The effects of poly I:C stimulation of primary bronchial epithelial cells and TSLP secretion on CD34+ progenitor cell eosinophil and basophil differentiation

Non-typeable Haemophilus influenzae (NTHi) is the most common respiratory pathogen in patients with chronic obstructive disease. Limited data is available investigating the impact of NTHi infections on cellular re-differentiation processes in the bronchial mucosa. The aim of this study was to assess the effects of stimulation with NTHi on the bronchial epithelium regarding cellular re-differentiation processes using primary bronchial epithelial cells harvested from infection-free patients undergoing bronchoscopy. The cells were then cultivated using an air-liquid interface and stimulated with NTHi and TGF-β. Markers of epithelial and mesenchymal cells were analyzed using immunofluorescence, Western blot and qRT-PCR. Stimulation with both NTHi and TGF-ß led to a marked increase in the expression of the mesenchymal marker vimentin, while E-cadherin as an epithelial marker maintained a stable expression throughout the experiments. Furthermore, expression of collagen 4 and the matrix-metallopeptidases 2 and 9 were increased after stimulation, while the expression of tissue inhibitors of metallopeptidases was not affected by pathogen stimulation. In this study we show a direct pathogen-induced trans-differentiation of primary bronchial epithelial cells resulting in a co-localization of epithelial and mesenchymal markers and an up-regulation of extracellular matrix components.

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Stimulation of both human bronchial epithelium and neutrophils is needed for maximal interactive adhesion

AJP Lung Cellular and Molecular Physiology ◽

10.1152/ajplung.1996.270.1.l80 ◽

1996 ◽

Vol 270 (1) ◽

pp. L80-L87 ◽

Cited By ~ 5

Author(s):

P. G. Bloemen ◽

M. C. Van den Tweel ◽

P. A. Henricks ◽

F. Engels ◽

M. J. Van de Velde ◽

...

Keyword(s):

Epithelial Cells ◽

Cultured Cells ◽

Bronchial Epithelium ◽

Bronchial Epithelial Cells ◽

Intercellular Adhesion Molecule ◽

Tnf Alpha ◽

Epithelial Cell Line ◽

Ifn Gamma ◽

Bronchial Epithelial ◽

Stimulation Of

It has become clear that the bronchial epithelium is not just a passive barrier but plays an active role in inflammation. It can produce several inflammatory mediators and does express cell adhesion molecules of which intercellular adhesion molecule (ICAM)-1 can be upregulated by cytokines like interferon (IFN)-gamma. In the present study, we analyzed in detail the interaction of neutrophils with human bronchial epithelial cells, both primary cultured cells and the bronchial epithelial cell line BEAS-2B. Confluent monolayers of epithelial cells were incubated with freshly isolated 51Cr-labeled neutrophils for 30 min at 37 degrees C; then the nonadherent cells were removed by washing gently. Stimulation of the epithelial cells with IFN-gamma or the combination of IFN-gamma and tumor necrosis factor-alpha (TNF-alpha) (which doubles the ICAM-1 expression) increased neutrophil adhesion. Activation of the neutrophils themselves with N-formylmethionyl-leucyl-phenylalanine (fMLP), platelet-activating factor, or TNF-alpha also caused a profound enhancement of the adhesion. A significant additional increase was found when the epithelial cells had been exposed to IFN-gamma and the neutrophils were stimulated with fMLP simultaneously. This effect was even more pronounced with epithelium preincubated with IFN-gamma and TNF-alpha. With the use of monoclonal antibodies against CD18 and ICAM-1, it was demonstrated that the increased adhesion was mainly mediated by the ICAM-1/beta 2-integrin interaction. This study highlights that both the activation state of the bronchial epithelial cells and the activation state of the neutrophils are critical for their interactive adhesion.

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ICAM-1-independent adhesion of neutrophils to phorbol ester-stimulated human airway epithelial cells

AJP Lung Cellular and Molecular Physiology ◽

10.1152/ajplung.1999.277.3.l465 ◽

1999 ◽

Vol 277 (3) ◽

pp. L465-L471 ◽

Cited By ~ 3

Author(s):

Alessandro Celi ◽

Silvana Cianchetti ◽

Stefano Petruzzelli ◽

Stefano Carnevali ◽

Filomena Baliva ◽

...

Keyword(s):

Epithelial Cells ◽

Airway Epithelial Cells ◽

Bronchial Epithelial Cells ◽

Neutrophil Adhesion ◽

Late Time ◽

Airway Epithelial ◽

Bronchial Epithelial ◽

Human Airway ◽

Stimulation Of ◽

Human Airway Epithelial Cells

Intercellular adhesion molecule-1 (ICAM-1) is the only inducible adhesion receptor for neutrophils identified in bronchial epithelial cells. We stimulated human airway epithelial cells with various agonists to evaluate whether ICAM-1-independent adhesion mechanisms could be elicited. Phorbol 12-myristate 13-acetate (PMA) stimulation of cells of the alveolar cell line A549 caused a rapid, significant increase in neutrophil adhesion from 11 ± 3 to 49 ± 7% (SE). A significant increase from 17 ± 4 to 39 ± 6% was also observed for neutrophil adhesion to PMA-stimulated human bronchial epithelial cells in primary culture. Although ICAM-1 expression was upregulated by PMA at late time points, it was not affected at 10 min when neutrophil adhesion was already clearly enhanced. Antibodies to ICAM-1 had no effect on neutrophil adhesion. In contrast, antibodies to the leukocyte integrin β-chain CD18 totally inhibited the adhesion of neutrophils to PMA-stimulated epithelial cells. These results demonstrate that PMA stimulation of human airway epithelial cells causes an increase in neutrophil adhesion that is not dependent on ICAM-1 upregulation.

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