Abstract
Natural killer (NK) cells play a crucial role in immunotherapy for cancer due to their natural ability to target and destroy cancer cells. However, current methods to visualize NK cells' activity against tumors in live organisms are limited. We introduce an imaging method that non-invasively tracks NK cell activation by cancer cells through the STAT1 protein. To achieve this, we modified NK cells to include a specific genetic sequence that binds to STAT1 when activated. These engineered NK cells (GAS-NK) demonstrate their functionality through various biological tests and analysis. Observations of changes in cancer environments and patient-derived cancer organoid models further confirm the effectiveness of this approach. Our method provides a way to monitor NK cell activity, which could improve the prediction and effectiveness of NK cell-based cancer therapies, contributing to advances in cancer treatment.