Leveraging glucan-induced trained immunity for the epigenetic and metabolic rewiring of macrophages to enhance colorectal cancer vaccine response.

Colorectal cancer (CRC) remains refractory to most immunotherapies, with cancer vaccines failing due to an immunosuppressive tumor microenvironment. Here, we show that β-glucan-induced trained immunity overcomes these barriers by reprogramming macrophages through H3K4me3-dependent epigenetic modifications and metabolic rewiring. In female mice vaccinated with peptide-coated adenovirus-based vaccine PeptiCrad, training enhances glycolysis with creatine metabolism sustaining CXCL9/10 production, enabling macrophages to recruit NK cells via CXCR3. In turn, NK cells produce CCL5, driving cDC1 infiltration and antigen presentation, which together amplify effector memory CD8⁺ T cell responses. Moreover, with human peripheral blood mononuclear cells and CRC patient-derived organoids, trained macrophages boost NK migration, antigen-specific T cell activation, and tumor killing. These findings highlight trained immunity as a powerful adjuvant to reinvigorate colorectal cancer vaccination.