A plasmid encoding Japanese encephalitis virus PrM and E proteins elicits protective immunity in suckling mice.
A plasmid encoding Japanese encephalitis virus (JEV) prM and E proteins was constructed, and its efficacy as a candidate vaccine against JEV was evaluated in suckling mice. Groups of 10 BALB/c mice (5-7 days old) were immunized twice via muscular injection with this DNA vaccine, an empty vector or PBS at an interval of 3 weeks, and were challenged with a lethal dose of JEV 3 weeks after the second inoculation. Both cellular and humoral immune responses were examined before the challenge. Two animals from each group were sacrificed to detect the JEV-specific cytotoxic T lymphocyte activity. JEV-specific lactate dehydrogenase release in the DNA vaccine, empty vector and PBS groups was 37.5%, 18% and 8.5% respectively. JEV-specific antibody was detected in 8 of 10 animals in DNA vaccine group with a geometrical mean titer of 1: 28.3. The pooled serum from the same group also showed a neutralizing activity. Six of 8 mice in the DNA vaccine group survived the challenge, with a protection rate of 75%, but all the mice died in the two control groups. These results show that this JEV prM and E DNA vaccine is immunogenic and protective against JEV infection in the mouse model.
Department of Microbiology, Fourth Military Medical University, Xi'an 710032, Shaanxi Province, China.
Yushui
Y
Wu
Fuquan
F
Zhang
Wenyu
W
Ma
Jianhua
J
Song
Qingsheng
Q
Huang
Hongyi
H
Zhang
D000818:Animals; D000833:Animals, Suckling; D000914:Antibodies, Viral / Q000097:blood; D004664:Encephalitis Virus, Japanese / Q000235:genetics / Q000276:immunology; D004672:Encephalitis, Japanese / Q000276:immunology / Q000517:prevention & control*; D007114:Immunization; D022321:Japanese Encephalitis Vaccines / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology*; D008562:Membrane Glycoproteins / Q000235:genetics / Q000276:immunology*; D051379:Mice; D008807:Mice, Inbred BALB C; D010957:Plasmids / Q000235:genetics / Q000276:immunology*; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology; D019444:Vaccines, DNA / Q000008:administration & dosage / Q000276:immunology*; D014759:Viral Envelope Proteins / Q000235:genetics / Q000276:immunology*
D000914:Antibodies, Viral; D022321:Japanese Encephalitis Vaccines; D008562:Membrane Glycoproteins; D019444:Vaccines, DNA; D014759:Viral Envelope Proteins; C080628:glycoprotein E, Japanese encephalitis virus; C074932:prM protein, Flavivirus