Modified vaccinia virus Ankara induces Toll-like receptor-independent type I interferon responses.
J Virol
; 81(22): 12102-10, 2007 Nov.
Article
en En
| MEDLINE
| ID: mdl-17855554
ABSTRACT
Modified vaccinia virus Ankara (MVA) is a highly attenuated vaccinia virus strain undergoing clinical evaluation as a replication-deficient vaccine vector against various infections and tumor diseases. To analyze the basis of its high immunogenicity, we investigated the mechanism of how MVA induces type I interferon (IFN) responses. MVA stimulation of bone marrow-derived dendritic cells (DC) showed that plasmacytoid DC were main alpha IFN (IFN-alpha) producers that were triggered independently of productive infection, viral replication, or intermediate and late viral gene expression. Increased IFN-alpha levels were induced upon treatment with mildly UV-irradiated MVA, suggesting that a virus-encoded immune modulator(s) interfered with the host cytokine response. Mice devoid of Toll-like receptor 9 (TLR9), the receptor for double-stranded DNA, mounted normal IFN-alpha responses upon MVA treatment. Furthermore, mice devoid of the adaptors of TLR signaling MyD88 and TRIF and mice deficient in protein kinase R (PKR) showed IFN-alpha responses that were only slightly reduced compared to those of wild-type mice. MVA-induced IFN-alpha responses were critically dependent on autocrine/paracrine triggering of the IFN-alpha/beta receptor and were independent of IFN-beta, thus involving "one-half" of a positive-feedback loop. In conclusion, MVA-mediated type I IFN secretion was primarily triggered by non-TLR molecules, was independent of virus propagation, and critically involved IFN feedback stimulation. These data provide the basis to further improve MVA as a vaccine vector.
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Virus Vaccinia
/
Células Dendríticas
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Vacuna contra Viruela
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Interferón-alfa
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Vacunas contra el Cáncer
Límite:
Animals
Idioma:
En
Revista:
J Virol
Año:
2007
Tipo del documento:
Article
País de afiliación:
Alemania