Publications by authors named "Tursi S"

The major biofilm pathway in Salmonella enterica serovar Typhimurium involves specific growth conditions that induce the csgA gene whose product forms surface curli fibers that mediate biofilm formation. We have found that the previously uncharacterized STM1266 gene in S. Typhimurium plays a role in regulating biofilm formation via the curli pathway.

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The bacterial amyloid curli, produced by Enterobacteriales including species and , is implicated in the pathogenesis of several complex autoimmune diseases. Curli binds to extracellular DNA, and these complexes drive autoimmunity production of anti-double-stranded DNA autoantibodies. Here, we investigated immune activation by phenol-soluble modulins (PSMs), the amyloid proteins expressed by species.

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Objective: Infections contribute to morbidity and mortality in systemic lupus erythematosus (SLE). Uropathogenic Escherichia coli (UPEC) are known to trigger urinary tract infections (UTIs) and form biofilms, which are multicellular communities of bacteria that are strengthened by amyloids such as curli. We previously reported that curli naturally form complexes with bacterial extracellular DNA (eDNA), and these curli/eDNA complexes induce hallmark features of lupus in mouse models.

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Reactive arthritis, an autoimmune disorder, occurs following gastrointestinal infection with invasive enteric pathogens, such as Salmonella enterica. Curli, an extracellular, bacterial amyloid with cross beta-sheet structure can trigger inflammatory responses by stimulating pattern recognition receptors. Here we show that S.

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Biofilms exist in complex environments, including the intestinal tract, as a part of the gastrointestinal microbiota. The interaction of planktonic bacteria with biofilms can be influenced by material properties of the biofilm. During previous confocal studies, we observed that amyloid curli-containing serotype Typhimurium and biofilms appeared rigid.

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Bacterial biofilms, especially those associated with implanted medical devices, are difficult to eradicate. Curli amyloid fibers are important components of the biofilms formed by the Enterobacteriaceae family. Here, we show that a human monoclonal antibody with pan-amyloid-binding activity (mAb 3H3) can disrupt biofilms formed by Salmonella enterica serovar Typhimurium in vitro and in vivo.

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Sepsis is a leading cause of morbidity and mortality in intensive care units. Previously, we identified Protein Kinase C-delta (PKCδ) as an important regulator of the inflammatory response in sepsis. An important issue in development of anti-inflammatory therapeutics is the risk of immunosuppression and inability to effectively clear pathogens.

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produce amyloid proteins called curli that are the major proteinaceous component of biofilms. Amyloids are also produced by humans and are associated with diseases such as Alzheimer's. During the multistep process of amyloid formation, monomeric subunits form oligomers, protofibrils, and finally mature fibrils.

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No data are available on the specific energy needs of patients affected with Urea Cycle disorders (UCD) and especially argininosuccinic aciduria (ASA). In our experience, ASA patients tend to develop central adiposity and hypertriglyceridemia when treated with apparently adequate energy intake, while the other UCD do not. The aim of this study was to evaluate anthropometric parameters, body composition, risk of metabolic syndrome (MS) and resting energy expenditure (REE), both by indirect calorimetry (IC) and predictive equations, in UCD patients.

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Article Synopsis
  • The study explores how the immune system affects gut bacteria, specifically how STAT2-dependent type I interferon signaling creates an environment that helps harmful bacteria like S. Typhimurium thrive.
  • In experiments with Stat2-/- mice (lacking STAT2), the researchers found these mice had less bacterial presence and different inflammatory responses compared to wild-type mice, despite both groups showing similar inflammation levels.
  • The findings suggest that without STAT2, there is less disruption in the gut's oxygen levels and a more balanced microbiota, indicating that STAT2 plays a crucial role in fostering conditions that favor pathogenic bacteria during infections.
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Biofilms of enteric bacteria are highly complex, with multiple components that interact to fortify the biofilm matrix. Within biofilms of enteric bacteria such as and species, the main component of the biofilm is amyloid curli. Other constituents include cellulose, extracellular DNA, O antigen, and various surface proteins, including BapA.

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The cytokine IFN-γ has well-established antibacterial properties against the bacterium in phagocytes, but less is known about the effects of IFN-γ on -infected nonphagocytic cells, such as intestinal epithelial cells (IECs) and fibroblasts. In this article, we show that exposing human and murine IECs and fibroblasts to IFN-γ following infection with triggers a novel form of cell death that is neither pyroptosis nor any of the major known forms of programmed cell death. Cell death required IFN-γ-signaling via STAT1-IRF1-mediated induction of guanylate binding proteins and the presence of live in the cytosol.

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Bacterial biofilms are associated with numerous human infections. The predominant protein expressed in enteric biofilms is the amyloid curli, which forms highly immunogenic complexes with DNA. Infection with curli-expressing bacteria or systemic exposure to purified curli-DNA complexes triggers autoimmunity via the generation of type I interferons (IFNs) and anti-double-stranded DNA antibodies.

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Article Synopsis
  • Disruption of the epithelial barrier can cause inflammation in the intestines, and the activation of TLR2 by microbial amyloid proteins, like curli, can help maintain gut integrity and health.
  • Research using mouse models showed that treatment with curli from both pathogenic and beneficial bacteria increased IL-10 levels, an important cytokine for intestinal health, and improved colitis symptoms.
  • The findings suggest that bacterial amyloids could be a promising new treatment for intestinal inflammatory diseases, as they help regulate immune responses through the TLR2/IL-10 pathway.
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Article Synopsis
  • - Amyloids, which are protein structures linked to diseases like Alzheimer's and Parkinson's, also play a role in bacteria forming biofilms, with specific focus on bacterial amyloids known as curli fibers.
  • - The study demonstrated that curli fibers activate the NLRP3 inflammasome, leading to the release of interleukin 1β (IL-1β) without causing cell death in macrophages.
  • - The activation mechanism involves the Toll-like receptor 2 (TLR2), indicating an interaction between TLR2 and NLRP3 in the immune response to bacterial amyloids.
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