| 1. |
- Webster, Steve J., et al.
(författare)
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Detection of a microbial metabolite by STING regulates inflammasome activation in response to Chlamydia trachomatis infection
- 2017
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Ingår i: PLoS Pathogens. - : Public Library Science. - 1553-7366 .- 1553-7374. ; 13:6
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Tidskriftsartikel (refereegranskat)abstract
- The innate immune system is a critical component of host defence against microbial pathogens, but effective responses require an ability to distinguish between infectious and noninfectious insult to prevent inappropriate inflammation. Using the important obligate intracellular human pathogen Chlamydia trachomatis; an organism that causes significant immunopathology, we sought to determine critical host and pathogen factors that contribute to the induction of inflammasome activation. We assayed inflammasome activation by immunoblotting and ELISA to detect IL-1 beta processing and LDH release to determine pyroptosis. Using primary murine bone marrow derived macrophages or human monocyte derived dendritic cells, infected with live or attenuated Chlamydia trachomatis we report that the live organism activates both canonical and non-canonical inflammasomes, but only canonical inflammasomes controlled IL-1 beta processing which preceded pyroptosis. NADPH oxidase deficient macrophages were permissive to Chlamydia trachomatis replication and displayed elevated type-1 interferon and inflammasome activation. Conversely, attenuated, non-replicating Chlamydia trachomatis, primed but did not activate inflammasomes and stimulated reduced type-1 interferon responses. This suggested bacterial replication or metabolism as important factors that determine interferon responses and inflammasome activation. We identified STING but not cGAS as a central mediator of interferon regulated inflammasome activation. Interestingly, exogenous delivery of a Chlamydia trachomatis metabolite and STING ligand D cyclic di-AMP, recovered inflammasome activation to attenuated bacteria in a STING dependent manner thus indicating that a bacterial metabolite is a key factor initiating inflammasome activation through STING, independent of cGAS. These data suggest a potential mechanism of how the innate immune system can distinguish between infectious and non-infectious insult and instigate appropriate immune responses that could be therapeutically targeted.
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| 2. |
- Figiel, Sandy, et al.
(författare)
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Spatial transcriptomic analysis of virtual prostate biopsy reveals confounding effect of tissue heterogeneity on genomic signatures
- 2023
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Ingår i: Molecular Cancer. - : Springer Nature. - 1476-4598. ; 22:1, s. 162-
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Genetic signatures have added a molecular dimension to prognostics and therapeutic decision-making. However, tumour heterogeneity in prostate cancer and current sampling methods could confound accurate assessment. Based on previously published spatial transcriptomic data from multifocal prostate cancer, we created virtual biopsy models that mimic conventional biopsy placement and core size. We then analysed the gene expression of different prognostic signatures (OncotypeDx®, Decipher®, Prostadiag®) using a step-wise approach with increasing resolution from pseudo-bulk analysis of the whole biopsy, to differentiation by tissue subtype (benign, stroma, tumour), followed by distinct tumour grade and finally clonal resolution. The gene expression profile of virtual tumour biopsies revealed clear differences between grade groups and tumour clones, compared to a benign control, which were not reflected in bulk analyses. This suggests that bulk analyses of whole biopsies or tumour-only areas, as used in clinical practice, may provide an inaccurate assessment of gene profiles. The type of tissue, the grade of the tumour and the clonal composition all influence the gene expression in a biopsy. Clinical decision making based on biopsy genomics should be made with caution while we await more precise targeting and cost-effective spatial analyses.
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| 3. |
- Guabiraba, Rodrigo, et al.
(författare)
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Mechanisms of type I interferon production by chicken TLR21
- 2024
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Ingår i: Developmental and comparative immunology. - 1879-0089. ; 151
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Tidskriftsartikel (refereegranskat)abstract
- The innate immune response relies on the ability of host cells to rapidly detect and respond to microbial nucleic acids. Toll-like receptors (TLRs), a class of pattern recognition receptors (PRRs), play a fundamental role in distinguishing self from non-self at the molecular level. In this study, we focused on TLR21, an avian TLR that recognizes DNA motifs commonly found in bacterial genomic DNA, specifically unmethylated CpG motifs. TLR21 is believed to act as a functional homologue to mammalian TLR9. By analysing TLR21 signalling in chickens, we sought to elucidate avian TLR21 activation outputs in parallel to that of other nucleic acid species. Our analyses revealed that chicken TLR21 (chTLR21) triggers the activation of NF-κB and induces a potent type-I interferon response in chicken macrophages, similar to the signalling cascades observed in mammalian TLR9 activation. Notably, the transcription of interferon beta (IFNB) by chTLR21 was found to be dependent on both NF-κB and IRF7 signalling, but independent of the TBK1 kinase, a distinctive feature of mammalian TLR9 signalling. These findings highlight the conservation of critical signalling components and downstream responses between avian TLR21 and mammalian TLR9, despite their divergent evolutionary origins. These insights into the evolutionarily conserved mechanisms of nucleic acid sensing contribute to the broader understanding of host-pathogen interactions across species.
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| 4. |
- Hepburn, Lucy, et al.
(författare)
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A Spaetzle-like role for nerve growth factor beta in vertebrate immunity to Staphylococcus aureus
- 2014
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Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 346:6209, s. 641-646
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Tidskriftsartikel (refereegranskat)abstract
- Many key components of innate immunity to infection are shared between Drosophila and humans. However, the fly Toll ligand Spaetzle is not thought to have a vertebrate equivalent. We have found that the structurally related cystine-knot protein, nerve growth factor β (NGFβ), plays an unexpected Spaetzle-like role in immunity to Staphylococcus aureus infection in chordates. Deleterious mutations of either human NGFβ or its high-affinity receptor tropomyosin-related kinase receptor A (TRKA) were associated with severe S. aureus infections. NGFβ was released by macrophages in response to S. aureus exoproteins through activation of the NOD-like receptors NLRP3 and NLRP4 and enhanced phagocytosis and superoxide-dependent killing, stimulated proinflammatory cytokine production, and promoted calcium-dependent neutrophil recruitment. TrkA knockdown in zebrafish increased susceptibility to S. aureus infection, confirming an evolutionarily conserved role for NGFβ-TRKA signaling in pathogen-specific host immunity.
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| 5. |
- Verrill, Clare, et al.
(författare)
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Altered expression of epithelial-to-mesenchymal transition proteins in extraprostatic prostate cancer.
- 2015
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Ingår i: Oncotarget. - : Impact Journals, LLC. - 1949-2553.
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Tidskriftsartikel (refereegranskat)abstract
- Epithelial to mesenchymal transition (EMT) of cancer cells involves loss of epithelial polarity and adhesiveness, and gain of invasive and migratory mesenchymal behaviours. EMT occurs in prostate cancer (PCa) but it is unknown whether this is in specific areas of primary tumours. We examined whether any of eleven EMT-related proteins have altered expression or subcellular localisation within the extraprostatic extension component of locally advanced PCa compared with other localisations, and whether similar changes may occur in in vitro organotypic PCa cell cultures and in vivo PCa models. Expression profiles of three proteins (E-cadherin, Snail, and α-smooth muscle actin) were significantly different in extraprostatic extension PCa compared with intra-prostatic tumour, and 18/27 cases had an expression change of at least one of these three proteins. Of the three significantly altered EMT proteins in pT3 samples, one showed similar significantly altered expression patterns in in vitro organotypic culture models, and two in in vivo Pten-/- model samples. These results suggest that changes in EMT protein expression can be observed in the extraprostatic extension component of locally invasive PCa. The biology of some of these changes in protein expression may be studied in certain in vitro and in vivo PCa models.
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