Human cytomegalovirus blocks tumor necrosis factor alpha- and interleukin-1beta-mediated NF-kappaB signaling.
J Virol
; 80(23): 11686-98, 2006 Dec.
Article
em En
| MEDLINE
| ID: mdl-17005669
ABSTRACT
NF-kappaB plays an important role in the early cellular response to pathogens by activating genes involved in inflammation, immune response, and cell proliferation and survival. NF-kappaB is also utilized by many viral pathogens, like human cytomegalovirus (HCMV), to activate their own gene expression programs, reflecting intricate roles for NF-kappaB in both antiviral defense mechanisms and viral physiology. Here we show that the NF-kappaB signaling pathway stimulated by proinflammatory cytokines tumor necrosis factor alpha (TNF-alpha) and interleukin-1beta (IL-1beta) becomes inhibited in HCMV-infected cells. The block to NF-kappaB signaling is first noticeable during the early phase of infection but is fully established only at later times. Biochemical and genetic evidence demonstrates that the viral inhibition of proinflammatory signaling by distinct cytokines occurs upstream of the convergence point of NF-kappaB-activating pathways, i.e., the IkappaB kinase complex, and that it is mediated via different mechanisms. Consistent with this, we further show that an HCMV variant that has lost the ability to downregulate TNF-alpha-induced NF-kappaB signaling also fails to downregulate surface expression of TNF receptor 1, thereby mechanistically linking the inhibition of TNF-alpha-induced NF-kappaB signaling by HCMV to TNF receptor targeting. Our data support a model whereby HCMV inhibits cytokine-induced NF-kappaB signaling at later times during infection, and we suggest that this contributes to the inhibition of the cell's antiviral defense program.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Transdução de Sinais
/
NF-kappa B
/
Fator de Necrose Tumoral alfa
/
Citomegalovirus
/
Interleucina-1beta
Tipo de estudo:
Prognostic_studies
Limite:
Humans
Idioma:
En
Revista:
J Virol
Ano de publicação:
2006
Tipo de documento:
Article
País de afiliação:
Alemanha