An epitope-directed selection strategy facilitating the identification of Frizzled receptor selective antibodies

Structure. 2023 Jan 5;31(1):33-43.e5. doi: 10.1016/j.str.2022.11.009. Epub 2022 Dec 12.

Abstract

The lack of incorporating epitope information into the selection process makes the conventional antibody screening method less effective in identifying antibodies with desired functions. Here, we developed an epitope-directed antibody selection method by designing a directed library favoring the target epitope and a precise "counter" antigen for clearing irrelevant binders in the library. With this method, we successfully isolated an antibody, pF7_A5, that targets the less conserved region on the FZD2/7 CRD as designed. Guided by the structure of pF7_A5-FZD2CRD, a further round of evolution was conducted together with the "counter" antigen selection strategy, and ultimately, an FZD2-specific antibody and an FZD7-preferred antibody were obtained. Because of targeting the predefined functional site, all these antibodies exhibited the expected modulatory activity on the Wnt pathway. Together, the method developed here will be useful in antibody drug discovery, and the identified FZD antibodies will have clinical potential in FZD-related cancer therapy.

Keywords: FZD; Wnt signaling; antibody identification; cancer therapy.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antibodies, Monoclonal* / immunology
  • Directed Molecular Evolution* / methods
  • Drug Discovery
  • Epitope Mapping* / methods
  • Epitopes* / chemistry
  • Epitopes* / genetics
  • Epitopes* / immunology
  • Frizzled Receptors* / chemistry
  • Frizzled Receptors* / genetics
  • Frizzled Receptors* / immunology
  • Humans
  • Protein Conformation
  • Wnt Signaling Pathway* / immunology

Substances

  • Epitopes
  • Frizzled Receptors
  • FZD2 protein, human
  • FZD7 protein, human
  • Antibodies, Monoclonal