title: Immunologic analysis induced by DNA vaccine encoding E protein of Beijing-1 strain derived from Japanese encephalitis virus.
abstract: OBJECTIVE
  We have compared the gene expression and DNA immunization efficacy encoding prME and E proteins of a different strain (JaGAr-01) derived from Japanese encephalitis virus. This study aimed to construct a recombinant encoding E protein of the Beijing-1 strain derived from Japanese encephalitis virus and analyze the humoral, cellular and protective immunity induced by the above recombinant.
  
  
  METHODS
  The recombinant pJBE containing E (1,500 bps) gene from the Beijing-1 strain of Japanese encephalitis virus was constructed and then transfected into the HepG2 cell line by liposome fusion. The expression of E (about 53 kD) protein in transfected cells was analyzed by Western blot using a specific anti-JEV-E antibody. BALB/c mice were vaccinated with 3 microg of pJBE by the gene-gun technique. JaGAr-01 and Beijing-1 strains (10(5) PFU/100 microl) of Japanese encephalitis virus were given to BALB/c mice by intraperitoneal injection 3 weeks after double DNA immunization with a lethal virus challenge. BALB/c mice were observed for 21 days after challenge. An 80% plaque reduction neutralization test was performed to titrate the neutralization antibody before and after viral challenge. A lactate dehydrogenase activity release test was used to examine cytotoxic T lymphocyte activity after double DNA immunization.
  
  
  RESULTS
  The expression of about 53 kD protein associated with pJBE was determined in transfected HepG2 cells with specific anti-JEV-E antibody. A higher level of neutralization antibodies and the cytotoxicity effect were induced with pJBE immunization using the gene-gun technique, and were similar to those induced with inactivated vaccine derive from the Beijing-1 strain of Japanese encephalitis virus. Balb/c mice immunized with pJBE survived the challenge with the different strains of Japanese encephalitis virus; however, Balb/c mice immunized with inactivated vaccine did not survive the challenge with the JaGAr-01 strain of Japanese encephalitis virus at all.
  
  
  CONCLUSIONS
  DNA vaccine containing the E protein gene derived from Japanese encephalitis virus can provide not only better efficacy including humoral and cellular immunity, but also cross-protection against infection with homologous and heterologous Japanese encephalitis virus.
authors.affiliation: Department of Infectious Diseases, Second Affiliated Hospital of China Medical University, Shenyang, China. fenggh@cmu2h.com
authors.forename: Guo-he
authors.initials: GH
authors.lastname: Feng
authors.forename: Ning
authors.initials: N
authors.lastname: Liu
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhou
authors.forename: Yong-zhen
authors.initials: YZ
authors.lastname: Zhai
authors.forename: Xi-mei
authors.initials: XM
authors.lastname: Li
authors.forename: Xiao-guang
authors.initials: XG
authors.lastname: Dou
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D019470:Biolistics; D015153:Blotting, Western; D002460:Cell Line; D004195:Disease Models, Animal; D004664:Encephalitis Virus, Japanese / Q000276:immunology*; D005260:Female; D022781:Hepatocytes / Q000737:chemistry / Q000821:virology; D006801:Humans; D007274:Injections, Intraperitoneal; D007770:L-Lactate Dehydrogenase / Q000032:analysis; D008562:Membrane Glycoproteins / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology*; D051379:Mice; D008807:Mice, Inbred BALB C; D009500:Neutralization Tests; D011994:Recombinant Proteins / Q000235:genetics / Q000276:immunology; D016019:Survival Analysis; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology; D019444:Vaccines, DNA / Q000276:immunology*; D014759:Viral Envelope Proteins / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology*; D010948:Viral Plaque Assay; D014765:Viral Vaccines / Q000276:immunology*
chemical_list: D000914:Antibodies, Viral; D008562:Membrane Glycoproteins; D011994:Recombinant Proteins; D019444:Vaccines, DNA; D014759:Viral Envelope Proteins; D014765:Viral Vaccines; C080628:glycoprotein E, Japanese encephalitis virus; D007770:L-Lactate Dehydrogenase