| 1. |
- Fallgren, Corina, et al.
(författare)
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Isolation and characterisation of a 17-kDa staphylococcal heparin-binding protein with broad specificity
- 2001
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Ingår i: Journal of Medical Microbiology. - 0022-2615. ; 50:6, s. 547-557
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Tidskriftsartikel (refereegranskat)abstract
- A previous study reported the ability of staphylococci to bind heparin and heparin-dependent host growth factors. The present study isolated and identified heparin- and basic fibroblast growth factor (bFGF)-binding surface components of S. epidermidis strain RP12 and S. haemolyticus strain SM 131. The staphylococcal heparin-binding component(s) were purified by affinity chromatography on heparin-Sepharose and a major heparin-binding protein, here designated HBP, was identified by immunoblot in these two coagulase-negative staphylococcal (CNS) species. The HBP was shown to be acidic with an approximate pI of 4.6 and a molecular mass around 17 kDa. The binding of heparin to HBP was inhibited by heparin, fucoidan, pentosan polysulphate and various other sulphated polysaccharides, but not by non-sulphated compounds. However, the purified HBP from both S. epidermidis and S. haemolyticus revealed broad specificity, and also bound bFGF, thrombospondin, von Willebrand factor and, weakly, fibrinogen. The N-terminal sequences of the 17-kDa HBP from S. epidermidis and S. haemolyticus showed only limited identity. Comparison of the first 15 amino acid residues derived from either strain with known sequences in the protein databases revealed no close similarities. Taken together, these results suggest that the adhesion of at least some CNS to host sulphated glycosaminoglycans may be mediated by a previously uncharacterised group of surface proteins.
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| 2. |
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| 3. |
- Kornilovska, Iryna, et al.
(författare)
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Immunogenic proteins of Helicobacter pullorum, Helicobacter bilis and Helicobacter hepaticus identified by two-dimensional gel electrophoresis and immunoblotting.
- 2002
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Ingår i: Proteomics. - 1615-9861. ; 2:6, s. 775-783
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Tidskriftsartikel (refereegranskat)abstract
- The ecological niches occupied by various species of Helicobacter are not yet known and the full spectrum of diseases associated with Helicobacter infections are not yet defined. Since these fastidious microaerofilic bacteria require special growth conditions new and improved molecular and serologic diagnostic methods have been developed to increase our understanding of their pathogenesis and virulence characteristics. Immunogenic cell surface proteins of Helicobacter pullorum, Helicobacter bilis, and Helicobacter hepaticus were characterised by proteomic techniques using two-dimensional electrophoresis and immunoblotting with antisera from immunised rabbits. Cross-reactivity between the three Helicobacter species were analysed after a four-step cross-absorption experiment. For H. pullorum, H. bilis and H. hepaticus 21, 13 and 27 specific immunogenic proteins, respectively, were identified. These proteins could be of important sero-diagnostic value for analyses of sera from humans, laboratory animals and for the veterinarian field.
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| 4. |
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| 5. |
- Nilsson, Ingrid, et al.
(författare)
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Separation and surveys of proteins of Helicobacter pylori.
- 2002
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Ingår i: Journal of Chromatography. B. - 1873-376X. ; 771:1-2, s. 251-260
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Forskningsöversikt (refereegranskat)abstract
- The analysis of Helicobacter pylori proteins is a demanding task for the elucidation of virulence factors, antigens and vaccines, all important for diagnosis, therapy and protection. In the "pre-genomic era" the purification of proteins was mostly performed by using various techniques such as detergent treatment of the bacterial cells, ultra-centrifugation, various chromatographic methods, antibody detection, N-terminal sequence determination and finally cloning and identification of the corresponding gene. In this review, the most representative methods used for purification, separation and identification of H. pylori proteins will be presented as well as some important developments in the "post-genomic era" that have improved the performance of these characterisation techniques.
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| 6. |
- Oona, M, et al.
(författare)
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Helicobacter pylori infection in children in Estonia: Decreasing seroprevalence during the 11-year period of profound socioeconomic changes
- 2004
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Ingår i: Helicobacter. - : Wiley. - 1083-4389 .- 1523-5378. ; 9:3, s. 233-241
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Tidskriftsartikel (refereegranskat)abstract
- Background. The prevalence of Helicobacter pylori infection is inversely associated with socioeconomic conditions in childhood. In Estonia, a high prevalence of H. pylori infection has been observed among children born in 1987 and earlier. Since 1991, after the dissolution of the USSR, profound social and economic changes have taken place in the country. The aim of the study was to evaluate changes in the seroprevalence of H. pylori infection among children in the period 1991-2002. Materials and Methods. The hospital-based study population consisted of two groups of children enrolled in 1991 (n = 425) and 2002 (n = 296) according to the same inclusion criteria. The immunoglobulin G antibodies to the cell surface proteins of H. pylori were determined by enzyme-linked immunosorbent assay, and the sera with the borderline results were analyzed by immunoblot analysis. Multiple regression analysis was used to determine the associations between H. pylori seropositivity and different variables such as demographic characteristics, diagnoses and year of enrolment. Results. The only two variables linked independently to H. pylori serostatus were age and year of enrolment: the adjusted odds of being H. pylori seropositive were 1.92 [95% confidence interval (CI) 1.33-2.76] times higher for the children enrolled in 1991 compared with the children enrolled in 2002. The age-standardized seroprevalence rate was 42.2% (95% CI 37.4-47.0%) for the group of 1991 and 28.1% (95% CI 23.1-33.6%) for the group of 2002. Conclusion. The prevalence of H. pylori infection among children has significantly decreased during the 11-year period of profound socioeconomic changes in Estonia.
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| 7. |
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| 8. |
- Teesalu, Kaupo, et al.
(författare)
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A modified ELISA for improved detection of IgA, IgG, and IgM anti-tissue transglutaminase antibodies in celiac disease
- 2009
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Ingår i: Clinica Chimica Acta. - : Elsevier BV. - 0009-8981. ; 403:1-2, s. 37-41
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Tidskriftsartikel (refereegranskat)abstract
- Background: Serum IgA antibodies against tissue transglutaminase (tTG) are reliable markers for celiac disease (CD), still the diagnostic performance of anti-tTG immunoassays can be improved. A novel ELISA, using fibronectin (FN) as tTG binding protein, was evaluated for the detection of anti-tTG antibodies in CD. Methods: Sera from 173 children with untreated CD and 97 controls were analyzed for IgA, IgG, and IgM anti-tTG antibodies with ELISA using human recombinant tTG with or without FN. Results: The areas under the ROC (receiver operating characteristic) curves were significantly higher for FN/tTG ELISA compared to tTG ELISA for IgG (0.930 versus 0.809; p < 0.001) and IgM (0.850 versus 0.811; p = 0.019), but not for IgA (0.977 versus 0.970; p = 0.356), respectively. At the fixed diagnostic specificity (100% for IgA and IgM, 99% for IgG), the sensitivity of all three FN/tTG ELISA (92.5% for IgA, 60.7% for IgG, 50.3% for IgM) exceeded those obtained in tTG ELISA (89.0% for IgA, 48.6% for IgG, 38.7% for IgM; p < 0.05). The combined use of IgA- and IgG-FN/tTG ELISA resulted in 95.4% sensitivity and 99.0% specificity for CD. Conclusions: Using FN to bind tTG improves the diagnostic performance of solid phase anti-tTG antibody assays for childhood CD. (C) 2009 Elsevier B.V. All rights reserved.
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| 9. |
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| 10. |
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| 11. |
- Utt, Meeme
(författare)
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Helicobacter pylori cell surface interactions with glycosaminoglycans. Identification and characterisation of proteins binding to heparin/heparan sulphate.
- 2002
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Helicobacter pylori is a gastric pathogen which cause chronic type B gastritis and peptic ulcer disease. H. pylori produces virulence factors such as urease, vacuolating cytotoxin VacA, cag pathogenicity island-associated proteins, flagella and adhesins. These proteins interact with several host cell molecules such as sialylated cell surface glycoproteins, some of glycolipids and mucins. Glycosaminoglycans are widely distributed molecules in human cells and extracellular matrix and interact with H. pylori cell surface proteins. Heparan sulphate shows a pH-dependent binding to all strains, which is inhibited by sulphated glycosaminoglycans and other polysulphated molecules such as dextran sulphate and fucoidan. Using bioinformatics methods, the binding of H. pylori VacA cytotoxin to heparin and heparan sulphate was predicted. Specific peptides were synthesised and their interactions with surface-immobilised heparan sulphate studied in a BIAcore biosensor. Synthetic peptides bound to heparan sulphate with a moderate affinity. It was shown that native toxin interacts with immobilised heparin. Heparan sulphate was proposed as a receptor/co-receptor for VacA cytotoxin binding to host cell surfaces. H. pylori urease binds to surface-immobilised heparin and heparan sulphate. The interaction was characterised using a BIAcore biosensor. The binding was a thousand-fold higher at pH 5.5 compared to pH 6.5. The binding epitopes were identified by SELDI-TOF MS technology. Using a proteomic technology, four immunogenic heparin-binding proteins were identified: cell binding factor 2, urease, one outer membrane protein and one hypothetical protein. The binding of three of these proteins to heparin was demonstrated for the first time. The cell binding factor was identified as a specific and highly immunogenic H. pylori surface protein. 2-DE and 2-D immunoblotting allow efficient separation and identification of immunogenic proteins. Understanding how GAGs interact with pathogens, will allow the design of new experimental putative anti-microbial compounds based on sulphated polysaccharide structures.
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| 12. |
- Utt, Meeme, et al.
(författare)
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Identification of novel immunogenic proteins of Helicobacter pylori by proteome technology.
- 2002
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Ingår i: Journal of Immunological Methods. - 1872-7905. ; 259:1-2, s. 1-10
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Tidskriftsartikel (refereegranskat)abstract
- Cell surface proteins of the human gastric pathogen Helicobacter pylori, reference strain CCUG 17874, were extracted with acid glycine and fractionated by heparin affinity chromatography. The extracts were subsequently analysed using high-resolution two-dimensional gel electrophoresis (2-DE) and immunoblotting. Four proteins of low molecular masses (25-30 kDa) stained by Coomassie R-350, were identified by peptide ESI-MS/MS sequencing after in-gel tryptic digestion. The identified proteins were recognised by sera from H. pylori-infected patients. Two of them are now described for the first time as immunogenic proteins of which one protein was determined to be distinct from all H. pylori proteins previously described. In addition, the specificity of the identified peptides was evaluated using both 1-D and 2-D immunoblotting against a panel of sera from patients with various bacterial infections. The present identification of highly specific antigens of H. pylori will encourage the improvement of serological diagnostic tests to diagnose and monitor H. pylori infection.
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| 13. |
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| 14. |
- Vorobjova, Tamara, et al.
(författare)
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Seropositivity to Helicobacter pylori heat shock protein 60 is strongly associated with intensity of chronic inflammation, particularly in antrum mucosa: an extension of an 18-year follow-up study of chronic gastritis in Saaremaa, Estonia
- 2001
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Ingår i: Pathogens and Disease. - 2049-632X. ; 30:2, s. 143-149
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Tidskriftsartikel (refereegranskat)abstract
- Helicobacter pylori is a cause of chronic gastritis and leads to development of atrophy in some cases. There is evidence that the heat shock protein 60 (HSP60) of H. pylori is involved in induction of chronic inflammation. Seroprevalence of IgG antibodies to H. pylori HSP60 in an adult cohort from Saaremaa, Estonia (68 persons, median age 57 years), with a high prevalence of antibodies to cell surface proteins of H. pylori (92%) and a well characterized dynamics of chronic gastritis in an 18-year follow-up study, was tested using purified H. pylori HSP60 at a concentration of 1 microg ml(-1) with ELISA. The state of the gastric mucosa and the presence of H. pylori in histological sections in the samples of 1979 and 1997 were assessed in accordance with the Sydney system. Seropositivity for H. pylori HSP60 was 65%. Immunological response to H. pylori HSP60 is associated with the morphological presence of H. pylori in the antrum and corpus (P=0.01) and is strongly correlated with the grade of chronic inflammation, particularly in the antrum mucosa (r=0.34; P=0.003; OR=5.97 (95% CI 1.21-29.3)), but is not associated with development of atrophy during 18 years of follow-up, or with the activity of gastritis. This finding supports the evidence that immunological response to H. pylori HSP60 may play a role in triggering of the inflammatory process in the gastric mucosa.
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