736 research outputs found
Perturbation of isotherms below topography: constraints from tunnel transects through the Alps, Gotthard road tunnel
For many years it has been known that
near surface isotherms are influenced
by the topography (Lees 1910). Recently,
a number of studies were pursued
to quantify the effect of topography
on low temperature isotherms (e.g.
Stüwe et al. 1994, Mancktelow & Grasemann
1997). The magnitude of perturbation
depends on several parameters:
exhumation rate, geothermal gradient,
wavelength and amplitude of topography,
and finally by the age of surface
relief change (Braun 2002).conferenc
Membrane recruitment of NOD2 in intestinal epithelial cells is essential for nuclear factor–κB activation in muramyl dipeptide recognition
Nucleotide oligomerization domain (NOD) 2 functions as a mammalian cytosolic pathogen recognition molecule, and mutant forms have been genetically linked to Crohn's disease (CD). NOD2 associates with the caspase activation and recruitment domain of RIP-like interacting caspase-like apoptosis regulatory protein kinase (RICK)/RIP2 and activates nuclear factor (NF)–κB in epithelial cells and macrophages, whereas NOD2 mutant 3020insC, which is associated with CD, shows an impaired ability to activate NF-κB. To gain insight into the molecular mechanisms of NOD2 function, we performed a functional analysis of deletion and substitution NOD2 mutants. NOD2, but not NOD2 3020insC mutant, associated with cell surface membranes of intestinal epithelial cells. Membrane targeting and subsequent NF-κB activation are mediated by two leucine residues and a tryptophan-containing motif in the COOH-terminal domain of NOD2. The membrane targeting of NOD2 is required for NF-κB activation after the recognition of bacterial muramyl dipeptide in intestinal epithelial cells
Cenozoic relief evolution of the Eastern Alps – constraints from apatite fission track age-provenance of Neogene intramontane sediments
GEF-H1 Mediated Control of NOD1 Dependent NF-κB Activation by Shigella Effectors
Shigella flexneri has evolved the ability to modify host cell function with intracellular active effectors to overcome the intestinal barrier. The detection of these microbial effectors and the initiation of innate immune responses are critical for rapid mucosal defense activation. The guanine nucleotide exchange factor H1 (GEF-H1) mediates RhoA activation required for cell invasion by the enteroinvasive pathogen Shigella flexneri. Surprisingly, GEF-H1 is requisite for NF-κB activation in response to Shigella infection. GEF-H1 interacts with NOD1 and is required for RIP2 dependent NF-κB activation by H-Ala-D-γGlu-DAP (γTriDAP). GEF-H1 is essential for NF-κB activation by the Shigella effectors IpgB2 and OspB, which were found to signal in a NOD1 and RhoA Kinase (ROCK) dependent manner. Our results demonstrate that GEF-H1 is a critical component of cellular defenses forming an intracellular sensing system with NOD1 for the detection of microbial effectors during cell invasion by pathogens
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Glucocorticoid-Induced TNF Receptor Family-Related Protein Ligand is Requisite for Optimal Functioning of Regulatory CD4+ T Cells
Glucocorticoid-induced tumor necrosis factor receptor family-related protein (TNFRSF18, CD357) is constitutively expressed on regulatory T cells (Tregs) and is inducible on effector T cells. In this report, we examine the role of glucocorticoid-induced TNF receptor family-related protein ligand (GITR-L), which is expressed by antigen presenting cells, on the development and expansion of Tregs. We found that GITR-L is dispensable for the development of naturally occurring FoxP3+ Treg cells in the thymus. However, the expansion of Treg in GITR-L−/− mice is impaired after injection of the dendritic cells (DCs) inducing factor Flt3 ligand. Furthermore, DCs from the liver of GITR-L−/− mice were less efficient in inducing proliferation of antigen-specific Treg cells in vitro than the same cells from WT littermates. Upon gene transfer of ovalbumin into hepatocytes of GITR-L−/−FoxP3(GFP) reporter mice using adeno-associated virus (AAV8-OVA) the number of antigen-specific Treg in liver and spleen is reduced. The reduced number of Tregs resulted in an increase in the number of ovalbumin specific CD8+ T effector cells. This is highly significant because proliferation of antigen-specific CD8+ cells itself is dependent on the presence of GITR-L, as shown by in vitro experiments and by adoptive transfers into GITR-L−/−Rag−/− and Rag−/− mice that had received AAV8-OVA. Surprisingly, administering αCD3 significantly reduced the numbers of FoxP3+ Treg cells in the liver and spleen of GITR-L−/− but not WT mice. Because soluble Fc-GITR-L partially rescues αCD3 induced in vitro depletion of the CD103+ subset of FoxP3+CD4+ Treg cells, we conclude that expression of GITR-L by antigen presenting cells is requisite for optimal Treg-mediated regulation of immune responses including those in response during gene transfer
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GEF-H1 controls microtubule-dependent sensing of nucleic acids for antiviral host defenses
Detailed understanding of the signaling intermediates that confer the sensing of intracellular viral nucleic acids for induction of type I interferons is critical for strategies to curtail viral mechanisms that impede innate immune defenses. Here we show that the activation of the microtubule-associated guanine nucleotide exchange factor GEF-H1, encoded by Arhgef2, is essential for sensing of foreign RNA by RIG-I-like receptors. Activation of GEF-H1 controls RIG-I and Mda5-dependent phosphorylation of IRF3 and induction of interferon-β expression in macrophages. Generation of Arhgef2−/− mice revealed a pronounced signaling defect that prevented antiviral host responses to encephalomyocarditis virus and influenza A virus. Microtubule networks sequester GEF-H1 that upon activation is released to enable antiviral signaling by intracellular nucleic acid detection pathways
Stress map of the Mediterranean and Central Europe 2016
The Stress Map of the Mediterranean and Central Europe 2016 displays 5011 A-C quality stress data records of the upper 40 km of the Earth’s crust from the WSM database release 2016 (Heidbach et al, 2016, http://doi.org/10.5880/WSM.2016.001). Focal mechanism solutions determined as being potentially unreliable (labelled as Possible Plate Boundary Events in the database) are not displayed. Further detailed information on the WSM quality ranking scheme, guidelines for the various stress indicators, and software for stress map generation and the stress pattern analysis is available at www.world-stress-map.org
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