Balance of bacterial pro- and anti-inflammatory mediators dictates net effect of enteropathogenicEscherichia colion intestinal epithelial cells

2006 ◽  
Vol 290 (4) ◽  
pp. G685-G694 ◽  
Author(s):  
Rachna Sharma ◽  
Samuel Tesfay ◽  
Farol L. Tomson ◽  
Rajani P. Kanteti ◽  
V. K. Viswanathan ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Intestinal Epithelial Cells ◽  
Host Cells ◽  
Intestinal Epithelial ◽  
E Coli ◽  
Inflammatory Proteins ◽  
Anti Inflammatory ◽  
Factor Α ◽  
Prior Infection

Enteropathogenic Escherichia coli (EPEC) virulence requires a type III secretion system (TTSS) to deliver effector molecules in host cells. Although the TTSS is crucial to EPEC pathogenesis, its function in EPEC-induced inflammation is not known. The aim of this study was to investigate the role of the TTSS in EPEC-induced inflammation. HT-29 intestinal epithelial cells were infected with wild-type (WT) EPEC or select mutant strains or exposed to corresponding filter-sterilized supernatants (SN), and interleukin-8 (IL-8) secretion was determined by ELISA. EPEC SN stimulated significantly greater IL-8 production than EPEC organisms. Flagellin, as well as a TTSS-independent >50-kDa nonflagellin protein, was found to significantly contribute to this response. Dose-response studies showed that increasing concentrations of WT SN proportionally increased IL-8, whereas increasing multiplicity of infection of EPEC inversely correlated with IL-8 secretion, suggesting that EPEC dampens this host response. Infection with Δ escN (nonfunctional TTSS) markedly increased IL-8 compared with WT, indicating that a functional TTSS is required for this anti-inflammatory property; complementation of escN restored the attenuated response. Mutation of espB also enhanced the IL-8 response, and complementation returned IL-8 to near WT levels, suggesting involvement of this effector. The anti-inflammatory effect extends to both bacterial and host-derived proinflammatory stimuli, since prior infection with EPEC suppressed the IL-8 response to tumor necrosis factor-α, IL-1β, and enterohemorrhagic E. coli flagellin. These findings indicate that EPEC-induced inflammation is a balance between pro- and anti-inflammatory proteins; extracellular factors, including flagellin and an unidentified TTSS-independent, >50-kDa protein, trigger inflammation while intracellular TTSS-dependent factors, including EspB, attenuate this response.

OmpD but not OmpC is involved in adherence ofSalmonella entericaserovar Typhimurium to human cells

2004 ◽  
Vol 50 (9) ◽  
pp. 719-727 ◽  
Author(s):  
Bochiwe Hara-Kaonga ◽  
Thomas G Pistole
Keyword(s):  
Epithelial Cells ◽  
Intestinal Epithelial Cells ◽  
Human Cells ◽  
Host Cells ◽  
Intestinal Epithelial ◽  
Wild Type ◽  
Human Macrophages ◽  
Significant Difference ◽  
Serovar Typhimurium

Conflicting reports exist regarding the role of porins OmpC and OmpD in infections due to Salmonella enterica serovar Typhimurium. This study investigated the role of these porins in bacterial adherence to human macrophages and intestinal epithelial cells. ompC and ompD mutant strains were created by transposon mutagenesis using P22-mediated transduction of Tn10 and Tn5 insertions, respectively, into wild-type strain 14028. Fluorescein-labeled wild-type and mutant bacteria were incubated with host cells at various bacteria to cell ratios for 1 h at 37 °C and analyzed by flow cytometry. The mean fluorescence intensity of cells with associated wild-type and mutant bacteria was used to estimate the number of bacteria bound per host cell. Adherence was also measured by fluorescence microscopy. Neither assay showed a significant difference in binding of the ompC mutant and wild-type strains to the human cells. In contrast, the ompD mutant exhibited lowered binding to both cell types. Our findings suggest that OmpD but not OmpC is involved in the recognition of Salmonella serovar Typhimurium by human macrophages and intestinal epithelial cells.Key words: Salmonella, adherence, porins, intestinal epithelial cells, macrophage.

Intestinal anti-inflammatory activity of luteolin: Role of the aglycone in NF-κB inactivation in macrophages co-cultured with intestinal epithelial cells

BioFactors ◽  
2013 ◽  
Vol 39 (5) ◽  
pp. 522-533 ◽  
Author(s):  
Yosuke Nishitani ◽  
Koji Yamamoto ◽  
Masaru Yoshida ◽  
Takeshi Azuma ◽  
Kazuki Kanazawa ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Intestinal Epithelial Cells ◽  
Inflammatory Activity ◽  
Intestinal Epithelial ◽  
Anti Inflammatory

scholarly journals Role of Decreased Levels of Fis Histone-Like Protein in Crohn's Disease-Associated Adherent Invasive Escherichia coli LF82 Bacteria Interacting with Intestinal Epithelial Cells

2010 ◽  
Vol 192 (7) ◽  
pp. 1832-1843 ◽  
Author(s):  
Sylvie Miquel ◽  
Laurent Claret ◽  
Richard Bonnet ◽  
Imen Dorboz ◽  
Nicolas Barnich ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Crohn’S Disease ◽  
Crohn's Disease ◽  
Epithelial Cells ◽  
Intestinal Epithelial Cells ◽  
Host Cells ◽  
Intestinal Epithelial ◽  
Type 1 Pili

ABSTRACT The interaction of Crohn's disease (CD)-associated adherent-invasive Escherichia coli (AIEC) strain LF82 with intestinal epithelial cells depends on surface appendages, such as type 1 pili and flagella. Histone-like proteins operate as global regulators to control the expression of these virulence factors. We evaluated the role of histone-like proteins in AIEC reference strain LF82 during infection of intestinal epithelial cells, Intestine-407, and observed that the fis mRNA level was decreased. The role of Fis in AIEC LF82 was determined by studying the phenotype of an LF82 fis::Km mutant. This was the first mutant of strain LF82 that has been described thus far that is unable to express flagellin but still able to produce type 1 pili. The cyclic-di-GMP pathway linking flagella and type 1 pilus expression is not involved in Fis-mediated regulation, and we identified in the present study Fis-binding sites located upstream of the fimE gene and in the intergenic region between fimB and nanC of the fim operon encoding type 1 pili. The major consequence of decreased Fis expression in AIEC bacteria in contact with host cells is a direct downregulation of fimE expression, leading to the preferential ON phase of the fimS element. Thus, by maintaining type 1 pilus expression, AIEC bacteria, which interact with the gut mucosa, have greater ability to colonize and to induce inflammation in CD patients.

scholarly journals Clustering of Tir during enteropathogenic E. coli infection triggers calcium influx–dependent pyroptosis in intestinal epithelial cells

PLoS Biology ◽  
2020 ◽  
Vol 18 (12) ◽  
pp. e3000986
Author(s):  
Qiyun Zhong ◽  
Theodoros I. Roumeliotis ◽  
Zuza Kozik ◽  
Massiel Cepeda-Molero ◽  
Luis Ángel Fernández ◽  
...  
Keyword(s):  
Cell Death ◽  
Epithelial Cells ◽  
Type Iii Secretion ◽  
Calcium Influx ◽  
Intestinal Epithelial Cells ◽  
Intestinal Epithelial ◽  
Independent Manner ◽  
E Coli ◽  
T3ss Effector

Clustering of the enteropathogenic Escherichia coli (EPEC) type III secretion system (T3SS) effector translocated intimin receptor (Tir) by intimin leads to actin polymerisation and pyroptotic cell death in macrophages. The effect of Tir clustering on the viability of EPEC-infected intestinal epithelial cells (IECs) is unknown. We show that EPEC induces pyroptosis in IECs in a Tir-dependent but actin polymerisation-independent manner, which was enhanced by priming with interferon gamma (IFNγ). Mechanistically, Tir clustering triggers rapid Ca2+ influx, which induces lipopolysaccharide (LPS) internalisation, followed by activation of caspase-4 and pyroptosis. Knockdown of caspase-4 or gasdermin D (GSDMD), translocation of NleF, which blocks caspase-4 or chelation of extracellular Ca2+, inhibited EPEC-induced cell death. IEC lines with low endogenous abundance of GSDMD were resistant to Tir-induced cell death. Conversely, ATP-induced extracellular Ca2+ influx enhanced cell death, which confirmed the key regulatory role of Ca2+ in EPEC-induced pyroptosis. We reveal a novel mechanism through which infection with an extracellular pathogen leads to pyroptosis in IECs.

Inflammatory cytokine TNF-α inhibits Na+–glutamine cotransport in intestinal epithelial cells

2013 ◽  
Vol 91 (4) ◽  
pp. 275-284 ◽  
Author(s):  
Jamilur R. Talukder ◽  
Brittney Boyd ◽  
Ashley Griffin ◽  
Antara Jaima ◽  
Vazhaikkurichi M. Rajendran
Keyword(s):  
Epithelial Cells ◽  
Intestinal Epithelial Cells ◽  
Kinetic Studies ◽  
Dependent Manner ◽  
Intestinal Epithelial ◽  
Cell Integrity ◽  
Tnf Α ◽  
Factor Α ◽  
Necrosis Factor

Glutamine (Gln), a preferred fuel source for enterocytes, is critical for intestinal epithelial cell integrity and barrier function. Chronic enteritis inhibits apical Na+–Gln cotransport. It is not known whether inflammatory cytokines that are secreted during inflammation inhibit Na+–Gln cotransport. Thus, this study aimed to examine whether TNF-α would affect apical Na+–Gln cotransport in intestinal epithelial cells. In this study, the presence of Na+–Gln cotransport was established by measuring Gln uptake in 10 days postconfluent IEC-6 cells grown on transwell plates. Cation, amino acid specificity, and siRNA transfection studies established that Na+–Gln cotransport is mediated via B0AT1. Immunoblotting and immunofluorescence studies established the apical membrane localization of B0AT1 in IEC-6 cells. Tumour necrosis factor α (TNF-α) inhibited Na+–Gln cotransport in a concentration- and time-dependent manner with an inhibitory concentration of 1.53 nmol·L−1. Quantitative real-time PCR and Western blot analyses indicated that TNF-α did not alter B0AT1-specific transcripts or protein expression level. Kinetic studies revealed that TNF-α inhibited Na+–Gln cotransport by reducing the affinity of the cotransporters for Gln, and this effect was antagonized by genistein. Thus, we conclude that the TNF-α inhibition of Na+–Gln cotransport occurs at the post-translational level, and that the IEC-6 cell line is an excellent system to study the role of cytokines in Na+–Gln cotransport.

The role of NF-κB in mediating the anti-inflammatory effects of IL-10 in intestinal epithelial cells

Cytokine ◽  
2006 ◽  
Vol 36 (1-2) ◽  
pp. 1-8 ◽  
Author(s):  
Randa Al-Ashy ◽  
Iman Chakroun ◽  
M.E. El-Sabban ◽  
Fadia R. Homaidan
Keyword(s):  
Epithelial Cells ◽  
Intestinal Epithelial Cells ◽  
Intestinal Epithelial ◽  
Anti Inflammatory

scholarly journals Protective Effects of Lactoferrin against SARS-CoV-2 Infection In Vitro

Nutrients ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 328 ◽  
Author(s):  
Claudio Salaris ◽  
Melania Scarpa ◽  
Marina Elli ◽  
Alice Bertolini ◽  
Simone Guglielmetti ◽  
...  
Keyword(s):  
Immune Response ◽  
Epithelial Cells ◽  
Intestinal Epithelial Cells ◽  
Plaque Assay ◽  
Immune Response Gene ◽  
Intestinal Epithelial ◽  
Antiviral Immune Response ◽  
Qrt Pcr ◽  
Anti Inflammatory

SARS-CoV-2 is a newly emerging virus that currently lacks curative treatments. Lactoferrin (LF) is a naturally occurring non-toxic glycoprotein with broad-spectrum antiviral, immunomodulatory and anti-inflammatory effects. In this study, we assessed the potential of LF in the prevention of SARS-CoV-2 infection in vitro. Antiviral immune response gene expression was analyzed by qRT-PCR in uninfected Caco-2 intestinal epithelial cells treated with LF. An infection assay for SARS-CoV-2 was performed in Caco-2 cells treated or not with LF. SARS-CoV-2 titer was determined by qRT-PCR, plaque assay and immunostaining. Inflammatory and anti-inflammatory cytokine production was determined by qRT-PCR. LF significantly induced the expression of IFNA1, IFNB1, TLR3, TLR7, IRF3, IRF7 and MAVS genes. Furthermore, LF partially inhibited SARS-CoV-2 infection and replication in Caco-2 intestinal epithelial cells. Our in vitro data support LF as an immune modulator of the antiviral immune response with moderate effects against SARS-CoV-2 infection.

Prevention of Dextran Sulfate Sodium-induced Mouse Colitis by a Fungal Protein Ling Zhi-8 via Promoting the Barrier Function of Intestinal Epithelial Cells

2021 ◽  
Author(s):  
Yu-Huan Chen ◽  
Jenn-Yeu Shin ◽  
Hsiu-Mei Wei ◽  
Chi-Chen Lin ◽  
Linda Chia-Hui Yu ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Immune Cells ◽  
Ganoderma Lucidum ◽  
Dextran Sulfate ◽  
Dextran Sulfate Sodium ◽  
Intestinal Epithelial Cells ◽  
Intestinal Epithelial ◽  
Fungal Protein ◽  
Fungal Immunomodulatory Protein

A fungal immunomodulatory protein Ling Zhi-8 (LZ-8) isolated from Ganoderma lucidum (GL) regulates immune cells and inhibits tumor growth; however, the role of LZ-8 in intestinal epithelial cells (IECs) is...

scholarly journals Rspo3 regulates the abnormal differentiation of small intestinal epithelial cells in diabetic state

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Ti-Dong Shan ◽  
Han Yue ◽  
Xue-Guo Sun ◽  
Yue-Ping Jiang ◽  
Li Chen
Keyword(s):  
Epithelial Cells ◽  
Bioinformatics Analysis ◽  
Intestinal Epithelial Cells ◽  
Underlying Mechanism ◽  
Luciferase Reporter ◽  
Intestinal Epithelial ◽  
Epithelial Stem Cells ◽  
Diabetic State ◽  
Definitive Evidence

Abstract Background The complications caused by diabetes mellitus (DM) are the focus of clinical treatment. However, little is known about diabetic enteropathy (DE) and its potential underlying mechanism. Methods Intestinal epithelial cells (IECs) and intestinal epithelial stem cells (IESCs) were harvested from BKS.Cg-Dock7m+/+Leprdb/JNju (DM) mice, and the expression of R-Spondin 3 (Rspo3) was detected by RT-qPCR, Western blotting, immunohistochemistry, and immunofluorescence. The role of Rspo3 in the abnormal differentiation of IECs during DM was confirmed by knockdown experiments. Through miRNA expression profiling, bioinformatics analysis, and RT-qPCR, we further analyzed the differentiation-related miRNAs in the IECs from mice with DM. Results Abnormal differentiation of IECs was observed in the mice with DM. The expression of Rspo3 was upregulated in the IECs from the mice with DM. This phenomenon was associated with Rspo3 overexpression. Additionally, Rspo3 is a major determinant of Lgr5+ stem cell identity in the diabetic state. Microarray analysis, bioinformatics analysis, and luciferase reporter assays revealed that microRNA (miR)-380-5p directly targeted Rspo3. Moreover, miR-380-5p upregulation was observed to attenuate the abnormal differentiation of IECs by regulating Rspo3 expression. Conclusions Together, our results provide definitive evidence of the essential role of Rspo3 in the differentiation of IECs in DM.

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