| 1. |
- Härtlova, Anetta, et al.
(author)
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A proteomic view of the host-pathogen interaction: The host perspective.
- 2011
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In: Proteomics. - : Wiley. - 1615-9861 .- 1615-9853. ; 11:15, s. 3212-20
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Research review (peer-reviewed)abstract
- The host-pathogen interaction represents a complex and dynamic biological system. The outcome of this interaction is dependent on the microbial pathogen properties to establish infection and the ability of the host to control infection. Although bacterial pathogens have evolved a variety of strategies to subvert host defense functions, several general mechanisms have been shown to be shared among these pathogens. As a result, host effectors that are critical for pathogen entry, survival and replication inside the host cells have become a new paradigm for antimicrobial targeting. This review focuses on the potential utility of a proteomics approach in defining the host-pathogen interaction from the host's perspective.
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| 2. |
- Härtlova, Anetta, et al.
(author)
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Membrane rafts: a potential gateway for bacterial entry into host cells.
- 2010
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In: Microbiology and immunology. - : Wiley. - 0385-5600 .- 1348-0421. ; 54:4, s. 237-45
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Research review (peer-reviewed)abstract
- Pathogenic bacteria have developed various mechanisms to evade host immune defense systems. Invasion of pathogenic bacteria requires interaction of the pathogen with host receptors, followed by activation of signal transduction pathways and rearrangement of the cytoskeleton to facilitate bacterial entry. Numerous bacteria exploit specialized plasma membrane microdomains, commonly called membrane rafts, which are rich in cholesterol, sphingolipids and a special set of signaling molecules which allow entry to host cells and establishment of a protected niche within the host. This review focuses on the current understanding of the raft hypothesis and the means by which pathogenic bacteria subvert membrane microdomains to promote infection.
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| 3. |
- Härtlova, Anetta, et al.
(author)
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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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In: Journal of Proteome Research. - : American Chemical Society (ACS). - 1535-3893 .- 1535-3907. ; 13:2, s. 796-804
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Journal article (peer-reviewed)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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| 4. |
- Krocova, Zuzana, et al.
(author)
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Interaction of B cells with intracellular pathogen Francisella tularensis.
- 2008
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In: Microbial pathogenesis. - : Elsevier BV. - 0882-4010. ; 45:2, s. 79-85
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Journal article (peer-reviewed)abstract
- Immunity to Francisella tularensis is largely mediated by T lymphocytes but an important role of B lymphocytes in early stage of infection was previously uncovered. We wanted to find out if F. tularensis is able to infect B cells and/or influence them by direct contact. To investigate this possibility we infected B cell lines from mouse (A20) or humans (Ramos RA-1), or primary mouse spleen cells, with F. tularensis LVS and F. tularensis FSC200 in vitro. In all cases, we detected bacteria on the cell surface and inside the B cells using transmission electron microscopy. More than 20% cells were infected by microbes after 24h. The number of bacteria, determined by CFU, increased about 1 log during 24h. Infection with live bacteria led to apoptosis of Ramos cells and mouse CD19(+) spleen cells. Approximately 30% of cells were apoptotic after 24h and 70% after 48 h, independently of the F. tularensis strain, while only 10% of non-infected cell were apoptotic at either time point. Apoptosis was confirmed by Western blot using anti-PARP antibodies. Thus, this study demonstrates unique phenomenon - namely, the ability of the intracellular pathogen F. tularensis to invade and induce apoptosis in B cells.
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| 5. |
- Straskova, Adela, et al.
(author)
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Proteome analysis of an attenuated Francisella tularensis dsbA mutant : identification of potential DsbA substrate proteins
- 2009
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In: Journal of Proteome Research. - : American Chemical Society (ACS). - 1535-3893 .- 1535-3907. ; 8:11, s. 5336-5346
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Journal article (peer-reviewed)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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| 6. |
- Zivna, Lucie, et al.
(author)
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Activation of B cell apoptotic pathways in the course of Francisella tularensis infection.
- 2010
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In: Microbial pathogenesis. - : Elsevier BV. - 1096-1208 .- 0882-4010. ; 49:5, s. 226-36
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Journal article (peer-reviewed)abstract
- Francisella tularensis is a facultative intracellular, gram-negative bacterium that induces apoptosis in macrophages and B cells. Here we show apoptotic pathways that are activated in the Ramos human B cell line in the course of F. tularensis infection. Live bacteria F. tularensis FSC200 activate caspases 8, 9 and 3, as well as Bid; release cytochrome c and apoptosis-inducing factor from mitochondria; and induce depolarization of mitochondrial membrane potential in the Ramos cell line, thus leading these cells to apoptosis. Unlike live bacteria, killed F. tularensis FSC200 bacteria activated only caspase 3, and did not cause apoptosis of Ramos cells as measured by annexin V. Killed bacteria also caused accumulation of anti-apoptotic protein Bclx(L) in mitochondrial membranes. Thus, live F. tularensis activates both caspase pathways (receptor-mediated and intrinsic) as well as caspase-independent mitochondrial death.
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