Suppression of immune response and protective immunity to a Japanese encephalitis virus DNA vaccine by coadministration of an IL-12-expressing plasmid.
J Immunol
; 166(12): 7419-26, 2001 Jun 15.
Article
em En
| MEDLINE
| ID: mdl-11390494
ABSTRACT
IL-12 plays a central role in both innate and acquired immunity and has been demonstrated to potentiate the protective immunity in several experimental vaccines. However, in this study, we show that IL-12 can be detrimental to the immune responses elicited by a plasmid DNA vaccine. Coadministration of the IL-12-expressing plasmid (pIL-12) significantly suppressed the protective immunity elicited by a plasmid DNA vaccine (pE) encoding the envelope protein of Japanese encephalitis virus. This suppressive effect was associated with marked reduction of specific T cell proliferation and Ab responses. A single dose of pIL-12 treatment with plasmid pE in initial priming resulted in significant immune suppression to subsequent pE booster immunization. The pIL-12-mediated immune suppression was dose dependent and evident only when the IL-12 gene was injected either before or coincident with the pE DNA vaccine. Finally, using IFN-gamma gene-disrupted mice, we showed that the suppressive activity of the IL-12 plasmid was dependent upon endogenous production of IFN-gamma. These results demonstrate that coexpression of the IL-12 gene can sometimes produce untoward effects to immune responses, and thus its application as a vaccine adjuvant should be carefully evaluated.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Plasmídeos
/
Encefalite Japonesa
/
Interleucina-12
/
Vacinas de DNA
/
Vacinas contra Encefalite Japonesa
/
Imunossupressores
Limite:
Animals
Idioma:
En
Revista:
J Immunol
Ano de publicação:
2001
Tipo de documento:
Article
País de afiliação:
Taiwan