scholarly journals Shiga toxin remodels the intestinal epithelial transcriptional response to Enterohemorrhagic Escherichia coli

2021 ◽  
Vol 17 (2) ◽  
pp. e1009290
Author(s):  
Alyson R. Warr ◽  
Carole J. Kuehl ◽  
Matthew K. Waldor
Keyword(s):  
Escherichia Coli ◽  
Epithelial Cells ◽  
Diarrheal Disease ◽  
Rabbit Model ◽  
Transcriptional Response ◽  
Enterohemorrhagic Escherichia Coli ◽  
Intestinal Epithelial ◽  
Transcriptional Responses ◽  
Gene Encoding ◽  
Uremic Syndrome

Enterohemorrhagic Escherichia coli (EHEC) is a food-borne pathogen that causes diarrheal disease and the potentially lethal hemolytic uremic syndrome. We used an infant rabbit model of EHEC infection that recapitulates many aspects of human intestinal disease to comprehensively assess colonic transcriptional responses to this pathogen. Cellular compartment-specific RNA-sequencing of intestinal tissue from animals infected with EHEC strains containing or lacking Shiga toxins (Stx) revealed that EHEC infection elicits a robust response that is dramatically shaped by Stx, particularly in epithelial cells. Many of the differences in the transcriptional responses elicited by these strains were in genes involved in immune signaling pathways, such as IL23A, and coagulation, including F3, the gene encoding Tissue Factor. RNA FISH confirmed that these elevated transcripts were found almost exclusively in epithelial cells. Collectively, these findings suggest that Stx potently remodels the host innate immune response to EHEC.

scholarly journals Shiga toxin remodels the intestinal epithelial transcriptional response to Enterohemorrhagic Escherichia coli

2020 ◽  
Author(s):  
Alyson R. Warr ◽  
Carole J. Kuehl ◽  
Matthew K. Waldor
Keyword(s):  
Escherichia Coli ◽  
Epithelial Cells ◽  
Shiga Toxin ◽  
Host Response ◽  
Diarrheal Disease ◽  
Rabbit Model ◽  
Innate Immune ◽  
Enterohemorrhagic Escherichia Coli ◽  
Transcriptional Responses ◽  
Immune Signaling

AbstractEnterohemorrhagic Escherichia coli (EHEC) is a food-borne pathogen that causes diarrheal disease and the potentially lethal hemolytic uremic syndrome. We used an infant rabbit model of EHEC infection that recapitulates many aspects of human intestinal disease to comprehensively assess colonic transcriptional responses to this pathogen. Cellular compartment-specific RNA-sequencing of intestinal tissue from animals infected with EHEC strains containing or lacking Shiga toxins (Stx) revealed that EHEC infection elicits a robust response that is dramatically shaped by Stx, particularly in epithelial cells. Many of the differences in the transcriptional responses elicited by these strains were in genes involved in immune signaling pathways, such as IL23A, and coagulation, including F3, the gene encoding Tissue Factor. RNA FISH confirmed that these elevated transcripts were found almost exclusively in epithelial cells. Collectively, these findings suggest that within the intestine, Stx primarily targets epithelial cells, and that the potent Stx-mediated modulation of innate immune signaling skews the host response to EHEC towards type 3 immunity.Significance StatementEnterohemorrhagic Escherichia coli (EHEC) is a potentially lethal foodborne pathogen. During infection, EHEC releases a potent toxin, Shiga toxin (Stx), into the intestine, but there is limited knowledge of how this toxin shapes the host response to infection. We used an infant rabbit model of infection that closely mimics human disease to profile intestinal transcriptomic responses to EHEC infection. Comparisons of the transcriptional responses to infection by strains containing or lacking Stx revealed that this toxin markedly remodels how the epithelial cell compartment responds to infection. Our findings suggest that Stx biases the intestinal innate immune response to EHEC and provide insight into the complex host-pathogen dialogue that underlies disease.

Analysis of the human intestinal epithelial cell transcriptional response to Lactobacillus acidophilus, Lactobacillus salivarius, Bifidobacterium lactis and Escherichia coli

2010 ◽  
Vol 1 (3) ◽  
pp. 283-295 ◽  
Author(s):  
H. Putaala ◽  
R. Barrangou ◽  
G. Leyer ◽  
A. Ouwehand ◽  
E. Bech Hansen ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Epithelial Cells ◽  
Lactobacillus Acidophilus ◽  
Intestinal Epithelial Cells ◽  
Transcriptional Response ◽  
Intestinal Epithelial ◽  
Transcriptional Responses ◽  
Lactobacillus Salivarius ◽  
Enterohaemorrhagic Escherichia Coli ◽  
Human Intestinal Epithelial Cells

The complex microbial population residing in the human gastrointestinal tract consists of commensal, potential pathogenic and beneficial species, which are probably perceived differently by the host and consequently could be expected to trigger specific transcriptional responses. Here, we provide a comparative analysis of the global in vitro transcriptional response of human intestinal epithelial cells to Lactobacillus acidophilus NCFM™, Lactobacillus salivarius Ls-33, Bifidobacterium animalis subsp. lactis 420, and enterohaemorrhagic Escherichia coli O157:H7 (EHEC). Interestingly, L. salivarius Ls-33 DCE-induced changes were overall more similar to those of B. lactis 420 than to L. acidophilus NCFM™, which is consistent with previously observed in vivo immunomodulation properties. In the gene ontology and pathway analyses both specific and unspecific changes were observed. Common to all was the regulation of apoptosis and adipogenesis, and lipid-metabolism related regulation by the probiotics. Specific changes such as regulation of cell-cell adhesion by B. lactis 420, superoxide metabolism by L. salivarius Ls-33, and regulation of MAPK pathway by L. acidophilus NCFM™ were noted. Furthermore, fundamental differences were observed between the pathogenic and probiotic treatments in the Toll-like receptor pathway, especially for adapter molecules with a lowered level of transcriptional activation of MyD88, TRIF, IRAK1 and TRAF6 by probiotics compared to EHEC. The results in this study provide insights into the relationship between probiotics and human intestinal epithelial cells, notably with regard to strain-specific responses, and highlight the differences between transcriptional responses to pathogenic and probiotic bacteria.

Efficacy of Plant-Derived Antimicrobials in Controlling Enterohemorrhagic Escherichia coli Virulence In Vitro

2016 ◽  
Vol 79 (11) ◽  
pp. 1965-1970 ◽  
Author(s):  
SANGEETHA ANANDA BASKARAN ◽  
ANUP KOLLANOOR-JOHNY ◽  
MEERA SURENDRAN NAIR ◽  
KUMAR VENKITANARAYANAN
Keyword(s):  
Escherichia Coli ◽  
Epithelial Cells ◽  
Antimicrobial Agents ◽  
Intestinal Epithelial Cells ◽  
Enterohemorrhagic Escherichia Coli ◽  
Host Cells ◽  
Intestinal Epithelial ◽  
Virulence Gene Expression ◽  
Human Intestinal Epithelial Cells

ABSTRACTEscherichia coli O157:H7 is a major foodborne pathogen that can cause serious human illness characterized by hemorrhagic diarrhea and kidney failure. The pathology of enterohemorrhagic E. coli O157:H7 (EHEC) infection is primarily mediated by verotoxins, which bind to the globotriaosylceramide receptor on host cells. Antibiotics are contraindicated for treating EHEC infection because they lead to increased verotoxin release, thereby increasing the risk of renal failure and death in patients. Thus, alternative strategies are needed for controlling EHEC infections in humans. This study investigated the effect of subinhibitory concentrations of five plant-derived antimicrobial agents (PDAs) that are generally considered as safe, i.e., trans-cinnamaldehyde, eugenol, carvacrol, thymol, and β-resorcylic acid, on EHEC motility, adhesion to human intestinal epithelial cells, verotoxin production, and virulence gene expression. All tested PDAs reduced EHEC motility and attachment to human intestinal epithelial cells (P < 0.05) and decreased verotoxin synthesis by EHEC. The reverse transcription real-time PCR data revealed that PDAs decreased the expression of critical virulence genes in EHEC (P < 0.05). The results collectively suggest that these PDAs could be used to reduce EHEC virulence, but follow-up studies in animal models are necessary to validate these findings.

scholarly journals Simultaneous Exposure to Escherichia coli Heat-Labile and Heat-Stable Enterotoxins Increases Fluid Secretion and Alters Cyclic Nucleotide and Cytokine Production by Intestinal Epithelial Cells

2014 ◽  
Vol 82 (12) ◽  
pp. 5308-5316 ◽  
Author(s):  
Lisa T. Read ◽  
Rachel W. Hahn ◽  
Carli C. Thompson ◽  
David L. Bauer ◽  
Elizabeth B. Norton ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Epithelial Cells ◽  
Diarrheal Disease ◽  
Water Movement ◽  
Intestinal Epithelial Cells ◽  
Intestinal Lumen ◽  
Intestinal Epithelial ◽  
Simultaneous Exposure ◽  
Heat Stable ◽  
Heat Labile

ABSTRACTEnterotoxigenicEscherichia coli(ETEC) is a significant cause of diarrheal disease and death, especially in children in developing countries. ETEC causes disease by colonizing the small intestine and producing heat-labile toxin (LT), heat-stable toxin (ST), or both LT and ST (LT+ST). The majority of ETEC strains produce both ST and LT. Despite the prevalence of LT+ST-producing organisms, few studies have examined the physiologic or immunologic consequences of simultaneous exposure to these two potent enterotoxins. In the current report, we demonstrate that when LT and ST are both present, they increase water movement into the intestinal lumen over and above the levels observed with either toxin alone. As expected, cultured intestinal epithelial cells increased their expression of intracellular cyclic GMP (cGMP) when treated with ST and their expression of intracellular cyclic AMP (cAMP) when treated with LT. When both toxins were present, cGMP levels but not cAMP levels were synergistically elevated compared with the levels of expression caused by the corresponding single-toxin treatment. Our data also demonstrate that the levels of inflammatory cytokines produced by intestinal epithelial cells in response to LT are significantly reduced in animals exposed to both enterotoxins. These findings suggest that there may be complex differences between the epithelial cell intoxication and, potentially, secretory outcomes induced by ETEC strains expressing LT+ST compared with strains that express LT or ST only. Our results also reveal a novel mechanism wherein ST production may reduce the hosts' ability to mount an effective innate or adaptive immune response to infecting organisms.

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 Verotoxin 2 Enhances Adherence of Enterohemorrhagic Escherichia coli O157:H7 to Intestinal Epithelial Cells and Expression of β1-Integrin by IPEC-J2 Cells

2010 ◽  
Vol 76 (13) ◽  
pp. 4461-4468 ◽  
Author(s):  
Bianfang Liu ◽  
Xianhua Yin ◽  
Yanni Feng ◽  
James R. Chambers ◽  
Aiguang Guo ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Epithelial Cells ◽  
Intestinal Epithelial Cells ◽  
Human Colon ◽  
Enterohemorrhagic Escherichia Coli ◽  
Β1 Integrin ◽  
Intestinal Epithelial ◽  
Wild Type ◽  
O157 Strain ◽  
Human Laryngeal Carcinoma

ABSTRACT Verotoxin (VT) has been implicated in the promotion of adherence to and colonization of intestinal epithelial cells by enterohemorrhagic Escherichia coli (EHEC) O157:H7. The present study investigated the effect of VT2 on the adherence of EHEC O157:H7 strain 86-24 to porcine jejunal (IPEC-J2), human colon (CaCo-2), and human laryngeal carcinoma (HEp-2) cell lines and on the expression in IPEC-J2 cells of synthases for β1-integrin and nucleolin, both of which are implicated in bacterial adherence. The effect on expression of globotriaosylceramide (Gb3) synthase, the receptor for VT, was also examined. Data were obtained by adherence assays and quantitative reverse transcriptase PCR, using EHEC O157 strain 86-24, a vt2 deletion mutant, a vt2 phage-negative strain, and complemented mutants in which the vt2 gene was restored. Compared with the adherence of the parent and complemented mutant strains, the vt2-negative strains adhered significantly less to all three types of cells. Adherence of the wild-type EHEC strain to IPEC-J2 cells was accompanied by increased expression of β1-integrin, nucleolin, and Gb3 synthase. IPEC-J2 cells in association with wild-type EHEC O157:H7 or the complemented mutants expressed higher levels of β1-integrin than did cells in association with the vt2-negative strains or with no bacteria. Expression of nucleolin was decreased by association with the vt2-negative mutant, but complementation failed to restore wild-type expression. The data indicate that VT2 plays a role in the adherence of EHEC O157:H7 to intestinal epithelial cells, possibly by increasing the expression of the host receptor β1-integrin.

scholarly journals Flagellin-Dependent and -Independent Inflammatory Responses following Infection by Enteropathogenic Escherichia coli and Citrobacter rodentium

2008 ◽  
Vol 76 (4) ◽  
pp. 1410-1422 ◽  
Author(s):  
Mohammed A. Khan ◽  
Saeid Bouzari ◽  
Caixia Ma ◽  
Carrie M. Rosenberger ◽  
Kirk S. B. Bergstrom ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Epithelial Cells ◽  
Diarrheal Disease ◽  
Intestinal Inflammation ◽  
Inflammatory Responses ◽  
Intestinal Epithelial Cells ◽  
Mitogen Activated Protein Kinase ◽  
Dependent Manner ◽  
Intestinal Epithelial ◽  
Citrobacter Rodentium

ABSTRACT Enteropathogenic Escherichia coli (EPEC) and the murine pathogen Citrobacter rodentium belong to the attaching and effacing (A/E) family of bacterial pathogens. These noninvasive bacteria infect intestinal enterocytes using a type 3 secretion system (T3SS), leading to diarrheal disease and intestinal inflammation. While flagellin, the secreted product of the EPEC fliC gene, causes the release of interleukin 8 (IL-8) from epithelial cells, it is unclear whether A/E bacteria also trigger epithelial inflammatory responses that are FliC independent. The aims of this study were to characterize the FliC dependence or independence of epithelial inflammatory responses to direct infection by EPEC or C. rodentium. Following infection of Caco-2 intestinal epithelial cells by wild-type and ΔfliC EPEC, a rapid activation of several proinflammatory genes, including those encoding IL-8, monocyte chemoattractant protein 1, macrophage inflammatory protein 3α (MIP3α), and β-defensin 2, occurred in a FliC-dependent manner. These responses were accompanied by mitogen-activated protein kinase activation, as well as the Toll-like receptor 5 (TLR5)-dependent activation of NF-κB. At later infection time points, a subset of these proinflammatory genes (IL-8 and MIP3α) was also induced in cells infected with ΔfliC EPEC. The nonmotile A/E pathogen C. rodentium also triggered similar innate responses through a TLR5-independent but partially NF-κB-dependent mechanism. Moreover, the EPEC FliC-independent responses were increased in the absence of the locus of enterocyte effacement-encoded T3SS, suggesting that translocated bacterial effectors suppress rather than cause the FliC-independent inflammatory response. Thus, we demonstrate that infection of intestinal epithelial cells by A/E pathogens can trigger an array of proinflammatory responses from epithelial cells through both FliC-dependent and -independent pathways, expanding our understanding of the innate epithelial response to infection by these pathogens.

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.

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