Leveraging glucan-induced trained immunity for the epigenetic and metabolic rewiring of macrophages to enhance colorectal cancer vaccine response
Firas Hamdan, Sara Gandolfi, Federica D’Alessio, Yvonne Giannoula, Julia Kolikova, Manlio Fusciello, Elisa Zaghen, Alessandra Napolano, Salvatore Russo, Ozan Izci, Paolo Bottega, Jacopo Chiaro, Kirsi-Marja Alanen, Gabriella Antignani, Michaela Feodoroff, Virpi Stigzelius, Milda Sakalauskaite, Janita Sandberg, Anni I. Nieminen, Nicola Zambrano, Ove Eriksson, Satu Mustjoki, Toni T. Seppälä, Mikaela Grönholm, Vincenzo Cerullo
Abstract
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. Beta-glucan is an inducer of trained immunity, an epigenetic and metabolic reprogramming of the innate immune cells conferring immunological memory. Here the authors show that glucan-induced trained immunity enhances response to a cancer vaccine platform in colorectal cancer models, by inducing epigenetic and metabolic rewiring of macrophages that promotes an NK-cDC1 axis boosting anti-tumor immunity.