Deciphering Membrane‐Protein Interactions and High‐Throughput Antigen Identification with Cell Doublets

Abstract Deciphering cellular interactions is essential to both understand the mechanisms underlying a broad range of human diseases, but also to manipulate therapies targeting these diseases. Here, the formation of cell doublets resulting from specific membrane ligand‐receptor interactions is discovered. Based on this phenomenon, the study developed DoubletSeeker, a novel high‐throughput method for the reliable identification of ligand‐receptor interactions. The study shows that DoubletSeeker can accurately identify T cell receptor (TCR)‐antigen interactions with high sensitivity and specificity. Notably, DoubletSeeker effectively captured paired TCR‐peptide major histocompatibility complex (pMHC) information during a highly complex library‐on‐library screening and successfully identified three mutant TCRs that specifically recognize the MART‐1 epitope. In turn, DoubletSeeker can act as an antigen discovery platform that allows for the development of novel immunotherapy targets, making it valuable for investigating fundamental tumor immunology.