Central amyloid-β-specific single chain variable fragment ameliorates Aβ aggregation and neurotoxicity

Area of Science:

• Neuroscience
• Immunology
• Biochemistry

Background:

• Alzheimer's disease (AD) is a neurodegenerative disorder characterized by amyloid-beta (Aβ) plaques.
• Anti-Aβ immunotherapies are a key therapeutic strategy for AD.
• Single chain antibody fragments (scFv) offer advantages over whole antibodies, including smaller size and reduced immune effector functions.

Purpose of the Study:

• To generate and characterize an scFv derivative of the anti-Aβ antibody 1E8.
• To evaluate the efficacy of 1E8 scFv in preventing Aβ fibril formation and reducing Aβ-mediated neurotoxicity in vitro.

Main Methods:

• Generation of the 1E8 scFv derivative.
• Binding affinity assessment of 1E8 scFv to Aβ.
• In vitro assays to measure Aβ(1-42) fibril formation.
• Cell-based assays (PC12 cell line, murine primary neuronal cultures) to assess Aβ(1-42)-mediated neurotoxicity.

Main Results:

• The 1E8 scFv derivative binds to the central region of Aβ with an affinity of approximately 55 nM.
• 1E8 scFv significantly inhibits the fibril formation of Aβ(1-42).
• 1E8 scFv demonstrates neuroprotective effects against Aβ(1-42)-induced toxicity in neuronal cell models.

Conclusions:

• The 1E8 scFv is a potent inhibitor of Aβ aggregation and neurotoxicity.
• This scFv derivative represents a promising therapeutic building block for Alzheimer's disease treatment.
• Further functionalization of 1E8 scFv could lead to advanced AD therapeutics.