Engineered probiotics recruit CAR macrophages and establish immune memory to eradicate heterogeneous glioblastoma in mice

Glioblastoma (GBM) remains a highly lethal form of cancer due to its molecular heterogeneity and the immunosuppressive microenvironment surrounding the tumor. Here, we report a modular immunotherapy platform characterized by its flexibility to simultaneously target multiple antigens. Specifically, we utilize engineered E. coli Nissle to colonize tumors and produce bispecific engagers that simultaneously target EGFRvIII and interleukin (IL)-13Rα2. These tags direct in situ -reprogrammed chimeric antigen receptor (CAR) macrophages, which are edited using nanoparticles and delivered within a shear-thinning hydrogel, to execute targeted phagocytosis. This probiotic-macrophage crosstalk eliminates tumor cells while converting protumor M2 macrophages into immunostimulatory M1 effectors. In aggressive orthotopic GBM mouse models, this strategy achieves 83% survival at the 120-day endpoint, representing a 5-fold improvement over single-target controls and establishing durable immunological memory that effectively combats recurrence. By functioning as multifunctional immune hubs, this platform offers a versatile framework designed to overcome the antigenic complexity of solid tumors.