Generation And Functional Identification Of Human Single-chain Fv Antibody Against Amyloid-β Peptide

The amyloid hypothesis holds the extracellular aggregations of β-amyloid (Aβ) as the culprit of Alzheimer's Disease (AD). In the brain, amyloid deposits act as potent and direct neurotoxic agents, or elicit a cascade of cellular events leading to neuronal pathology. Thus, clearance of amyloid from brain becomes the first choice of therapies for AD patients. The AP-targeted immunotherapy can lead to clearance of diffuse amyloid deposits and reverse memory deficits in transgenic mice. However, murine monoclonal antibodies are limited to be used directly in the treatment with AD patients because of the immunogenicity. Thus a human single-chain Fv antibody (scFv) against Aβ was generated to pave a path to a human antibody-based immunotherapy for AD.The human scFv against Aβ was screened from human scFv library via its interaction with solid phase-bound Aβ_1-40. After five rounds of panning, 58 clones were picked randomly from the plates. Of these, E3 clone showed strongest binding ability to Aβ_1-40 by phage ELISA. After the phagemid of E3 positive clone was transformed into E. coli HB2151, the scFv was harvested by culture of E. coli and purified from the bacterial supernatant by HiTrap chelating HP column. With western bolt...