Towards the Application of a Label-Free Approach for Anti-CD47/PD-L1 Bispecific Antibody Discovery

• Published in: Biosensors (Basel) 2023-12, Vol.13 (12), p.1022
• Main Authors: Grevtsev, Artem S, Azarian, Alexandra D, Misorin, Alexey K, Chernyshova, Daria O, Iakovlev, Pavel A, Karbyshev, Mikhail S
• Format: Article
• Language: English
• Subjects: Affinity; Analysis; Antibodies; Antigens; Apoptosis; Aqueous solutions; Bioassays; Bispecific antibodies; BLI; CD47; Chromatography; Comparative analysis; Fc receptors; Immunotherapy; Interferometry; label-free; Labels; Ligands; Molecular dynamics; PD-L1; PD-L1 protein; Protein-protein interactions; Proteins; Receptors; Sensors; Signal regulatory protein-α; Viral antibodies
• ISSN: 2079-6374; 2079-6374
• DOI: 10.3390/bios13121022

The engineering of bispecific antibodies that exhibit optimal affinity and functional activity presents a significant scientific challenge. To tackle this, investigators employ an assortment of protein assay techniques, such as label-free interaction methodologies, which offer rapidity and convenience for the evaluation of extensive sample sets. These assays yield intricate data pertaining to the affinity towards target antigens and Fc-receptors, instrumental in predicting cellular test outcomes. Nevertheless, the fine-tuning of affinity is of paramount importance to mitigate potential adverse effects while maintaining efficient obstruction of ligand-receptor interactions. In this research, biolayer interferometry (BLI) was utilized to probe the functional characteristics of bispecific antibodies targeting cluster of differentiation 47 (CD47) and programmed death-ligand 1 (PD-L1) antigens, encompassing affinity, concurrent binding to two disparate antigens, and the inhibition of ligand-receptor interactions. The findings derived from BLI were juxtaposed with data from in vitro signal regulatory protein-α (SIRP-α)/CD47 blockade reporter bioassays for two leading bispecific antibody candidates, each demonstrating distinct affinity to CD47.