Engineering Universal Cancer Immunity: Non-Tumor-Specific mRNA Vaccines Trigger Epitope Spreading in Cold Tumors

The landscape of cancer immunotherapy must shift from personalized neoantigen vac-cines toward universal platforms that leverage innate immune activation. This review examines a novel mRNA vaccine strategy that encodes non-tumor-specific antigens, carefully selected pathogen-derived or synthetic sequences designed to transform im-munologically "cold" tumors into inflamed, therapy-responsive microenvironments. Unlike conventional approaches requiring patient-specific tumor sequencing and 8–12-week manufacturing timelines, this platform utilizes pathogen-associated molecular patterns (PAMPs) and damage-associated molecular patterns (DAMPs) to trigger broad innate immune activation through multiple pattern recognition receptors (PRRs). The key therapeutic mechanism is epitope spreading, where vaccine-induced inflammation re-veals previously hidden tumor antigens, enabling the immune system to mount re-sponses against cancer-specific targets without prior knowledge of these antigens. De-livered via optimized lipid nanoparticles (LNPs), these vaccines induce epitope spreading, enhance checkpoint inhibitor responsiveness, and establish durable antitumor memory. This approach offers several potential advantages, including immediate treatment availability, a cost reduction of up to 100-fold compared to personalized vac-cines, scalability for global deployment, and efficacy across diverse tumor types. How-ever, risks such as cytokine release syndrome (CRS) and potential for off-target auto-immunity must be addressed, as highlighted in related mRNA applications. By elimi-nating barriers of time, cost, and infrastructure, this universal platform could help de-mocratize access to advanced cancer treatment, potentially benefiting the 70% of cancer patients in low- and middle-income countries (LMICs) who currently lack immunotherapy options.