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Interferon establishes an antiviral state in numerous cell types through the induction of a set of immediate-early response genes. Activation of these genes is mediated by phosphorylation of latent transcription factors of the STAT family. We found that infection of primary foreskin fibroblasts with human cytomegalovirus (HCMV) causes selective(More)
Pathogenic bacteria of the genus Yersinia employ a type III secretion system to inject bacterial effector proteins directly into the host cytosol. One of these effectors, the Yersinia serine/threonine protein kinase YpkA, is an essential virulence determinant involved in host actin cytoskeletal rearrangements and in inhibition of phagocytosis. Here we(More)
The innate immune system is the first line of defense against invading pathogens. Innate immune cells recognize molecular patterns from the pathogen and mount a response to resolve the infection. The production of proinflammatory cytokines and reactive oxygen species, phagocytosis, and induced programmed cell death are processes initiated by innate immune(More)
The invasion strategies used by Yersinia species involve the 'hijacking' of host cellular signaling pathways, often involving microbial gene products that mimic the functions of the cellular proteins. Yersinia uses a type III secretion system to inject these microbial gene products, referred to as Yersinia effector proteins, into the host cytosol. Yersinia(More)
Interferon regulatory factor 3 (IRF3) is known to participate in the transcriptional induction of interferon (IFN) alpha and IFNbeta genes, as well as of a number of interferon-stimulated genes (ISGs), as a result of viral infection. In the present study we demonstrate the activation of IRF3 followed by ISG induction after exposure of cells to the bacterial(More)
Viruses utilize numerous mechanisms to counteract the host's immune response. Interferon production is a major component of the host antiviral response. Many viruses, therefore, produce proteins or RNA molecules that inhibit interferon-induced signal transduction pathways and their associated antiviral effects. Surprisingly, some viruses directly induce(More)
Interferon regulatory factor 3 (IRF3) mediates the transcriptional induction of interferon-stimulated genes (ISGs) in response to viral and bacterial infections. Here we show that the hydroxystilbene piceatannol inhibits the LPS-mediated activation of IRF3 and subsequent ISG induction. Consequently, piceatannol blocks the LPS-induced up-regulation of(More)
IFN-regulatory factor 3 (IRF3) is known to participate in the transcriptional induction of chemokines and cytokines, including IFNs, as a result of viral or bacterial infection. In this study, we demonstrate that the LPS-mediated activation of IRF3 and subsequent induction of chemokine genes or IRF3-responsive reporter constructs are inhibited after(More)
The serine/threonine protein kinase YpkA is an essential virulence factor produced by pathogenic Yersinia species. YpkA is delivered into host mammalian cells via a type III secretion system and localizes to the inner side of the plasma membrane. We have previously shown that YpkA binds to and phosphorylates the α subunit of the heterotrimeric G protein(More)
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