Multiplexed activation of endogenous genes by CRISPRa elicits potent anti-tumor immunity

Immunotherapy has transformed cancer treatment. However, current immunotherapy modalities face various limitations. Here, we developed MAEGI, a new form of immunotherapy that elicits anti-tumor immunity through multiplexed activation of endogenous genes. We leveraged CRISPR activation (CRISPRa) to directly augment the in situ expression of endogenous genes, thereby the presentation of tumor antigens, leading to dramatic anti-tumor immune responses. Deploying this as a cell-based vaccination strategy showed efficacy in both prophylactic and therapeutic settings. Intratumoral adeno-associated virus delivery of CRISPRa libraries elicited strong anti-tumor immunity across multiple cancer types. Precision targeting of mutated gene sets eradicated a large fraction of established tumors at both local and distant sites. This treatment modality led to alterations of the tumor microenvironment, marked by enhanced T cell infiltration and anti-tumor immune signatures. Multiplexed endogenous gene activation is a versatile and highly scalable strategy to elicit potent immune responses against cancer, distinct from existing cancer therapies.