Effects of verocytotoxin-1 on nonadherent human monocytes: binding characteristics, protein synthesis, and induction of cytokine release
| Autor: | L.P.W.J. van den Heuvel, R.G.G. Verstraten, P.A. van Setten, L.A.H. Monnens, V.W.H. van Hinsbergh |
|---|---|
| Přispěvatelé: | Gaubius Instituut TNO |
| Rok vydání: | 1996 |
| Předmět: |
Lipopolysaccharides
Male Enterobacter infection Verotoxin Lipopolysaccharide Messenger rna medicine.medical_treatment Cell Culture Techniques Ligands Biochemistry Monocytes Globotriaosylceramide chemistry.chemical_compound Hemolytic uremic syndrome Polytetrafluoroethylene Cells Cultured Cell stimulation Trihexosylceramides Hematology Endothelial stem cell medicine.anatomical_structure Cytokine Reverse transcription polymerase chain reaction Interleukin 19 Tumor necrosis factor alpha Cell activation Cell Survival Bacterial Toxins Immunology Biology Microbiology Escherichia coli medicine Humans Interleukin 8 Inflammation Binding Sites Interleukin-6 Tumor Necrosis Factor-alpha Interleukins Monocyte Interleukin-8 Cell Biology Shiga-Like Toxin I Human cell Gene Expression Regulation chemistry Protein Biosynthesis Hemolytic-Uremic Syndrome Glomerulus Protein synthesis Controlled study Interleukin-1 |
| Zdroj: | Blood, 1, 88, 174-183 |
| ISSN: | 1528-0020 0006-4971 |
| DOI: | 10.1182/blood.v88.1.174.174 |
| Popis: | The epidemic form of the hemolytic uremic syndrome (HUS) has been associated with a verocytotoxin producing Escherichia coli infection. Endothelial cell damage of glomeruli and arterioles of the kidney plays a central role in the pathogenesis of HUS. A number of observations in vivo and in vitro indicate that inflammatory mediators contribute to this process. In this study we investigated the binding of 125I-verocytotoxin-1 (VT-1) to freshly isolated human nonadherent monocytes as well as the nature of the ligand to which VT-1 binds on monocytes. On the average, freshly isolated monocytes have 0.07 x 105 specific binding sites for 125I-VT-1 per cell. Preincubation of nonadherent monocytes with bacterial lipopolysaccharide (LPS) caused a 23- to 30-fold increase of specific binding sites for VT-1 as shown by Scatchard plot analysis. Thin-layer chromatography of extracted neutral glycolipids of the cells and subsequent binding of 125I-VT-1 showed that human monocytes bind VT-1 to a globotriaosylceramide (Gb3) species that is different from that found on endothelial cells, probably a short-chain fattyacyl Gb3 or an α-OH-Gb3. In addition, we evaluated the functional consequences of VT-1 binding to human monocytes by investigating the effects of VT-1 on the total protein synthesis and, specifically, the production of the cytokines interleukin-1β (IL-1β), tumor necrosis factor- α (TNF-α), IL-6, and IL-8. We observed that VT-1 did not inhibit overall protein synthesis, nor under basal conditions, neither after stimulation with LPS, in contrast to previous observations with endothelial cells. Furthermore, we found that VT-1 induces the synthesis of the cytokines IL- 1β, TNF-α, IL-6, and IL-8 in nonstimulated monocytes by a LPS-independent cell activation. The increase in the production of cytokines was parallelled by an increase in mRNA, as was demonstrated for IL-6 by reverse transcription-polymerase chain reaction. These data suggest that inflammatory mediators locally produced by VT-1-stimulated monocytes may contribute to the pathogenic mechanism of the HUS. Chemicals/CAS: Bacterial Toxins; globotriaosylceramide, 71965-57-6; Interleukin-1; Interleukin-6; Interleukin-8; Interleukins; Ligands; Lipopolysaccharides; Polytetrafluoroethylene, 9002-84-0; Shiga-Like Toxin I; Trihexosylceramides; Tumor Necrosis Factor-alpha |
| Databáze: | OpenAIRE |
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