Hollow mesoporous silica nanoparticles as delivery vehicle of foot-and-mouth disease virus-like particles induce persistent immune responses in guinea pigs

Foot-and-mouth disease (FMD) is an acute and febrile infectious disease, which can cause great economic losses. Virus-like particles (VLPs) as an advantageous antigen can induce significant specific immune response. To improve immunity of VLPs, especially, make it induce persistent immune response, the hollow mesoporous silica nanoparticles (HMSNs) as a potential nano-adjuvant were synthesized and loaded the FMD virus (FMDV) VLPs. They were injected into guinea pigs and the specific immune response was detected. The results confirmed that HMSNs/VLPs can induce persistent humoral immunity with high-level antibody titer for more than three months. HMSNs also improve the T-lymphocyte proliferation and IFN-γ induced by FMDV VLPs, and provides the ideal protection against FMDV challenge. These consequences indicated that HMSNs were good protein delivery vehicle and potential nano-adjuvant of vaccines. Highlights We synthesized Hollow mesoporous silica nanoparticles (HMSNs), as a delivery vehicle, are ideal candidate and have many unique structural features, including relatively larger surface areas, and controlled release capability, especially, good biocompatibility compared to golden nanoparticles as adjuvant. VLPs are composed of one or more structural proteins of virus, and without viral genetic material. As a new type of safe vaccine, FMDV VLPs can induce excellent immune response as traditional vaccines. To improve specific and persistent immune responses of FMDV VLPs, It is first time that HMSN was used as delivery of FMDV VLPs. The results confirmed that HMSNs can improve specific and persistent immune responses of FMDV VLPs, as new generation adjuvant.