scholarly journals Respiratory Viruses Augment the Adhesion of Bacterial Pathogens to Respiratory Epithelium in a Viral Species- and Cell Type-Dependent Manner

2006 ◽  
Vol 80 (4) ◽  
pp. 1629-1636 ◽  
Author(s):  
Vasanthi Avadhanula ◽  
Carina A. Rodriguez ◽  
John P. DeVincenzo ◽  
Yan Wang ◽  
Richard J. Webby ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Epithelial Cells ◽  
Airway Epithelial Cells ◽  
Airway Epithelial ◽  
Respiratory Epithelial Cells ◽  
Bronchial Epithelial ◽  
Immortalized Cell ◽  
Respiratory Epithelial ◽  
Primary Bronchial Epithelial Cells ◽  
Small Airway Epithelial Cells

ABSTRACT Secondary bacterial infections often complicate respiratory viral infections, but the mechanisms whereby viruses predispose to bacterial disease are not completely understood. We determined the effects of infection with respiratory syncytial virus (RSV), human parainfluenza virus 3 (HPIV-3), and influenza virus on the abilities of nontypeable Haemophilus influenzae and Streptococcus pneumoniae to adhere to respiratory epithelial cells and how these viruses alter the expression of known receptors for these bacteria. All viruses enhanced bacterial adhesion to primary and immortalized cell lines. RSV and HPIV-3 infection increased the expression of several known receptors for pathogenic bacteria by primary bronchial epithelial cells and A549 cells but not by primary small airway epithelial cells. Influenza virus infection did not alter receptor expression. Paramyxoviruses augmented bacterial adherence to primary bronchial epithelial cells and immortalized cell lines by up-regulating eukaryotic cell receptors for these pathogens, whereas this mechanism was less significant in primary small airway epithelial cells and in influenza virus infections. Respiratory viruses promote bacterial adhesion to respiratory epithelial cells, a process that may increase bacterial colonization and contribute to disease. These studies highlight the distinct responses of different cell types to viral infection and the need to consider this variation when interpreting studies of the interactions between respiratory cells and viral pathogens.

Resting and Cytokine-Stimulated Human Small Airway Epithelial Cells Recognize and Engulf Apoptotic Eosinophils

Blood ◽  
1999 ◽  
Vol 94 (8) ◽  
pp. 2827-2835 ◽  
Author(s):  
Garry M. Walsh ◽  
Darren W. Sexton ◽  
Morgan G. Blaylock ◽  
Catherine M. Convery
Keyword(s):  
Epithelial Cells ◽  
Interleukin 1 ◽  
Airway Epithelial Cells ◽  
Small Airway ◽  
Airway Epithelial ◽  
Human Bronchial Epithelial Cells ◽  
Bronchial Epithelial ◽  
Small Airway Epithelial Cells ◽  
Necrosis Factor

Eosinophils, which are prominent cells in asthmatic inflammation, undergo apoptosis and are recognized and engulfed by phagocytic macrophages in vitro. We have examined the ability of human small airway epithelial cells (SAEC) to recognize and ingest apoptotic human eosinophils. Cultured SAEC ingested apoptotic eosinophils but not freshly isolated eosinophils or opsonized erythrocytes. The ability of SAEC to ingest apoptotic eosinophils was enhanced by interleukin-1 (IL-1) or tumor necrosis factor  (TNF) in a time- and concentration-dependent fashion. IL-1 was found to be more potent than TNF and each was optimal at 10−10 mol/L, with a significant (P < .05) effect observed at 1 hour postcytokine incubation that was maximal at 5 hours. IL-1 stimulation not only increased the number of SAEC engulfing apoptotic eosinophils, but also enhanced their capacity for ingestion. The amino sugars glucosamine, n-acetyl glucosamine, and galactosamine significantly inhibited uptake of apoptotic eosinophils by both resting and IL-1–stimulated SAEC, in contrast to the parent sugars glucose, galactose, mannose, and fucose. Incubation of apoptotic eosinophils with the tetrapeptide RGDS, but not RGES, significantly inhibited their uptake by both resting and IL-1–stimulated SAEC, as did monoclonal antibody against vβ3 and CD36. Thus, SAEC recognize apoptotic eosinophils via lectin- and integrin-dependent mechanisms. These data demonstrate a novel function for human bronchial epithelial cells that might represent an important mechanism in the resolution of eosinophil-induced asthmatic inflammation.

Respiratory epithelial cells regulate lung inflammation in response to inhaled endotoxin

2004 ◽  
Vol 287 (1) ◽  
pp. L143-L152 ◽  
Author(s):  
Shawn J. Skerrett ◽  
H. Denny Liggitt ◽  
Adeline M. Hajjar ◽  
Robert K. Ernst ◽  
Samuel I. Miller ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Inflammatory Response ◽  
Transgenic Mice ◽  
Lung Inflammation ◽  
Airway Epithelial Cells ◽  
Airway Epithelial ◽  
Respiratory Epithelial Cells ◽  
Distal Airway ◽  
Tnf Α ◽  
Respiratory Epithelial

To determine the role of respiratory epithelial cells in the inflammatory response to inhaled endotoxin, we selectively inhibited NF-κB activation in the respiratory epithelium using a mutant IκB-α construct that functioned as a dominant negative inhibitor of NF-κB translocation (dnIκB-α). We developed two lines of transgenic mice in which expression of dnIκB-α was targeted to the distal airway epithelium using the human surfactant apoprotein C promoter. Transgene expression was localized to the epithelium of the terminal bronchioles and alveoli. After inhalation of LPS, nuclear translocation of NF-κB was evident in bronchiolar epithelium of nontransgenic but not of transgenic mice. This defect was associated with impaired neutrophilic lung inflammation 4 h after LPS challenge and diminished levels of TNF-α, IL-1β, macrophage inflammatory protein-2, and KC in lung homogenates. Expression of TNF-α within bronchiolar epithelial cells and of VCAM-1 within peribronchiolar endothelial cells was reduced in transgenic animals. Thus targeted inhibition of NF-κB activation in distal airway epithelial cells impaired the inflammatory response to inhaled LPS. These data provide causal evidence that distal airway epithelial cells and the signals they transduce play a physiological role in lung inflammation in vivo.

Cigarette smoke irreversibly modifies glutathione in airway epithelial cells

2007 ◽  
Vol 293 (5) ◽  
pp. L1156-L1162 ◽  
Author(s):  
Marco van der Toorn ◽  
Maria P. Smit-de Vries ◽  
Dirk-Jan Slebos ◽  
Harold G. de Bruin ◽  
Nicolas Abello ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Cigarette Smoke ◽  
A549 Cells ◽  
Airway Epithelial Cells ◽  
Chronic Obstructive ◽  
Airway Epithelial ◽  
Obstructive Pulmonary Disease ◽  
Bronchial Epithelial ◽  
Gsh Metabolism ◽  
Primary Bronchial Epithelial Cells

In patients with chronic obstructive pulmonary disease (COPD), an imbalance between oxidants and antioxidants is acknowledged to result in disease development and progression. Cigarette smoke (CS) is known to deplete total glutathione (GSH + GSSG) in the airways. We hypothesized that components in the gaseous phase of CS may irreversibly react with GSH to form GSH derivatives that cannot be reduced (GSX), thereby causing this depletion. To understand this phenomenon, we investigated the effect of CS on GSH metabolism and identified the actual GSX compounds. CS and H2O2 (control) deplete reduced GSH in solution [Δ = −54.1 ± 1.7 μM ( P < 0.01) and −39.8 ± 0.9 μM ( P < 0.01), respectively]. However, a significant decrease of GSH + GSSG was observed after CS (Δ = −75.1 ± 7.6 μM, P < 0.01), but not after H2O2. Exposure of A549 cells and primary bronchial epithelial cells to CS decreased free sulfhydryl (-SH) groups (Δ = −64.2 ± 14.6 μM/mg protein, P < 0.05) and irreversibly modified GSH + GSSG (Δ = −17.7 ± 1.9 μM, P < 0.01) compared with nonexposed cells or H2O2 control. Mass spectrometry (MS) showed that GSH was modified to glutathione-aldehyde derivatives. Further MS identification showed that GSH was bound to acrolein and crotonaldehyde and another, yet to be identified, structure. Our data show that CS does not oxidize GSH to GSSG but, rather, reacts to nonreducible glutathione-aldehyde derivatives, thereby depleting the total available GSH pool.

scholarly journals Hydrogen Sulfide Inhibits TMPRSS2 in Human Airway Epithelial Cells: Implications for SARS-CoV-2 Infection

Biomedicines ◽  
2021 ◽  
Vol 9 (9) ◽  
pp. 1273
Author(s):  
Giulia Pozzi ◽  
Elena Masselli ◽  
Giuliana Gobbi ◽  
Prisco Mirandola ◽  
Luis Taborda-Barata ◽  
...  
Keyword(s):  
Hydrogen Sulfide ◽  
Epithelial Cells ◽  
Airway Epithelial Cells ◽  
Surface Proteins ◽  
Lower Airway ◽  
Target Cells ◽  
Airway Epithelial ◽  
Respiratory Epithelial Cells ◽  
Respiratory Epithelial

The COVID-19 pandemic has now affected around 190 million people worldwide, accounting for more than 4 million confirmed deaths. Besides ongoing global vaccination, finding protective and therapeutic strategies is an urgent clinical need. SARS-CoV-2 mostly infects the host organism via the respiratory system, requiring angiotensin-converting enzyme 2 (ACE2) and transmembrane protease serine 2 (TMPRSS2) to enter target cells. Therefore, these surface proteins are considered potential druggable targets. Hydrogen sulfide (H2S) is a gasotransmitter produced by several cell types and is also part of natural compounds, such as sulfurous waters that are often inhaled as low-intensity therapy and prevention in different respiratory conditions. H2S is a potent biological mediator, with anti-oxidant, anti-inflammatory, and, as more recently shown, also anti-viral activities. Considering that respiratory epithelial cells can be directly exposed to H2S by inhalation, here we tested the in vitro effects of H2S-donors on TMPRSS2 and ACE2 expression in human upper and lower airway epithelial cells. We showed that H2S significantly reduces the expression of TMPRSS2 without modifying ACE2 expression both in respiratory cell lines and primary human upper and lower airway epithelial cells. Results suggest that inhalational exposure of respiratory epithelial cells to natural H2S sources may hinder SARS-CoV-2 entry into airway epithelial cells and, consequently, potentially prevent the virus from spreading into the lower respiratory tract and the lung.

Effects of aqueous extracts of PM10 filters from the Utah Valley on human airway epithelial cells

1999 ◽  
Vol 277 (5) ◽  
pp. L960-L967 ◽  
Author(s):  
Mark W. Frampton ◽  
Andrew J. Ghio ◽  
James M. Samet ◽  
Johnny L. Carson ◽  
Jacqueline D. Carter ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Ambient Air ◽  
Airway Epithelial Cells ◽  
Aqueous Extracts ◽  
Airway Epithelial ◽  
Steel Mill ◽  
Respiratory Epithelial Cells ◽  
Lactate Dehydrogenase Release ◽  
Oxidant Production ◽  
Respiratory Epithelial

We hypothesized that the reduction in hospital respiratory admissions in the Utah Valley during closure of a local steel mill in 1986–1987 was attributable in part to decreased toxicity of ambient air particles. Sampling filters for particulate matter < 10 μm (PM10) were obtained from a Utah Valley monitoring station for the year before ( year 1), during ( year 2), and after ( year 3) the steel mill closure. Aqueous extracts of the filters were analyzed for metal content and oxidant production and added to cultures of human respiratory epithelial (BEAS-2B) cells for 2 or 24 h. Year 2 dust contained the lowest concentrations of soluble iron, copper, and zinc and showed the least oxidant generation. Only dust from year 3 caused cytotoxicity (by microscopy and lactate dehydrogenase release) at 500 μg/ml. Year 1 and year 3, but not year 2, dust induced expression of interleukin-6 and -8 in a dose-response fashion. The effects of ambient air particles on human respiratory epithelial cells vary significantly with time and metal concentrations.

Visualization of labile zinc and its role in apoptosis of primary airway epithelial cells and cell lines

2000 ◽  
Vol 279 (6) ◽  
pp. L1172-L1183 ◽  
Author(s):  
Ai Q. Truong-Tran ◽  
Richard E. Ruffin ◽  
Peter D. Zalewski
Keyword(s):  
Hydrogen Peroxide ◽  
Epithelial Cells ◽  
Airway Epithelial Cells ◽  
Zn Deficiency ◽  
The Novel ◽  
Airway Epithelial ◽  
Caspase Activation ◽  
Respiratory Epithelial Cells ◽  
Upper Respiratory ◽  
Respiratory Epithelial

The respiratory epithelium is vulnerable to noxious substances, resulting in the shedding of cells and decreased protection. Zinc (Zn), an antioxidant and cytoprotectant, can suppress apoptosis in a variety of cells. Here we used the novel Zn-specific fluorophore Zinquin to visualize and quantify labile intracellular Zn in respiratory epithelial cells. Zinquin fluorescence in isolated ciliated tracheobronchial epithelial cells and intact epithelium from sheep and pigs revealed an intense fluorescence in the apical and mitochondria-rich cytoplasm below the cilia. Zinquin fluorescence was quenched by the Zn chelator N, N, N′, N′-tetrakis(2-pyridylmethyl)ethylenediamine (TPEN) and increased by the Zn ionophore pyrithione. We also assessed whether changes in intracellular labile Zn would influence susceptibility of these cells to apoptosis by hydrogen peroxide. Our results confirm that Zn deficiency enhanced hydrogen peroxide-induced caspase activation from 1.24 ± 0.12 to 2.58 ± 0.53 units · μg protein−1· h−1( P ≤ 0.05); Zn supplementation suppressed these effects. These findings are consistent with the hypothesis that Zn protects upper respiratory epithelial cells and may have implications for human asthma where there is hypozincemia and epithelial damage.

Respiratory epithelial cells demonstrate lactoferrin receptors that increase after metal exposure

1999 ◽  
Vol 276 (6) ◽  
pp. L933-L940 ◽  
Author(s):  
Andrew J. Ghio ◽  
Jacqueline D. Carter ◽  
Lisa A. Dailey ◽  
Robert B. Devlin ◽  
James M. Samet
Keyword(s):  
Oxidative Stress ◽  
Fly Ash ◽  
Epithelial Cells ◽  
Airway Epithelial Cells ◽  
Metal Exposure ◽  
Airway Epithelial ◽  
Respiratory Epithelial Cells ◽  
Catalytically Active ◽  
Oil Fly Ash ◽  
Respiratory Epithelial

Human airway epithelial cells can increase expression of both lactoferrin and ferritin after exposure to catalytically active metal. These proteins transport and store metal, with coordination sites fully complexed, and therefore can diminish the oxidative stress. The intracellular transport of lactoferrin results in a transfer of complexed metal to ferritin, where it is stored in a less reactive form. This effort to control the injurious properties of metals would be facilitated by lactoferrin receptors (LfRs) on airway epithelial cells. We tested the hypotheses that 1) LfRs exist on respiratory epithelial cells and 2) exposure to both an air pollution particle, which has abundant concentrations of metals, and individual metal salts increase the expression of LfRs. Before exposure to either the particle or metals, incubation of BEAS-2B cells with varying concentrations of125I-labeled lactoferrin demonstrated lactoferrin binding that was saturable. Measurement of125I-lactoferrin binding after the inclusion of 100 μg/ml of oil fly ash in the incubation medium demonstrated increased binding within 5 min of exposure, which reached a maximal value at 45 min. Inclusion of 1.0 mM deferoxamine in the incubation of BEAS-2B cells with 100 μg/ml of oil fly ash decreased lactoferrin binding. Comparable to the particle, exposure of BEAS-2B cells to either 1.0 mM vanadyl sulfate or 1.0 mM iron (III) sulfate, but not to nickel sulfate, for 45 min elevated LfR activity. We conclude that LfRs on respiratory epithelial cells increased after exposure to metal. LfRs could participate in decreasing the oxidative stress presented to the lower respiratory tract by complexing catalytically active metals.

scholarly journals Crystalline silica particles cause rapid NLRP3-dependent mitochondrial depolarization and DNA damage in airway epithelial cells

2020 ◽  
Vol 17 (1) ◽  
Author(s):  
Rongrong Wu ◽  
Johan Högberg ◽  
Mikael Adner ◽  
Patricia Ramos-Ramírez ◽  
Ulla Stenius ◽  
...  
Keyword(s):  
Dna Damage ◽  
Epithelial Cells ◽  
Airway Epithelial Cells ◽  
Silica Particles ◽  
Airway Epithelial ◽  
Respiratory Epithelial Cells ◽  
Damage Response ◽  
Exposure Levels ◽  
Respiratory Epithelial

Abstract Background Respirable crystalline silica causes lung carcinomas and many thousand future cancer cases are expected in e.g. Europe. Critical questions are how silica causes genotoxicity in the respiratory epithelium and if new cases can be avoided by lowered permissible exposure levels. In this study we investigate early DNA damaging effects of low doses of silica particles in respiratory epithelial cells in vitro and in vivo in an effort to understand low-dose carcinogenic effects of silica particles. Results We find DNA damage accumulation already after 5–10 min exposure to low doses (5 μg/cm2) of silica particles (Min-U-Sil 5) in vitro. DNA damage was documented as increased levels of γH2AX, pCHK2, by Comet assay, AIM2 induction, and by increased DNA repair (non-homologous end joining) signaling. The DNA damage response (DDR) was not related to increased ROS levels, but to a NLRP3-dependent mitochondrial depolarization. Particles in contact with the plasma membrane elicited a Ser198 phosphorylation of NLRP3, co-localization of NLRP3 to mitochondria and depolarization. FCCP, a mitochondrial uncoupler, as well as overexpressed NLRP3 mimicked the silica-induced depolarization and the DNA damage response. A single inhalation of 25 μg silica particles gave a similar rapid DDR in mouse lung. Biomarkers (CC10 and GPRC5A) indicated an involvement of respiratory epithelial cells. Conclusions Our findings demonstrate a novel mode of action (MOA) for silica-induced DNA damage and mutagenic double strand breaks in airway epithelial cells. This MOA seems independent of particle uptake and of an involvement of macrophages. Our study might help defining models for estimating exposure levels without DNA damaging effects.

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

1999 ◽  
Vol 277 (3) ◽  
pp. L465-L471 ◽  
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.

Sign in / Sign up

Export Citation Format

Share Document