scholarly journals Characterization of Candidate Live Oral Salmonella typhi Vaccine Strains Harboring Defined Mutations inaroA, aroC, and htrA

1999 ◽  
Vol 67 (2) ◽  
pp. 700-707 ◽  
Author(s):  
David C. Lowe ◽  
Tor C. Savidge ◽  
Derek Pickard ◽  
Lars Eckmann ◽  
Martin F. Kagnoff ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Salmonella Typhi ◽  
Scid Mice ◽  
Intestinal Epithelial ◽  
Human Intestinal Epithelial Cells ◽  
U937 Macrophage ◽  
Ht 29

ABSTRACT The properties of two candidate Salmonella typhi-based live oral typhoid vaccine strains, BRD691 (S. typhi Ty2 harboring mutations in aroA and aroC) and BRD1116 (S. typhi Ty2 harboring mutations inaroA, aroC, and htrA), were compared in a number of in vitro and in vivo assays. BRD1116 exhibited an increased susceptibility to oxidative stress compared with BRD691, but both strains were equally resistant to heat shock. Both strains showed a similar ability to invade Caco-2 and HT-29 epithelial cells and U937 macrophage-like cells, but BRD1116 was less efficient at surviving in epithelial cells than BRD691. BRD1116 and BRD691 were equally susceptible to intracellular killing within U937 cells. Similar findings were demonstrated in vivo, with BRD1116 being less able to survive and translocate to secondary sites of infection when inoculated into the lumen of human intestinal xenografts in SCID mice. However, translocation of BRD1116 to spleens and livers in SCID mice occurred as efficiently as that of BRD691 when inoculated intraperitonally. The ability of BRD1116 to increase the secretion of interleukin-8 following infection of HT-29 epithelial cells was comparable to that of BRD691. Therefore, loss of the HtrA protease inS. typhi does not seem to alter its ability to invade epithelial cells or macrophages or to induce proinflammatory cytokines such as IL-8 but significantly reduces intracellular survival in human intestinal epithelial cells in vitro and in vivo.

scholarly journals CD14 Is Expressed and Released as Soluble CD14 by Human Intestinal Epithelial Cells In Vitro: Lipopolysaccharide Activation of Epithelial Cells Revisited

2001 ◽  
Vol 69 (6) ◽  
pp. 3772-3781 ◽  
Author(s):  
David P. Funda ◽  
Ludmila Tučková ◽  
Maria A. Farré ◽  
Takashi Iwase ◽  
Itaru Moro ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Cell Lines ◽  
Intestinal Epithelial Cells ◽  
Intestinal Epithelial ◽  
Soluble Cd14 ◽  
Human Intestinal Epithelial Cells ◽  
Membrane Bound ◽  
Ht 29

ABSTRACT Human endothelial as well as epithelial cells were shown to respond to lipopolysaccharides (LPSs). However, the expression and release of CD14 by these so-called CD14-negative cells have not been studied in detail. We investigated three human intestinal epithelial cell lines (ECLs), SW-480, HT-29, and Caco-2, for their expression of CD14 and CD11c/CD18 as well as their responsiveness to endotoxins. Fluorescence-activated cell sorter analysis revealed no expression of CD11c/CD18, but there was low expression of membrane-bound CD14 on HT-29, Caco-2, and SW-480 ECLs. Both Western blotting and reverse transcription-PCR confirmed the CD14 positivity of all three intestinal ECLs. No substantial modulation of CD14 expression was achieved after 6, 8, 18, 24, and 48 h of cultivation with 10-fold serial dilutions of LPS ranging from 0.01 ng/ml to 100 μg/ml. Interestingly, soluble CD14 was found in the tissue culture supernatants of all three ECLs. Finally, only HT-29 and SW-480, and not Caco-2, cells responded to LPS exposure (range, 0.01 ng/ml to 100 μg/ml) by interleukin 8 release. Thus, we show that HT-29, SW-480, and Caco-2 human intestinal ECLs express membrane-bound CD14. As Caco-2 cells did not respond to LPS, these cell lines might be an interesting model for studying the receptor complex for LPS. The fact that human intestinal epithelial cells are capable not only of expression but also of release of soluble CD14 may have important implications in vivo, e.g., in shaping the interaction between the mucosal immune system and bacteria in the gut and/or in the pathogenesis of endotoxin shock.

Progastrin1–80stimulates growth of intestinal epithelial cells in vitro via high-affinity binding sites

2003 ◽  
Vol 284 (2) ◽  
pp. G328-G339 ◽  
Author(s):  
P. Singh ◽  
X. Lu ◽  
S. Cobb ◽  
B. T. Miller ◽  
N. Tarasova ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Binding Sites ◽  
Intestinal Epithelial Cells ◽  
Full Length ◽  
Intestinal Epithelial ◽  
Growth Effects ◽  
High Affinity ◽  
Significant Difference

Proliferation and carcinogenesis of the large intestinal epithelial cells (IEC) cells is significantly increased in transgenic mice that overexpress the precursor progastrin (PG) peptide. It is not known if the in vivo growth effects of PG on IEC cells are mediated directly or indirectly. Full-length recombinant human PG (rhPG1–80) was generated to examine possible direct effects of PG on IEC cells. Surprisingly, rhPG (0.1–1.0 nM) was more effective than the completely processed gastrin 17 (G17) peptide as a growth factor. Even though IEC cells did not express CCK1and CCK2receptors (-R), fluorescently labeled G17 and Gly-extended G17 (G-Gly) were specifically bound to the cells, suggesting the presence of binding proteins other than CCK1-R and CCK2-R on IEC cells. High-affinity ( Kd= 0.5–1.0 nM) binding sites for125I-rhPG were discovered on IEC cells that demonstrated relative binding affinity for gastrin-like peptides in the order PG ≥ COOH-terminally extended G17 ≥ G-Gly > G17 > *CCK-8 (* significant difference; P< 0.05). In conclusion, our studies demonstrate for the first time direct growth effects of the full-length precursor peptide on IEC cells in vitro that are apparently mediated by the high-affinity PG binding sites that were discovered on these cells.

Comparison of gene expression and activation of transcription factors in organoid-derived monolayer intestinal epithelial cells and organoids

2021 ◽  
Author(s):  
Yu Takahashi ◽  
Yu Inoue ◽  
Keitaro Kuze ◽  
Shintaro Sato ◽  
Makoto Shimizu ◽  
...  
Keyword(s):  
Gene Expression ◽  
Epithelial Cells ◽  
Gene Expression Regulation ◽  
Intestinal Epithelial Cells ◽  
Three Dimensional ◽  
Culture Conditions ◽  
Dependent Manner ◽  
Intestinal Epithelial

Abstract Intestinal organoids better represent in vivo intestinal properties than conventionally used established cell lines in vitro. However, they are maintained in three-dimensional culture conditions that may be accompanied by handling complexities. We characterized the properties of human organoid-derived two-dimensionally cultured intestinal epithelial cells (IECs) compared with those of their parental organoids. We found that the expression of several intestinal markers and functional genes were indistinguishable between monolayer IECs and organoids. We further confirmed that their specific ligands equally activate intestinal ligand-activated transcriptional regulators in a dose-dependent manner. The results suggest that culture conditions do not significantly influence the fundamental properties of monolayer IECs originating from organoids, at least from the perspective of gene expression regulation. This will enable their use as novel biological tools to investigate the physiological functions of the human intestine.

7 LACTOBACILLUS REUTERI SUPPRESSES PRO-INFLAMMATORY DRIVEN REACTIVE OXYGEN SPECIES IN VITRO IN HUMAN INTESTINAL EPITHELIAL CELLS AND IN VIVO IN A TNBS COLITIS MOUSE MODEL

2020 ◽  
Vol 26 (Supplement_1) ◽  
pp. S41-S41 ◽  
Author(s):  
Wenly Ruan ◽  
Melinda Engevik ◽  
Alexandra Chang-Graham ◽  
Joseph Hyser ◽  
James Versalovic
Keyword(s):  
Reactive Oxygen Species ◽  
Epithelial Cells ◽  
Lactobacillus Reuteri ◽  
Intestinal Inflammation ◽  
Intestinal Epithelial Cells ◽  
Oxygen Species ◽  
Intestinal Epithelial ◽  
Colitis Model

Abstract Background Reactive oxygen species (ROS) play a role in maintaining intestinal epithelial homeostasis and are normally kept at low levels via antioxidant compounds. Dysregulation of ROS can lead to intestinal inflammation and contribute to inflammatory bowel disease (IBD). Select gut microbes possess the enzymatic machinery to produce antioxidants whereas others can dysregulate levels of ROS. Our model microbe, Lactobacillus reuteri (ATCC PTA 6475), has been demonstrated to reduce intestinal inflammation in mice models. It contains the genes encoding two distinct GshA-like glutamylcysteine ligases. We hypothesize that L. reuteri can secrete γ-glutamylcysteine to suppress ROS, minimize NFκB activation and regulate secretion of e pithelial cytokines. Methods & Results Conditioned media from L. reuteri was analyzed via mass spectrometry to confirm the presence of γ-glutamylcysteine. All cysteine containing products including γ-glutamylcysteine were fluorescently tagged in the conditioned media and then incubated with HT29 cell monolayers as well as human jejunal enteroid (HJE) monolayers. γ-glutamylcysteine was demonstrated to enter intestinal epithelial cells based on microscopy. Next, a Thioltracker assay was used to show increased intracellular glutathione levels by L. reuteri secreted γ-glutamylcysteine. HT29 cells and HJEs were then treated with IL-1β or hydrogen peroxide, and L. reuteri metabolites as well as γ-glutamylcysteine significantly suppressed pro-inflammatory cytokine driven ROS and IL-8 production. L. reuteri secreted products also reduced activity of NFκB as determined by a luciferase reporter assay. γ-glutamylcysteine deficient mutants were generated by targeted mutagenesis of GshA genes, and these mutant L. reuteri strains had a diminished ability to suppress IL-8 production and ROS. To further test the role of L. reuteri secreted γ-glutamylcysteine in vivo, a 2,4,6-Trinitrobenzenesulfonic acid (TNBS)- induced mouse colitis model was used. Adolescent mice were orogavaged with PBS, L. reuteri, L. reuteri GshA2 mutant, or γ-glutamylcysteine for a week after which TNBS was rectally administered to induce colitis. We demonstrate that L. reuteri and γ-glutamylcysteine can suppress histologic inflammation compared to PBS control and L. reuteri GshA2 mutant groups. Conclusions Together these data indicate that L. reuteri secretes γ-glutamylcysteine which can enter the intestinal epithelial cells and modulate epithelial cytokine production. It acts via suppression of ROS and NFκB which then decreases IL-8 production. We are able to demonstrate this in vitro in both HT 29 cells and HJEs. We now also demonstrate this in vivo in a mouse colitis model. These experiments highlight a prominent role for ROS intermediates in microbiome-mammalian cell signaling processes involved in immune responses and intestinal inflammation.

scholarly journals Functional and Genomic Characterization of Ligilactobacillus salivarius TUCO-L2 Isolated From Lama glama Milk: A Promising Immunobiotic Strain to Combat Infections

2020 ◽  
Vol 11 ◽  
Author(s):  
Sandra Quilodrán-Vega ◽  
Leonardo Albarracin ◽  
Flavia Mansilla ◽  
Lorena Arce ◽  
Binghui Zhou ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Functional Characterization ◽  
Comparative Genomic ◽  
Cytokines And Chemokines ◽  
Isolation And Characterization ◽  
Intestinal Pathogens ◽  
Lama Glama

Potential probiotic or immunobiotic effects of lactic acid bacteria (LAB) isolated from the milk of the South American camelid llama (Lama glama) have not been reported in published studies. The aim of the present work was to isolate beneficial LAB from llama milk that can be used as potential probiotics active against bacterial pathogens. LAB strains were isolated from llama milk samples. In vitro functional characterization of the strains was performed by evaluating the resistance against gastrointestinal conditions and inhibition of the pathogen growth. Additionally, the adhesive and immunomodulatory properties of the strains were assessed. The functional studies were complemented with a comparative genomic evaluation and in vivo studies in mice. Ligilactobacillus salivarius TUCO-L2 showed enhanced probiotic/immunobiotic potential compared to that of other tested strains. The TUCO-L2 strain was resistant to pH and high bile salt concentrations and demonstrated antimicrobial activity against Gram-negative intestinal pathogens and adhesion to mucins and epithelial cells. L. salivarius TUCO-L2 modulated the innate immune response triggered by Toll-like receptor (TLR)-4 activation in intestinal epithelial cells. This effect involved differential regulation of the expression of inflammatory cytokines and chemokines mediated by the modulation of the negative regulators of the TLR signaling pathway. Moreover, the TUCO-L2 strain enhanced the resistance of mice to Salmonella infection. This is the first report on the isolation and characterization of a potential probiotic/immunobiotic strain from llama milk. The in vitro, in vivo, and in silico investigation performed in this study reveals several research directions that are needed to characterize the TUCO-L2 strain in detail to position this strain as a probiotic or immunobiotic that can be used against infections in humans or animals, including llama.

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