Lihao Ji, Tianze Zhu, Tianqi Jiang, Li Wang, Zhonghui Qiu, Shiqi Gao, Yuqi Wang, Jing Wang, Jingyi Zhang, Haomiao Huang, Yunlong Mao, Chen Lin, Jing Zhao, Xiuxiu Wang, Wei Wei
Bacterial therapeutics hold great promise for cancer treatment by targeting oxygen-poor tumor regions and complementing existing therapies. However, current approaches often struggle with safety concerns and complex engineering. Developing a safe, effective delivery platform relying entirely on natural bacterial biosynthesis remains a challenge. Here we show that attenuated Serratia marcescens serves as a powerful biohybrid platform for cancer therapy by leveraging its natural biosynthesis of prodigiosin, a photosensitive pigment. We engineer S. marcescens to yield high prodigiosin levels, which exhibit strong intrinsic anti-cancer activity and near-infrared photosensitivity. In female mouse models of melanoma and colorectal cancer, this platform triggers robust systemic immune responses, including enhanced T cell recruitment and long-term memory against tumor recurrence. Furthermore, the bacteria induces tumor cell death via mitophagy, while photothermal properties of prodigiosin enables rapid, light-controlled bacterial clearance post-treatment. These findings establish S. marcescens as a versatile, self-regulating biosynthetic platform for precise and safe cancer immunotherapy.