Yersinia enterocolitica YopT and Clostridium difficile Toxin B Induce Expression of GILZ in Epithelial Cells
et al. (2012) Yersinia enterocolitica YopT and Clostridium difficile Toxin B Induce Expression of
GILZ in Epithelial Cells. PLoS ONE 7(7): e40730. doi:10.1371/journal.pone.0040730
Yersinia enterocolitica YopT and Clostridium difficile Toxin B Induce Expression of GILZ in Epithelial Cells
Martin Ko berle 0
David Go ppel 0
Tanja Grandl 0
Peer Gaentzsch 0
Birgit Manncke 0
Susanne Berchtold 0
Steffen Mu ller 0
Bernhard Lu scher 0
Marie-Liesse Asselin-Labat 0
Marc Pallardy 0
Isabel Sorg 0
Simon Langer 0
Holger Barth 0
Robert Zumbihl 0
Ingo B. Autenrieth 0
Erwin Bohn 0
Esteban Chaves-Olarte, Universidad de Costa Rica, Costa Rica
0 1 Interfaculty Institute of Microbiology and Infection Medicine, Eberhard Karls University of T u bingen , Tu bingen, Germany, 2 Dermatology , Eberhard Karls University of Tu bingen , Tu bingen, Germany , 3 Institut f u r Biochemie und Molekularbiologie, Universita tsklinikum RWTH Aachen , Aachen, Germany, 4 Universud, NSERM UMR-S 996 , Faculte de Pharmacie Paris-Sud, Chatenay-Malabry, France, 5 The Walter and Eliza Hall Institute of Medical Research , Parkville, Melbourne , Australia , 6 Biozentrum der Universita t Basel, Basel , Switzerland , 7 Institute of Pharmacology and Toxicology, University of Ulm Medical Center , Ulm, Germany, 8 INRA, UMR1333 , Laboratoire Diversite , Ge nomes et Interactions Microorganismes Insectes, Montpellier, France, 9 Universite de Montpellier 2 , Montpellier , France
Glucocorticoid induced-leucine zipper (GILZ) has been shown to be induced in cells by different stimuli such as glucocorticoids, IL-10 or deprivation of IL-2. GILZ has anti-inflammatory properties and may be involved in signalling modulating apoptosis. Herein we demonstrate that wildtype Yersinia enterocolitica which carry the pYV plasmid upregulated GILZ mRNA levels and protein expression in epithelial cells. Infection of HeLa cells with different Yersinia mutant strains revealed that the protease activity of YopT, which cleaves the membrane-bound form of Rho GTPases was sufficient to induce GILZ expression. Similarly, Clostridium difficile toxin B, another bacterial inhibitor of Rho GTPases induced GILZ expression. YopT and toxin B both increased transcriptional activity of the GILZ promoter in HeLa cells. GILZ expression could not be linked to the inactivation of an individual Rho GTPase by these toxins. However, forced expression of RhoA and RhoB decreased basal GILZ promoter activity. Furthermore, MAPK activation proved necessary for profound GILZ induction by toxin B. Promoter studies and gel shift analyses defined binding of upstream stimulatory factor (USF) 1 and 2 to a canonical c-Myc binding site (E-box) in the GILZ promoter as a crucial step of its trans-activation. In addition we could show that USF-1 and USF-2 are essential for basal as well as toxin B induced GILZ expression. These findings define a novel way of GILZ promoter trans-activation mediated by bacterial toxins and differentiate it from those mediated by dexamethasone or deprivation of IL-2.
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Yersinia enterocolitica is an enteropathogenic bacterium which
causes gastrointestinal disorders such as enteritis and enterocolitis,
and extraintestinal manifestations such as lymphadenitis, reactive
arthritis, erythema nodosum, uveitis and septicaemia [1,2]. Host
cells can sense Y. enterocolitica by recognizing bacterial factors like
LPS, invasin, YadA and YopB and can react with a
proinflammatory response [3,4,5].
In line with this, gene expression analysis of epithelial cells
revealed that upon interaction with Yersinia, chromosomally
encoded bacterial factors such as the adhesin invasin lead to gene
expression of a large number of pro-inflammatory genes [6]. In
cells infected with wildtype Yersinia this host response is suppressed
by injection of virulence plasmid (pYV)-encoded factors into host
cells [7]. In contrast, only a few host genes were found exclusively
induced by pYV-encoded factors such as glucocorticoid induced
leucine zipper (GILZ) and krueppel like factor (KLF) 2 [6,8].
GILZ or TSC22 domain family, member 3 (Tsc22d3),
a member of the leucine zipper protein family, was identified by
comparing mRNA species expressed in dexamethasone (DEX)
treated and untreated murine thymocytes [9]. Furthermore, GILZ
gene expression was also found to be induced by interleukin (IL)
10 signaling or by IL-2 deprivation in T-cells and macrophages
[10,11]. GILZ expression protects T cells from apoptosis induced
by treatment with anti-CD3 monoclonal antibodies, probably via
down-regulation of Fas/FasL expression [9]. Most notably, GILZ
has been demonstrated to be an important mediator of the
antiinflammatory und anti-proliferative effects of glucocorticoids [12].
For instance it has been shown that anti-inflammatory effects of
DEX in lung epithelial cells are mediated by GILZ [13]. It
prevents NF-kB activation by inhibition of NF-kB nuclear
translocation and DNA-binding due to a direct protein-protein
interaction with the (...truncated)