synNotch CAR-Macrophages promote persistent antitumour activity through enhanced adaptive immunity

However, their efficacy is limited by challenges in precisely controlling tumour-specific immune activation and sustaining adaptive antitumour responses due to systemic off-target risks and inefficient antigen presentation. To overcome these limitations, we engineered an antigen prime-and-kill circuit, wherein tumour-specific synthetic Notch (syN) receptors locally induce the production of a kill antigen.

This circuit enhances the precision of CAR-M while establishing self-sustaining antigen-presentation networks, amplifying tumour-specific T-cell adaptive immunity without eliciting systemic cytokine toxicity. To enable in situ CAR-M generation, we developed a macrophage-derived exosome-based delivery system to introduce syN-CAR genes into tumour-associated macrophages (TAMs), thereby generating syN-CAR-M within the TME.