The Experts below are selected from a list of 53028 Experts worldwide ranked by ideXlab platform
Yoshio Yamaoka - One of the best experts on this subject based on the ideXlab platform.
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helicobacter pylori Outer Membrane Proteins on gastric mucosal interleukin 6 and 11 expression in mongolian gerbils
Journal of Gastroenterology and Hepatology, 2011Co-Authors: Mitsushige Sugimoto, Tomoyuki Ohno, David Y Graham, Yoshio YamaokaAbstract:Background and Aim The levels of interleukin (IL)-6 and IL-11 in the gastric mucosa are related to mucosal inflammation; however, the chronological changes in cytokine expression during different phases of Helicobacter pylori infection and the effects of H. pylori virulence factors, particularly those of Outer Membrane Proteins, remain obscure. The aim of this study was to clarify the chronological changes in cytokine levels in relation to several H. pylori Outer Membrane Proteins.
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helicobacter pylori Outer Membrane Proteins and gastroduodenal disease
Gut, 2006Co-Authors: Yoshio Yamaoka, Olabisi Olaniyi Ojo, Saori Fujimoto, Stefan Odenbreit, Rainer Haas, Oscar Gutierrez, Hala M T Elzimaity, Rita Reddy, Anna Arnqvist, David Y GrahamAbstract:Background and aims: A number of Helicobacter pylori Outer Membrane Proteins (OMPs) undergo phase variations. This study examined the relation between OMP phase variations and clinical outcome. Methods: Expression of H pylori BabA, BabB, SabA, and OipA Proteins was determined by immunoblot. Multiple regression analysis was performed to determine the relation among OMP expression, clinical outcome, and mucosal histology. Results: H pylori were cultured from 200 patients (80 with gastritis, 80 with duodenal ulcer (DU), and 40 with gastric cancer). The most reliable results were obtained using cultures from single colonies of low passage number. Stability of expression with passage varied with OipA > BabA > BabB > SabA. OipA positive status was significantly associated with the presence of DU and gastric cancer, high H pylori density, and severe neutrophil infiltration. SabA positive status was associated with gastric cancer, intestinal metaplasia, and corpus atrophy, and negatively associated with DU and neutrophil infiltration. The Sydney system underestimated the prevalence of intestinal metaplasia/atrophy compared with systems using proximal and distal corpus biopsies. SabA expression dramatically decreased following exposure of H pylori to pH 5.0 for two hours. Conclusions: SabA expression frequently switched on or off, suggesting that SabA expression can rapidly respond to changing conditions in the stomach or in different regions of the stomach. SabA positive status was inversely related to the ability of the stomach to secrete acid, suggesting that its expression may be regulated by changes in acid secretion and/or in antigens expressed by the atrophic mucosa.
Matthias Horn - One of the best experts on this subject based on the ideXlab platform.
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Comprehensive in silico prediction and analysis of chlamydial Outer Membrane Proteins reflects evolution and life style of the Chlamydiae
BMC Genomics, 2009Co-Authors: Eva Heinz, Patrick Tischler, Thomas Rattei, Garry Myers, Michael Wagner, Matthias HornAbstract:Background Chlamydiae are obligate intracellular bacteria comprising some of the most important bacterial pathogens of animals and humans. Although chlamydial Outer Membrane Proteins play a key role for attachment to and entry into host cells, only few have been described so far. We developed a comprehensive, multiphasic in silico approach, including the calculation of clusters of orthologues, to predict Outer Membrane Proteins using conservative criteria. We tested this approach using Escherichia coli (positive control) and Bacillus subtilis (negative control), and applied it to five chlamydial species; Chlamydia trachomatis , Chlamydia muridarum , Chlamydia (a.k.a. Chlamydophila ) pneumoniae , Chlamydia (a.k.a. Chlamydophila ) caviae , and Protochlamydia amoebophila . Results In total, 312 chlamydial Outer Membrane Proteins and lipoProteins in 88 orthologous clusters were identified, including 238 Proteins not previously recognized to be located in the Outer Membrane. Analysis of their taxonomic distribution revealed an evolutionary conservation among Chlamydiae , Verrucomicrobia , Lentisphaerae and Planctomycetes as well as lifestyle-dependent conservation of the chlamydial Outer Membrane protein composition. Conclusion This analysis suggested a correlation between the Outer Membrane protein composition and the host range of chlamydiae and revealed a common set of Outer Membrane Proteins shared by these intracellular bacteria. The collection of predicted chlamydial Outer Membrane Proteins is available at the online database pCOMP http://www.microbial-ecology.net/pcomp and might provide future guidance in the quest for anti-chlamydial vaccines.
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Comprehensive in silico prediction and analysis of chlamydial Outer Membrane Proteins reflects evolution and life style of the Chlamydiae
BMC genomics, 2009Co-Authors: Eva Heinz, Patrick Tischler, Thomas Rattei, Michael Wagner, Garry S A Myers, Matthias HornAbstract:Chlamydiae are obligate intracellular bacteria comprising some of the most important bacterial pathogens of animals and humans. Although chlamydial Outer Membrane Proteins play a key role for attachment to and entry into host cells, only few have been described so far. We developed a comprehensive, multiphasic in silico approach, including the calculation of clusters of orthologues, to predict Outer Membrane Proteins using conservative criteria. We tested this approach using Escherichia coli (positive control) and Bacillus subtilis (negative control), and applied it to five chlamydial species; Chlamydia trachomatis, Chlamydia muridarum, Chlamydia (a.k.a. Chlamydophila) pneumoniae, Chlamydia (a.k.a. Chlamydophila) caviae, and Protochlamydia amoebophila. In total, 312 chlamydial Outer Membrane Proteins and lipoProteins in 88 orthologous clusters were identified, including 238 Proteins not previously recognized to be located in the Outer Membrane. Analysis of their taxonomic distribution revealed an evolutionary conservation among Chlamydiae, Verrucomicrobia, Lentisphaerae and Planctomycetes as well as lifestyle-dependent conservation of the chlamydial Outer Membrane protein composition. This analysis suggested a correlation between the Outer Membrane protein composition and the host range of chlamydiae and revealed a common set of Outer Membrane Proteins shared by these intracellular bacteria. The collection of predicted chlamydial Outer Membrane Proteins is available at the online database pCOMP http://www.microbial-ecology.net/pcomp and might provide future guidance in the quest for anti-chlamydial vaccines.
David Y Graham - One of the best experts on this subject based on the ideXlab platform.
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helicobacter pylori Outer Membrane Proteins on gastric mucosal interleukin 6 and 11 expression in mongolian gerbils
Journal of Gastroenterology and Hepatology, 2011Co-Authors: Mitsushige Sugimoto, Tomoyuki Ohno, David Y Graham, Yoshio YamaokaAbstract:Background and Aim The levels of interleukin (IL)-6 and IL-11 in the gastric mucosa are related to mucosal inflammation; however, the chronological changes in cytokine expression during different phases of Helicobacter pylori infection and the effects of H. pylori virulence factors, particularly those of Outer Membrane Proteins, remain obscure. The aim of this study was to clarify the chronological changes in cytokine levels in relation to several H. pylori Outer Membrane Proteins.
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helicobacter pylori Outer Membrane Proteins and gastroduodenal disease
Gut, 2006Co-Authors: Yoshio Yamaoka, Olabisi Olaniyi Ojo, Saori Fujimoto, Stefan Odenbreit, Rainer Haas, Oscar Gutierrez, Hala M T Elzimaity, Rita Reddy, Anna Arnqvist, David Y GrahamAbstract:Background and aims: A number of Helicobacter pylori Outer Membrane Proteins (OMPs) undergo phase variations. This study examined the relation between OMP phase variations and clinical outcome. Methods: Expression of H pylori BabA, BabB, SabA, and OipA Proteins was determined by immunoblot. Multiple regression analysis was performed to determine the relation among OMP expression, clinical outcome, and mucosal histology. Results: H pylori were cultured from 200 patients (80 with gastritis, 80 with duodenal ulcer (DU), and 40 with gastric cancer). The most reliable results were obtained using cultures from single colonies of low passage number. Stability of expression with passage varied with OipA > BabA > BabB > SabA. OipA positive status was significantly associated with the presence of DU and gastric cancer, high H pylori density, and severe neutrophil infiltration. SabA positive status was associated with gastric cancer, intestinal metaplasia, and corpus atrophy, and negatively associated with DU and neutrophil infiltration. The Sydney system underestimated the prevalence of intestinal metaplasia/atrophy compared with systems using proximal and distal corpus biopsies. SabA expression dramatically decreased following exposure of H pylori to pH 5.0 for two hours. Conclusions: SabA expression frequently switched on or off, suggesting that SabA expression can rapidly respond to changing conditions in the stomach or in different regions of the stomach. SabA positive status was inversely related to the ability of the stomach to secrete acid, suggesting that its expression may be regulated by changes in acid secretion and/or in antigens expressed by the atrophic mucosa.
Eva Heinz - One of the best experts on this subject based on the ideXlab platform.
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Comprehensive in silico prediction and analysis of chlamydial Outer Membrane Proteins reflects evolution and life style of the Chlamydiae
BMC Genomics, 2009Co-Authors: Eva Heinz, Patrick Tischler, Thomas Rattei, Garry Myers, Michael Wagner, Matthias HornAbstract:Background Chlamydiae are obligate intracellular bacteria comprising some of the most important bacterial pathogens of animals and humans. Although chlamydial Outer Membrane Proteins play a key role for attachment to and entry into host cells, only few have been described so far. We developed a comprehensive, multiphasic in silico approach, including the calculation of clusters of orthologues, to predict Outer Membrane Proteins using conservative criteria. We tested this approach using Escherichia coli (positive control) and Bacillus subtilis (negative control), and applied it to five chlamydial species; Chlamydia trachomatis , Chlamydia muridarum , Chlamydia (a.k.a. Chlamydophila ) pneumoniae , Chlamydia (a.k.a. Chlamydophila ) caviae , and Protochlamydia amoebophila . Results In total, 312 chlamydial Outer Membrane Proteins and lipoProteins in 88 orthologous clusters were identified, including 238 Proteins not previously recognized to be located in the Outer Membrane. Analysis of their taxonomic distribution revealed an evolutionary conservation among Chlamydiae , Verrucomicrobia , Lentisphaerae and Planctomycetes as well as lifestyle-dependent conservation of the chlamydial Outer Membrane protein composition. Conclusion This analysis suggested a correlation between the Outer Membrane protein composition and the host range of chlamydiae and revealed a common set of Outer Membrane Proteins shared by these intracellular bacteria. The collection of predicted chlamydial Outer Membrane Proteins is available at the online database pCOMP http://www.microbial-ecology.net/pcomp and might provide future guidance in the quest for anti-chlamydial vaccines.
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Comprehensive in silico prediction and analysis of chlamydial Outer Membrane Proteins reflects evolution and life style of the Chlamydiae
BMC genomics, 2009Co-Authors: Eva Heinz, Patrick Tischler, Thomas Rattei, Michael Wagner, Garry S A Myers, Matthias HornAbstract:Chlamydiae are obligate intracellular bacteria comprising some of the most important bacterial pathogens of animals and humans. Although chlamydial Outer Membrane Proteins play a key role for attachment to and entry into host cells, only few have been described so far. We developed a comprehensive, multiphasic in silico approach, including the calculation of clusters of orthologues, to predict Outer Membrane Proteins using conservative criteria. We tested this approach using Escherichia coli (positive control) and Bacillus subtilis (negative control), and applied it to five chlamydial species; Chlamydia trachomatis, Chlamydia muridarum, Chlamydia (a.k.a. Chlamydophila) pneumoniae, Chlamydia (a.k.a. Chlamydophila) caviae, and Protochlamydia amoebophila. In total, 312 chlamydial Outer Membrane Proteins and lipoProteins in 88 orthologous clusters were identified, including 238 Proteins not previously recognized to be located in the Outer Membrane. Analysis of their taxonomic distribution revealed an evolutionary conservation among Chlamydiae, Verrucomicrobia, Lentisphaerae and Planctomycetes as well as lifestyle-dependent conservation of the chlamydial Outer Membrane protein composition. This analysis suggested a correlation between the Outer Membrane protein composition and the host range of chlamydiae and revealed a common set of Outer Membrane Proteins shared by these intracellular bacteria. The collection of predicted chlamydial Outer Membrane Proteins is available at the online database pCOMP http://www.microbial-ecology.net/pcomp and might provide future guidance in the quest for anti-chlamydial vaccines.
Timothy L Cover - One of the best experts on this subject based on the ideXlab platform.
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analysis of surface exposed Outer Membrane Proteins in helicobacter pylori
Journal of Bacteriology, 2014Co-Authors: Bradley J Voss, Jennifer A Gaddy, Hayes W Mcdonald, Timothy L CoverAbstract:More than 50 Helicobacter pylori genes are predicted to encode Outer Membrane Proteins (OMPs), but there has been relatively little experimental investigation of the H. pylori cell surface proteome. In this study, we used selective biotinylation to label Proteins localized to the surface of H. pylori, along with differential detergent extraction procedures to isolate Proteins localized to the Outer Membrane. Proteins that met multiple criteria for surface-exposed Outer Membrane localization included known adhesins, as well as Cag Proteins required for activity of the cag type IV secretion system, putative lipoProteins, and other Proteins not previously recognized as cell surface components. We identified sites of nontryptic cleavage consistent with signal sequence cleavage, as well as C-terminal motifs that may be important for protein localization. A subset of surface-exposed Proteins were highly susceptible to proteolysis when intact bacteria were treated with proteinase K. Most Hop and Hom OMPs were susceptible to proteolysis, whereas Hor and Hof Proteins were relatively resistant. Most of the protease-susceptible OMPs contain a large protease-susceptible extracellular domain exported beyond the Outer Membrane and a protease-resistant domain at the C terminus with a predicted β-barrel structure. These features suggest that, similar to the secretion of the VacA passenger domain, the N-terminal domains of protease-susceptible OMPs are exported through an autotransporter pathway. Collectively, these results provide new insights into the repertoire of surface-exposed H. pylori Proteins that may mediate bacterium-host interactions, as well as the cell surface topology of these Proteins.
