Canine parvovirus VP2 protein expressed in silkworm pupae self-assembles into virus-like particles with high immunogenicity

PLoS One. 2014 Jan 17;9(1):e79575. doi: 10.1371/journal.pone.0079575. eCollection 2014.

Abstract

The VP2 structural protein of parvovirus can produce virus-like particles (VLPs) by a self-assembly process in vitro, making VLPs attractive vaccine candidates. In this study, the VP2 protein of canine parvovirus (CPV) was expressed using a baculovirus expression system and assembled into parvovirus-like particles in insect cells and pupae. Electron micrographs of VLPs showed that they were very similar in size and morphology when compared to the wild-type parvovirus. The immunogenicity of the VLPs was investigated in mice and dogs. Mice immunized intramuscularly with purified VLPs, in the absence of an adjuvant, elicited CD4(+) and CD8(+) T cell responses and were able to elicit a neutralizing antibody response against CPV, while the oral administration of raw homogenates containing VLPs to the dogs resulted in a systemic immune response and long-lasting immunity. These results demonstrate that the CPV-VLPs stimulate both cellular and humoral immune responses, and so CPV-VLPs may be a promising candidate vaccine for the prevention of CPV-associated disease.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antibodies / immunology
  • Blotting, Western
  • Bombyx / metabolism*
  • CD4-Positive T-Lymphocytes / cytology
  • CD8-Positive T-Lymphocytes / cytology
  • Cell Proliferation
  • Dog Diseases / immunology
  • Dog Diseases / prevention & control
  • Dogs
  • Erythrocytes / metabolism
  • Fluorescent Antibody Technique
  • Hemagglutination
  • Hemagglutination Inhibition Tests
  • Immunization
  • Mice
  • Mice, Inbred BALB C
  • Neutralization Tests
  • Parvovirus, Canine / genetics
  • Parvovirus, Canine / immunology
  • Parvovirus, Canine / metabolism*
  • Pupa / metabolism
  • Recombination, Genetic / genetics
  • Sus scrofa
  • Viral Proteins / genetics
  • Viral Proteins / immunology
  • Viral Proteins / metabolism*
  • Viral Vaccines / chemistry
  • Viral Vaccines / immunology
  • Viral Vaccines / metabolism
  • Virion / immunology*
  • Virion / metabolism*
  • Virion / ultrastructure
  • Virus Assembly*

Substances

  • Antibodies
  • Viral Proteins
  • Viral Vaccines

Grants and funding

This work was supported by the Special Fund for Agri-scientific Research in the Public Interest (No. 201303042). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.