(517t) Antibody Based Therapeutic for Parkinson's Disease

Protein misfolding and aggregation are thought to cause numerous neurodegenerative diseases such as Parkinson's Disease (PD). A protein correlated with PD, alpha-synuclein, can adopt different aggregated morphologies, including oligomers, protofibrils and fibrils. Small oligomeric aggregates have been shown to be particularly toxic. Antibodies that neutralize the neurotoxic aggregates without interfering with beneficial functions of monomeric alpha-synuclein may be useful diagnostics and therapeutics. A single chain antibody fragment (scFv) from a phage displayed antibody library has been isolated against the oligomeric form of alpha-synuclein through a unique biopanning technique that utilizes Atomic Force Microscopy (AFM) to image and immobilize specific morphologies of alpha-synuclein. The original scFv however, has relatively low affinity and stability. To facilitate use of the scFv for in vitro and in vivo assays, affinity maturation techniques were used to improve the properties of the scFv. A library of variants of the original scFv were generated by using site directed mutagenesis to introduce a sequence of four random amino acids into the CDR3 light chain region using Polymerase Chain Reaction (PCR). A library size of approximately 10^6 was generated. Variants were selected using an AFM biopanning protocol where increasing urea and decreasing antigen target concentrations are utilized to select for scFvs with increased affinity and stability.