A5005685657- Helicobacter pylori-related gastroenterology studies
- Galectins and Cancer Biology
- Toxin Mechanisms and Immunotoxins
- Veterinary medicine and infectious diseases
- Clostridium difficile and Clostridium perfringens research
- Neutrophil, Myeloperoxidase and Oxidative Mechanisms
- Nanoparticle-Based Drug Delivery
- Immune Response and Inflammation
- Nitric Oxide and Endothelin Effects
- Transgenic Plants and Applications
- Microbial Inactivation Methods
- Botulinum Toxin and Related Neurological Disorders
- Nanoplatforms for cancer theranostics
- Bacterial Infections and Vaccines
- Microbial Metabolites in Food Biotechnology
- Antimicrobial Peptides and Activities
- Biochemical Acid Research Studies
- Eosinophilic Esophagitis
- Immunotherapy and Immune Responses
- Pneumonia and Respiratory Infections
- Complement system in diseases
- Biochemical and Structural Characterization
- Gastroesophageal reflux and treatments
- Immune cells in cancer
- Photodynamic Therapy Research Studies
University of Padua
2015-2025
Scuola Normale Superiore
2024
University of Bari Aldo Moro
1999-2014
Novartis (Italy)
2009
University of Verona
1984-1999
Medical Research Council
1999
University of Bristol
1999
University of Siena
1991-1998
Iris Vernici (Italy)
1998
MRC Laboratory for Molecular Cell Biology
1995
Helicobacter pylori has been associated with gastritis, peptic ulcer, and gastric adenocarcinoma. We report the nucleotide sequence expression of an immunodominant antigen H. immune response to during disease. The antigen, named CagA (cytotoxin-associated gene A), is a hydrophilic, surface-exposed protein 128 kDa produced by most clinical isolates. size cagA its varies in different strains mechanism that involves duplication regions within gene. Clinical isolates do not produce have are...
The effects of the vacuolating toxin (VacA) released by pathogenic strains Helicobacter pylori on several polarized epithelial monolayers were investigated. Trans-epithelial electric resistance (TER) formed canine kidney MDCK I, human gut T84, and murine mammary gland epH4, was lowered acid-activated VacA. Independent cell type starting TER value, VacA reduced it to a minimal value 1,000-1,300 Omega x cm2. decrease paralleled three- fourfold increase [14C]-mannitol (molecular weight 182.2)...
Pathogenic strains of Helicobacter pylori cause progressive vacuolation and death epithelial cells. To identify the nature vacuoles, distribution markers various membrane traffic compartments was studied. Vacuoles derive from endocytic pathway since they include fluid-phase marker Lucifer yellow. Early endosome such as rab5, transferrin, transferrin receptor, well lysosomal hydrolase cathepsin D, are excluded these structures. In contrast, vacuolar is specifically stained by...
The protein toxin VacA, produced by cytotoxic strains of Helicobacter pylori, causes a vacuolar degeneration cells, which eventually die. VacA is strongly activated short exposure to acidic solutions in the pH 1.5-5.5 range, followed neutralization. Activated has different CD and fluorescence spectra limited proteolysis fragmentation pattern from kept at neutral pH. Moreover, resistant 1.5 pepsin. relevance these findings pathogenesis H. pylori-induced gastrointestinal ulcers discussed.
Poly(2-methyl-2-oxazoline) (PMOXA) is an alternative promising polymer to poly(ethylene glycol) (PEG) for design and engineering of macrophage-evading nanoparticles (NPs). Although PMOXA-engineered NPs have shown comparable pharmacokinetics in vivo performance PEGylated stealth the murine model, its interaction with elements human innate immune system has not been studied. From a translational angle, we studied fully characterized PMOXA-coated vinyltriethoxysilane-derived organically...
The Helicobacter pylori toxin VacA causes vacuolar degeneration in mammalian cell lines vitro and plays a key role peptic ulcer disease. Two alleles, m1 m2, of the mid-region vacA gene have been described, m2 cytotoxin always has described as inactive HeLa assay. However, allele is associated with prevalent populations which gastric cancer high incidence. In this paper, we show that, despite absence toxicity on cells, able to induce vacuolization primary cells other such RK-13. Hela activity...
Summary Bafilomycin A1, a specific inhibitor of the vacuolar‐type H + ‐ATPase, responsible for acidification intra‐cellular compartments, prevents vacuolization Hela cells induced by H. pylori , with an inhibitory concentration giving 50% maximal (ID 50 ) 4 nM. A1 is also very efficient in restoring vacuolated to normal appearance. The vacuolating activity Helicobacter not inhibited series inhibitors vacuolar ‐ATPases. These findings indicate that transmembrane pH gradient needed formation...
Tetanus toxin is composed of a heavy chain (100 kDa) and light (50 held together by single interchain disulfide bridge. An additional intrachain present in the carboxy-terminal part chain. Reduction two bonds tetanus with both chemical proteinaceous reducing agents was studied. Dithiothreitol 2-mercaptoethanol cleaved inter- bridges toxin, while glutathione cysteine were ineffective. Specific reduction link achieved thioredoxin-thioredoxin reductase system, thus indicating that this bond...
The complement system, professional phagocytes and other cells such as Natural killer mast are among the important components of innate arm immune system. These constituents provide an orchestrated array defences responses against tissue injury foreign particles, including nanopharmaceuticals. While interception nanopharmaceuticals by system is beneficial for immunomodulation treatment phagocytic cell disorders, it imperative to understand multifaceted mechanisms which interacts with...
Cells exposed to Helicobacter pylori toxin VacA develop large vacuoles that originate from massive swelling of membranous compartments late stages the endocytic pathway. To determine if is active cell cytosol, cells were either microinjected with or transfected plasmids encoding VacA. Both procedures cause formation intracellular vacuoles. Cytosolic localization was assessed by indirect immunofluorescence specific antibodies and expression an green fluorescence protein (GFP)–VacA chimera....
The effect of vacuolating toxin (VacA) from<i>Helicobacter pylori</i> on endosomal and lysosomal functions was studied by following procathepsin D maturation epidermal growth factor (EGF) degradation in HeLa cells exposed to the toxin. VacA inhibited conversion (53 kDa) into both intermediate (47 mature (31 form. Nonprocessed cathepsin partly retained inside secreted extracellular medium via constitutive secretion pathway. Intracellular EGF also with a similar dose-response curve. did not...
ABSTRACT Cells exposed to Helicobacter pylori toxin VacA develop large vacuoles which originate from massive swelling of membranous compartments at late stages the endocytic pathway. When expressed in cytosol, induces vacuolization as it does when added outside. This and other evidence indicate that is a capable entering cell where displays its activity. In this study, we have used cytosolic expression identify portion molecule responsible for vacuolating mutants with deletions C N termini...
The pathway of cell penetration diphtheria toxin (DT) was studied in Vero cells by following the kinetics uptake, reduction, degradation, and sub-cellular distribution "'I-DT absence or presence bafilomycin AI (baf-Al), a powerful inhibitor endosomal H+-ATPase.After lag phase 4 min, DT, bound to cells, reached an acidic intracellular compartment, where about one-third it underwent transition state competent for subsequent reduction membrane translocation.After further this DT fraction...
Urease and the cytotoxin VacA are two major virulence factors of human pathogen Helicobacter pylori, which is responsible for severe gastroduodenal diseases. Diffusion urea, substrate urease, into stomach critically required survival infecting H. pylori. We now show that increases transepithelial flux urea across model epithelia by inducing an unsaturable permeation pathway. This transcellular pathway selective, as it conducts thiourea, but not glycerol mannitol, demonstrating due to a...
In this study we evaluated temoporfin-loaded polyethylene glycol (PEG) Poly-(D,L-lactide-co-glycolide) (PLGA) nanoparticles (NPs) as a new formulation for potential use in cancer treatment.NPs were characterized their photophysical properties, temoporfin release, cellular uptake and intracellular localization, dark photocytotoxicities of by using A549, MCF10A neoT U937 cell lines. vivo imaging was performed on athymic nude-Foxn1 mice.Temoporfin highly aggregated within the NPs release...
One protein, histidine rich glycoprotein, prevails in the corona of SiO<sub>2</sub>-NPs excess human plasma and interferes with macrophage capture.
Poly(ethylene glycol) (PEG) is widely used in nanomedicine design, but emerging PEG immunogenicity the general population of therapeutic concern. As alternative, polyoxazolines are gaining popularity, since "polyoxazolinated" nanoparticles show long-circulating properties comparable to PEGylated mice. Here, we species differences opsonization and differential uptake by monocytes macrophages coated with either poly-2-methyl-2-oxazoline or poly-2-ethyl-2-oxazoline. These evade murine process...