Recognition of viruses by pattern recognition receptors (PRRs) causes interferon-β (IFN-β) induction, a key event in the anti-viral innate immune response, and also a target of viral immune evasion. Here the vaccinia virus (VACV) protein C6 is identified as an inhibitor of PRR-induced IFN-β expression by a functional screen of select VACV open reading frames expressed individually in mammalian cells. C6 is a member of a family of Bcl-2-like poxvirus proteins, many of which have been shown to inhibit innate immune signalling pathways. PRRs activate both NF-κB and IFN regulatory factors (IRFs) to activate the IFN-β promoter induction. Data presented here show that C6 inhibits IRF3 activation and translocation into the nucleus, but does not inhibit NF-κB activation. C6 inhibits IRF3 and IRF7 activation downstream of the kinases TANK binding kinase 1 (TBK1) and IκB kinase-ε (IKKε), which phosphorylate and activate these IRFs. However, C6 does not inhibit TBK1- and IKKε-independent IRF7 activation or the induction of promoters by constitutively active forms of IRF3 or IRF7, indicating that C6 acts at the level of the TBK1/IKKε complex. Consistent with this notion, C6 immunoprecipitated with the TBK1 complex scaffold proteins TANK, SINTBAD and NAP1. C6 is expressed early during infection and is present in both nucleus and cytoplasm. Mutant viruses in which the C6L gene is deleted, or mutated so that the C6 protein is not expressed, replicated normally in cell culture but were attenuated in two in vivo models of infection compared to wild type and revertant controls. Thus C6 contributes to VACV virulence and might do so via the inhibition of PRR-induced activation of IRF3 and IRF7.
Pubmed ID: 21931555 RIS Download
Publication data is provided by the National Library of Medicine ® and PubMed ®. Data is retrieved from PubMed ® on a weekly schedule. For terms and conditions see the National Library of Medicine Terms and Conditions.
A database of information on pox viruses. Goals of this project are to acquire and annotate data on poxviruses, and to develop and utilize new tools to facilitate the study of this group of organisms. This basic research is being undertaken with an eye toward the development of novel antiviral therapies, vaccines against human orthopoxvirus infections, new approaches for the environmental detection of virions, and methods to accomplish more rapid diagnosis of disease.
View all literature mentionsDigital image processing system where microscope settings and processing steps may be adjusted in single user interface. Can acquire images from variety of cameras. Includes software package for capturing, archiving and preparing images for publication. Allows users to visualize and present images in several dimensions. Functionality of imaging toolbox expands constantly with wide range of different modules that are tailored to specific applications or microscope accessories. This resource is duplicated by SCR_018376
View all literature mentionsCell line NIH 3T3 is a Spontaneously immortalized cell line with a species of origin Mus musculus
View all literature mentionsCell line HEK293 is a Transformed cell line with a species of origin Homo sapiens (Human)
View all literature mentionsCell line HeLa is a Cancer cell line with a species of origin Homo sapiens
View all literature mentionsCell line BS-C-1 is a Spontaneously immortalized cell line with a species of origin Chlorocebus pygerythrus (Vervet monkey)
View all literature mentionsCell line RK 13 is a Spontaneously immortalized cell line with a species of origin Oryctolagus cuniculus
View all literature mentionsCell line HEK293T is a Transformed cell line with a species of origin Homo sapiens (Human)
View all literature mentionslaboratory mouse with name BALB/cAnNCrl from MGI.
View all literature mentionsMus musculus with name C57BL/6J from IMSR.
View all literature mentionsCell line NIH 3T3 is a Spontaneously immortalized cell line with a species of origin Mus musculus
View all literature mentions