE3-Aβ.
• This antibody is suitable for detecting pE3-Aβ in various research applications, including diagnostics and therapeutic development for AD and DS.
• The antibody's ability to label plaques and blood vessels suggests its broad applicability in understanding AD and DS pathology.