A Multivalent Personalized Vaccine Orchestrating Two‐Signal Activation Rebuilds the Bridge Between Innate and Adaptive Antitumor Immunity

Abstract Personalized vaccines capable of circumventing tumor heterogeneity have exhibited compelling prospects. However, their therapeutic benefit is greatly hindered by the limited antigen repertoire and poor response of CD8 ⁺ T‐cell immunity. Here, a double‐signal coregulated cross‐linking hydrogel‐based vaccine (Bridge‐Vax) is engineered to rebuild the bridge between innate and adaptive immunity for activating CD8 ⁺ T‐cells against full repertoire of tumor antigens. Mechanistically, unlike prominent CD4 ⁺ T‐cell responses in most cases, administration of Bridge‐Vax encapsulated with granulocyte‐macrophage colony‐stimulating factor concentrates a wave of dendritic cells (DCs), which further promotes DCs activation with costimulatory signal by the self‐adjuvanted nature of polysaccharide hydrogel. Simultaneously, synergy with the increased MHC‐I epitopes by codelivered simvastatin for cross‐presentation enhancement, Bridge‐Vax endows DCs with necessary two signals for orchestrating CD8 ⁺ T‐cell activation. Bridge‐Vax elicits potent antigen‐specific CD8 ⁺ T‐cell responses in vivo, which not only shows efficacy in B16‐OVA model but confers specific immunological memory to protect against tumor rechallenge. Moreover, personalized multivalent Bridge‐Vax tailored by leveraging autologous tumor cell membranes as antigens inhibits postsurgical B16F10 tumor recurrence. Hence, this work provides a facile strategy to rebuild the bridge between innate and adaptive immunity for inducing potent CD8 ⁺ T‐cell immunity and would be a powerful tool for personalized cancer immunotherapy.