Immunogenicity and safety of virus-like particle of the porcine encephalomyocarditis virus in pig

Hye-Young Jeoung,Won-Ha Lee,Dong-Jun An,Bo-Hye Shin,Hwan-Won Choi,Wooseog Jeong,Hee Soo Lee

doi:10.1186/1743-422x-8-170

Abstract

BackgroundIn this study, porcine encephalomyocarditis virus (EMCV) virus-like particles (VLPs) were generated using a baculovirus expression system and were tested for immunogenicity and protective efficacy in vivo.ResultsVLPs were successfully generated from Sf9 cells infected with recombinant baculovirus and were confirmed to be approximately 30-40 nm by transmission electron microscopy (TEM). Immunization of mice with 0.5 μg crude protein containing the VLPs resulted in significant protection from EMCV infection (90%). In swine, increased neutralizing antibody titers were observed following twice immunization with 2.0 μg crude protein containing VLPs. In addition, high levels of neutralizing antibodies (from 64 to 512 fold) were maintained during a test period following the second immunization. No severe injection site reactions were observed after immunization and all swine were healthy during the immunization periodConclusionRecombinant EMCV VLPs could represent a new vaccine candidate to protect against EMCV infection in pig farms.

Highlights

In this study, porcine encephalomyocarditis virus (EMCV) virus-like particles (VLPs) were generated using a baculovirus expression system and were tested for immunogenicity and protective efficacy in vivo
Cells were infected with Bac-P12A3C at an multiplicity of infection (MOI) of 10, and cells and supernatants were harvested and analyzed at 3 dpi, at which point most of the cells showed cytopathic effects (CPE)
Western blotting showed that a specific protein of the predicted size of 30 kDa (VP1) was observed in both Vero cells with the pEMCV-K3 strain and in Sf9 cells infected with Bac-P12A3C (Figure 1B). 3.2

Summary

Introduction

Porcine encephalomyocarditis virus (EMCV) virus-like particles (VLPs) were generated using a baculovirus expression system and were tested for immunogenicity and protective efficacy in vivo. Vaccination with porcine EMCV virus-like particles (VLPs) has been examined as a novel candidate for protection against porcine EMCV [7]. VLP-based vaccines against porcine EMCV produced using a baculovirus system have not yet been developed. VLPs represent a highly effective alternative vaccine strategy. VLPs have been developed as novel vaccine candidate for many kinds of viruses including bluetongue virus [12], rabbit hemorrhagic disease virus [13], severe acute respiratory syndrome (SARS) virus [14], Norwalk-like viruses [15], and parvovirus [16]. Hepatitis B virus (Recombivax HB, Merck) and human papillomavirus (Gardasil®, Merck) VLPs have been approved for use as vaccines

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