SELEX-HTCFQ Platform: Developing DNA Enhancers of ADAR1 to Suppress ZBP1-Dependent Immunopathology

Excessive immune activation drives pathological inflammation through dysregulated ZBP1 signaling, yet this sensor remains crucial for immune surveillance, necessitating targeted therapies that selectively inhibit pathology, while preserving protective functions. Here, we developed an innovative SELEX-HTCFQ platform that combines the Systematic Evolution of Ligands by Exponential Enrichment (SELEX) with high-throughput competitive fluorescence quenching (HTCFQ) to identify ADAR1-specific enhancers. Capitalizing on ADAR1's natural ability to suppress ZBP1 via competitive Z-nucleic acid binding, this platform's dual assessment of affinity and selectivity identified aptamer A4, a highly specific ADAR1 enhancer demonstrating over 40-fold selectivity over ZBP1. A4 allosterically modulates ADAR1's activity, thereby potentiating its inhibitory effect on ZBP1, which not only mitigates the excessive inflammatory response but also maintains the delicate balance of the immune system. These ADAR1 enhancers represent precision molecular tools for reprogramming Z-nucleic acid sensing, offering a promising therapeutic paradigm for cytokine storm syndromes and necroptosis-driven disorders through selective pathway modulation.