A Potent Athero-protective Nanovaccine Cocktail by Two-Pronged Intracellular Delivery of Antigen and Adjuvant for Dendritic Cell Activation

Abstract Current clinical therapies for atherosclerosis primarily consist of surgical interventions or medical therapeutics but lack prophylactic treatments. Vaccines against atherosclerosis show great promise in managing the disease, particularly those capable of eliciting both effector T cell and antibody responses, requiring effective delivery of antigen and adjuvant to activate dendritic cells. Different from the commonly adopted co-delivery strategy by nanovaccines, we individually conjugate antigen p210 and adjuvant CpG-ODN as mannose and TLR ligands, respectively, onto superparamagnetic iron oxide nanoparticles (SPIONs) as a nanovaccine cocktail against atherosclerosis to incorporate multiple immune-stimulatory components. Indeed, the model nanovaccine SP-D1+P1, made from SPIONs coated with p210 (SP-P) and CpG-ODN (SP-D) at a mixing ratio of 1:1, enters dendritic cells (DCs) via mannose and scavenger receptor, respectively, which favors the cross-presentation of antigens and induces significantly higher levels of co-stimulatory molecules and cytokines compared to the counterpart nanoformulation containing both p210 and CpG-ODN (SP-D1/P1). After intradermal administration of three doses of SP-D1+P1, the ApoE -/- mice exhibited a mitigated development of atherosclerosis with reduced and stabilized plaques. SP-D1+P1 modulates the DCs in the draining lymph nodes (dLNs), generates regulatory responses in both CD4 + and CD8 + T cells, elicits memory responses, and induces both anti-p210 IgM and IgG antibodies to achieve the atheroreduction effect. We, therefore, have developed a potent nanovaccine formulation that was able to provoke both cellular and humoral regulatory responses in hypercholesterolemic ApoE –/– mice, which is not only a potential vaccine candidate but also offers further clinical translation opportunities for nanobiomaterials.