Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
2008-7-2
pubmed:abstractText
Blocking the function of Stat (signal transducer and activator of transcription) proteins, which are critical for antiviral responses, has evolved as a common mechanism for pathogen immune evasion. The poxvirus-encoded phosphatase H1 is critical for viral replication, and may play an additional role in the evasion of host defense by dephosphorylating Stat1 and blocking interferon (IFN)-stimulated innate immune responses. Vaccinia virus (VACV) H1 can inhibit the phosphorylation of the transcription factor Stat1 after IFN-gamma stimulation of epithelial cells, greatly attenuating IFN-induced biological functions. In this study, we demonstrate that VACV infection is capable of inhibiting the phosphorylation of Stat1 and Stat2 after stimulation of fibroblasts or bone marrow-derived macrophages with either type I or type II IFNs, but did not inhibit the activation of Stat3 or Stat5 in either cell type. By using recombinant proteins for in vitro assays, we observe that variola virus H1 is more active than VACV H1, although it has similar selectivity for Stat targets. Differential effects of VACV infection were observed on the induction of IFN-stimulated genes, with complete inhibition of some genes by VACV infection, while others were less affected. Despite the IFN-gamma-induced expression of some genes in VACV-infected cells, IFN-gamma was unable to rescue the VACV-mediated inhibition of MHC class II antigen presentation. Moreover, VACV infection can affect the IFN-induced expression of Stat1-dependent and Stat1-independent genes, suggesting that the virus may target additional IFN-activated pathways. Thus, VACV targets multiple signaling pathways in the evasion of antiviral immune responses.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
1557-7465
pubmed:author
pubmed:issnType
Electronic
pubmed:volume
28
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
367-80
pubmed:dateRevised
2011-3-1
pubmed:meshHeading
pubmed-meshheading:18593332-Animals, pubmed-meshheading:18593332-Antigen Presentation, pubmed-meshheading:18593332-Cell Culture Techniques, pubmed-meshheading:18593332-Cytokines, pubmed-meshheading:18593332-Fibroblasts, pubmed-meshheading:18593332-Gene Expression Regulation, pubmed-meshheading:18593332-Humans, pubmed-meshheading:18593332-Interferon Type I, pubmed-meshheading:18593332-Interferon-gamma, pubmed-meshheading:18593332-Macrophages, pubmed-meshheading:18593332-Mice, pubmed-meshheading:18593332-Mice, Inbred C57BL, pubmed-meshheading:18593332-Mice, Knockout, pubmed-meshheading:18593332-NIH 3T3 Cells, pubmed-meshheading:18593332-STAT1 Transcription Factor, pubmed-meshheading:18593332-Signal Transduction, pubmed-meshheading:18593332-T-Lymphocytes, pubmed-meshheading:18593332-Vaccinia virus, pubmed-meshheading:18593332-Variola virus
pubmed:year
2008
pubmed:articleTitle
Vaccinia virus blocks Stat1-dependent and Stat1-independent gene expression induced by type I and type II interferons.
pubmed:affiliation
Department of Pediatrics, Herman B. Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, IN 46202, USA.
pubmed:publicationType
Journal Article, Research Support, N.I.H., Extramural