Inhibition of Cancer Cell Adhesion, Migration and Proliferation by a Bispecific Antibody that Targets two Distinct Epitopes on αv Integrins

J Mol Biol. 2021 Jul 23;433(15):167090. doi: 10.1016/j.jmb.2021.167090. Epub 2021 Jun 4.

Abstract

Members of the αv family of integrins regulate activation of transforming growth factor beta (TGFβ) and are directly involved in pro-tumorigenic phenotypes. Thus, αv integrins may be therapeutic targets for fibrosis and cancer, yet the isolation of selective inhibitors is currently a challenge. We generated synthetic antibodies selective for αv integrins by phage display selections on cell lines that displayed integrin heterodimers. We identified antibodies that targeted two distinct epitopes on cell-surface αv integrins and partially inhibited cell adhesion mediated by interactions between integrins and the latency-associated peptide, part of the pro-form of TGFβ. Using the isolated antibody paratope sequences we engineered a bispecific antibody capable of binding to both epitopes simultaneously; this antibody potently and completely inhibited cell adhesion mediated by integrins αvβ1, αvβ3 and αvβ5. In addition, the bispecific antibody inhibited proliferation and migration of lung carcinoma lines, where the highest and lowest potencies observed correlated with integrin-αv cell surface expression levels. Taken together, our results demonstrate that phage display selections with live cells can yield high quality anti-integrin antibodies, which we used as biparatopic building blocks to construct a bispecific antibody that strongly inhibited integrin function and may be a therapeutic candidate for cancer and fibrosis.

Keywords: CellectSeq; bispecific antibody; cancer therapeutics; integrins; αvβ1.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • A549 Cells
  • Animals
  • Antibodies, Bispecific / chemistry
  • Antibodies, Bispecific / pharmacology*
  • Antineoplastic Agents, Immunological / chemistry
  • Antineoplastic Agents, Immunological / pharmacology*
  • CHO Cells
  • Cell Adhesion / drug effects
  • Cell Movement / drug effects
  • Cell Proliferation / drug effects
  • Cricetulus
  • Drug Screening Assays, Antitumor
  • Epitopes / metabolism*
  • Humans
  • Integrin alphaV / chemistry*
  • Integrin alphaV / metabolism
  • Lung Neoplasms / drug therapy
  • Lung Neoplasms / metabolism*
  • Peptide Library

Substances

  • Antibodies, Bispecific
  • Antineoplastic Agents, Immunological
  • Epitopes
  • Integrin alphaV
  • Peptide Library

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