AND-Gate Logic Forster\nResonance Energy Transfer/Magnetic\nResonance Tuning Nanoprobe for Programmable Antitumor Immunity Imaging

Simultaneous detection of different biomarkers related\nto the spatiotemporally\ndynamic immune events is of particular importance for the accurate\nevaluation of antitumor immune effects. Here, we have developed an\nAND-gate logic dual resonance energy transfer nanoprobe (named DRET)\nfor dynamic monitoring of programmed CD8<sup>+</sup> T cell activation\nand tumor cell apoptosis. Immunotherapy-induced granzyme B secretion\nfrom CD8<sup>+</sup> T cells and the subsequent caspase-3 release\nfrom apoptotic tumor cells individually activate one of the tiers\nof the “AND-gate” logic DRET. The resulting fluorescence\nrecovery and magnetic resonance T1 enhancement can be used for precise\nimmunomodulatory drug screening, early efficacy prediction, and immune\nstratification. Particularly, not only “Responders”\ncan be distinguished from “Non-responders”, but also\n“Acquired resistance” can be identified from “Maintain\nresponders”, providing a novel approach to put forward the\naccurate evaluation of antitumor immunity.