| 1. |
- Pihl, Maria, et al.
(författare)
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Effects of clinical isolates of Pseudomonas aeruginosa on Staphylococcus epidermidis biofilm formation
- 2010
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Ingår i: FEMS Immunology and Medical Microbiology. - : Wiley-Blackwell. - 0928-8244 .- 1574-695X. ; 59:3, s. 504-512
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Tidskriftsartikel (refereegranskat)abstract
- Pseudomonas aeruginosa is often found in chronic infections, including cystic fibrosis lung infections and those related to chronic wounds and venous ulcers. At the latter sites, P. aeruginosa can be isolated together with Staphylococcus epidermidis, and we have therefore explored the effect of clinical isolates and laboratory strains of P. aeruginosa strains on colonisation by S. epidermidis in dual-species biofilms. Biofilm formation was assayed using 16S rRNA fluorescence in situ hybridization and confocal laser scanning microscopy. Amongst the six P. aeruginosa strains tested, one particular strain, denoted 14:2, exerted a significant inhibitory effect and even after six hours, S. epidermidis levels in dual-species biofilms were reduced by more than 85% compared to biofilms without P. aeruginosa. Interestingly strain 14:2 was found to be negative for classical virulence determinants including pyocyanin, elastase and alkaline protease. Therefore, we suggest that less virulent phenotypes of P. aeruginosa which may develop over time in chronic infections, could counteract colonisation by S. epidermidis, ensuring persistence and dominance by P. aeruginosa in the host micro-habitat. Further studies are required to explain the inhibitory effect on S. epidermidis, although, extracellular polysaccharides produced by P. aeruginosa might play a role in this phenomenon.
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| 2. |
- Andersson, C., et al.
(författare)
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Protection against respiratory syncytial virus (RSV) elicited in mice by plasmid DNA immunisation encoding a secreted RSV G protein-derived antigen
- 2000
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Ingår i: FEMS Immunology and Medical Microbiology. - 0928-8244 .- 1574-695X. ; 29:4, s. 247-253
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Tidskriftsartikel (refereegranskat)abstract
- Plasmid vectors encoding two different variants, one cytoplasmic and one secreted version, of a candidate vaccine BBG2Na to respiratory syncytial virus (RSV), were constructed and evaluated in a nucleic acid vaccination study. The two different vectors, which employed the Semliki Forest virus gene amplification system, were found to express BBG2Na appropriately in in vitro cell cultures. Immunisation of mice with the plasmid vectors elicited significant serum anti-BBG2Na IgG responses only in the mice receiving the plasmid encoding the secreted version of BBG2Na. Consistent with antibody induction data, sterilising lung protection against RSV-A challenge was also only observed in this group. These results indicate that the targeting of antigen expression (intracellular versus secreted) would be an important factor to consider in the design of nucleic acid vaccines.
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| 3. |
- Strindhall, Jan, et al.
(författare)
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Variations among clinical isolates of Staphylococcus aureus to induce expression of E-selectin and ICAM-1 in human endothelial cells
- 2002
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Ingår i: FEMS Immunology and Medical Microbiology. - 0928-8244 .- 1574-695X. ; 32:3, s. 227-235
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Tidskriftsartikel (refereegranskat)abstract
- Eighteen clinical isolates of Staphylococcus aureus, nine methicillin-sensitive and nine methicillin-resistant, were investigated for their ability to induce expression of E-selectin and ICAM-1 in human endothelial cells. Upregulation of adhesion molecules varied between isolates; 17 isolates induced expression of E-selectin and 13 of ICAM-1. Some isolates induced a significant expression of E-selectin without stimulation of ICAM-1, whereas the opposite was not found. Bacterial viability was required for induction of the adhesion molecules. The kinetics of ICAM-1 expression in S. aureus-infected cells differed from those stimulated with interleukin-1β (IL-1β). On the other hand, expression of E-selectin was very similar in S. aureus-infected and IL-1β-stimulated cells. There was no correlation between ability of S. aureus to induce expression of cell adhesion molecules, methicillin susceptibility, pulse field gel electrophoresis patterns, biochemical characteristics, phage typing and toxin production.
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| 4. |
- Schöier, Johan, et al.
(författare)
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Chlamydia (Chlamydophila) pneumoniae-induced cell death in human coronary artery endothelial cells is caspase-independent and accompanied by subcellular translocations of Bax and apoptosis-inducing factor.
- 2006
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Ingår i: FEMS Immunology and Medical Microbiology. - 0928-8244 .- 1574-695X. ; 47:2, s. 207-216
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Tidskriftsartikel (refereegranskat)abstract
- Atherosclerosis and coronary heart disease are causing high morbidity and mortality worldwide. Different risk factors have been demonstrated, but the exact mechanisms behind these diseases are still not fully understood. Recent studies have suggested Chlamydia pneumoniae to be involved in the pathogenesis, and increased apoptotic indexes in atherosclerotic plaques have been documented. In this study, we show that C. pneumoniae induces apoptosis and necrosis in populations of human coronary artery endothelial cells. Apoptosis was determined by TUNEL and flow cytometry after staining of cells with annexin V and propidium iodide, and defined as TUNEL-reactive or annexin V-positive, propidium iodide-negative cells. The apoptosis was induced within 2 h postinfection and increased with inoculation dose. The general caspase inhibitor z-VAD-fmk did not affect apoptotic frequencies. By immunochemistry and immunoblot, we demonstrated activation and subcellular translocation of the proapoptotic protein Bax, and translocation of apoptosis-inducing factor from the cytosol to the nucleus. These results indicate that C. pneumoniae-induced apoptosis in human coronary artery endothelial cells is caspase-independent and regulated by Bax and apoptosis-inducing factor.
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| 5. |
- Bjarnsholt, Thomas, et al.
(författare)
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Understanding biofilms : are we there yet?
- 2012
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Ingår i: FEMS Immunology and Medical Microbiology. - 0928-8244 .- 1574-695X. ; 65:2, s. 125-126
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
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| 6. |
- Eberhard, Thomas, et al.
(författare)
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Interaction of vitronectin with Haemophilus influenzae
- 2002
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Ingår i: FEMS Immunology and Medical Microbiology. - 0928-8244 .- 1574-695X. ; 34:3, s. 215-219
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Tidskriftsartikel (refereegranskat)abstract
- Eight strains of Haemophilus influenzae were tested for binding to human vitronectin. All strains adhered to vitronectin-coated glass slides but no binding was detected using soluble vitronectin, suggesting that surface association of vitronectin is a prerequisite. Vitronectin binding was not likely to be mediated by fimbriae as non-fimbriated and fimbriated isogenic strains adhered equally. Adhesion could be blocked by heparin, which is also known to block vitronectin binding to Staphylococcus aureus. However, no blocking was achieved with sialic acid-rich glycoproteins such as fetuin and mucin contrasting with Helicobacter pylori for which sialic acid seems to play an important role. With Streptococcus pneumoniae binding was detected both with soluble and surface-associated vitronectin and could not be blocked by heparin. Our results suggest that H. influenzae, Streptococcus pneumoniae and Helicobacter pylori all use distinct modes to interact with vitronectin.
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| 7. |
- Engström, Patrik, 1982-, et al.
(författare)
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A comparative study of RNA and DNA as internal gene expression controls early in the developmental cycle of Chlamydia pneumoniae
- 2010
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Ingår i: FEMS Immunology and Medical Microbiology. - 0928-8244 .- 1574-695X. ; 58:2, s. 244-253
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Tidskriftsartikel (refereegranskat)abstract
- Many microbial pathogens invade and proliferate within host cells and the molecular mechanism underlying this behavior is currently being revealed for several bacterial species. Testing clinically relevant antibacterial compounds and elucidating their effects on gene expression requires adequate controls, especially when studying genetically intractable organisms such as Chlamydia spp., for which various gene fusions cannot be constructed. Until now, relative mRNA levels in Chlamydia have been measured using different internal gene expression controls, including 16S rRNA, mRNAs, and DNA. Here, we compared the advantages and disadvantages of various internal expression controls during the early phase of Chlamydia pneumoniae development. The relative abundance of target mRNAs varied using the different internal control RNAs. This was partly due to variation in the transcript stability of the RNA species. Also, seven out of nine of the analyzed RNAs increased fivefold or more between 2 and 14 h postinfection, while the amount of DNA and number of cells remained essentially unaltered. Our results suggest that RNA should not be used as a gene expression control during the early phase of Chlamydia development, and that intrinsic bacterial DNA is preferable for that purpose because it is stable, abundant, and its relative amount is generally correlated with bacterial numbers.
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| 8. |
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| 9. |
- Karlsson, Mattias, 1981-, et al.
(författare)
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Substances released from probiotic Lactobacillus rhamnosus GR-1 potentiate NF-κB activity in Escherichia coli-stimulated urinary bladder cells
- 2012
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Ingår i: FEMS Immunology and Medical Microbiology. - Hoboken, USA : Wiley-Blackwell. - 0928-8244 .- 1574-695X. ; 66:2, s. 147-156
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Tidskriftsartikel (refereegranskat)abstract
- Lactobacillus rhamnosus GR-1 is a probiotic bacterium used to maintain urogenital health. The putative mechanism for its probiotic effect is by modulating the host immunity. Urinary tract infections (UTI) are often caused by uropathogenic Escherichia coli that frequently evade or suppress immune responses in the bladder and can target pathways, including nuclear factor-kappaB (NF-κB). We evaluated the role of L. rhamnosus GR-1 on NF-κB activation in E. coli-stimulated bladder cells. Viable L. rhamnosus GR-1 was found to potentiate NF-κB activity in E. coli-stimulated T24 bladder cells, whereas heat-killed lactobacilli demonstrated a marginal increase in NF-κB activity. Surface components released by trypsin- or LiCl treatment, or the resultant heat-killed shaved lactobacilli, had no effect on NF-κB activity. Isolation of released products from L. rhamnosus GR-1 demonstrated that the induction of NF-κB activity was owing to released product(s) with a relatively large native size. Several putative immunomodulatory proteins were identified, namely GroEL, elongation factor Tu and NLP/P60. GroEL and elongation factor Tu have previously been shown to elicit immune responses from human cells. Isolating and using immune-augmenting substances produced by lactobacilli is a novel strategy for the prevention or treatment of UTI caused by immune-evading E. coli.
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| 10. |
- Maripuu, Linda, et al.
(författare)
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Superantigen gene profile diversity among clinical group A streptococcal isolates.
- 2008
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Ingår i: FEMS Immunology and Medical Microbiology. - 0928-8244 .- 1574-695X. ; 54:2, s. 236-44
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Tidskriftsartikel (refereegranskat)abstract
- This study examines the diversity of superantigen gene profiles between and within emm-genotypes of 92 clinical group A streptococcal isolates (30 STSS, 24 sepsis, 25 erysipelas, and 12 tonsillitis) collected in Sweden between 1986 and 2001. The emm-genotype and the distribution of smeZ, speG, speJ, speA, speC, speH, speI, speK/L, speL/M, speM, and ssa genes, and the smeZ allelic variant were determined using PCR and DNA sequencing. Forty-five emm1 isolates revealed 10 superantigen gene profiles. One profile dominated and was identified in 22 isolates collected over 14 years. The results indicate that a selective advantage maintained this genotype in circulation. The superantigen content among the emm1 isolates ranged from three to seven, with smeZ-1, speG, and speA present in all but one profile. The 47 isolates of 27 other emm-genotypes exhibited 29 superantigen gene profiles. Thus, the distribution of superantigen genes was highly variable within isolates regardless of emm-genotype. Two novel emm1 subtypes and 14 novel smeZ allelic variants were identified. The 22 smeZ alleles were generally linked to the emm-genotype. The results of the investigation show that superantigen gene profiling is useful for tracking spread of clones in the community.
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| 11. |
- Pedersen, Lisbeth Nørum, et al.
(författare)
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Typing Chlamydia trachomatis : from egg yolk to nanotechnology
- 2009
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Ingår i: FEMS Immunology and Medical Microbiology. - 0928-8244 .- 1574-695X. ; 55:2, s. 120-130
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Forskningsöversikt (refereegranskat)abstract
- A historical review is provided of the various methods used for half a century to differentiate and type Chlamydia trachomatis strains. Typing of C. trachomatis is an important tool for revealing transmission patterns in sexual networks, and enabling association with clinical manifestations and pathogenicity. Serotyping using the major outer membrane protein (MOMP) has been the mainstay of epidemiological work for several decades. However, the development of nucleic acid amplification techniques (NAAT) and easy access to sequencing have shifted the focus from MOMP serotypes to omp1 genotypes. However, insufficient epidemiological resolution is achieved by characterization of both MOMP and omp1. This calls for new high-resolution genotyping methods applying for example a multilocus variable number tandem repeat assay (MLVA) or multilocus sequence typing (MLST). The futuristic nanotechnology already seems at hand to further simplify and automate the high-resolution genotyping method based on NAAT and sequencing of various targets in the C. trachomatis genome. Thereby, a high throughput can be achieved and more epidemiological information can be obtained. However, it is important to realize that culture of C. trachomatis may still be needed to detect and characterize new variants of C. trachomatis.
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| 12. |
- Pihl, Maria, et al.
(författare)
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Differential effects of Pseudomonas aeruginosa on biofilm formation by different strains of Staphylococcus epidermidis.
- 2010
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Ingår i: FEMS Immunology and Medical Microbiology. - : Wiley-Blackwell. - 0928-8244 .- 1574-695X. ; 46:3, s. 439-446
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Tidskriftsartikel (refereegranskat)abstract
- Pseudomonas aeruginosa and Staphylococcus epidermidis are common opportunistic pathogens associated with medical device-related biofilm infections. 16S rRNA fluorescence in situ hybridization and confocal scanning laser microscopy were used to study these two bacteria in dual-species biofilms. We have shown that fresh isolates of S. epidermidis form biofilms more avidly on polymer surfaces than laboratory strains. In dual-species biofilms the presence of P. aeruginosa reduced biofilm formation by S. epidermidis, although the different clinical isolates differed in their susceptibility to this effect. The most resistant fresh isolate coexisted with P. aeruginosa for up to 18 hours and was also resistant to the effects of culture supernatant from P. aeruginosa biofilms which caused dispersal of other S. epidermidis strains from established biofilms. Thus, different strains of S. epidermidis differed in their capacity to withstand the action of P. aeruginosa, with some fresh isolates being better equipped than laboratory strains to coexist in biofilms with P. aeruginosa. Our data suggest that where S. epidermidis and P. aeruginosa are present on abiotic surfaces such as medical devices, S. epidermidis biofilm-formation can be inhibited by P. aeruginosa through two mechanisms: disruption by extracellular products, possibly polysaccharides, and, in the later stages, by cell lysis.
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| 13. |
- Wilsson, Åsa, et al.
(författare)
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Apoptotic neutrophils containing Staphylococcus epidermidis stimulate macrophages to release the proinflammatory cytokines tumor necrosis factor-a and interleukin-6
- 2008
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Ingår i: FEMS Immunology and Medical Microbiology. - : Oxford University Press. - 0928-8244 .- 1574-695X. ; 53:1, s. 126-135
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Tidskriftsartikel (refereegranskat)abstract
- Staphylococcus epidermidis infections are usually nosocomial and involve colonization of biomaterials. The immune defense system cannot efficiently control the bacteria during these infections, which often results in protracted chronic inflammation, in which a key event is disturbed removal of neutrophils by tissue macrophages. While ingesting uninfected apoptotic neutrophils, macrophages release anti-inflammatory cytokines that lead to resolution of inflammation. In clinical studies, we have previously found elevated levels of the proinflammatory cytokines tumor necrosis factor-alpha (TNF-a) and interleukin-6 in synovial fluid from prostheses infected with coagulase negative staphylococci. We show that macrophages phagocytosing apoptotic neutrophils containing S. epidermidis released TNF-a and interleukin-6, whereas macrophages phagocytosing spontaneously apoptotic neutrophils did not. This difference was not due to dissimilar phagocytic capacities, because macrophages ingested both types of neutrophils to the same extent. The activation was induced mainly by the apoptotic neutrophils themselves, not by the few remaining extracellular bacteria. Macrophages were not activated by apoptotic neutrophils that contained paraformaldehyde-killed S. epidermidis. Proinflammatory reactions induced by clearance of apoptotic neutrophils containing S. epidermidis might represent an important mechanism to combat the infective agent. This activation of macrophages may contribute to the development of chronic inflammation instead of inflammation resolution. © 2008 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.
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| 14. |
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| 15. |
- Andersen, LP, et al.
(författare)
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Gastric inflammatory markers and interleukins in patients with functional dyspepsia, with and without Helicobacter pylori infection
- 2005
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Ingår i: Pathogens and Disease. - : Oxford University Press (OUP). - 2049-632X. ; 44:2, s. 233-238
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Tidskriftsartikel (refereegranskat)abstract
- Helicobacter pylori is the most important cause of gastritis, peptic ulcers and the development of gastric cancer. The chronic active inflammation is dominated by neutrophils, macrophages, lymphocytes and plasma cells. Several interleukins (IL-8, IL-10 and IFN-gamma) are involved in the inflammatory process in the gastric mucosa. The aim of this study was to investigate the gastric inflammation in patients with functional dyspepsia. Fifty-three consecutive patients were included and antral biopsies were obtained for histology, culture and immunohistochemistry. The sections were examined for the interleukins IL-4, IL-6, IL-8, IL-10 and IFN-gamma as well as for the cell markers CD4, CD8, CD14, U19, CD25 and CD30. Only CD4 and CD19 were significantly increased in patients with increased gastric inflammation and increased density of H. pylori. However, several of the examined markers (IFN-gamma, IL-8, IL-10 and CD14) showed a non-significant trend to be increased in patients with extensive gastric inflammation and high density of H. pylori. Therefore, an arbitrary index (IM11) for all the 11 immunological markers was made as an average value for each of the four morphological groups. For the four morphologically different groups of patients the values were 0.49, 0.77, 0.86 and 1.25, respectively. Significant increases in the index from none to moderate antral inflammation as well as the density of H. pylori were found (p < 0.001). By using an index of inflammatory markers trends can be summarized and thereby significant which may be of importance when gastric inflammation is investigated in children and patients with functional dyspepsia. (c) 2004 Federation of European Microbiological Societies.
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| 16. |
- Bergin, Philip, 1975, et al.
(författare)
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Secretion of matrix metalloproteinase-9 by macrophages, in vitro, in response to Helicobacter pylori.
- 2005
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Ingår i: FEMS immunology and medical microbiology. - : Oxford University Press (OUP). - 0928-8244 .- 1574-695X. ; 45:2, s. 159-69
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Forskningsöversikt (refereegranskat)abstract
- We have previously shown that matrix metalloproteinase-9 (MMP-9) activity is greatly enhanced within the active chronic inflammation of Helicobacter pylori infected individuals, of which a major fraction derives from macrophages in the tissue. Here, we have investigated the ability of macrophages to secrete MMPs in response to H. pylori. Human macrophages secrete MMP-9 in response to live and inactivated H. pylori, as well as to specific bacterial products. Protein kinase C, phosphatiolylinositol 3-kinase and calcium uptake channels all play a role in MMP-9 secretion, whereas neither tumour necrosis factor alpha, interleukin-8, nor interleukin-1beta autocrine stimulation appear to contribute. We conclude that human macrophages have the ability to react directly against several H. pylori derived factors, utilising several signalling pathways.
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| 17. |
- Elgh, Fredrik, 1957-, et al.
(författare)
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Development of humoral cross-reactivity to the nucleocapsid protein of heterologous hantaviruses in nephropathia epidemica.
- 1998
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Ingår i: FEMS Immunology and Medical Microbiology. - 0928-8244 .- 1574-695X. ; 22:4, s. 309-15
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Tidskriftsartikel (refereegranskat)abstract
- A hantavirus infection is followed by a prominent antibody response to the viral nucleocapsid protein. Antibodies from patients infected with one hantavirus cross-react to varying degrees with the nucleocapsid protein of other viruses of the genus. We studied the cross-reactivity in serially obtained blood samples from 17 patients with nephropathia epidemica, a European form of hemorrhagic fever with renal syndrome caused by Puumala virus. Recombinant truncated nucleocapsid protein (aa 1-117) of Puumala virus and four other hantaviruses, Hantaan, Seoul, Dobrava and Sin Nombre viruses, were used as antigens in an indirect ELISA. In most patients, an IgG response to the Puumala virus derived recombinant protein was detected within 2-8 days of onset of disease, remained high for 2-5 months, and declined gradually within 2-3 years. All patients had IgG antibodies cross-reacting with the nucleocapsid protein of Sin Nombre virus. The ratio of the ELISA values obtained with Sin Nombre vs. Puumala virus protein as antigen increased with time after onset of disease. To a lesser extent, cross-reacting IgG antibodies also occurred to Hantaan, Seoul, and Dobrava virus antigens. In the acute phase of the disease, two patients showed IgG antibodies to one or more of these viruses whereas 2-5 months later, 11 of 16 patients had IgG antibodies to all three viruses. IgM and IgA responses to the nucleocapsid protein of Puumala virus were transitory and cross-reactivities were weak. In conclusion, after onset of nephropathia epidemica the IgG response to the Puumala virus nucleocapsid protein was associated with a gradually increasing cross-reactivity to the nucleocapsid protein of heterologous hantavirus. Our findings have implications for the interpretation of serological data, both in the diagnostics of nephropathia epidemica and in seroprevalence studies.
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| 18. |
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| 19. |
- Janulaityte-Gunther, D, et al.
(författare)
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Helicobacter pylori antibodies and gastric cancer: a gender-related difference
- 2005
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Ingår i: Pathogens and Disease. - : Oxford University Press (OUP). - 2049-632X. ; 44:2, s. 191-195
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Tidskriftsartikel (refereegranskat)abstract
- Helicobacter pylori has been proposed as a causative agent of gastric cancer. The aim of this study was to define serum antibodies response against different H. pylori antigens in patients with gastric cancer. Serum samples were collected from 115 Lithuanian patients with non-cardia gastric cancer and 110 age- and sex-matched controls without cancer. Heat-stable, low-molecular-mass, and outer membrane proteins were used as antigens to analyze serum IgG antibody response against H. pylori by enzyme-linked immunosorbent assay. Seroprevalence of H. pylori using low-molecular-mass antigen was significantly higher in gastric cancer patients, compared to controls (77% versus 57%, p < 0.05). Significant differences in the prevalence of H. pylori infection between gastric cancer patients and controls were found in females using all three studied antigens: heat-stable (98% versus 84%, p < 0.05), low-molecular-mass (88% versus 48%, p < 0.05) and outer membrane proteins (78% versus 57%, p < 0.05). In males, no significant differences were revealed between gastric cancer patients and controls. There may be other cofactors in addition to H. pylori that are important for the development of gastric cancer. H. pylori seems, however, to be a more important for development of gastric cancer in females than in males or males may have more confounding risk factors for gastric cancer than females.
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| 20. |
- Janulaityte-Gunther, D, et al.
(författare)
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The humoral immune response to Helicobacter pylori infection in children with gastrointestinal symptoms
- 2005
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Ingår i: Pathogens and Disease. - : Oxford University Press (OUP). - 2049-632X. ; 44:2, s. 205-212
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Tidskriftsartikel (refereegranskat)abstract
- The prevalence of Helicobacter pylori is high in Eastern Europe. The purpose of this study was to estimate the prevalence of H. pylori in symptomatic Lithuanian children and to identify the infection by clinicopathological and serological analyses. One hundred sixteen symptomatic children (age 8-16) with gastritis and duodenal ulcer were included. Biopsies were histologically assessed according to the Sydney-System. Serum IgG antibodies against H. pylori were detected by an enzyme-linked immunosorbent assay (ELISA), using low molecular mass antigen. The western blot technique was used to detect serum antibodies against the cytotoxin-associated protein (CagA) using whole cell antigen. Histologically the prevalence of H. pylori infection was 79% and not influenced by demographic factors. Mucosal inflammation and atrophy were associated with a H. pylori infection. Intestinal metaplasia was found in eight children, suggesting early H. pylori acquisition in life. Increased levels of IgG antibodies were detected in 57% of children. The prevalence of IgG antibodies was significantly higher in patients with duodenal ulcer compared to children with gastritis. Forty-four (67%) H. pylori-seropositive children had antibodies against CagA. Low molecular weight-ELISA and whole cell-western blot results were significantly associated with histopathology, the presence of duodenal ulcer and the CagA status. A high number of false seronegative cases were due to poor immunological responses in children and poor locally validated tests. The prevalence of H. pylori infection in Lithuanian children is higher compared to Western Europe. The infection is acquired in early life. Diagnosing H. pylori infection, serology is helpful, but endoscopy/histology remains as gold standard.
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| 21. |
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| 22. |
- Rasti, N, et al.
(författare)
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Molecular aspects of malaria pathogenesis
- 2004
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Ingår i: FEMS immunology and medical microbiology. - : Oxford University Press (OUP). - 0928-8244 .- 1574-695X. ; 41:1, s. 9-26
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Tidskriftsartikel (refereegranskat)
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| 23. |
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| 24. |
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| 25. |
- Rudnicka, W, et al.
(författare)
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Helicobacter pylori lipopolysaccharide in the IL-2 milieu activates lymphocytes from dyspeptic children
- 2003
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Ingår i: FEMS Immunology and Medical Microbiology (Helicobacter Pathogenesis and Immunology. Selected papers). - 2049-632X .- 0928-8244. ; 36:3, s. 141-145
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Konferensbidrag (refereegranskat)abstract
- In this study, we assessed the proliferative response of peripheral blood mononuclear leukocytes (PBML) from 33 children/young adolescents with chronic dyspepsia, to H. pylori LPS in the presence and absence of IL-2 as a T cell growth factor. A rapid urease test (RUT) and a presence of Helicobacter-like organisms (HLO) in the biopsy specimens allowed us to distinguish RUT/HLO-positive (17/33) and -negative (16/33) patients. H. pylori LPS alone induced a proliferation of PBML from 4 out of 33 dyspeptic patients. IL-2 increased the prevalence of the response to LPS to 59% and 74% of RUT/HLO-positive and -negative patients, respectively. PBML from RUT/HLO-positive patients responded significantly less intensively to H. pylori LPS in the presence of IL-2, to IL-2 alone and to H. pylori LPS+IL-2. However, there was no difference in PHA-driven proliferation of PBML from the patients of those two groups. A negative correlation between the responsiveness to H. pylori LPS of PBML and occurrence of type B inflammation in gastric mucosa was demonstrated. The results suggest a contribution of H. pylori LPS to an outcome of H. pylori infection. It is speculated that H. pylori LPS by an activation of immunocompetent cells may reduce gastric inflammation, decrease bacterial load and prolong H. pylori infection. (C) 2003 Federation of European Microbiological Societies. Published by Elsevier Science B.V. All rights reserved.
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| 26. |
- Bogefors, Jesper, et al.
(författare)
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Reduced tonsillar expression of human β-defensin 1, 2 and 3 in allergic rhinitis.
- 2012
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Ingår i: FEMS Immunology and Medical Microbiology. - 1574-695X. ; 65:3, s. 431-438
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Tidskriftsartikel (refereegranskat)abstract
- Airway infections are known to cause exacerbations of allergy and asthma. Tonsils constitute a primary site for microbial recognition and triggering of the immune system in the airways. Human β-defensins (HBDs) are antimicrobial peptides with an important role in this defense. Our aim was to investigate HBD1-3 in tonsillar tissue and their potential role in allergic rhinitis (AR). Tonsils, obtained from patients with AR and non-allergic controls, and isolated tonsillar CD4(+) , CD8(+) and CD19(+) lymphocytes were analyzed for HBD1-3 expression using real-time RT-PCR and/or immunohistochemistry. Tonsillar tissue, mixed tonsillar lymphocytes and airway epithelial cells (AECs) were cultured with or without IL-4, IL-5, IL-13 or histamine followed by measurements of HBD1-3 release using ELISA. HBD1-3 were present in tonsillar tissue, including epithelial, CD4(+) , CD8(+) and CD19(+) cells. The expression was reduced in allergic compared to healthy tonsils. Stimulation of AECs with IL-4, IL-5 and histamine down-regulated the HBD release, whereas no effects were seen in cultured tonsils or lymphocytes. This study demonstrates presence of HBD1-3 in tonsils and that the levels are reduced in patients with AR. Together with the down-regulation of HBDs in epithelial cells in the presence of allergic mediators suggest that AR patients have an impaired antimicrobial defense that might make them more susceptible to respiratory tract infections. © 2012 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.
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| 27. |
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| 28. |
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| 29. |
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| 30. |
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| 31. |
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| 32. |
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| 33. |
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| 34. |
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| 35. |
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| 36. |
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| 37. |
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| 38. |
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| 39. |
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| 40. |
- Bergin, Philip, 1975, et al.
(författare)
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Gastric gelatinase B/matrix metalloproteinase-9 is rapidly increased in Helicobacter felis-induced gastritis.
- 2008
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Ingår i: FEMS immunology and medical microbiology. - 0928-8244. ; 52:1, s. 88-98
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Tidskriftsartikel (refereegranskat)abstract
- It has previously been shown that matrix metalloproteinase-9 (MMP-9) levels, originating from macrophages, are considerably increased in human Helicobacter pylori-associated gastritis. Here, the early kinetics of the MMP-9 response resulting from Helicobacter infection in C57BL/6 and MMP-9 knock-out mice using the murine Helicobacter felis model were examined. H. felis infection induced severe gastritis in the murine stomach at just 2 weeks after infection. Before gastritis, an increase was observed in MMP-9-positive cells detected by immunohistochemistry in the basal lamina propria. This finding was corroborated by gelatin zymography of stomach samples. As the gastritis increased so did the concentration of MMP-9 and the incidence of gastric MMP-9-positive cells, their location corresponding to that of macrophages. In contrast, systemic levels of MMP-9 remained unchanged. When MMP-9-deficient mice were infected with H. felis, no significant difference in gastritis development was detected compared with disease development in wild-type animals. We conclude that MMP-9 production is an early event in the response to gastric Helicobacter infection, a feature that may favor the recruitment of immune cells early during infection. At later stages, however, the increased levels of MMP-9 may damage the integrity of the stomach mucosa.
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| 41. |
- Bhuiyan, Taufiqur Rahman, 1974, et al.
(författare)
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Comparison of mucosal B- and T-cell responses in Helicobacter pylori-infected subjects in a developing and a developed country.
- 2008
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Ingår i: FEMS immunology and medical microbiology. - 0928-8244. ; 54:1, s. 70-9
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Tidskriftsartikel (refereegranskat)abstract
- Helicobacter pylori is highly endemic in developing countries, but comparatively little is known about mucosal immune responses to H. pylori in these settings. Therefore, we have compared B- and T-cell responses, with a focus on the gastrointestinal mucosa, in H. pylori-infected adults in a developing (Bangladesh) and a developed (Sweden) country. We found comparable numbers of CD19(+) B cells and CD4 (+)T cells and similar levels of H. pylori-specific IgA antibodies in gastric mucosa from Bangladeshi and Swedish volunteers. However, about threefold higher numbers of CD19(+) B cells and 12-fold increased levels of H. pylori-specific IgA antibodies were found in the duodenum of Bangladeshi subjects. The gastric and duodenal immune responses in Bangladeshi asymptomatic carriers and duodenal ulcer patients were comparable. Bangladeshi subjects had about twofold lower titers of H. pylori-specific IgA and IgG antibodies in the circulation compared with Swedish volunteers. In conclusion, our findings suggest that Bangladeshi individuals have comparable gastric immune responses, but lower systemic antibody responses to H. pylori, compared with Swedish volunteers. Increased inflammation is present in the duodenum of Bangladeshi volunteers, maybe as a result of frequent exposure to enteric infections in these individuals.
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| 42. |
- Bryborn, Malin, et al.
(författare)
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Differentiated S100A7 expression in infected tonsils and tonsils from allergic individuals.
- 2008
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Ingår i: Pathogens and Disease. - 2049-632X. ; 53:3, s. 413-420
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Tidskriftsartikel (refereegranskat)abstract
- Palatine tonsils are continuously exposed to microorganisms and antigens and secrete antimicrobial peptides as a first line of defense. S100A7 is a protein with antimicrobial and chemotactic properties. Our aim was to investigate how the expression of S100A7 in human palatine tonsils is affected by inflammatory processes. Tonsils obtained from 109 patients undergoing tonsillectomy were divided into groups of infected and noninfected as well as allergic and nonallergic, based on the results from tonsillar core culture tests and Phadiatop analysis, respectively. Western blot and immunohistochemistry were used to assess protein expression and real-time PCR was used to quantify mRNA levels. To explore the induction of S100A7, tonsils were stimulated with lipopolysaccharide in vitro. The immunohistochemical staining for S100A7 was most intense in the tonsillar epithelium, but the protein was also detected in B- and T-cell regions, which was confirmed with Western blot on isolated B and T cells. The S100A7 expression appeared to be the highest in CD8(+) T cells. Reduced mRNA levels of S100A7 were detected in infected tonsils as well as in tonsils from allergic individuals. In vitro stimulation of tonsils with lipopolysaccharide did not have any effect on the expression. The results suggest a role for S100A7 in recurrent tonsillitis and allergic disease.
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