Spatially confined IL-12 programs CAR-NK through mTORC1 to coordinate antitumor immune networks

Solid tumors evade immunotherapy because of immunosuppressive microenvironments that limit immune cell persistence and function. Although interleukin-12 (IL-12) potently activates antitumor immunity, its clinical use has been constrained by systemic toxicity. Here we engineered a CAR natural killer (NK) cell platform that integrated IL-12 signaling to enhance antitumor immunity. IL-12 signaling synergized with CAR activation to sustain mTORC1 activity through convergent Ras-ERK and PI3K pathways, promoting metabolic fitness, autonomous expansion, and sustained effector function. IL-12 also activated bystander NK cells, T cells, and macrophages to remodel the tumor microenvironment. To improve safety, IL-12 was tethered to a collagen-binding A3-domain, restricting its activity to the extracellular matrix and limiting systemic exposure. In ovarian and pancreatic cancer models, matrix-anchored IL-12 CAR NK cells expanded without exogenous cytokines and achieved durable tumor control. These findings suggest that mTORC1-mediated integration of CAR and cytokine signaling can enhance immune fitness and overcome immunosuppressive tumor microenvironments.