scholarly journals ExoT of Cytotoxic Pseudomonas aeruginosaPrevents Uptake by Corneal Epithelial Cells

2000 ◽  
Vol 68 (1) ◽  
pp. 403-406 ◽  
Author(s):  
Brigitte A. Cowell ◽  
David Y. Chen ◽  
Dara W. Frank ◽  
Amy J. Vallis ◽  
Suzanne M. J. Fleiszig
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Epithelial Cell ◽  
Epithelial Cells ◽  
Cell Line ◽  
Inhibitory Activity ◽  
Transcriptional Activator ◽  
Effector Proteins ◽  
Epithelial Cell Line ◽  
Corneal Epithelial Cells ◽  
Corneal Epithelial

ABSTRACT The presence of invasion-inhibitory activity that is regulated by the transcriptional activator ExsA of cytotoxic Pseudomonas aeruginosa has previously been proposed. The results of this study show that both ExoT and ExoS, known type III secreted effector proteins of P. aeruginosa that are regulated by ExsA, possess this activity. Invasion was reduced 94.4% by ExoT and 96.0% by ExoS. Invasion-inhibitory activity is not linked to ADP-ribosylation activity, at least for ExoS, since a noncatalytic mutant also inhibits uptake by an epithelial cell line (invasion was reduced 96.0% by ExoSE381A).

scholarly journals Expression of immune response genes in human corneal epithelial cells interacting with Aspergillus flavus conidia

BMC Genomics ◽  
2022 ◽  
Vol 23 (1) ◽  
Author(s):  
Divya Arunachalam ◽  
Shruthi Mahalakshmi Ramanathan ◽  
Athul Menon ◽  
Lekshmi Madhav ◽  
Gopalakrishna Ramaswamy ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Cell Line ◽  
Differentially Expressed Genes ◽  
Primary Cultures ◽  
Differentially Expressed ◽  
Corneal Epithelial Cell ◽  
Epithelial Cell Line ◽  
Corneal Epithelial Cells ◽  
Corneal Epithelial ◽  
Human Corneal Epithelial Cells

Abstract Background Aspergillus flavus, one of the causative agents of human fungal keratitis, can be phagocytosed by human corneal epithelial (HCE) cells and the conidia containing phagosomes mature into phagolysosomes. But the immunological responses of human corneal epithelial cells interacting with A. flavus are not clear. In this study, we report the expression of immune response related genes of HCE cells exposed to A. flavus spores using targeted transcriptomics. Methods Human corneal epithelial cell line and primary cultures were grown in a six-well plate and used for coculture experiments. Internalization of the conidia was confirmed by immunofluorescence microscopy of the colocalized endosomal markers CD71 and LAMP1. Total RNA was isolated, and the quantity and quality of the isolated RNA were assessed using Qubit and Bioanalyzer. NanoString nCounter platform was used for the analysis of mRNA abundance using the Human Immunology panel. R-package and nSolver software were used for data analysis. KEGG and FunRich 3.1.3 tools were used to analyze the differentially expressed genes. Results Different morphotypes of conidia were observed after 6 h of coculture with human corneal epithelial cells and found to be internalized by epithelial cells. NanoString profiling showed more than 20 differentially expressed genes in immortalized human corneal epithelial cell line and more than ten differentially expressed genes in primary corneal epithelial cells. Distinct set of genes were altered in their expression in cell line and primary corneal epithelial cells. KEGG pathway analysis revealed that genes associated with TNF signaling, NF-KB signaling, and Th17 signaling were up-regulated, and genes associated with chemokine signaling and B cell receptor signaling were down regulated. FunRich pathway analysis showed that pathways such as CDC42 signaling, PI3K signaling, and Arf6 trafficking events were activated by the clinical isolates CI1123 and CI1698 in both type of cells. Conclusions Combining the transcript analysis data from cell lines and primary cultures, we showed the up regulation of immune defense genes in A. flavus infected cells. At the same time, chemokine signaling and B cell signaling pathways are downregulated. The variability in the expression levels in the immortalized cell line and the primary cultures is likely due to the variable epigenetic reprogramming in the immortalized cells and primary cultures in the absence of any changes in the genome. It highlights the importance of using both cell types in host-pathogen interaction studies.

scholarly journals The Pseudomonas aeruginosa Exopolysaccharide Psl Facilitates Surface Adherence and NF-κB Activation in A549 Cells

mBio ◽  
2010 ◽  
Vol 1 (3) ◽  
Author(s):  
Matthew S. Byrd ◽  
Bing Pang ◽  
Meenu Mishra ◽  
W. Edward Swords ◽  
Daniel J. Wozniak
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Epithelial Cell ◽  
Epithelial Cells ◽  
Cell Line ◽  
A549 Cells ◽  
Luciferase Reporter ◽  
Epithelial Cell Line ◽  
Bacterial Cells ◽  
Burn Wound ◽  
The Impact

ABSTRACTIn order for the opportunistic Gram-negative pathogenPseudomonas aeruginosato cause an airway infection, the pathogen interacts with epithelial cells and the overlying mucous layer. We examined the contribution of the biofilm polysaccharide Psl to epithelial cell adherence and the impact of Psl on proinflammatory signaling by flagellin. Psl has been implicated in the initial attachment ofP. aeruginosato biotic and abiotic surfaces, but its direct role in pathogenesis has not been evaluated (L. Ma, K. D. Jackson, R. M. Landry, M. R. Parsek, and D. J. Wozniak, J. Bacteriol. 188:8213–8221, 2006). Using an NF-κB luciferase reporter system in the human epithelial cell line A549, we show that both Psl and flagellin are necessary for full activation of NF-κB and production of the interleukin 8 (IL-8) chemokine. We demonstrate that Psl does not directly stimulate NF-κB activity, but indirectly as a result of increasing contact between bacterial cells and epithelial cells, it facilitates flagellin-mediated proinflammatory signaling. We confirm differential adherence of Psl and/or flagellin mutants by scanning electron microscopy and identify Psl-dependent membrane structures that may participate in adherence. Although we hypothesized that Psl would protectP. aeruginosafrom recognition by the epithelial cell line A549, we instead observed a positive role for Psl in flagellin-mediated NF-κB activation, likely as a result of increasing contact between bacterial cells and epithelial cells.IMPORTANCEPseudomonas aeruginosais the predominant airway pathogen causing morbidity and mortality in individuals affected by the genetic disease cystic fibrosis.P. aeruginosacan also cause severe pneumonia, burn wound infections, and sepsis, making its overall impact on human health significant. The attachment ofP. aeruginosato host tissues, often leading to recalcitrant biofilm infections, and inflammation induced by flagellin are both important mechanisms of virulence. We explored the role of the biofilm polysaccharide Psl in the pathogenesis ofP. aeruginosaand found that Psl is required for surface adherence to A549 epithelial cells, and as an adhesin, it facilitates flagellin-mediated NF-κB activation. This work was done to better understand the initial events of infection and revealed that a biofilm polysaccharide contributes to inflammation in a novel manner.

scholarly journals FlhA, a Component of the Flagellum Assembly Apparatus of Pseudomonas aeruginosa, Plays a Role in Internalization by Corneal Epithelial Cells

2001 ◽  
Vol 69 (8) ◽  
pp. 4931-4937 ◽  
Author(s):  
Suzanne M. J. Fleiszig ◽  
Shiwani K. Arora ◽  
Rajana Van ◽  
Reuben Ramphal
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Epithelial Cell ◽  
Epithelial Cells ◽  
Vector Control ◽  
Plasmid Vector ◽  
Wild Type ◽  
Corneal Epithelial Cells ◽  
Corneal Epithelial

ABSTRACT Pseudomonas aeruginosa invades various epithelial cell types in vitro and in vivo. The P. aeruginosa genome possesses a gene (flhA) which encodes a protein that is believed to be part of the export apparatus for flagellum assembly and which is homologous to invA of Salmonella spp. Because invA is required for invasion ofSalmonella spp., a role for flhA in P. aeruginosa invasion was explored using cultured rabbit corneal epithelial cells. An flhA mutant of P. aeruginosa strain PAO1 was constructed and was shown to be nonmotile. Complementation with flhA in transrestored motility. Corneal cells were infected for 3 h with the wild type (PAO1), the flhA mutant, the flhA mutant complemented with flhA in trans, anflhA mutant containing the plasmid vector control, or anfliC mutant (nonmotile mutant control). Invasion was quantified by amikacin exclusion assays. Both the flhA and the fliC mutants invaded at a lower level than the wild-type strain did, suggesting that both fliC andflhA played roles in invasion. However, loss of motility was not sufficient to explain the reduced invasion by flhAmutants, since centrifugation of bacteria onto cells did not restore invasion to wild-type levels. Unexpectedly, the flhA mutant adhered significantly better to corneal epithelial cells than wild-type bacteria or the fliC mutant did. The percentage of adherent bacteria that invaded was reduced by ∼80% for the flhAmutant and ∼50% for the fliC mutant, showing that only part of the role of flhA in invasion involvesfliC. Invasion was restored by complementing theflhA mutant with flhA in trans but not by the plasmid vector control. Intracellular survival assays, in which intracellular bacteria were enumerated after continued incubation in the presence of antibiotics, showed that although flhAand fliC mutants had a reduced capacity for epithelial cell entry, they were not defective in their ability to survive within those cells after entry. These results suggest that the flagellum assembly type III secretion system plays a role in P. aeruginosainvasion of epithelial cells. Since the flhA mutants were not defective in their ability to adhere to corneal epithelial cells, to retain viability at the cell surface, or to survive inside epithelial cells after entry, the role of flhA in invasion of epithelial cells is likely to occur during the process of bacterial internalization.

scholarly journals Development of a spontaneous permanent cell line of rabbit corneal epithelial cells that undergoes sequential stages of differentiation in cell culture

1994 ◽  
Vol 107 (8) ◽  
pp. 2343-2351 ◽  
Author(s):  
F. Castro-Munozledo
Keyword(s):  
Epithelial Cell ◽  
Epithelial Cells ◽  
Cell Line ◽  
Primary Cultures ◽  
Population Doubling ◽  
Corneal Epithelial Cells ◽  
Differentiation Potential ◽  
Corneal Epithelial ◽  
Permanent Cell Line ◽  
Permanent Cell

Established epithelial cell lines that retain their differentiation potential and growth regulatory characteristics can provide valuable tools for studying gene regulation, extracellular matrix synthesis or growth factor response. They are also useful for drug development and toxicity testing. Experiments were therefore carried out to optimize culture conditions for the long-term, serial transfer of corneal epithelial cells in the presence of 3T3 feeder layers; and to establish a permanent cell line. In such experiments, rabbit corneal epithelial cells were seeded at low inoculation densities, and transferred every 5 days. After 80 population doublings, an epithelial cell line, RCE1, emerged. The cell line is heteroploid, with an average population doubling time of 15.5 hours (vs 18 hours for primary cultures). When RCE1 cells reached confluence, they stratified to form a three- to five-layered epithelium and expressed the differentiation-related keratin pair K3/K12 as shown by immunoblot and immunostaining. Biosynthetic labeling of proliferating, confluent and stratified cultures further showed that RCE1 cells expressed keratin pairs K5/K14, K6/K16 and K3/K12, thus mimicking faithfully the stage-dependent differentiation of primary cultures of rabbit corneal keratinocytes. The results demonstrated that RCE1 cells provide a useful model for studying corneal cell growth and differentiation.

Studying Permeability in a Commonly Used Epithelial Cell Line: T84 Intestinal Epithelial Cells

2011 ◽  
pp. 115-137 ◽  
Author(s):  
Rino P. Donato ◽  
Adaweyah El-Merhibi ◽  
Batjargal Gundsambuu ◽  
Kai Yan Mak ◽  
Emma R. Formosa ◽  
...  
Keyword(s):  
Epithelial Cell ◽  
Epithelial Cells ◽  
Cell Line ◽  
Intestinal Epithelial Cells ◽  
Epithelial Cell Line ◽  
Intestinal Epithelial

The lack of attachment of transformed embryonic lung epithelial cells to collagen I is corrected by fibronectin and FXIII

1986 ◽  
Vol 86 (1) ◽  
pp. 95-107
Author(s):  
M. Paye ◽  
C.M. Lapiere
Keyword(s):  
Epithelial Cell ◽  
Epithelial Cells ◽  
Cell Line ◽  
Lung Epithelial Cells ◽  
Collagen I ◽  
Epithelial Cell Line ◽  
Embryonic Lung ◽  
Lung Epithelial ◽  
Minimal Concentration ◽  
Pulmonary Epithelial Cell

PER cells, a transformed pulmonary epithelial cell line that adhered to a large extent to a fibronectin substratum, were found to be attachment-deficient to collagen I. Although fibronectin can bind to collagen I monomers and polymers, the addition of exogenous fibronectin in the attachment medium induced the adhesion of these cells to collagen I polymers but not to monomers. By adding the transglutaminase of blood coagulation, FXIII, in the presence of fibronectin, the attachment of PER cells to collagen I monomers could be recovered while the minimal concentration of fibronectin needed to promote their adhesion to polymers was lowered. These studies indicate that FXIII enhances the fibronectin-mediated attachment of PER cells to collagen I.

Basolateral secretion of kappa light chain in the polarised epithelial cell line, Caco-2

1989 ◽  
Vol 94 (2) ◽  
pp. 327-332
Author(s):  
E.J. Hughson ◽  
D.F. Cutler ◽  
C.R. Hopkins
Keyword(s):  
Epithelial Cell ◽  
Epithelial Cells ◽  
Cell Line ◽  
Light Chain ◽  
Intracellular Trafficking ◽  
Epithelial Cell Line ◽  
Kappa Light Chain ◽  
Immunoglobulin Kappa ◽  
Selective Delivery ◽  
Secretory Products

The immunoglobulin kappa light chain is constitutively secreted in non-polarised cells. It is therefore unlikely to display any of the signals thought to be required for the selective delivery of proteins to the apical or basolateral borders of polarised epithelial cells. We have transfected the gene for the kappa light chain into a polarised epithelial cell line (Caco-2) and shown that it is secreted predominantly from the basolateral surface. Metabolically labelled endogenous secretory products show the same polarity and we conclude, therefore, that in Caco-2 cells there is a major intracellular trafficking route to the basolateral border that requires no sorting signal.

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