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

Hao Feng; Gui-qiu Hu; Hua-lei Wang; Meng Liang; Hongru Liang; He Guo; Pingsen Zhao; Yu-jiao Yang; Xue-xing Zheng; Zhi-fang Zhang; Yong-kun Zhao; Yu-wei Gao; Song-tao Yang; Xian-zhu Xia

doi:10.1371/journal.pone.0079575

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.

Authors

Affiliations

¹ Institute of Military Veterinary, Academy of Military Medical Sciences, Changchun, Jilin Province, China.
² Agricultural Division, College of Animal Science and Veterinary Medicine, Jilin University, Changchun, Jilin Province, China ; College of Animal Science and Technology, Jilin Agricultural University, Changchun, Jilin Province, China.
³ Agricultural Division, College of Animal Science and Veterinary Medicine, Jilin University, Changchun, Jilin Province, China.
⁴ Institute of Laboratory Animal Sciences, Chinese Academy of Medical Sciences & Peking Union Medical College, Bejing, China.
⁵ Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing, China.

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.