Spatiotemporal Delivery of Dual Nanobodies by Engineered Probiotics to Reverse Tumor Immunosuppression via Targeting Tumor-Derived Exosomes.

The anti-PD-L1 and its bispecific antibodies have exhibited durable antitumor immunity but still elicit immunosuppression mainly caused by tumor-derived exosomes (TDEs), leading to difficulty in clinical transformation. Herein, engineered Escherichia coli Nissle 1917 (EcN) coexpressing anti-PD-L1 and anti-CD9 nanobodies (EcN-Nb) are developed and decorated with zinc-based metal-organic frameworks (MOFs) loaded with indocyanine green (ICG), to generate EcN-Nb-ZIF-8 _CHO -ICG (ENZC) for spatiotemporal lysis of bacteria for immunotherapy. The tumor-homing hybrid system can specifically release nanobodies in response to near-infrared (NIR) radiation, thereby targeting TDEs and changing their biological distribution, remodeling tumor-associated macrophages to M1 states, activating more effective and cytotoxic T lymphocytes, and finally, leading to the inhibition of tumor proliferation and metastasis. Altogether, the microfluidic-enabled MOF-modified engineered probiotics target TDEs and activate the antitumor immune response in a spatiotemporally manipulated manner, offering promising TDE-targeted immune therapy.