Bacteria of Shigella spp. are responsible for shigellosis in humans. They use a type III secretion system to inject effector proteins into host cells and induce their entry into epithelial cells or ...trigger apoptosis in macrophages. We present evidence that the effector OspG is a protein kinase that binds various ubiquitinylated ubiquitin-conjugating enzymes, including UbcH5, which belongs to the stem cell factor SCFβ - TrCPcomplex promoting ubiquitination of phosphorylated inhibitor of NF-κB type α (phospho-IκBα). Transfection experiments indicated that OspG can prevent phospho-IκBα degradation and NF-κB activation induced by TNF-α stimulation. Infection of epithelial cells by the S. flexneri wild-type strain, but not an ospG mutant, led to accumulation of phospho-IκBα, consistent with OspG inhibiting SCFβ - TrCPactivity. Upon infection of ileal loops in rabbits, the ospG mutant induced a stronger inflammatory response than the wild-type strain. This finding indicates that OspG negatively controls the host innate response induced by S. flexneri upon invasion of the epithelium.
VUV absorbing vapours in n-perfluorocarbons Albrecht, E.; Baum, G.; Bellunato, T. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
09/2003, Letnik:
510, Številka:
3
Journal Article
Recenzirano
Odprti dostop
The optical transparency of perfluorocarbons used as Cherenkov media is of prime importance to many Ring Imaging Cherenkov detectors. We will in this paper show that the main photon absorbers in ...these fluids are hydrocarbons with double or triple bonds. We will moreover discuss a process which can eliminate these pollutants and restore the intrinsic excellent optical transparency of these fluids in the VUV range.
With the availability of complete DNA sequences for many prokaryotic and eukaryotic genomes, and soon for the human genome itself, it is important to develop reliable proteome-wide approaches for a ...better understanding of protein function. As elementary constituents of cellular protein complexes and pathways, protein-protein interactions are key determinants of protein function. Here we have built a large-scale protein-protein interaction map of the human gastric pathogen Helicobacter pylori. We have used a high-throughput strategy of the yeast two-hybrid assay to screen 261 H. pylori proteins against a highly complex library of genome-encoded polypeptides. Over 1,200 interactions were identified between H. pylori proteins, connecting 46.6% of the proteome. The determination of a reliability score for every single protein-protein interaction and the identification of the actual interacting domains permitted the assignment of unannotated proteins to biological pathways.
Allergic diseases represent a major health problem in Europe. They are increasing in prevalence, severity and costs. The Global Allergy and Asthma European Network (GA²LEN), a Sixth EU Framework ...Program for Research and Technological Development (FP6) Network of Excellence, was created in 2005 as a vehicle to ensure excellence in research bringing together research and clinical institutions to combat fragmentation in the European research area and to tackle Allergy in its globality. The Global Allergy and Asthma European Network has benefited greatly from the voluntary efforts of researchers who are strongly committed to this model of pan-European collaboration. The network was organized in order to increase networking for scientific projects in allergy and asthma around Europe and to make GA²LEN the world leader in the field. Besides these activities, research has also been carried out and the first papers are being published. Achievements of the Global Allergy and Asthma European Network can be grouped as follows: (i) those for a durable infrastructure built up during the project phase, (ii) those which are project-related and based on these novel infrastructures, and (iii) the development and implementation of guidelines. The major achievements of GA²LEN are reported in this paper.
Allergic diseases represent a major health problem in Europe. They are increasing in prevalence, severity and costs. GA2LEN (Global Allergy and Asthma European Network), an FP6 Network of Excellence, ...was created in 2005 as a vehicle to ensure excellence in research bringing together research and clinical institutions to combat fragmentation in the European research area and to tackle Allergy in its globality. GA2LEN benefited greatly from the voluntary efforts of researchers who are strongly committed to this model of pan-European collaboration. The network was organized in order to increase networking for scientific projects in allergy and asthma around Europe and to make GA2LEN the world leader in the field. Besides these activities, research has been jointly made and the first papers are being published. GA2LEN achievements in general can be grouped as those for a durable infrastructure built up during the project phase those which are project-related work based on these novel infrastructures, and the development and implementations of guidelines. The major achievements of GA2LEN are reported in this paper.
The strategy chosen for cloning potential vaccine antigens of Toxoplasma gondii was based on the hypothesis that the definitive protection observed in natural infection is due to the presence of ...encysted bradyzoite forms in host tissues throughout life. The antigens released by the bradyzoites would maintain an immune response against the invading tachyzoites. This led us to identify in tachyzoite in vitro translation products a polypeptide of 24 kDa that is an excreted-secreted antigen (ESA) and is cross-reactive with bradyzoites. In addition, the detection of anti-P24 IgG antibodies is correlated with the chronic infection in man. The gene encoding P24 has been isolated, sequenced, and expressed in Escherichia coli and eukaryotic cells. The recombinant proteins were immunogenic in mice, producing anti-native P23 antibodies. Immunocytochemical analysis located the native antigen in the dense granules of both tachyzoite and bradyzoite forms and showed that it is secreted within host-cell-modified phagosome. Moreover 45Ca2+ labeling as well as regional homologies indicate that this protein has Ca2+-binding properties, suggesting its physiological importance in host-cell invasion. P23 is of diagnostic interest as a marker of chronic toxoplasmosis and is proposed as a vaccine component.
The design of an ultra light structure, the so-called “stave”, to support and cool the sensitive elements of the Barrel Pixel detector, the innermost part of the ATLAS detector to be installed on the ...new Large Hadron Collider at CERN (Geneva), is presented.
Very high-dimensional stability, minimization of the material and ability of operating 10 years in a high radiation environment are the key design requirements.
The proposed solution consists of a combination of different carbon-based materials (impregnated carbon–carbon, ultra high modulus carbon fibre composites) coupled to a thin aluminum tube to form a very light support with an integrated cooling channel.
Our design has proven to successfully fulfil the requirements. The extensive prototyping and testing program to fully qualify the design and release the production are discussed.
Operation, optimisation, and performance of the DELPHI RICH detectors Albrecht, E.; van Apeldoorn, G.; Augustinus, A. ...
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment,
1999, Letnik:
433, Številka:
1
Journal Article, Conference Proceeding
Recenzirano
The Ring Imaging Cherenkov detectors of DELPHI represent a large-scale particle identification system which covers almost the full angular acceptance of DELPHI. The combination of liquid and gas ...radiators (C
4F
10, C
5F
12, and C
6F
14) provides particle identification over the whole secondary particle momentum spectrum at LEP I and LEP II. Continuing optimisation on the hardware as well as on the online and offline software level have resulted in a stable operation of the complete detector system for more than five years at full physics performance.
The lacZ gene from Streptococcus thermophilus A054, a commercial yogurt strain, was cloned on a 7.2 kb PstI fragment in Escherichia coli and compared with the previously cloned lacZ gene from S. ...thermophilus ATCC 19258. Using the dideoxy chain termination method, the DNA sequences of both lacZ structural genes were determined and found to be 3071 bp in length. When the two sequences were more closely analysed, 21 nucleotide differences were detected, of which only nine resulted in amino acid changes in the proteins, the remainder occurring in wobble positions of the respective codons. Only three bases separated the termination codon for the lacS gene from the initiation codon for lacZ, suggesting that the lactose utilization genes are organized as an operon. The amino acid sequence of the beta-galactosidase, derived from the DNA sequence, corresponds to a protein with a molecular mass of 116860 Da. Comparison of the S. thermophilus amino acid sequences with those from Lactobacillus bulgaricus, E. coli and Klebsiella pneumoniae showed 48, 35 and 32.5% identity respectively. Although little sequence homology was observed at the DNA level, many regions conserved in the amino acid sequence were identified when the beta-galactosidase proteins from S. thermophilus, E. coli and L. bulgaricus were compared.
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