| 1. |
- Fabrik, Ivo, et al.
(författare)
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Application of SILAC labeling to primary bone marrow-derived dendritic cells reveals extensive GM-CSF-dependent arginine metabolism
- 2014
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Ingår i: Journal of Proteome Research. - : American Chemical Society (ACS). - 1535-3893 .- 1535-3907. ; 13:2, s. 752-762
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Tidskriftsartikel (refereegranskat)abstract
- Although dendritic cells (DCs) control the priming of the adaptive immunity response, a comprehensive description of their behavior at the protein level is missing. The introduction of the into the field of DC research would therefore be highly beneficial. quantitative proteomic technique of metabolic labeling (SILAC) To achieve this, we applied SILAC labeling to primary bone marow-derived DCs (BMDCs). These cells combine both biological relevance and experimental feasibility, as their in vitro generation permits the use of C-13/N-15-labeled amino acids.. Interestingly, BMDCs appear to exhibit a very active arginine metabolism. Using standard cultivation conditions, similar to 20% of all protein-incorporated proline was a byproduct of heavy arginine degradation. In addition, the dissipation of N-15 from labeled arginine to the whole proteome was observed. The latter decreased the mass accuracy in MS and affected the natural isotopic distribution of peptides. SILAC-connected metabolic issues were shown to be enhanced by GM-CSF, which is used for the differentiation of DC progenitors. Modifications of the cultivation procedure suppressed the arginine-related effects, yielding cells with a proteome labeling efficiency of >= 90%. Importantly, BMDCs generated according to the new cultivation protocol preserved their resemblance to inflammatory DCs in vivo, as evidenced by their response to LPS treatment.
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| 2. |
- Härtlova, Anetta, et al.
(författare)
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Quantitative proteomics analysis of macrophage-derived lipid rafts reveals induction of autophagy pathway at the early time of Francisella tularensis LVS infection
- 2014
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Ingår i: Journal of Proteome Research. - : American Chemical Society (ACS). - 1535-3893 .- 1535-3907. ; 13:2, s. 796-804
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Tidskriftsartikel (refereegranskat)abstract
- Francisella tularensis is a highly infectious intracellular pathogen that has evolved an efficient strategy to subvert host defense response to survive inside the host. The molecular mechanisms regulating these host-pathogen interactions and especially those that are initiated at the time of the bacterial entry via its attachment to the host plasma membrane likely predetermine the intracellular fate of pathogen. Here, we provide the evidence that infection of macrophages with F. tularensis leads to changes in protein composition of macrophage-derived lipid rafts, isolated as detergent-resistant membranes (DRMs). Using SILAC-based quantitative proteomic approach, we observed the accumulation of autophagic adaptor protein p62 at the early, stages of microbe-host cell interaction. We confirmed the colocalization of the p62 with ubiquitinated and LC3-decorated intracellular F. tularensis microbes with its maximum at 1 h postinfection. Furthermore, the infection of p62-knockdown host cells led to the transient increase in the intracellular number of microbes up to 4 h after in vitro infection. Together, these data suggest that the activation of the autophagy pathway in F. tularensis infected macrophages, which impacts the early phase of microbial proliferation, is subsequently circumvented by ongoing infection.
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| 3. |
- Sheshko, Valeria, et al.
(författare)
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Utilization of a tetracycline-inducible system for high-level expression of recombinant proteins in Francisella tularensis LVS
- 2021
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Ingår i: Plasmid. - : Elsevier. - 0147-619X .- 1095-9890. ; 115
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Tidskriftsartikel (refereegranskat)abstract
- Francisella tularensis is a Gram-negative intracellular pathogen causing tularemia. A number of its potential virulence factors have been identified, but their biology and functions are not precisely known. Understanding the biological and immunological functions of these proteins requires adequate genetic tools for homologous and heterologous expression of cloned genes, maintaining both original structure and post-translational modifications. Here, we report the construction of a new multipurpose shuttle plasmid – pEVbr – which can be used for high-level expression in F. tularensis. The pEVbr plasmid has been constructed by modifying the TetR-regulated expression vector pEDL17 (LoVullo, 2012) that includes (i) a strong F. tularensis bfr promoter, and (ii) two tet operator sequences cloned into the promoter. The cloned green fluorescent protein (GFP), used as a reporter, demonstrated almost undetectable basal expression level under uninduced conditions and a highly dynamic dose-dependent response to the inducer. The utility of the system was further confirmed by cloning the gapA and FTT_1676 genes into the pEVbr vector and quantifying proteins expression in F. tularensis LVS, as well as by studying post-translational modification of the cloned genes. This study demonstrates that high levels of recombinant native-like Francisella proteins can be produced in Francisella cells. Hence, this system may be beneficial for the analysis of protein function and the development of new treatments and vaccines.
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| 4. |
- Straskova, Adela, et al.
(författare)
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Proteome analysis of an attenuated Francisella tularensis dsbA mutant : identification of potential DsbA substrate proteins
- 2009
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Ingår i: Journal of Proteome Research. - : American Chemical Society (ACS). - 1535-3893 .- 1535-3907. ; 8:11, s. 5336-5346
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Tidskriftsartikel (refereegranskat)abstract
- Francisella tularensis (F. tularensis) is highly infectious for humans via aerosol route and untreated infections with the highly virulent subsp. tularensis can be fatal. Our knowledge regarding key virulence determinants has increased recently but is still somewhat limited. Surface proteins are potential virulence factors and therapeutic targets, and in this study, we decided to target three genes encoding putative membrane lipoproteins in F. tularensis LVS. One of the genes encoded a protein with high homology to the protein family of disulfide oxidoreductases DsbA. The two other genes encoded proteins with homology to the VacJ, a virulence determinant of Shigella flexneri. The gene encoding the DsbA homologue was verified to be required for survival and replication in macrophages and importantly also for in vivo virulence in the mouse infection model for tularemia. Using a combination of classical and shotgun proteome analyses, we were able to identify several proteins that accumulated in fractions enriched for membrane-associated proteins in the dsbA mutant. These proteins are substrate candidates for the DsbA disulfide oxidoreductase as well as being responsible for the virulence attenuation of the dsbA mutant.
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