Screening of protective antigens of Japanese encephalitis virus by DNA immunization: a comparative study with conventional viral vaccines.
In this study, we evaluated the relative role of the structural and nonstructural proteins of the Japanese encephalitis virus (JEV) in inducing protective immunities and compared the results with those induced by the inactivated JEV vaccine. Several inbred and outbred mouse strains immunized with a plasmid (pE) encoding the JEV envelope protein elicited a high level of protection against a lethal JEV challenge similar to that achieved by the inactivated vaccine, whereas all the other genes tested, including those encoding the capsid protein and the nonstructural proteins NS1-2A, NS3, and NS5, were ineffective. Moreover, plasmid pE delivered by intramuscular or gene gun injections produced much stronger and longer-lasting JEV envelope-specific antibody responses than immunization of mice with the inactivated JEV vaccine did. Interestingly, intramuscular immunization of plasmid pE generated high-avidity antienvelope antibodies predominated by the immunoglobulin G2a (IgG2a) isotype similar to a sublethal live virus immunization, while gene gun DNA immunization and inactivated JEV vaccination produced antienvelope antibodies of significantly lower avidity accompanied by a higher IgG1-to-IgG2a ratio. Taken together, these results demonstrate that the JEV envelope protein represents the most critical antigen in providing protective immunity.
Chen
H W
HW
Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan.
Pan
C H
CH
Liau
M Y
MY
Jou
R
R
Tsai
C J
CJ
Wu
H J
HJ
Lin
Y L
YL
Tao
M H
MH
D000818:Animals; D000914:Antibodies, Viral / Q000276:immunology; D000956:Antigens, Viral / Q000235:genetics* / Q000276:immunology; D002213:Capsid / Q000235:genetics / Q000276:immunology; D002460:Cell Line; D006224:Cricetinae; D004279:DNA, Viral / Q000276:immunology*; D004664:Encephalitis Virus, Japanese / Q000235:genetics* / Q000276:immunology; D004672:Encephalitis, Japanese / Q000517:prevention & control*; D005260:Female; D005822:Genetic Vectors; D006801:Humans; D008562:Membrane Glycoproteins / Q000235:genetics / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D008809:Mice, Inbred C3H; D008813:Mice, Inbred ICR; D008915:Minute Virus of Mice; D010957:Plasmids; D020365:RNA Helicases; D012697:Serine Endopeptidases; D019444:Vaccines, DNA / Q000276:immunology*; D015164:Vaccines, Inactivated / Q000276:immunology; D014759:Viral Envelope Proteins / Q000235:genetics / Q000276:immunology; D017361:Viral Nonstructural Proteins / Q000235:genetics / Q000276:immunology; D014765:Viral Vaccines / Q000276:immunology*; D043583:Nucleoside-Triphosphatase; D053487:DEAD-box RNA Helicases; D000085242:Viral Proteases
D000914:Antibodies, Viral; D000956:Antigens, Viral; D004279:DNA, Viral; D008562:Membrane Glycoproteins; D020365:RNA Helicases; D012697:Serine Endopeptidases; D019444:Vaccines, DNA; D015164:Vaccines, Inactivated; D014759:Viral Envelope Proteins; D017361:Viral Nonstructural Proteins; D014765:Viral Vaccines; C100315:NS1 protein, Flavivirus; C060028:NS3 protein, flavivirus; D043583:Nucleoside-Triphosphatase; D053487:DEAD-box RNA Helicases; D000085242:Viral Proteases; C096041:NS5 protein, flavivirus; C080628:glycoprotein E, Japanese encephalitis virus