PME Immuno Special Seminar- Dr. Nicholas A. Kalogriopoulos

Synthetic G Protein-Coupled Receptors for Programmable Sensing and Control of Cell Behavior Synthetic receptors that mediate antigen-dependent cell responses are transforming therapeutics, drug discovery, and basic research. However, established technologies such as chimeric antigen receptors can only detect immobilized antigens, have limited output scope, and lack built-in drug control. To address these limitations, we engineered synthetic G-protein-coupled receptors (GPCRs) that can drive a wide range of native or non-native cellular processes in response to a user-defined antigen. We achieve modular antigen gating by engineering and fusing a conditional auto-inhibitory domain onto GPCR scaffolds. Antigen binding to a fused nanobody relieves auto-inhibition and enables receptor activation by drug, thus generating programmable antigen-gated G-protein-coupled engineered receptors (PAGERs). We created PAGERs that are responsive to more than a dozen biologically and therapeutically important soluble and cell-surface antigens in a single step from corresponding nanobody binders. Different PAGER scaffolds allow antigen binding to drive transgene expression, real-time fluorescence, or endogenous G-protein activation, enabling control of diverse cellular functions. We demonstrated multiple applications of PAGER, including induction of T cell migration along a soluble antigen gradient, control of macrophage differentiation, secretion of therapeutic antibodies, and inhibition of neuronal activity in mouse brain slices. Due to its modular design and generalizability, we expect PAGERs to have broad utility in discovery and translational science.