scholarly journals The Nod1, Nod2, and Rip2 Axis Contributes to Host Immune Defense against Intracellular Acinetobacter baumannii Infection

2013 ◽  
Vol 82 (3) ◽  
pp. 1112-1122 ◽  
Author(s):  
Pradeep Bist ◽  
Neha Dikshit ◽  
Tse Hsien Koh ◽  
Alessandra Mortellaro ◽  
Thuan Tong Tan ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Acinetobacter Baumannii ◽  
Airway Epithelial Cells ◽  
Immune Defense ◽  
Innate Immune ◽  
Lung Epithelial Cells ◽  
Airway Epithelial ◽  
Content Type ◽  
Mitogen Activated Protein

ABSTRACTAcinetobacter baumanniiis a major extensively drug-resistant lethal human nosocomial bacterium. However, the host innate immune mechanisms controllingA. baumanniiare not well understood. Although viewed as an extracellular pathogen,A. baumanniican also invade and survive intracellularly. However, whether host innate immune pathways sensing intracellular bacteria contribute to immunity againstA. baumanniiis not known. Here, we provide evidence for the first time that intracellular antibacterial innate immune receptors Nod1 and Nod2, and their adaptor Rip2, play critical roles in the sensing and clearance ofA. baumanniiby human airway epithelial cellsin vitro.A. baumanniiinfection upregulated Rip2 expression. Silencing of Nod1, Nod2, and Rip2 expression profoundly increased intracellular invasion and prolonged the multiplication and survival ofA. baumanniiin lung epithelial cells. Notably, the Nod1/2-Rip2 axis did not contribute to the control ofA. baumanniiinfection of human macrophages, indicating that they play cell type-specific roles. The Nod1/2-Rip2 axis was needed forA. baumanniiinfection-induced activation of NF-κB but not mitogen-activated protein kinases. Moreover, the Nod1/2-Rip2 axis was critical to induce optimal cytokine and chemokine responses toA. baumanniiinfection. Mechanistic studies showed that the Nod1/2 pathway contributed to the innate control ofA. baumanniiinfection through the production of β-defensin 2 by airway epithelial cells. This study revealed new insights into the immune control ofA. baumanniiand may contribute to the development of effective immune therapeutics and vaccines againstA. baumannii.

scholarly journals Arsenic upregulates MMP-9 and inhibits wound repair in human airway epithelial cells

2008 ◽  
Vol 295 (2) ◽  
pp. L293-L302 ◽  
Author(s):  
Colin E. Olsen ◽  
Andrew E. Liguori ◽  
Yue Zong ◽  
R. Clark Lantz ◽  
Jefferey L. Burgess ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Wound Repair ◽  
Arsenic Exposure ◽  
Airway Epithelial Cells ◽  
Immune Defense ◽  
Lung Epithelial Cells ◽  
Airway Epithelial ◽  
Lung Epithelium ◽  
Vitro Model

As part of the innate immune defense, the polarized conducting lung epithelium acts as a barrier to keep particulates carried in respiration from underlying tissue. Arsenic is a metalloid toxicant that can affect the lung via inhalation or ingestion. We have recently shown that chronic exposure of mice or humans to arsenic (10–50 ppb) in drinking water alters bronchiolar lavage or sputum proteins consistent with reduced epithelial cell migration and wound repair in the airway. In this report, we used an in vitro model to examine effects of acute exposure of arsenic (15–290 ppb) on conducting airway lung epithelium. We found that arsenic at concentrations as low as 30 ppb inhibits reformation of the epithelial monolayer following scrape wounds of monolayer cultures. In an effort to understand functional contributions to epithelial wound repair altered by arsenic, we showed that acute arsenic exposure increases activity and expression of matrix metalloproteinase (MMP)-9, an important protease in lung function. Furthermore, inhibition of MMP-9 in arsenic-treated cells improved wound repair. We propose that arsenic in the airway can alter the airway epithelial barrier by restricting proper wound repair in part through the upregulation of MMP-9 by lung epithelial cells.

scholarly journals Eosinophil Responses at the Airway Epithelial Barrier during the Early Phase of Influenza a Virus Infection in C57BL/6 Mice

Cells ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 509 ◽  
Author(s):  
Meenakshi Tiwary ◽  
Robert J. Rooney ◽  
Swantje Liedmann ◽  
Kim S. LeMessurier ◽  
Amali E. Samarasinghe
Keyword(s):  
Epithelial Cells ◽  
Influenza A Virus ◽  
Early Phase ◽  
Influenza A ◽  
Airway Epithelial Cells ◽  
Epithelial Barrier ◽  
Virus Infectivity ◽  
Airway Epithelial ◽  
In Vivo Models

Eosinophils, previously considered terminally differentiated effector cells, have multifaceted functions in tissues. We previously found that allergic mice with eosinophil-rich inflammation were protected from severe influenza and discovered specialized antiviral effector functions for eosinophils including promoting cellular immunity during influenza. In this study, we hypothesized that eosinophil responses during the early phase of influenza contribute to host protection. Using in vitro and in vivo models, we found that eosinophils were rapidly and dynamically regulated upon influenza A virus (IAV) exposure to gain migratory capabilities to traffic to lymphoid organs after pulmonary infection. Eosinophils were capable of neutralizing virus upon contact and combinations of eosinophil granule proteins reduced virus infectivity through hemagglutinin inactivation. Bi-directional crosstalk between IAV-exposed epithelial cells and eosinophils occurred after IAV infection and cross-regulation promoted barrier responses to improve antiviral defenses in airway epithelial cells. Direct interactions between eosinophils and airway epithelial cells after IAV infection prevented virus-induced cytopathology in airway epithelial cells in vitro, and eosinophil recipient IAV-infected mice also maintained normal airway epithelial cell morphology. Our data suggest that eosinophils are important in the early phase of IAV infection providing immediate protection to the epithelial barrier until adaptive immune responses are deployed during influenza.

Innate immune response in CF airway epithelia: hyperinflammatory?

2006 ◽  
Vol 291 (2) ◽  
pp. C218-C230 ◽  
Author(s):  
Terry E. Machen
Keyword(s):  
Immune Response ◽  
Epithelial Cells ◽  
Innate Immune Response ◽  
Cellular Signaling ◽  
Basolateral Membrane ◽  
Airway Epithelial Cells ◽  
Innate Immune ◽  
Airway Epithelial ◽  
Airway Epithelia ◽  
Intracellular Ca

The lack of functional cystic fibrosis (CF) transmembrane conductance regulator (CFTR) in the apical membranes of CF airway epithelial cells abolishes cAMP-stimulated anion transport, and bacteria, eventually including Pseudomonas aeruginosa, bind to and accumulate in the mucus. Flagellin released from P. aeruginosa triggers airway epithelial Toll-like receptor 5 and subsequent NF-κB signaling and production and release of proinflammatory cytokines that recruit neutrophils to the infected region. This response has been termed hyperinflammatory because so many neutrophils accumulate; a response that damages CF lung tissue. We first review the contradictory data both for and against the idea that epithelial cells exhibit larger-than-normal proinflammatory signaling in CF compared with non-CF cells and then review proposals that might explain how reduced CFTR function could activate such proinflammatory signaling. It is concluded that apparent exaggerated innate immune response of CF airway epithelial cells may have resulted not from direct effects of CFTR on cellular signaling or inflammatory mediator production but from indirect effects resulting from the absence of CFTRs apical membrane channel function. Thus, loss of Cl−, HCO3−, and glutathione secretion may lead to reduced volume and increased acidification and oxidation of the airway surface liquid. These changes concentrate proinflammatory mediators, reduce mucociliary clearance of bacteria and subsequently activate cellular signaling. Loss of apical CFTR will also hyperpolarize basolateral membrane potentials, potentially leading to increases in cytosolic [Ca2+], intracellular Ca2+, and NF-κB signaling. This hyperinflammatory effect of CF on intracellular Ca2+and NF-κB signaling would be most prominently expressed during exposure to both P. aeruginosa and also endocrine, paracrine, or nervous agonists that activate Ca2+signaling in the airway epithelia.

scholarly journals Bordetella pertussisAdenylate Cyclase Toxin Disrupts Functional Integrity of Bronchial Epithelial Layers

2017 ◽  
Vol 86 (3) ◽  
Author(s):  
Shakir Hasan ◽  
Nikhil Nitin Kulkarni ◽  
Arni Asbjarnarson ◽  
Irena Linhartova ◽  
Radim Osicka ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Airway Epithelium ◽  
Immune Defense ◽  
Innate Immune ◽  
Camp Signaling ◽  
Apical Surface ◽  
Bronchial Epithelial ◽  
Content Type ◽  
Functional Integrity ◽  
Cell Layers

ABSTRACTThe airway epithelium restricts the penetration of inhaled pathogens into the underlying tissue and plays a crucial role in the innate immune defense against respiratory infections. The whooping cough agent,Bordetella pertussis, adheres to ciliated cells of the human airway epithelium and subverts its defense functions through the action of secreted toxins and other virulence factors. We examined the impact ofB. pertussisinfection and of adenylate cyclase toxin-hemolysin (CyaA) action on the functional integrity of human bronchial epithelial cells cultured at the air-liquid interface (ALI).B. pertussisadhesion to the apical surface of polarized pseudostratified VA10 cell layers provoked a disruption of tight junctions and caused a drop in transepithelial electrical resistance (TEER). The reduction of TEER depended on the capacity of the secreted CyaA toxin to elicit cAMP signaling in epithelial cells through its adenylyl cyclase enzyme activity. Both purified CyaA and cAMP-signaling drugs triggered a decrease in the TEER of VA10 cell layers. Toxin-produced cAMP signaling caused actin cytoskeleton rearrangement and induced mucin 5AC production and interleukin-6 (IL-6) secretion, while it inhibited the IL-17A-induced secretion of the IL-8 chemokine and of the antimicrobial peptide beta-defensin 2. These results indicate that CyaA toxin activity compromises the barrier and innate immune functions ofBordetella-infected airway epithelia.

The wound healing capacity of undifferentiated and differentiated airway epithelial cells in vitro

2018 ◽  
Vol 112 ◽  
pp. 163-168 ◽  
Author(s):  
Cynthia M. Schwartz ◽  
Braedyn A. Dorn ◽  
Selam Habtemariam ◽  
Cynthia L. Hill ◽  
Tendy Chiang ◽  
...  
Keyword(s):  
Wound Healing ◽  
Epithelial Cells ◽  
Airway Epithelial Cells ◽  
Airway Epithelial

scholarly journals In Vitro Investigations on Optimizing and Nebulization of IVT-mRNA Formulations for Potential Pulmonary-Based Alpha-1-Antitrypsin Deficiency Treatment

Pharmaceutics ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1281
Author(s):  
Shan Guan ◽  
Max Darmstädter ◽  
Chuanfei Xu ◽  
Joseph Rosenecker
Keyword(s):  
Epithelial Cells ◽  
Transfection Efficiency ◽  
Genetic Diseases ◽  
Airway Epithelial Cells ◽  
Airway Epithelial ◽  
Significant Toxicity ◽  
Antitrypsin Deficiency ◽  
Alpha 1 Antitrypsin Deficiency ◽  
Alpha 1 Antitrypsin

In vitro-transcribed (IVT) mRNA has come into focus in recent years as a potential therapeutic approach for the treatment of genetic diseases. The nebulized formulations of IVT-mRNA-encoding alpha-1-antitrypsin (A1AT-mRNA) would be a highly acceptable and tolerable remedy for the protein replacement therapy for alpha-1-antitrypsin deficiency in the future. Here we show that lipoplexes containing A1AT-mRNA prepared in optimum conditions could successfully transfect human bronchial epithelial cells without significant toxicity. A reduction in transfection efficiency was observed for aerosolized lipoplexes that can be partially overcome by increasing the initial number of components. A1AT produced from cells transfected by nebulized A1AT-mRNA lipoplexes is functional and could successfully inhibit the enzyme activity of trypsin as well as elastase. Our data indicate that aerosolization of A1AT-mRNA therapy constitutes a potentially powerful means to transfect airway epithelial cells with the purpose of producing functional A1AT, while bringing along the unique advantages of IVT-mRNA.

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