A functional antibody cross-reactive to both human and murine cytotoxic T-lymphocyte-associated protein 4 via binding to an N-glycosylation epitope

MAbs. 2020 Jan-Dec;12(1):1725365. doi: 10.1080/19420862.2020.1725365.

Abstract

Cytotoxic T-lymphocyte-associated protein 4 (CTLA-4, CD152) is a receptor on T cells that inhibits the cell's functions. Blocking CTLA-4 with an antibody has proven effective for the treatment of cancer patients. Anti-CTLA-4 antibodies currently approved for clinical use can bind to human CTLA-4, but do not cross-react to murine CTLA-4. Here, we report the generation and characterization of a functional humanized antibody, mAb146, against both human and murine CTLA-4. Alanine scanning of CTLA-4 using mammalian cell expression cassette identified the unique epitopes of this novel antibody. In addition to the amino acid residues interacting with ligands CD80 and CD86, an N-glycosylation site on N110, conserved in CTLA-4 of human, monkey, and mouse, was identified as the specific epitope that might contribute to the cross-species binding and function of this antibody. This finding may also contribute to the understanding of the glycosylation of CTLA-4 and its related biologic function. In addition to facilitating preclinical development of anti-CTLA-4 antibodies, mAb146 may be useful as a therapeutic agent.

Keywords: CD152; Cytotoxic T-lymphocyte-associated protein 4 (CTLA-4); N-glycosylation; antibody; cross-species binding; epitope mapping.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antibodies, Monoclonal / immunology*
  • CTLA-4 Antigen / antagonists & inhibitors*
  • CTLA-4 Antigen / chemistry*
  • Cross Reactions
  • Epitopes / chemistry*
  • Epitopes / immunology*
  • Glycosylation
  • Humans
  • Mice

Substances

  • Antibodies, Monoclonal
  • CTLA-4 Antigen
  • Epitopes

Grants and funding

This work was supported by the Shanghai Rising-Star Program [19QB1406000].