An inducible RIPK3-driven necroptotic system enhances cancer cell-based immunotherapy and ensures safety.

Recent progress in cancer cell-based therapies has led to effective targeting and robust immune responses against cancer. However, the inherent safety risks of using live cancer cells necessitate the creation of an optimized safety switch without hindering the efficacy of immunotherapy. The existing safety switches typically induce tolerogenic cell death, potentially leading to an immunosuppressive tumor immune microenvironment (TIME), which is counterproductive to the goals of immunotherapy. Here, we developed and characterized an inducible receptor-interacting protein kinase 3-driven (RIPK3-driven) necroptotic system that serves a dual function of safety switch as well as inducer of immunogenic cell death, which in turn stimulates antitumor immune responses. We show that activation of the RIPK3 safety switch triggered immunogenic responses marked by an increased release of ATP and damage-associated molecular patterns (DAMPs). Compared with other existing safety switches, incorporating the RIPK3 system inhibited tumor growth, improved survival outcomes in tumor-bearing mice, and fostered long-term antitumor immunity. Moreover, the RIPK3 system reinvigorated the TIME by promoting DC maturation, polarizing the macrophages toward a M1 phenotype, and reducing the exhaustion of CD4+ and CD8+ T lymphocytes. Our study highlights the dual role of the RIPK3-driven necroptotic system in improving the safety and efficacy of cancer cell-based therapy, with broader implications for cellular therapies.