Immunogenicity evaluation of MS2 phage-mediated chimeric nanoparticle displaying an immunodominant B cell epitope of foot-and-mouth disease virus.

Guoqiang Wang,Dongmin Liu,Qiang Wei,Yunchao Liu,Yumei Chen,Hua Feng,Suzhen Yang,Juan Wang,Gaiping Zhang

doi:10.7717/peerj.4823

Abstract

Foot-and-mouth disease (FMD) is a highly contagious disease of cloven-hoofed animals that has caused tremendous economic losses worldwide. In this study, we designed a chimeric nanoparticles (CNPs) vaccine that displays the predominant epitope of the serotype O foot-and-mouth disease virus (FMDV) VP1 131-160 on the surface of MS2 phage. The recombinant protein was expressed in Escherichia Coli and can self-assemble into CNPs with diameter at 25–30 nm in vitro. A tandem repeat peptide epitopes (TRE) was prepared as control. Mice were immunized with CNPs, TRE and commercialized synthetic peptide vaccines (PepVac), respectively. The ELISA results showed that CNPs stimulated a little higher specific antibody levels to PepVac, but was significantly higher than the TRE groups. Moreover, the results from specific IFN-γ responses and lymphocyte proliferation test indicated that CNP immunized mice exhibited significantly enhanced cellular immune response compared to TRE. These results suggested that the CNPs constructed in current study could be a potential alternative vaccine in future FMDV control.

Highlights

Foot-and-mouth disease virus (FMDV) infects more than 70 species of cloven-hoofed animals and has caused enormous economic losses to stockbreeding industry worldwide (Diaz-SanSegundo et al 2016; Pereira 1976)
The upstream, downstream and the full length chimeric genes were amplified by PCR with the expected molecular size of 1260 bp, 487 bp and 1734 bp (Fig.1A), which showed that the LOOP 131-160 was successfully inserted into coat protein (CP) of MS2
The purity of purified chimeric nanoparticles (CNPs) and TRE was estimated to be over 90% and 85%

Summary

Introduction

Foot-and-mouth disease virus (FMDV) infects more than 70 species of cloven-hoofed animals and has caused enormous economic losses to stockbreeding industry worldwide (Diaz-SanSegundo et al 2016; Pereira 1976). Epitopebased polypeptide vaccines are well known for their abilities to provide more accurate, larger numbers of effective antigens and effectively distinguish between infected and vaccinated animals. These epitope vaccines induce limited cellular immune response and immune protection in large host animals (Rodriguez et al 2003; Taboga et al 1997). G–H loop has been identified as a primary antigenic epitope on FMDV VP1, which can effectively inducing FMDV specific neutralizing antibodies (Bittle et al 1982; DiMarchi et al 1986). G–H loop of FMDV has a precise spatial conformation on the surface of natural virus particle and correct conformation is essential for inducing effective immune protection (Acharya et al 1990; Cao et al 2016)

Methods

Results

Discussion

Conclusion