A recombinant rabies virus encoding two copies of the glycoprotein gene confers protection in dogs against a virulent challenge

Xiaohui Liu; Youtian Yang; Zhaojin Sun; Jing Chen; Jun Ai; Can Dun; Zhen F Fu; Xuefeng Niu; Xiaofeng Guo

doi:10.1371/journal.pone.0087105

A recombinant rabies virus encoding two copies of the glycoprotein gene confers protection in dogs against a virulent challenge

PLoS One. 2014 Feb 3;9(2):e87105. doi: 10.1371/journal.pone.0087105. eCollection 2014.

Authors

Xiaohui Liu¹, Youtian Yang¹, Zhaojin Sun¹, Jing Chen¹, Jun Ai¹, Can Dun¹, Zhen F Fu², Xuefeng Niu³, Xiaofeng Guo¹

Affiliations

¹ College of Veterinary Medicine, South China Agricultural University, Guangzhou, China.
² State-key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China ; Department of Pathology, College of Veterinary Medicine, University of Georgia, Athens, Georgia, United States of America.
³ College of Veterinary Medicine, South China Agricultural University, Guangzhou, China ; Department of Pathology, College of Veterinary Medicine, University of Georgia, Athens, Georgia, United States of America.

Abstract

The rabies virus (RABV) glycoprotein (G) is the principal antigen responsible for the induction of virus neutralizing antibodies (VNA) and is the major modality of protective immunity in animals. A recombinant RABV HEP-Flury strain was generated by reverse genetics to encode two copies of the G-gene (referred to as HEP-dG). The biological properties of HEP-dG were compared to those of the parental virus (HEP-Flury strain). The HEP-dG recombinant virus grew 100 times more efficiently in BHK-21 cell than the parental virus, yet the virulence of the dG recombinant virus in suckling mice was lower than the parental virus. The HEP-dG virus can improve the expression of G-gene mRNA and the G protein and produce more offspring viruses in cells. The amount of G protein revealed a positive relationship with immunogenicity in mice and dogs. The inactivated HEP-dG recombinant virus induced higher levels of VNA and conferred better protection against virulent RABV in mice and dogs than the inactivated parental virus and a commercial vaccine. The protective antibody persisted for at least 12 months. These data demonstrate that the HEP-dG is stable, induces a strong VNA response and confers protective immunity more effectively than the RABV HEP-Flury strain. HEP-dG could be a potential candidate in the development of novel inactivated rabies vaccines.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Animals
Animals, Suckling
Antibodies, Viral / immunology
Blotting, Western
Cell Line
Cell Line, Tumor
Dog Diseases / immunology*
Dog Diseases / virology
Dogs
Female
Gene Expression Regulation, Viral
Glycoproteins / genetics
Glycoproteins / immunology*
Glycoproteins / metabolism
Humans
Immunization
Mice
Rabies / immunology*
Rabies / veterinary
Rabies / virology
Rabies Vaccines / immunology*
Rabies virus / genetics
Rabies virus / immunology*
Rabies virus / pathogenicity
Recombination, Genetic
Reverse Transcriptase Polymerase Chain Reaction
Time Factors
Vaccines, Inactivated / immunology
Viral Proteins / genetics
Viral Proteins / immunology*
Viral Proteins / metabolism
Virulence / genetics
Virulence / immunology

Substances

Antibodies, Viral
Glycoproteins
Rabies Vaccines
Vaccines, Inactivated
Viral Proteins

Grants and funding

This study was partially supported by a grant from the National Nature Science Foundation of China (Nos. 30671565 and 31172322) and High-tech Research Development Plan of China (863 plan, Nos. 2006AA10A204) and Special Fund for Agro-scientific Research in the Public Interest (Nos. 201103032) and Research of Guangdong Province and Ministry of Education (No. 2010A090200083). Otherwise no additional external funding was received for this study. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.