Hybridoma and phage display are two powerful technologies for isolating target-specific monoclonal antibodies based on the binding. However, for complex membrane proteins, such as G protein-coupled receptors (GPCRs), binding-based screening rarely results in functional antibodies. Here we describe a function-based high-throughput screening method for quickly identifying antibody antagonists and agonists against GPCRs by combining glycosylphosphatidylinositol-anchored antibody cell display with β-arrestin recruitment-based cell sorting and screening. This method links antibody genotype with phenotype and is applicable to all GPCR targets. We validated this method by identifying a panel of antibody antagonists and an antibody agonist to the human apelin receptor from an immune antibody repertoire. In contrast, we obtained only neutral binders and antibody antagonists from the same repertoire by phage display, suggesting that the new approach described here is more efficient than traditional methods in isolating functional antibodies. This new method may create a new paradigm in antibody drug discovery.

杂交瘤和噬菌体展示是基于结合分离靶标特异性单克隆抗体的两项强大技术。但是，对于复杂的膜蛋白，例如G蛋白偶联受体（GPCR），基于结合的筛选很少会产生功能性抗体。在这里，我们描述了一种基于功能的高通量筛选方法，该方法通过结合糖基磷脂酰肌醇固定的抗体细胞展示与基于β-arrestin募集的细胞分选和筛选来快速识别针对GPCR的抗体拮抗剂和激动剂。该方法将抗体基因型与表型联系起来，适用于所有GPCR靶标。我们通过从免疫抗体库中鉴定出针对人apelin受体的抗体拮抗剂和抗体激动剂来验证了该方法。相反，我们通过噬菌体展示仅从同一库中获得中性结合剂和抗体拮抗剂，这表明本文所述的新方法在分离功能性抗体方面比传统方法更有效。这种新方法可能会在抗体药物发现中创建新的范例。