| 1. |
- Elmarghani, Ahmed, 1975-, et al.
(författare)
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Contribution of pharmaceuticals, fecal bacteria and endotoxin to the inflammatory responses to inland waters
- 2014
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Ingår i: Science of the Total Environment. - : Elsevier. - 0048-9697 .- 1879-1026. ; 488-489, s. 228-235
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Tidskriftsartikel (refereegranskat)abstract
- The increasing contamination of freshwater with pharmaceuticals, surfactants, pesticides and other organic compounds are of major concern. As these contaminants are detected at trace levels in the environment it is important to determine if they elicit biological responses at the observed levels. In addition to chemical pollutants, there is also a concern for increasing levels of bacteria and other microorganisms in freshwater systems. In an earlier study, we observed the activation of inflammatory systems downstream of a wastewater treatment plant (WWTP) in southern Sweden. We also observed that the water contained unidentified components that were pro-inflammatory and potentiated the immune response in human urinary bladder epithelial cells. In order to determine if these effects were unique for the studied site or represent a common response in Swedish water, we have now performed a study on three WWTPs and their recipient waters in central Sweden. Analysis of immune responses in urinary bladder epithelial cells, monocyte-like cells and blood mononuclear cells confirm that these waters activate the immune system as well as induce pro-inflammatory responses. The results indicate that the cytokine profiles correlate to the endotoxin load of the waters rather than to the levels of pharmaceuticals or culturable bacteria load, suggesting that measurements of endotoxin levels and immune responses would be a valuable addition to the analysis of inland waters.
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| 2. |
- Jacobsen, Annette, et al.
(författare)
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Reference gene selection for qPCR Is dependent on cell type rather than treatment in colonic and vaginal human epithelial cell lines
- 2014
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Ingår i: PLOS ONE. - San Fransisco, USA : Punlic Library of Science. - 1932-6203. ; 9:12, s. e115592-
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Tidskriftsartikel (refereegranskat)abstract
- The ability of commensal bacteria to influence gene expression in host cells under the influence of pathogenic bacteria has previously been demonstrated, however the extent of this interaction is important for understanding how bacteria can be used as probiotics. Real-time quantitative polymerase chain reaction is the most sensitive tool for evaluating relative changes to gene expression levels. However as a result of its sensitivity an appropriate method of normalisation should be used to account for any variation incurred in preparatory experimental procedures. These variations may result from differences in the amount of starting material, quality of extracted RNA, or in the efficiency of the reverse transcriptase or polymerase enzymes. Selection of an endogenous control gene is the preferred method of normalisation, and ideally a proper validation of the gene's appropriateness for the study in question should be performed. In this study we used quantitative polymerase chain reaction data and applied four different algorithms (geNorm, BestKeeper, NormFinder, and comparative ΔCq) to evaluate eleven different genes as to their suitability as endogenous controls for use in studies involving colonic (HT-29) and vaginal (VK2/E6E7) human mucosal epithelial cells treated with probiotic and pathogenic bacteria. We found phosphoglycerate kinase 1 to be most appropriate for HT-29 cells, and ribosomal protein large P0 to be the best choice for VK2/E6E7 cells. We also showed that use of less stable reference genes can lead to less accurate quantification of expression levels of gene of interest (GOI) and also can result in decreased statistical significance for GOI expression levels when compared to control. Additionally, we found the cell type being analysed had greater influence on reference gene selection than the treatment performed. This study provides recommendations for stable endogenous control genes for use in further studies involving colonic and vaginal cell lines after bacterial challenge.
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| 3. |
- Karlsson, Mattias, 1981-, et al.
(författare)
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Lactobacilli differently regulate expression and secretion of CXCL8 in urothelial cells
- 2012
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Ingår i: Beneficial Microbes. - : Wageningen Academic Publishers. - 1876-2883 .- 1876-2891. ; 3:3, s. 195-203
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Tidskriftsartikel (refereegranskat)abstract
- Modulation of the immune response is an established feature of certain lactobacilli. CXCL8 is an inflammatory chemokine released by the urinary tract mucosa after contact with uropathogenic Escherichia coli during urinary tract infection and is crucial for proper infiltration of immune cells. Nevertheless, persistently high levels of CXCL8 are associated with pathogenicity and malignancy. In this study, we tested twelve Lactobacillus strains for their ability to influence CXCL8 release from urothelial cells. We evaluated how strains from different Lactobacillus species could regulate CXCL8 in human 5637 urothelial cells, either resting cells or cells concomitantly challenged with heat-killed E. coli. A majority of the tested species altered CXCL8 release from the urothelial cells after 24 hours of stimulation. Most species increased CXCL8 release, whereas a few lactobacilli efficiently suppressed CXCL8 secretion from E. coli-challenged cells. While strong CXCL8 modulators such as Lactobacillus reuteri and Lactobacillus delbrueckii were unable to degrade CXCL8 in the extracellular environment, effects on IL8 transcription were evident for selected lactobacilli. Although IL8 transcription was affected by lactobacilli, the influence on mRNA transcript did not correlate to the impact on CXCL8 release. Phylogenetic analysis based on a 16S rRNA dendrogram of the tested lactobacilli and their effect on CXCL8 revealed some linkage to specific Lactobacillus groups. Testing the immunomodulatory nature of lactobacilli can prove important when selecting new probiotic microbes. Moreover, we believe that phylogenetic and phenotypic similarities could be used to analyse the traits governing such modulation.
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| 4. |
- 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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| 5. |
- Khalaf, Hazem, 1981-, et al.
(författare)
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The role of calcium, NF-κB and NFAT in the regulation of CXCL8 and IL-6 expression in Jurkat T-cells
- 2013
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Ingår i: International Journal of Biochemistry and Molecular Biology. - 2152-4114. ; 4:3, s. 150-156
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Tidskriftsartikel (refereegranskat)abstract
- T-cells play an important role in host immunity against invading pathogens. Determining the underlying regulatory mechanisms will provide a better understanding of T-cell-derived immune responses. In this study, we have shown the differential regulation of IL-6 and CXCL8 by NF-κB and NFAT in Jurkat T-cells, in response to PMA, heat killed Escherichia coli and calcium. CXCL8 was closely associated with the activation pattern of NFAT, while IL-6 expression was associated with NF-κB. Furthermore, increasing the intracellular Ca(2+) concentration by calcium ionophore treatment of the cells resulted in NFAT induction without affecting the NF-κB activity. Interestingly, NF-κB activation by heat killed E. coli, as well as CXCL8 and IL-6 expression was significantly suppressed following addition of the calcium ionophore. This indicates that calcium plays an important role in regulating protein trafficking and T-cell signalling, and the subsequent inflammatory gene expression infers an involvement of NFAT in CXCL8 regulation.Understanding these regulatory patterns provide clarification of conditions that involve altered intracellular signalling leading to T-cell-derived cytokine expression.
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| 6. |
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| 7. |
- Rahman, Aminur, 1984-, et al.
(författare)
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Isolation and characterization of a Lysinibacillus strain B1-CDA showing potential for bioremediation of arsenics from contaminated water
- 2014
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Ingår i: Journal of Environmental Science and Health. Part A. - : Taylor & Francis. - 1093-4529 .- 1532-4117. ; 49:12, s. 1349-1360
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Tidskriftsartikel (refereegranskat)abstract
- The main objective of this study was to identify and isolate arsenic resistant bacteria that can be used for removing arsenic from thecontaminated environment. Here we report a soil borne bacterium, B1-CDA that can serve this purpose. B1-CDA was isolated fromthe soil of a cultivated land in Chuadanga district located in the southwest region of Bangladesh. The morphological, biochemicaland 16S rRNA analysis suggested that the isolate belongs to Lysinibacillus sphaericus. The minimum inhibitory concentration (MIC)value of the isolate is 500 mM (As) as arsenate. TOF-SIMS and ICP-MS analysis confirmed intracellular accumulation and removalof arsenics. Arsenic accumulation in cells amounted to 5.0 mg g¡1 of the cells dry biomass and thus reduced the arsenicconcentration in the contaminated liquid medium by as much as 50%. These results indicate that B1-CDA has the potential forremediation of arsenic from the contaminated water. We believe the benefits of implementing this bacterium to efficiently reducearsenic exposure will not only help to remove one aspect of human arsenic poisoning but will also benefit livestock and native animalspecies. Therefore, the outcome of this research will be highly significant for people in the affected area and also for humanpopulations in other countries that have credible health concerns as a consequence of arsenic-contaminated water.
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