scholarly journals The Contribution of the Airway Epithelial Cell to Host Defense

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Frauke Stanke
Keyword(s):  
Cystic Fibrosis ◽  
Epithelial Cell ◽  
Ion Transport ◽  
Host Defense ◽  
Immune Defense ◽  
Bicarbonate Transport ◽  
Airway Epithelial ◽  
Defense Proteins ◽  
Inflammatory Conditions

In the context of cystic fibrosis, the epithelial cell has been characterized in terms of its ion transport capabilities. The ability of an epithelial cell to initiate CFTR-mediated chloride and bicarbonate transport has been recognized early as a means to regulate the thickness of the epithelial lining fluid and recently as a means to regulate the pH, thereby determining critically whether or not host defense proteins such as mucins are able to fold appropriately. This review describes how the epithelial cell senses the presence of pathogens and inflammatory conditions, which, in turn, facilitates the activation of CFTR and thus directly promotes pathogens clearance and innate immune defense on the surface of the epithelial cell. This paper summarizes functional data that describes the effect of cytokines, chemokines, infectious agents, and inflammatory conditions on the ion transport properties of the epithelial cell and relates these key properties to the molecular pathology of cystic fibrosis. Recent findings on the role of cystic fibrosis modifier genes that underscore the role of the epithelial ion transport in host defense and inflammation are discussed.

Role of copper in defending against bacterial infection

2015 ◽  
Author(s):  
◽  
Erik Ladomersky
Keyword(s):  
Bacterial Infection ◽  
Host Defense ◽  
Immune Defense ◽  
Copper Proteins ◽  
University Of Missouri ◽  
Susceptibility To Infection ◽  
Essential Nutrient ◽  
The University ◽  
The Relationship

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT REQUEST OF AUTHOR.] Copper is an essential nutrient. It plays an important role in development, pigmentation, neurological function, and immune defense. Copper deficiency is known to make host's more susceptible to infection. In this work we show that two copper proteins, ATP7A and ceruloplasmin, are important for host defense against bacterial infection. Studies have shown ATP7A is responsible for increasing copper concentrations inside the phagosome. Our study sheds light on the role of Atp7a and copper in adaptive immunity, and provide a biochemical model for understanding the relationship between copper malnutrition and susceptibility to infection. Iron, another essential nutrient, is linked with copper through the actions of copper-dependent proteins which play a role in maintaining normal iron levels in the blood. One of these proteins is ceruloplasmin, a protein that is also upregulated during infection. Our study sheds light onto why this protein is necessary for host defense against Salmonella infection.

scholarly journals The Virulence Potential of Livestock-Associated Methicillin-Resistant Staphylococcus aureus Cultured from the Airways of Cystic Fibrosis Patients

Toxins ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 360
Author(s):  
Janina Treffon ◽  
Sarah Ann Fotiadis ◽  
Sarah van Alen ◽  
Karsten Becker ◽  
Barbara C. Kahl
Keyword(s):  
Cystic Fibrosis ◽  
Staphylococcus Aureus ◽  
Airway Epithelial Cells ◽  
Farm Animals ◽  
Airway Epithelial ◽  
Methicillin Resistant ◽  
Virulence Potential ◽  
Airway Infections ◽  
Severe Infections

Staphylococcus aureus is one of the most common pathogens that infects the airways of patients with cystic fibrosis (CF) and contributes to respiratory failure. Recently, livestock-associated methicillin-resistant S. aureus (LA-MRSA), usually cultured in farm animals, were detected in CF airways. Although some of these strains are able to establish severe infections in humans, there is limited knowledge about the role of LA-MRSA virulence in CF lung disease. To address this issue, we analyzed LA-MRSA, hospital-associated (HA-) MRSA and methicillin-susceptible S. aureus (MSSA) clinical isolates recovered early in the course of airway infection and several years after persistence in this hostile environment from pulmonary specimens of nine CF patients regarding important virulence traits such as their hemolytic activity, biofilm formation, invasion in airway epithelial cells, cytotoxicity, and antibiotic susceptibility. We detected that CF LA-MRSA isolates were resistant to tetracycline, more hemolytic and cytotoxic than HA-MRSA, and more invasive than MSSA. Despite the residence in the animal host, LA-MRSA still represent a serious threat to humans, as such clones possess a virulence potential similar or even higher than that of HA-MRSA. Furthermore, we confirmed that S. aureus individually adapts to the airways of CF patients, which eventually impedes the success of antistaphylococcal therapy of airway infections in CF.

scholarly journals Prostasin, a membrane-anchored serine peptidase, regulates sodium currents in JME/CF15 cells, a cystic fibrosis airway epithelial cell line

2004 ◽  
Vol 287 (5) ◽  
pp. L928-L935 ◽  
Author(s):  
Zhenyue Tong ◽  
Beate Illek ◽  
Vikash J. Bhagwandin ◽  
George M. Verghese ◽  
George H. Caughey
Keyword(s):  
Cystic Fibrosis ◽  
Epithelial Cell ◽  
Epithelial Cells ◽  
Airway Epithelial Cell ◽  
Epithelial Cell Line ◽  
Airway Epithelial ◽  
Ussing Chambers ◽  
Serine Peptidase ◽  
Cystic Fibrosis Airway ◽  
Interfering Rna

Prostasin is a tryptic peptidase expressed in prostate, kidney, lung, and airway. Mammalian prostasins are related to Xenopus channel-activating protease, which stimulates epithelial Na+ channel (ENaC) activity in frogs. In human epithelia, prostasin is one of several membrane peptidases proposed to regulate ENaC. This study tests the hypothesis that prostasin can regulate ENaC in cystic fibrosis epithelia in which excessive Na+ uptake contributes to salt and water imbalance. We show that prostasin mRNA and protein are strongly expressed by human airway epithelial cell lines, including immortalized JME/CF15 nasal epithelial cells homozygous for the ΔF508 cystic fibrosis mutation. Epithelial cells transfected with vectors encoding recombinant soluble prostasin secrete active, tryptic peptidase that is highly sensitive to inactivation by aprotinin. When studied as monolayers in Ussing chambers, JME/CF15 cells exhibit amiloride-sensitive, transepithelial Na+ currents that are markedly diminished by aprotinin, suggesting regulation by serine-class peptidases. Overproduction of membrane-anchored prostasin in transfected JME/CF15 cells does not augment Na+ currents, and trypsin-induced increases are small, suggesting that baseline serine peptidase-dependent ENaC activation is maximal in these cells. To probe prostasin’s involvement in basal ENaC activity, we silenced expression of prostasin using short interfering RNA targeting of prostasin mRNA’s 3′-untranslated region. This drops ENaC currents to 26 ± 9% of baseline. These data predict that prostasin is a major regulator of ENaC-mediated Na+ current in ΔF508 cystic fibrosis epithelia and suggest that airway prostasin is a target for therapeutic inhibition to normalize ion current in cystic fibrosis airway.

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