1. Rational affinity maturation of anti-amyloid antibodies with high conformational and sequence specificity
- Author
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Jennifer M. Zupancic, Shannon J. Moore, Henry L. Paulson, Alexandra B. Sutter, Edward Ionescu, Julia E. Gerson, Magdalena I. Ivanova, Yulei Zhang, Geoffrey G. Murphy, Peter M. Tessier, Matthew D. Smith, Alec A. Desai, Charles G. Starr, and Emily K. Makowski
- Subjects
0301 basic medicine ,Models, Molecular ,yeast surface display ,Protein Conformation ,Aβ, amyloid beta ,Protein aggregation ,Biochemistry ,scFv ,Mice ,directed evolution ,biology ,antibody engineering ,Chemistry ,fibril ,neurodegeneration ,Antibodies, Monoclonal ,Brain ,ELISA, enzyme-linked immunosorbent assay ,3. Good health ,aggregate ,Aducanumab ,Research Article ,Amyloid ,Amyloid beta ,medicine.drug_class ,VH, variable domain of heavy chain ,Monoclonal antibody ,Affinity maturation ,03 medical and health sciences ,CDR, complementarity-determining region ,medicine ,Single-chain variable fragment ,Animals ,Humans ,Molecular Biology ,mAb ,030102 biochemistry & molecular biology ,scFv, single-chain variable fragment ,VL, variable domain of light chain ,Cell Biology ,030104 developmental biology ,Case-Control Studies ,Crenezumab ,biology.protein ,Alzheimer ,BSA, bovine serum albumin ,Binding Sites, Antibody ,Fc, fragment crystallizable - Abstract
The aggregation of amyloidogenic polypeptides is strongly linked to several neurodegenerative disorders, including Alzheimer's and Parkinson's diseases. Conformational antibodies that selectively recognize protein aggregates are leading therapeutic agents for selectively neutralizing toxic aggregates, diagnostic and imaging agents for detecting disease, and biomedical reagents for elucidating disease mechanisms. Despite their importance, it is challenging to generate high-quality conformational antibodies in a systematic and site-specific manner due to the properties of protein aggregates (hydrophobic, multivalent, and heterogeneous) and limitations of immunization (uncontrolled antigen presentation and immunodominant epitopes). Toward addressing these challenges, we have developed a systematic directed evolution procedure for affinity maturing antibodies against Alzheimer's Aβ fibrils and selecting variants with strict conformational and sequence specificity. We first designed a library based on a lead conformational antibody by sampling combinations of amino acids in the antigen-binding site predicted to mediate high antibody specificity. Next, we displayed this library on the surface of yeast, sorted it against Aβ42 aggregates, and identified promising clones using deep sequencing. The resulting antibodies displayed similar or higher affinities than clinical-stage Aβ antibodies (aducanumab and crenezumab). Moreover, the affinity-matured antibodies retained high conformational specificity for Aβ aggregates, as observed for aducanumab and unlike crenezumab. Notably, the affinity-maturated antibodies displayed extremely low levels of nonspecific interactions, as observed for crenezumab and unlike aducanumab. We expect that our systematic methods for generating antibodies with unique combinations of desirable properties will improve the generation of high-quality conformational antibodies specific for diverse types of aggregated conformers.
- Published
- 2020