scholarly journals EnterohemorrhagicEscherichia coliinfection stimulates Shiga toxin 1 macropinocytosis and transcytosis across intestinal epithelial cells

2011 ◽  
Vol 301 (5) ◽  
pp. C1140-C1149 ◽  
Author(s):  
Valeriy Lukyanenko ◽  
Irina Malyukova ◽  
Ann Hubbard ◽  
Michael Delannoy ◽  
Edgar Boedeker ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Shiga Toxin ◽  
Molecular Mechanisms ◽  
Intestinal Epithelial Cells ◽  
Enterohemorrhagic Escherichia Coli ◽  
Intestinal Epithelial ◽  
Systemic Complications ◽  
E Coli ◽  
Systemic Spread ◽  
Uremic Syndrome

Gastrointestinal infection with Shiga toxins producing enterohemorrhagic Escherichia coli causes the spectrum of gastrointestinal and systemic complications, including hemorrhagic colitis and hemolytic uremic syndrome, which is fatal in ∼10% of patients. However, the molecular mechanisms of Stx endocytosis by enterocytes and the toxins cross the intestinal epithelium are largely uncharacterized. We have studied Shiga toxin 1 entry into enterohemorrhagic E. coli-infected intestinal epithelial cells and found that bacteria stimulate Shiga toxin 1 macropinocytosis through actin remodeling. This enterohemorrhagic E. coli-caused macropinocytosis occurs through a nonmuscle myosin II and cell division control 42 (Cdc42)-dependent mechanism. Macropinocytosis of Shiga toxin 1 is followed by its transcytosis to the basolateral environment, a step that is necessary for its systemic spread. Inhibition of Shiga toxin 1 macropinocytosis significantly decreases toxin uptake by intestinal epithelial cells and in this way provides an attractive, antibiotic-independent strategy for prevention of the harmful consequences of enterohemorrhagic E. coli infection.

scholarly journals Macropinocytosis in Shiga toxin 1 uptake by human intestinal epithelial cells and transcellular transcytosis

2009 ◽  
Vol 296 (1) ◽  
pp. G78-G92 ◽  
Author(s):  
Irina Malyukova ◽  
Karen F. Murray ◽  
Chengru Zhu ◽  
Edgar Boedeker ◽  
Anne Kane ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Shiga Toxin ◽  
Intestinal Epithelial Cells ◽  
Enterohemorrhagic Escherichia Coli ◽  
Apical Surface ◽  
Intestinal Epithelial ◽  
Shiga Toxins ◽  
E Coli ◽  
Human Intestinal Epithelial Cells ◽  
Toxin Uptake

Shiga toxin 1 and 2 production is a cardinal virulence trait of enterohemorrhagic Escherichia coli infection that causes a spectrum of intestinal and systemic pathology. However, intestinal sites of enterohemorrhagic E. coli colonization during the human infection and how the Shiga toxins are taken up and cross the globotriaosylceramide (Gb3) receptor-negative intestinal epithelial cells remain largely uncharacterized. We used samples of human intestinal tissue from patients with E. coli O157:H7 infection to detect the intestinal sites of bacterial colonization and characterize the distribution of Shiga toxins. We further used a model of largely Gb3-negative T84 intestinal epithelial monolayers treated with B-subunit of Shiga toxin 1 to determine the mechanisms of non-receptor-mediated toxin uptake. We now report that E. coli O157:H7 were found at the apical surface of epithelial cells only in the ileocecal valve area and that both toxins were present in large amounts inside surface and crypt epithelial cells in all tested intestinal samples. Our in vitro data suggest that macropinocytosis mediated through Src activation significantly increases toxin endocytosis by intestinal epithelial cells and also stimulates toxin transcellular transcytosis. We conclude that Shiga toxin is taken up by human intestinal epithelial cells during E. coli O157:H7 infection regardless of the presence of bacterial colonies. Macropinocytosis might be responsible for toxin uptake by Gb3-free intestinal epithelial cells and transcytosis. These observations provide new insights into the understanding of Shiga toxin contribution to enterohemorrhagic E. coli-related intestinal and systemic diseases.

scholarly journals Shiga Toxin Translocation across Intestinal Epithelial Cells Is Enhanced by Neutrophil Transmigration

2001 ◽  
Vol 69 (10) ◽  
pp. 6148-6155 ◽  
Author(s):  
Bryan P. Hurley ◽  
Cheleste M. Thorpe ◽  
David W. K. Acheson
Keyword(s):  
Epithelial Cells ◽  
Shiga Toxin ◽  
Intestinal Epithelial Cells ◽  
Biologically Active ◽  
Intestinal Lumen ◽  
Intestinal Epithelial ◽  
T84 Cells ◽  
Inflammatory Infiltration ◽  
E Coli ◽  
Intestinal Epithelia

ABSTRACT Shiga toxin-producing E. coli (STEC) is a food-borne pathogen that causes serious illness, including hemolytic-uremic syndrome (HUS). STEC colonizes the lower intestine and produces Shiga toxins (Stxs). Stxs appear to translocate across intestinal epithelia and affect sensitive endothelial cell beds at various sites. We have previously shown that Stxs cross polarized intestinal epithelial cells (IECs) via a transcellular route and remain biologically active. Since acute inflammatory infiltration of the gut and fecal leukocytes is seen in many STEC-infected patients and since polymorphonuclear leukocyte (PMN) transmigration across polarized IECs diminishes the IEC barrier function in vitro, we hypothesized that PMN transmigration may enhance Stx movement across IECs. We found that basolateral-to-apical transmigration of neutrophils significantly increased the movement of Stx1 and Stx2 across polarized T84 IECs in the opposite direction. The amount of Stx crossing the T84 barrier was proportional to the degree of neutrophil transmigration, and the increase in Stx translocation appears to be due to increases in paracellular permeability caused by migrating PMNs. STEC clinical isolates applied apically induced PMN transmigration across and interleukin-8 (IL-8) secretion from T84 cells. Of the 10 STEC strains tested, three STEC strains lackingeae and espB (eae- andespB-negative STEC strains) induced significantly more neutrophil transmigration and significantly greater IL-8 secretion thaneae- and espB-positive STEC or enteropathogenic E. coli. This study suggests that STEC interaction with intestinal epithelia induces neutrophil recruitment to the intestinal lumen, resulting in neutrophil extravasation across IECs, and that during this process Stxs may pass in greater amounts into underlying tissues, thereby increasing the risk of HUS.

scholarly journals EnterohemorrhagicEscherichia colisuppresses inflammatory response to cytokines and its own toxin

2009 ◽  
Vol 297 (3) ◽  
pp. G576-G581 ◽  
Author(s):  
Amy Bellmeyer ◽  
Cynthia Cotton ◽  
Rajani Kanteti ◽  
Athanasia Koutsouris ◽  
V. K. Viswanathan ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Inflammatory Response ◽  
Inflammatory Responses ◽  
Intestinal Epithelial Cells ◽  
Enterohemorrhagic Escherichia Coli ◽  
Receptor Expression ◽  
Intestinal Epithelial ◽  
Potent Inducer ◽  
Life Threatening ◽  
Uremic Syndrome

Infection with the enteric pathogen enterohemorrhagic Escherichia coli (EHEC) causes a variety of symptoms ranging from nonbloody diarrhea to more severe sequelae including hemorrhagic colitis, altered sensorium and seizures, and even life-threatening complications, such as hemolytic uremic syndrome and thrombotic thrombocytopenic purpura. The more severe consequences of EHEC infection are attributable to the production of Shiga toxin (Stx) and its subsequent effects on the vasculature, which expresses high levels of the Stx receptor, Gb3. Interestingly, the intestinal epithelium does not express Gb3. Despite the lack of Gb3 receptor expression, intestinal epithelial cells translocate Stx. The effect of Stx on intestinal epithelial cells is controversial with some studies demonstrating induction of inflammation and others not. This may be difficult to resolve because EHEC expresses both proinflammatory molecules, such as flagellin, and factor(s) that dampen the inflammatory response of epithelial cells. The goal of our study was to define the effect of Stx on the inflammatory response of intestinal epithelial cells and to determine whether infection by EHEC modulates this response. Here we show that Stx is a potent inducer of the inflammatory response in intestinal epithelial cells and confirm that EHEC attenuates the induction of IL-8 by host-derived proinflammatory cytokines. More importantly, however, we show that infection with EHEC attenuates the inflammatory response by intestinal epithelial cells to its own toxin. We speculate that the ability of EHEC to dampen epithelial cell inflammatory responses to Stx and cytokines facilitates intestinal colonization.

scholarly journals Shiga Toxin 2e-Producing Escherichia coli Isolates from Humans and Pigs Differ in Their Virulence Profiles and Interactions with Intestinal Epithelial Cells

2005 ◽  
Vol 71 (12) ◽  
pp. 8855-8863 ◽  
Author(s):  
Anne-Katharina Sonntag ◽  
Martina Bielaszewska ◽  
Alexander Mellmann ◽  
Nadine Dierksen ◽  
Peter Schierack ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Epithelial Cell ◽  
Epithelial Cells ◽  
Shiga Toxin ◽  
Intestinal Epithelial Cell ◽  
Intestinal Epithelial Cells ◽  
Epithelial Cell Line ◽  
Uptake System ◽  
Intestinal Epithelial ◽  
E Coli

ABSTRACT Thirteen Escherichia coli strains harboring stx 2e were isolated from 11,056 human stools. This frequency corresponded to the presence of the stx 2e allele in 1.7% of all Shiga toxin-producing E. coli (STEC) strains. The strains harboring stx 2e were associated with mild diarrhea (n = 9) or asymptomatic infections (n= 4). Because STEC isolates possessing stx 2e are porcine pathogens, we compared the human STEC isolates with stx 2e-harboring E. coli isolated from piglets with edema disease and postweaning diarrhea. All pig isolates possessed the gene encoding the F18 adhesin, and the majority possessed adhesin involved in diffuse adherence; these adhesins were absent from all the human STEC isolates. In contrast, the high-pathogenicity island encoding an iron uptake system was found only in human isolates. Host-specific patterns of interaction with intestinal epithelial cells were observed. All human isolates adhered to human intestinal epithelial cell lines T84 and HCT-8 but not to pig intestinal epithelial cell line IPEC-J2. In contrast, the pig isolates completely lysed human epithelial cells but not IPEC-J2 cells, to which most of them adhered. Our data demonstrate that E. coli isolates producing Shiga toxin 2e have imported specific virulence and fitness determinants which allow them to adapt to the specific hosts in which they cause various forms of disease.

scholarly journals Anaerobic Conditions Promote Expression of Sfp Fimbriae and Adherence of Sorbitol-Fermenting Enterohemorrhagic Escherichia coli O157:NM to Human Intestinal Epithelial Cells

2007 ◽  
Vol 74 (4) ◽  
pp. 1087-1093 ◽  
Author(s):  
Anne Müsken ◽  
Martina Bielaszewska ◽  
Lilo Greune ◽  
Christian H. Schweppe ◽  
Johannes Müthing ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Epithelial Cells ◽  
Intestinal Epithelial Cells ◽  
Enterohemorrhagic Escherichia Coli ◽  
Intestinal Epithelial ◽  
Anaerobic Conditions ◽  
E Coli ◽  
Fimbrial Subunit ◽  
Solid Media ◽  
Human Intestinal Epithelial Cells

ABSTRACT The sfp gene cluster, unique to sorbitol-fermenting (SF) enterohemorrhagic Escherichia coli (EHEC) O157:NM strains, encodes fimbriae that mediate mannose-resistant hemagglutination in laboratory E. coli strains but are not expressed in wild-type SF EHEC O157:NM strains under standard laboratory conditions. We investigated whether Sfp fimbriae are expressed under conditions that mimic the intestinal environment and whether they contribute to the adherence of SF EHEC O157:NM strains to human intestinal epithelial cells. The transcription of sfpA (encoding the major fimbrial subunit) was upregulated in all strains investigated, and all expressed SfpA and possessed fimbriae that reacted with an anti-SfpA antibody when the strains were grown on solid media under anaerobic conditions. Sfp expression was absent under aerobic conditions and in liquid media. Sfp upregulation under anaerobic conditions was significantly higher on blood agar and a medium simulating the colonic environment than on a medium simulating the ileal environment (P < 0.05). The induction of Sfp fimbriae in SF E. coli O157:NM strains correlates with increased adherence to Caco-2 and HCT-8 cells. Our data indicate that the expression of Sfp fimbriae in SF E. coli O157:NM strains is induced under conditions resembling those of the natural site of infection and that Sfp fimbriae may contribute to the adherence of the organisms to human intestinal epithelium.

scholarly journals Shiga Toxin (Stx)-Binding Glycosphingolipids of Primary Human Renal Cortical Epithelial Cells (pHRCEpiCs) and Stx-Mediated Cytotoxicity

Toxins ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 139
Author(s):  
Johanna Detzner ◽  
Elisabeth Krojnewski ◽  
Gottfried Pohlentz ◽  
Daniel Steil ◽  
Hans-Ulrich Humpf ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Epithelial Cells ◽  
Shiga Toxin ◽  
Saturated Fatty Acids ◽  
Human Kidney ◽  
Enterohemorrhagic Escherichia Coli ◽  
Highly Sensitive ◽  
Liquid Ordered ◽  
Uremic Syndrome

Human kidney epithelial cells are supposed to be directly involved in the pathogenesis of the hemolytic–uremic syndrome (HUS) caused by Shiga toxin (Stx)-producing enterohemorrhagic Escherichia coli (EHEC). The characterization of the major and minor Stx-binding glycosphingolipids (GSLs) globotriaosylceramide (Gb3Cer) and globotetraosylceramide (Gb4Cer), respectively, of primary human renal cortical epithelial cells (pHRCEpiCs) revealed GSLs with Cer (d18:1, C16:0), Cer (d18:1, C22:0), and Cer (d18:1, C24:1/C24:0) as the dominant lipoforms. Using detergent-resistant membranes (DRMs) and non-DRMs, Gb3Cer and Gb4Cer prevailed in the DRM fractions, suggesting their association with microdomains in the liquid-ordered membrane phase. A preference of Gb3Cer and Gb4Cer endowed with C24:0 fatty acid accompanied by minor monounsaturated C24:1-harboring counterparts was observed in DRMs, whereas the C24:1 fatty acid increased in relation to the saturated equivalents in non-DRMs. A shift of the dominant phospholipid phosphatidylcholine with saturated fatty acids in the DRM to unsaturated species in the non-DRM fractions correlated with the GSL distribution. Cytotoxicity assays gave a moderate susceptibility of pHRCEpiCs to the Stx1a and Stx2a subtypes when compared to highly sensitive Vero-B4 cells. The results indicate that presence of Stx-binding GSLs per se and preferred occurrence in microdomains do not necessarily lead to a high cellular susceptibility towards Stx.

scholarly journals Lactoferrin inhibits E. coli O157:H7 growth and attachment to intestinal epithelial cells

2010 ◽  
Vol 55 (No. 8) ◽  
pp. 359-368 ◽  
Author(s):  
M. Atef Yekta ◽  
F. Verdonck ◽  
W. Van Den Broeck ◽  
BM Goddeeris ◽  
E. Cox ◽  
...  
Keyword(s):  
Colorectal Adenocarcinoma ◽  
Bacterial Attachment ◽  
Enterohemorrhagic Escherichia Coli ◽  
Intestinal Epithelial ◽  
Antimicrobial Proteins ◽  
Haemolytic Uremic Syndrome ◽  
E Coli ◽  
Uremic Syndrome ◽  
High Concentrations ◽  
Extracellular Environment

Enterohemorrhagic Escherichia coli (EHEC) serotype O157:H7 strains are associated with haemorraghic colitis and haemolytic uremic syndrome (HUS) in humans. Cattle are a reservoir of E. coli O157:H7. We studied the ability of bovine and human lactoferrin, two natural antimicrobial proteins present in milk, to inhibit E. coli O157:H7 growth and attachment to a human epithelial colorectal adenocarcinoma cell line (Caco-2). The direct antibacterial effect of bLF on E. coli O157:H7 was stronger than that of hLF. Nevertheless, both lactoferrins had bacteriostatic effects even at high concentrations (10 mg/ml), suggesting blocking of LF activity by a yet undefined bacterial defence mechanism. Additionally, both lactoferrins significantly inhibited E. coli O157:H7 attachment to Caco-2 cells. However, hLF was more effective than bLF, probably due to more efficient binding of bLF to intelectin present on human enterocytes leading to uptake and thus removal of bLF from the extracellular environment. Inhibition of bacterial attachment to Caco-2 cells was at least partly due to the catalytic effect of lactoferrins on the type III secreted proteins EspA and EspB

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