Journal of Cell Science & Therapy
Open Access

Abstract

Development of Cell-Based SPR Competition Assays to Support mAbs Potency Characterization

A.Mariani*, S. Salvi, I. Longobardo, M. Gabrielli, N. Torre

Antibody-based therapeutics constitute a significant class of biological drugs, approved for treating a broad spectrum of diseases from cancer to autoimmune disorders. These antibodies achieve their pharmacological effects through diverse mechanisms, including direct neutralization of target antigens, Antibody-Dependent Cell-Mediated Cytotoxicity (ADCC), Complement-Dependent Cytotoxicity (CDC), and immune activation. Consequently, the development of monoclonal Antibodies (mAbs) as biopharmaceuticals demands a comprehensive characterization of their mechanisms of action. Both the biological activities and pharmacokinetics of mAbs are highly dependent on their binding to the target antigen, making precise control of this binding crucial for thorough characterization. Surface Plasmon Resonance (SPR) technology is a valuable tool for assessing the in vitro biological activity of mAbs during their development. It enables precise measurement of mAb binding to receptors and antigens, and allows for the determination of the active concentration required for binding. This technology is widely employed to investigate mAb competition, encompassing both epitope binding and neutralization capacity. However, conventional SPR assays, which rely on recombinant targets, often fall short in fully reflecting the intricate in vivo interactions of mAbs with cell-surface antigens. To address this limitation, the present study introduces a novel analytical approach: Utilizing live cells in SPR binding assays to achieve a more physiologically relevant assessment of mAb potency. This proposed method facilitates the characterization of two distinct competitive mechanisms: Neutralization activity, assessed by inhibiting ligand-receptor binding on live cells immobilized on the sensor chip, and epitope competition between two mAbs targeting the same cell-surface antigen. This advancement in SPR technology promises to significantly improve the accuracy and relevance of mAb characterization, even at the early stages of therapeutic development.

Published Date: 2025-09-08; Received Date: 2025-07-14