Discovery of antibodies targeting multipass transmembrane proteins using a suspension cell-based evolutionary approach.

Due to their critical functions in cell sensing and signal processing, membrane proteins are highly preferred as pharmacological targets, and antibody drugs constitute the fastest growing category of therapeutic agents on the pharmaceutical market. However, major limitations exist in developing antibodies that recognize complex, multipass transmembrane proteins, such as G-protein-coupled receptors (GPCRs). These challenges, largely due to difficulties with recombinant expression of multipass transmembrane proteins, can be overcome using whole-cell screening techniques, which enable presentation of the functional antigen in its native conformation. Here, we developed suspension cell-based whole-cell panning methodologies to screen for specific binders against GPCRs within a naive yeast-displayed antibody library. We implemented our strategy to discover high-affinity antibodies against four distinct GPCR target proteins, demonstrating the potential for our cell-based screening workflow to advance the discovery of antibody therapeutics targeting membrane proteins.