Immunization with pseudotype baculovirus expressing envelope protein of Japanese encephalitis virus elicits protective immunity in mice.
BACKGROUND
Japanese encephalitis (JE) is a serious infection and disease in southern and eastern Asia. The design and development of safer and more efficacious vaccines against Japanese encephalitis virus (JEV) is a high-priority target in the world. Recently, baculovirus pseudotyped with vesicular stomatitis virus glycoprotein (VSVG) was described as an attractive gene delivery vehicle in mammalian cells and a potential vector for vaccine development. In the present study, we constructed a recombinant pseudotype baculovirus encoding the JEV envelope (E) protein and demonstrated that it could elicit high protective immunity in mice.


METHODS
Recombinant pseudotype baculovirus (BV-G-E) was generated by inserting JEV E gene fragment into pFastBac-VSV/G vector. BALB/c mice were immunized with BV-G-E and challenged with JEV wild-type strain. The neutralization antibody, interferon (IFN)-gamma expression and release, and survival rate were analysed and compared with the group of immunized with inactivated vaccine and DNA vaccine (pc-E) encoding the same gene of JEV.


RESULTS
We demonstrated that intramuscular injections of BV-G-E at various doses into mice produced higher levels of JEV-specific neutralizing antibodies, IFN-gamma and better protective efficacy against a lethal challenge with JEV than that of pc-E. Furthermore, BV-G-E could elicit a higher level of cellular immunity response and provide equal protective efficacy against JEV challenge compared to inactivated vaccine.


CONCLUSIONS
Our data demonstrate that BV-G-E elicited higher levels of protective immunity compared to DNA vaccine and that pseudotype baculovirus-mediated gene delivery can be utilized as an alternative strategy to develop new generations of vaccines against JEV infection.
Li
Yaoming
Y
State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, Hubei, China.
Ye
Jing
J
Cao
Shengbo
S
Xiao
Shaobo
S
Zhao
Qian
Q
Liu
Xueqin
X
Jin
Meilin
M
Chen
Huanchun
H
D000818:Animals; D016367:Baculoviridae / Q000235:genetics* / Q000276:immunology; D002478:Cells, Cultured; D004664:Encephalitis Virus, Japanese / Q000235:genetics* / Q000276:immunology*; D005260:Female; D007111:Immunity, Cellular; D007114:Immunization; D007371:Interferon-gamma / Q000276:immunology / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D009500:Neutralization Tests; D013552:Swine; D019444:Vaccines, DNA / Q000235:genetics / Q000276:immunology; D014759:Viral Envelope Proteins / Q000235:genetics / Q000276:immunology*
D019444:Vaccines, DNA; D014759:Viral Envelope Proteins; D007371:Interferon-gamma