Virus-like particles (VLPs) have emerged as promising vaccine candidates against foot-and-mouth disease (FMD). However, such vaccines provide a relatively low level of protection against FMD virus (FMDV) because of their poor immunogenicity. Therefore, it is necessary to design effective vaccine strategies that induce more potent immunogenicity. In order to investigate the means to improve FMD VLP vaccine (VLP FMDV ) immunogenicity, we encapsulated VLPs (MPL/DDA-VLP FMDV ) with cationic liposomes based on dimethyldioctadecylammonium bromide (DDA) and/or monophosphoryl lipid A (MPL, TLR4 agonist) as adjuvants. Unlike inactivated whole-cell vaccines, VLP FMDV were successfully encapsulated in this MPL/DDA system. We found that MPL/DDA-VLP FMDV could induce strong cell-mediated immune responses by inducing not only VLP-specific IFN-γ + CD4 + (Th1), IL-17A + CD4 + (Th17), and IFN-γ + CD8 + (activated CD8 response) T cells, but also the development of VLP-specific multifunctional CD4 + and CD8 + memory T cells co-expressing IFN-γ, TNF-α, and IL-2. In addition, the MPL/DDA-VLP FMDV vaccine markedly induced VLP-specific antibody titers; in particular, the vaccine induced greater Th1-predominant IgG responses than VLP FMDV only and DDA-VLP FMDV . These results are expected to provide important clues for the development of an effective VLP FMDV that can induce cellular and humoral immune responses, and address the limitations seen in current VLP vaccines for various diseases.
【저자키워드】 Vaccine, immunogenicity, virus-like particles, Liposome, foot-and-mouth disease, TLR4 agonist,