Dual-targeting exosome vaccine confers efficient protection against CVB3-induced myocarditis

Abstract

Coxsackievirus B3 (CVB3) is a common cause of viral myocarditis, necessitating the development of prophylactic vaccines.. AD-Exo, a dual-targeting exosome vaccine, was developed to induce immune responses via targeting draining lymph nodes (dLNs) and dendritic cells (DCs). By incorporating an albumin-binding domain (ABD) peptide and a DC-guiding peptide (DCpep) into our previous CVB3 exosome vaccine (Exo), the AD-Exo vaccine demonstrated superior immunogenicity. It efficiently bound to mouse serum albumin, amplified antigen enrichment in dLNs, and enhanced DC uptake and maturation. Subcutaneous immunization in mice elicited significantly higher CVB3-specific serum neutralizing IgG with greater affinity than Exo and single-targeting vaccines. It induced robust T cell proliferation and CTL responses, increasing IFN-γ-producing CD4⁺ and CD8⁺ T cells. Ultimately, the AD-Exo vaccine reduced cardiac viral load, minimized histopathological damage, and significantly improved survival in challenged mice. This strategy provided novel perspectives for the development of dual-targeting prophylactic vaccines against viral myocarditis.