| 1. |
- Bielig, H, et al.
(författare)
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NOD-like receptor activation by outer-membrane vesicles (OMVs) from non-O1 non-O139 Vibrio cholerae is modulated by the quorum sensing regulator HapR
- 2011
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Ingår i: Infection and Immunity. - : American Society for Microbiology. - 0019-9567 .- 1098-5522. ; 79:4, s. 1418-1427
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Tidskriftsartikel (refereegranskat)abstract
- Vibrio cholerae is an inhabitant of aquatic systems and one of the causative agents of severe dehydrating diarrhea in humans. It has also emerged as an important cause of different kinds of inflammatory responses and in particular, V. cholerae strains of the non-O1 non-O139 serogroups (NOVC) have been associated with such infections in human. We analyzed the potential of outer membrane vesicles (OMVs) derived from the NOVC strain V:5/04 to induce inflammatory responses in human host cells. V:5/04 OMVs were taken up by human epithelial cells and induced inflammatory responses. siRNA-mediated gene knock-down revealed that the inflammatory potential of NOVC OMVs was partially mediated by the nucleotide-binding domain, leucine rich repeat containing family member NOD1. Physiochemical analysis of the content of these OMVs, in conjunction with NOD1 and NOD2 reporter assays in HEK293T cells, confirmed the presence of both NOD1 and NOD2 active peptidoglycan in the OMVs. Furthermore, we show that deletion of the quorum sensing regulator HapR which mimics an infective life style, specifically reduced the inflammatory potential of the V:5/04 OMVs and their ability to activate NOD1 and NOD2. In conclusion, our study shows that NOVC OMVs elicit immune responses mediated by NOD1 and NOD2 in mammalian host cells. Moreover, we provide evidence that the quorum sensing machinery plays an important regulatory role in this process by attenuating the inflammatory potential of OMVs in infective conditions. This work thus identified a new facet of how Vibrio affects host immune responses and defines a role for the quorum sensing machinery in this process.
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| 2. |
- Pollnau, Markus, et al.
(författare)
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Combined microfluidic-optical DNA analysis with single-base-pair sizing capability
- 2016
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Ingår i: Biomedical Optics Express. - : Optical Society of America. - 2156-7085. ; 7:12, s. 5201-5207
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Tidskriftsartikel (refereegranskat)abstract
- DNA sequencing by microchip capillary electrophoresis (CE) enables cheap, highspeed analysis of low reagent volumes. One of its potential applications is the identification of genomic deletions or insertions associated with genetic illnesses. Detecting single base-pair insertions or deletions from DNA fragments in the diagnostically relevant size range of 150−1000 base-pairs requires a variance of σ2 < 10−3. In a microfluidic chip post-processed by femtosecond-laser writing of an optical waveguide we CE-separated 12 blue-labeled and 23 red-labeled DNA fragments in size. Each set was excited by either of two lasers powermodulated at different frequencies, their fluorescence detected by a photomultiplier, and blue and red signals distinguished by Fourier analysis. We tested different calibration strategies. Choice of the fluorescent label as well as the applied fit function strongly influence the obtained variance, whereas fluctuations between two consecutive experiments are less detrimental in a laboratory environment. We demonstrate a variance of σ2 ≈4 × 10−4, lower than required for the detection of single base-pair insertion or deletion in an optofluidic chip.
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| 3. |
- Shanbhag, S., et al.
(författare)
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Ectopic Bone Tissue Engineering in Mice Using Human Gingiva or Bone Marrow-Derived Stromal/Progenitor Cells in Scaffold-Hydrogel Constructs
- 2021
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Ingår i: Frontiers in Bioengineering and Biotechnology. - : Frontiers Media S.A.. - 2296-4185. ; 9
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Tidskriftsartikel (refereegranskat)abstract
- Three-dimensional (3D) spheroid culture can promote the osteogenic differentiation and bone regeneration capacity of mesenchymal stromal cells (MSC). Gingiva-derived progenitor cells (GPC) represent a less invasive alternative to bone marrow MSC (BMSC) for clinical applications. The aim of this study was to test the in vivo bone forming potential of human GPC and BMSC cultured as 3D spheroids or dissociated cells (2D). 2D and 3D cells encapsulated in constructs of human platelet lysate hydrogels (HPLG) and 3D-printed poly (L-lactide-co-trimethylene carbonate) scaffolds (HPLG-PLATMC) were implanted subcutaneously in nude mice; cell-free HPLG-PLATMC constructs served as a control. Mineralization was assessed using micro-computed tomography (µCT), histology, scanning electron microscopy (SEM) and in situ hybridization (ISH). After 4–8 weeks, µCT revealed greater mineralization in 3D-BMSC vs. 2D-BMSC and 3D-GPC (p < 0.05), and a similar trend in 2D-GPC vs. 2D-BMSC (p > 0.05). After 8 weeks, greater mineralization was observed in cell-free constructs vs. all 2D- and 3D-cell groups (p < 0.05). Histology and SEM revealed an irregular but similar mineralization pattern in all groups. ISH revealed similar numbers of 2D and 3D BMSC/GPC within and/or surrounding the mineralized areas. In summary, spheroid culture promoted ectopic mineralization in constructs of BMSC, while constructs of dissociated GPC and BMSC performed similarly. The combination of HPLG and PLATMC represents a promising scaffold for bone tissue engineering applications.
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