A Phase Separation-Fortified Bi-Specific Adaptor for Conditional Tumor Killing

A common approach in the development of therapeutic proteins is the use of synthetic ligands with multivalency, allowing for sophisticated control of signal transduction. Leveraging the emerging concept of liquid-liquid phase separation (LLPS) and its ability to organize cell surface receptors into functional compartments, we herein have designed modular ligands with phase-separation modalities to engineer programmable interreceptor communications and precise control of signal pathways, thus inducing the rapid, potent, and specific apoptosis of tumor cells. Despite their simplicity, these "triggers", named phase-separated Tumor Killers (hereafter referred to as psTK), are sufficient to yield interreceptor clustering of death receptors (represented by DR5) and tumor-associated receptors, with the following features: LLPS-mediated robust high-order organization, well-choreographed conditional activation, and broad-spectrum capacity for potently inducing apoptosis of tumor cells. The development of novel therapeutic proteins with phase-separation modalities showcases the power of spatially reorganizing signal transduction. This approach enables the branching of cell fate and holds promising potential for targeted therapies against challenging tumors. One-Sentence SummaryEngineered modular ligands with phase-separation modalities can drive lethal dialog with tumor cells.