A dual-gated engineered bacterial platform for spatiotemporally controlled precise protein degradation

Lysosome-targeting chimeras (LYTACs) have attracted much attention due to their ability to specifically target and degrade disease-related proteins on the cell membrane. However, their clinical application is limited by poor tumor specificity, systemic off-target effects, and a lack of temporal regulation. Engineered bacteria naturally home to tumors and serve as in situ production factories, but current approaches typically lack orthogonal regulation over payload release and functional activation, leading to premature exposure and suboptimal efficacy. Here, we develop a dual-gated engineered bacterial platform (DGTPB) that decouples LYTAC delivery from functional activation. Upon tumor colonization, DGTPB constitutively produces genetically encoded LYTACs, triggers their release via L-arabinose-induced bacterial lysis, and subsequently activates targeted degradation through red-light irradiation. This dual-gating design ensures high local LYTAC concentrations while minimizing systemic exposure. We demonstrate that DGTPB-mediated degradation of EGFR and PD-L1 potently suppresses tumor growth and metastasis in both melanoma and breast cancer models. Owing to its modular architecture, DGTPB is readily reprogrammable against diverse disease-associated membrane proteins by simply exchanging targeting ligands. Collectively, DGTPB establishes a versatile, programmable, and safe framework for precision extracellular targeted protein degradation, thereby providing a new tool for engineered-bacteria-based platforms in cancer immunotherapy.