Ferroptosis-armed dendritic cell vaccines for glioma immunotherapy

The type of cell death has proven to play a crucial role in cancer immunotherapy efficacy. Immunogenic cell death (ICD) enhances tumor adjuvanticity and antigenicity by releasing danger signals and altering the immune peptidome. The immunogenicity of ferroptosis, an iron-dependent form of cell death, remains uncertain. Here, we show that dendritic cell (DC) vaccines loaded with ferroptotic lysates protect mice against glioma growth, inducing IFN-γ production, and promoting robust CD8⁺ T cell infiltration, activation, and effector memory formation in the tumor microenvironment. The intrinsic immunogenicity of ferroptosis was independent of the glioma type and the ferroptosis inducer. Instead, it critically required the presence of the damage-associated molecular patterns calreticulin and ATP, rather than involving HMGB1-TLR4 signaling. However, supplementing these DAMPs into DC vaccines loaded with non-ICD lysates did not restore efficacy to the level of the ferroptosis-based DC vaccine, suggesting a more complex mechanism beyond a purely DAMP-mediated effect. These findings demonstrate that ferroptosis-loaded DC vaccines elicit a potent, tumor-specific immune response, capable of eradicating intracranial gliomas in mice, which highlights their potential in cancer immunotherapy.