Production of monoclonal antibodies against carcinoembryonic antigen-related cell adhesion molecule 6 and detection of their binding affinities.

Objectives: Carcinoembryonic antigen-related cell adhesion molecule 6 (CEACAM6) is a glycophosphatidylinositol-anchored member of the immunoglobulin superfamily, often overexpressed in various malignancies. Targeting CEACAM6 by suppressing its expression can potentially reverse these effects, making it a promising therapeutic target. In this study, we generated five monoclonal antibodies (CEAS1, CEAS2, CEAS3, CEAS4, and CEAS5; CEAS1-S5) against the recombinant CEACAM6 protein. Materials and Methods: Through enzyme-linked immunosorbent assay (ELISA) and surface plasmon resonance (SPR) assay, we demonstrated that each antibody specifically binds to CEACAM6 without interfering with the binding of others. SPR analysis further revealed the rate of association (Ka), dissociation (Kd), and equilibrium dissociation constants (KD) for each antibody. Results: The KD values ranged from 5.089 × 10-11 to 1.213 × 10-13 M, with CEAS5 exhibiting the highest binding affinity. In addition, CEAS5, unlike CEAS1-S4, could bind to both CEACAM5 and CEACAM6, indicating its bivalent nature. Conclusion: These findings highlight the strong antigen-binding capabilities of CEAS1-S5, warranting further investigation.