Analysis of Helicobacter pylori VacA-containing vacuoles and VacA intracellular trafficking

The human pathogen Helicobacter pylori colonizes half of the global population. Residing at the stomach epithelium, it contributes to the development of diseases like gastritis, duodenal and gastric ulcers, and gastric cancer. It has evolved a range of mechanisms to aid in colonization and persistence, manipulating the host immune response to avoid clearance. A major factor in this is the secreted vacuolating cytotoxin VacA which has a variety of effects on host cells. VacA is endocytosed and forms anion-selective channels in the endosome membrane, causing the compartment to swell. The resulting VacA-containing vacuoles (VCVs) can take up most of the cellular cytoplasm. Even though vacuolation is VacA's most prominent and namesake effect, the purpose of the vacuoles is still unknown. VacA exerts influence on the host immune response in various ways, both pro- and anti- inflammatorily. Most importantly, it disrupts calcium signaling in T-lymphocytes, inhibiting T-cell activation and proliferation and thereby suppressing the host immune response. Furthermore, VacA is transported to mitochondria, where it activates the mitochondrial apoptosis pathway. Within the cell, VacA has only been shown to localize to endocytic compartments/VCVs and mitochondria. Considering its diverse effects, however, the existence of other cellular sites of action seems plausible. In this study, the VCV proteome was comprehensively analyzed for the first time in order to investigate VCV function. To this end, three different strategies for VCV purification from T-cells were devised and tested. Eventually, VCVs were successfully isolated via immunomagnetic separation, using a VacA-specific primary antibody and a secondary antibody coupled to magnetic beads. The purified vacuoles were then measured by mass spectrometry, revealing not only proteins of the endocytic system, but also proteins usually localized in other cellular compartments. This apparent recruitment of proteins involved in all kinds of cellular pathways indicates a central function of VCVs in VacA intoxication effects. In a global evaluation, the VCV proteome exhibited an enrichment of proteins implicated in immune response, cell death, and cellular signaling; all of these are processes that VacA is known to influence. One of the individual proteins contained in the sample was STIM1, a calcium sensor normally residing in the endoplasmic reticulum (ER) that is important in store- operated calcium entry (SOCE). This corroborates the findings of a concurrent report, in which VacA severely influenced SOCE and colocalized with STIM1. A direct interaction of STIM1 with VacA was examined in a pull-down assay, but could be neither shown nor excluded. Immunofluorescence experiments conducted in HeLa cells confirmed the presence of VacA in the ER and also found it to traffic to the Golgi apparatus, identifying these two cellular compartments as novel VacA target structures. The exact route of VacA transport remains unclear, but the involvement of both the ER and the Golgi suggests the possibility of retrograde trafficking, analogous to other bacterial toxins like shiga and cholera toxins. In summary, the elucidation of the VCV proteome and the discovery of the ER and the Golgi apparatus as VacA target structures have generated intriguing starting points for future studies. The detection of many proteins implicated in VacA intoxication effects in the VCV proteome leads to the proposal of VCVs as signaling hubs that may coordinate the complex meshwork of VacA effects. Further investigation of individual proteins is expected to help greatly in illuminating this matter

APELACIÓN Y ATENUACIÓN: COMPARACIÓN INTERGENÉRICA ENTRE JUICIOS ORALES Y DEBATES PARLAMENTARIOS ESPAÑOLES

El objetivo de este trabajo es estudiar los mecanismos de apelación que desarrollan una función atenuante en contextos formales. Más concretamente, nos proponemos centrar nuestro estudio en las formas de tratamiento nominales (como señoría) y en las fórmulas apelativas convencionalizadas (como mira). Para ello, esta investigación se basa en dos corpus de dos géneros pertenecientes al registro oral formal: el debate parlamentario y el juicio oral. Tras analizar las muestras tomando como referencia la función (preventiva o reparadora) del atenuante, la fuerza ilocutiva, la posición y los roles de los participantes, se ha comprobado que incluso en contextos formales, estos mecanismos pueden desarrollar valores estratégicos relacionados con la atenuación. Además, el análisis destaca los beneficios de realizar estudios intergenéricos pues, por un lado, ayudan a conocer con más precisión la manera en que se configura la atenuación en distintos contextos y, por otro lado, la observación de fenómenos pragmáticos desde una perspectiva contrastiva podría permitir añadir nuevos detalles para la caracterización de los géneros

SÄHN, Thomas. 2022. Analyse sémiologique des personnages dans les récits graphiques. Berlin et al.: Peter Lang.

Rezensio

Kritische Diskursanalyse

Diese Masterarbeit untersucht, wie MigrantInnen in Sachunterrichtsbüchern an Wiener Volksschulen dargestellt werden. Geben Sachunterrichtsbücher der Volksschulen ein differenziertes Bild der Realität wieder, indem sie die Pluralität der Gesellschaft ausreichend in der Bebilderung und in der Textauswahl berücksichtigen? Werden Identifikationsmöglichkeiten für SchülerInnen mit Migrationshintergrund ausreichend geboten? Mit anderen Worten: Welches Bild wird den SchülerInnen von MigrantInnen, also ihren MitschülerInnen und Einwohnern der Stadt Wien, gezeigt? Wie werden BürgerInnen mit Migrationshintergrund thematisiert? Die Methode der Kritischen Diskursanalyse wurde als Basis verwendet. Die Begriffe Diskurs und Dispositiv werden vorgestellt, ebenso der Philosoph Michel Foucault. Die besondere Vermittlerrolle von Schulbüchern in einer sich verändernden multikulturellen Welt wird aufgezeigt. Anhand der Diskursthemen Mitmenschen, Feiertage, Typische Berufe, Abgebildete Kinder, Vornamen, Religiöse Symbole, Interkulturelles Lernen und Europa werden 31 ausgewählte Sachunterrichtsbücher der zweiten bis vierten Klasse Volksschule nach einem extra erstellten Kriterienkatalog untersucht. Zusammenfassend ergibt sich folgendes: Es gibt zu wenige Ansätze, die Multikulturalität der Gesellschaft in der Bebilderung darzustellen. Gerade bei der Darstellung von Klassengemeinschaften hätte mehr Rücksicht auf die Veränderung im Bild unserer Gesellschaft genommen werden müssen. Das homogene Bild der Gesellschaft, welches in den meisten Schulbüchern gezeichnet wird, stimmt für viele Bezirke Wiens nicht (mehr). In Kombination mit entsprechenden Inhalten könnte die Verwendung von ‚fremden‘ Namen zur Bewusstmachung der gesellschaftlichen Zusammensetzung beitragen. Die SchülerInnen könnten durch Namen, die nicht eindeutig aus dem österreichischen Sprachgebrauch stammen, für die Pluralität der Gesellschaft sensibilisiert werden. Die untersuchten Sachunterrichtsbücher lassen diese Chancen aus. BürgerInnen mit Migrationshintergrund werden in den Sachunterrichtsbücher an Wiener Volksschulen nicht ausreichend thematisiert

Analysis of Helicobacter pylori VacA-containing vacuoles and VacA intracellular trafficking

The human pathogen Helicobacter pylori colonizes half of the global population. Residing at the stomach epithelium, it contributes to the development of diseases like gastritis, duodenal and gastric ulcers, and gastric cancer. It has evolved a range of mechanisms to aid in colonization and persistence, manipulating the host immune response to avoid clearance. A major factor in this is the secreted vacuolating cytotoxin VacA which has a variety of effects on host cells. VacA is endocytosed and forms anion-selective channels in the endosome membrane, causing the compartment to swell. The resulting VacA-containing vacuoles (VCVs) can take up most of the cellular cytoplasm. Even though vacuolation is VacA's most prominent and namesake effect, the purpose of the vacuoles is still unknown. VacA exerts influence on the host immune response in various ways, both pro- and anti- inflammatorily. Most importantly, it disrupts calcium signaling in T-lymphocytes, inhibiting T-cell activation and proliferation and thereby suppressing the host immune response. Furthermore, VacA is transported to mitochondria, where it activates the mitochondrial apoptosis pathway. Within the cell, VacA has only been shown to localize to endocytic compartments/VCVs and mitochondria. Considering its diverse effects, however, the existence of other cellular sites of action seems plausible. In this study, the VCV proteome was comprehensively analyzed for the first time in order to investigate VCV function. To this end, three different strategies for VCV purification from T-cells were devised and tested. Eventually, VCVs were successfully isolated via immunomagnetic separation, using a VacA-specific primary antibody and a secondary antibody coupled to magnetic beads. The purified vacuoles were then measured by mass spectrometry, revealing not only proteins of the endocytic system, but also proteins usually localized in other cellular compartments. This apparent recruitment of proteins involved in all kinds of cellular pathways indicates a central function of VCVs in VacA intoxication effects. In a global evaluation, the VCV proteome exhibited an enrichment of proteins implicated in immune response, cell death, and cellular signaling; all of these are processes that VacA is known to influence. One of the individual proteins contained in the sample was STIM1, a calcium sensor normally residing in the endoplasmic reticulum (ER) that is important in store- operated calcium entry (SOCE). This corroborates the findings of a concurrent report, in which VacA severely influenced SOCE and colocalized with STIM1. A direct interaction of STIM1 with VacA was examined in a pull-down assay, but could be neither shown nor excluded. Immunofluorescence experiments conducted in HeLa cells confirmed the presence of VacA in the ER and also found it to traffic to the Golgi apparatus, identifying these two cellular compartments as novel VacA target structures. The exact route of VacA transport remains unclear, but the involvement of both the ER and the Golgi suggests the possibility of retrograde trafficking, analogous to other bacterial toxins like shiga and cholera toxins. In summary, the elucidation of the VCV proteome and the discovery of the ER and the Golgi apparatus as VacA target structures have generated intriguing starting points for future studies. The detection of many proteins implicated in VacA intoxication effects in the VCV proteome leads to the proposal of VCVs as signaling hubs that may coordinate the complex meshwork of VacA effects. Further investigation of individual proteins is expected to help greatly in illuminating this matter

Getrennt schreiben oder zusammenschreiben? Eine Untersuchung zu den Regeln der Getrennt- und Zusammenschreibung der zusammengesetzten Verben

This thesis explores the usage of the new spelling rules in the complex area of separate and compound spelling. This area was a main topic in the reform of German orthography 1996/98. The old rules can be characterized as a complex and incoherent system. The primary ambition in defining new rules for separate and compound spelling was to simplify the writing process in order to facilitate an easier usage of written language for the German speaking community. The basic concept of the new rules is the declaration of separate spelling as the default, making compound spelling the exception. As a consequence, most words of the German vocabulary, which were spelled as compounds before, are now to be spelled separately. The publication of the new rules for this orthographic area in the year 1996 caused a lot of criticism amongst linguists, the main point of criticism being that words, which grew together on the basis of grammatical processes, had been robbed of their status as words. They are now word-groups in which the two parts do not belong together and have their own individual status and meaning in the sentence. These rules are in opposition to the productive tendency of ?Univerbierung? in the German written language. This means a process whereby words, which stand next to each other in a written text, grow together under special conditions. This thesis has two main aims: The first aim is to define the system of separate and compound spelling as a combination of grammatical and orthographic aspects. It will be shown how grammatical categories are influencing the orthography of these words. Additionally, it will be shown how the new rules produce spellings which are grammatically incorrect. The second is to verify the prognosis that the new rules were not accepted by the German language community. This thesis presents the results of a corpus analysis drawn from the text corpora of contemporary German language which is available on the website of the Institut für deutsche Sprache. Articles from six different newspapers were analyzed to see if and how the new rules for the groups verb and verb, adjective and verb and noun and verb were used in these texts. The results of this research have been compiled for the period of time from August 1999 to December 2000 (Corpus 1) and August 1999 to June 2003 (Corpus 2). It was uncovered that for more than half of the analyzed verbs the new rules were not used consistently. The divergence from the spelling norms ranged from 10 to 50 percent. In particular the group adjective and verb showed a high deviation from the new rules for compound and separate spelling. These results can be explained both with semantic and syntactic reasoning

A comprehensive analysis of Helicobacter pylori plasticity zones reveals that they are integrating conjugative elements with intermediate integration specificity

Background: The human gastric pathogen Helicobacter pylori is a paradigm for chronic bacterial infections. Its persistence in the stomach mucosa is facilitated by several mechanisms of immune evasion and immune modulation, but also by an unusual genetic variability which might account for the capability to adapt to changing environmental conditions during long-term colonization. This variability is reflected by the fact that almost each infected individual is colonized by a genetically unique strain. Strain-specific genes are dispersed throughout the genome, but clusters of genes organized as genomic islands may also collectively be present or absent. Results: We have comparatively analysed such clusters, which are commonly termed plasticity zones, in a high number of H. pylori strains of varying geographical origin. We show that these regions contain fixed gene sets, rather than being true regions of genome plasticity, but two different types and several subtypes with partly diverging gene content can be distinguished. Their genetic diversity is incongruent with variations in the rest of the genome, suggesting that they are subject to horizontal gene transfer within H. pylori populations. We identified 40 distinct integration sites in 45 genome sequences, with a conserved heptanucleotide motif that seems to be the minimal requirement for integration. Conclusions: The significant number of possible integration sites, together with the requirement for a short conserved integration motif and the high level of gene conservation, indicates that these elements are best described as integrating conjugative elements (ICEs) with an intermediate integration site specificity

À propos apropos: Opening Romanistik: Ein Access, mehrere Perspektiven

Vorwort zur ersten Ausgabe von apropos [Perspektiven auf die Romania]Editorial for the first issue of apropos [Perspektiven auf die Romania

apropos: [Perspektiverweiterung auf die Romania und darüber hinaus]

Vorwort zur Nummer 5Editoria

Prozessbezogene Kompetenzen: Fördern, Beobachten, Bewerten ; Tagungsband des AK Grundschule in der GDM 2012

Dieser Tagungsband dokumentiert Ergebnisse der Herbsttagung des Arbeitskreises Grundschule in der Gesellschaft für Didaktik der Mathematik (GDM) in Tabarz vom 9. bis 11. November 2012 zum Thema „Prozessbezogene Kompetenzen: Fördern, Beobachten, Bewerten“. Das Rahmenthema wurde in fünf Hauptvorträgen im Plenum diskutiert. Zusätzlich setzten sich Arbeitsgruppen zu den klassischen Themenfeldern Arithmetik, Daten, Zufall und Wahrscheinlichkeit, Geometrie und Sachrechnen sowie Gruppen zu den Bereichen Kommunikation & Kooperation, Lehrerbildung, Lernen, Lehren & Forschen mit digitalen Medien und Vorschulische Bildung, intensiv mit aktuellen Forschungs- und Praxisfragen auseinander