Dendritic Cell-Based Biomimetic Nanoparticles for Foot-and-mouth Disease Induce Robust Cellular Immunity

Foot-and-mouth disease (FMD) is a highly contagious and economically devastating viral disease of ruminants and swine, badly affecting the livestock industry worldwide. In clinical practice, vaccination is a frequently employed strategy to prevent foot-and-mouth disease (FMDV). However, commercial inactivated vaccines for FMD mainly rely on humoral immunity, exhibiting poor cellular immune responses and causing adverse reactions. Here, we use the double emulsion method to prepare poly(lactic-co-glycolic acid) nanoparticles (PLGA-NP) encapsulated with IL-2 cytokines, wrap the dendritic cell (DC) membrane carrying FMDV antigen information on the surface of the nanoparticles, obtaining a biomimetic nanoparticle vaccine Biom@DC with uniform size. This vaccine can effortlessly move through lymph nodes due to its nanoscale size advantage. It also possesses DC cells' ability to present antigens, and antigen presentation can be made more effective with high biocompatibility. The sustained release of IL-2 encapsulated in the core of PLGA-NP in vivo can effectively promote the body's cellular immune response. Immune tests on mice have shown that Biom@DC may greatly increase T cell activation and proliferation both in vivo and in vitro, while also significantly reducing the fraction of inhibitory Treg cells. Furthermore, in the micro serum neutralization assay for FMDV, it has been demonstrated that the group vaccinated with Biom@DC exhibits a clear neutralizing effect. Given its strong immunogenicity, Biom@DC has the potential to develop into a novel, potent anti-FMDV vaccination.