scholarly journals Spatial and temporal analysis of neutrophil trans-epithelial migration in response to RSV infection

2021 ◽  
Author(s):  
Elisabeth Robinson ◽  
Jenny Amanda Herbert ◽  
Machaela Palor ◽  
Luo Ren ◽  
Isobel Larken ◽  
...  

In the airways, recruitment and activation of neutrophils occurs early following respiratory virus (RSV) infection and is associated with the development of severe disease. We investigated whether activated neutrophils selectively migrate across virus infected airway epithelial cells, or whether trans-epithelial migration is sufficient and necessary for neutrophil activation. We profiled the movement and adherence of fluorescently labelled human neutrophils during migration across primary human airway epithelial cells (AECs) infected with RSV in vitro. In RSV infected AECs neutrophil adherence, with clustering occurs after 15-18 minutes. Using flow cytometry, we found that, when migration occurred, expression of CD11b, CD62L, CD64, NE and MPO were increased in all compartments of our system and RSV infection further increased CD11b and NE expression. We found evidence suggesting that migrated neutrophils can migrate in reverse to the basolateral membrane. Our study provides novel insights into how airway activated neutrophils mediate systemic disease in respiratory virus infection.

2006 ◽  
Vol 291 (2) ◽  
pp. C218-C230 ◽  
Author(s):  
Terry E. Machen

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.


Viruses ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 2055
Author(s):  
Andrew R. Connelly ◽  
Brian M. Jeong ◽  
Mackenzie E. Coden ◽  
Jacob Y. Cao ◽  
Tatiana Chirkova ◽  
...  

Respiratory syncytial virus (RSV) is a seasonal mucosal pathogen that infects the ciliated respiratory epithelium and results in the most severe morbidity in the first six months of life. RSV is a common cause of acute respiratory infection during infancy and is an important early-life risk factor strongly associated with asthma development. While this association has been repeatedly demonstrated, limited progress has been made on the mechanistic understanding in humans of the contribution of infant RSV infection to airway epithelial dysfunction. An active infection of epithelial cells with RSV in vitro results in heightened central metabolism and overall hypermetabolic state; however, little is known about whether natural infection with RSV in vivo results in lasting metabolic reprogramming of the airway epithelium in infancy. To address this gap, we performed functional metabolomics, 13C glucose metabolic flux analysis, and RNA-seq gene expression analysis of nasal airway epithelial cells (NAECs) sampled from infants between 2–3 years of age, with RSV infection or not during the first year of life. We found that RSV infection in infancy was associated with lasting epithelial metabolic reprogramming, which was characterized by (1) significant increase in glucose uptake and differential utilization of glucose by epithelium; (2) altered preferences for metabolism of several carbon and energy sources; and (3) significant sexual dimorphism in metabolic parameters, with RSV-induced metabolic changes most pronounced in male epithelium. In summary, our study supports the proposed phenomenon of metabolic reprogramming of epithelial cells associated with RSV infection in infancy and opens exciting new venues for pursuing mechanisms of RSV-induced epithelial barrier dysfunction in early life.


2014 ◽  
Vol 307 (2) ◽  
pp. L186-L196 ◽  
Author(s):  
April Kalinowski ◽  
Iris Ueki ◽  
Gundula Min-Oo ◽  
Eric Ballon-Landa ◽  
David Knoff ◽  
...  

Airway epithelial cells are the primary cell type involved in respiratory viral infection. Upon infection, airway epithelium plays a critical role in host defense against viral infection by contributing to innate and adaptive immune responses. Influenza A virus, rhinovirus, and respiratory syncytial virus (RSV) represent a broad range of human viral pathogens that cause viral pneumonia and induce exacerbations of asthma and chronic obstructive pulmonary disease. These respiratory viruses induce airway epithelial production of IL-8, which involves epidermal growth factor receptor (EGFR) activation. EGFR activation involves an integrated signaling pathway that includes NADPH oxidase activation of metalloproteinase, and EGFR proligand release that activates EGFR. Because respiratory viruses have been shown to activate EGFR via this signaling pathway in airway epithelium, we investigated the effect of virus-induced EGFR activation on airway epithelial antiviral responses. CXCL10, a chemokine produced by airway epithelial cells in response to respiratory viral infection, contributes to the recruitment of lymphocytes to target and kill virus-infected cells. While respiratory viruses activate EGFR, the interaction between CXCL10 and EGFR signaling pathways is unclear, and the potential for EGFR signaling to suppress CXCL10 has not been explored. Here, we report that respiratory virus-induced EGFR activation suppresses CXCL10 production. We found that influenza virus-, rhinovirus-, and RSV-induced EGFR activation suppressed IFN regulatory factor (IRF) 1-dependent CXCL10 production. In addition, inhibition of EGFR during viral infection augmented IRF1 and CXCL10. These findings describe a novel mechanism that viruses use to suppress endogenous antiviral defenses, and provide potential targets for future therapies.


2005 ◽  
Vol 289 (1) ◽  
pp. L14-L23 ◽  
Author(s):  
Funmei Yang ◽  
David J. Haile ◽  
Xinchao Wang ◽  
Lisa A. Dailey ◽  
Jacqueline G. Stonehuerner ◽  
...  

Ferroportin 1 (FPN1; aka MTP1, IREG1, and SLC40A1), which was originally identified as a basolateral iron transporter crucial for nutritional iron absorption in the intestine, is expressed in airway epithelia and upregulated when these cells are exposed to iron. Using immunofluorescence labeling and confocal microscopic imaging techniques, we demonstrate that in human and rodent lungs, FPN1 localizes subcellularly to the apical but not basolateral membrane of the airway epithelial cells. The role of airway epithelial cells in iron mobilization in the lung was studied in an in vitro model of the polarized airway epithelium. Normal human bronchial epithelial cells, grown on membrane supports until differentiated, were exposed to iron, and the efficiency and direction of iron transportation were studied. We found that these cells can efficiently take up iron across the apical but not basolateral surface in a concentration-dependent manner. Most of the iron taken up by the cells is then released into the medium within 8 h in the form of less reactive protein-bound complexes including ferritin and transferrin. Interestingly, iron release also occurred across the apical but not basolateral membrane. Our findings indicate that FPN1, depending on its subcellular location, could have distinct functions in iron homeostasis in different cells and tissues. Although it is responsible for exporting nutrient iron from enterocytes to the circulation in the intestine, it could play a role in iron detoxification in airway epithelial cells in the lung.


1990 ◽  
Vol 258 (6) ◽  
pp. L343-L348 ◽  
Author(s):  
J. D. McCann ◽  
M. J. Welsh

We previously described a Ca2(+)-activated K+ channel (KCLIC) in airway epithelial cells [J. D. McCann, J. Matsuda, M. Garcia, G. Kaczorowski, and M. J. Welsh. Am. J. Physiol 258 (Lung Cell. Mol. Physiol. 2): L334-L342, 1990]. To determine whether the KCLIC channel is a basolateral membrane channel and to understand its role in Cl- secretion, we studied airway epithelial cells grown on permeable supports. When cells were stimulated with A23187, charybdotoxin (ChTX) inhibited Cl- secretion and 86Rb efflux at the same concentrations, indicating that the KCLIC channel is required for Ca2(+)-stimulated Cl- secretion. We also investigated the function of K+ channels in adenosine 3',5'-cyclic monophosphate-stimulated secretion. Addition of isoproterenol caused a biphasic increase in Cl- secretion; the time course of the transient component correlated with the time course of the isoproterenol-induced increase in Ca2+ concentration [( Ca2+]c). ChTX inhibited the transient component, but not the prolonged component of secretion; Ba2+ inhibited the sustained component. These results suggest that when cells are grown on permeable supports isoproterenol-induced secretion depends on activation of two types of K+ channel: the KCLIC channel that is stimulated initially and a ChTX-insensitive K+ channel that is stimulated during sustained secretion. This conclusion was supported by measurement of 86Rb efflux from cell monolayers


2016 ◽  
Vol 90 (21) ◽  
pp. 9618-9631 ◽  
Author(s):  
Yashoda M. Hosakote ◽  
Allan R. Brasier ◽  
Antonella Casola ◽  
Roberto P. Garofalo ◽  
Alexander Kurosky

ABSTRACTRespiratory syncytial virus (RSV) is the leading cause of lower respiratory tract infections in infant and elderly populations worldwide. Currently, there is no efficacious vaccine or therapy available for RSV infection. The molecular mechanisms underlying RSV-induced acute airway disease and associated long-term consequences remain largely unknown; however, experimental evidence suggests that the lung inflammatory response plays a fundamental role in the outcome of RSV infection. High-mobility group box 1 (HMGB1) is a nuclear protein that triggers inflammation when released from activated immune or necrotic cells and drives the pathogenesis of various infectious agents. Although HMGB1 has been implicated in many inflammatory diseases, its role in RSV-induced airway inflammation has not been investigated. This study investigates the molecular mechanism of action of extracellularly released HMGB1 in airway epithelial cells (A549 and small airway epithelial cells) to establish its role in RSV infection. Immunofluorescence microscopy and Western blotting results showed that RSV infection of human airway epithelial cells induced a significant release of HMGB1 as a result of translocation of HMGB1 from the cell nuclei to the cytoplasm and subsequent release into the extracellular space. Treating RSV-infected A549 cells with antioxidants significantly inhibited RSV-induced HMGB1 extracellular release. Studies using recombinant HMGB1 triggered immune responses by activating primary human monocytes. Finally, HMGB1 released by airway epithelial cells due to RSV infection appears to function as a paracrine factor priming epithelial cells and monocytes to inflammatory stimuli in the airways.IMPORTANCERSV is a major cause of serious lower respiratory tract infections in young children and causes severe respiratory morbidity and mortality in the elderly. In addition, to date there is no effective treatment or vaccine available for RSV infection. The mechanisms responsible for RSV-induced acute airway disease and associated long-term consequences remain largely unknown. The oxidative stress response in the airways plays a major role in the pathogenesis of RSV. HMGB1 is a ubiquitous redox-sensitive multifunctional protein that serves as both a DNA regulatory protein and an extracellular cytokine signaling molecule that promotes airway inflammation as a damage-associated molecular pattern. This study investigated the mechanism of action of HMGB1 in RSV infection with the aim of identifying new inflammatory pathways at the molecular level that may be amenable to therapeutic interventions.


1997 ◽  
Vol 272 (3) ◽  
pp. L512-L520 ◽  
Author(s):  
S. Becker ◽  
W. Reed ◽  
F. W. Henderson ◽  
T. L. Noah

Infection of airway epithelial cells with respiratory syncytial virus (RSV) results in the production of a restricted number of cytokines, which may modulate the inflammatory response to infection. To get a better understanding of epithelial cell-mediated inflammatory processes in RSV disease, the aim of the present study was to identify the production of mononuclear cell/eosinophil/mast cell inflammatory chemokines [monocyte chemotactic protein (MCP)-1, MCP-3, macrophage inflammatory protein-1beta, and RANTES] during productive RSV infection in airway epithelial cells. Normal human primary bronchial epithelial cell cultures, nasal epithelial cell explants, and the BEAS-2B airway epithelial cell line were inoculated with RSV, and chemokine induction was assessed during the phase of logarithmic increase in infectious virus production. Only RANTES was found to increase in epithelial cell cultures in an infection-dependent manner. Furthermore, RANTES was released only by RSV-producing cells. To determine whether RANTES was induced by RSV infection in vivo, RANTES was measured in nasal lavage fluids (NLF) from children with RSV-positive and RSV-negative upper respiratory infection and children when they were well. RANTES was increased significantly during RSV infection (128 +/- 38 pg/ml NFL) compared with non-RSV infection (42 +/- 12 pg/ml NFL) and with asymptomatic baseline (13 +/- 4 ng/ml NFL) in the same children. Because RANTES is an effective eosinophil and memory T cell chemoattractant and activator and because eosinophil-dominated inflammation is a hallmark of asthmatic airways, RANTES may play a role in the pathogenesis of RSV-induced exacerbations of airway reactivity and wheezing.


2020 ◽  
Vol 94 (13) ◽  
Author(s):  
Yu Deng ◽  
Jenny A. Herbert ◽  
Elisabeth Robinson ◽  
Luo Ren ◽  
Rosalind L. Smyth ◽  
...  

ABSTRACT Respiratory syncytial virus (RSV) is a major cause of pediatric respiratory disease. Large numbers of neutrophils are recruited into the airways of children with severe RSV disease. It is not clear whether or how neutrophils enhance recovery from disease or contribute to its pathology. Using an in vitro model of the differentiated airway epithelium, we found that the addition of physiological concentrations of neutrophils to RSV-infected nasal cultures was associated with greater epithelial damage with lower ciliary activity, cilium loss, less tight junction expression (ZO-1), and more detachment of epithelial cells than is seen with RSV infection alone. This was also associated with a decrease in infectious virus and fewer RSV-positive cells in cultures after neutrophil exposure than in preexposure cultures. Epithelial damage in response to RSV infection was associated with neutrophil activation (within 1 h) and neutrophil degranulation, with significantly greater cellular expression of CD11b and myeloperoxidase and higher levels of neutrophil elastase and myeloperoxidase activity in apical surface media than in media with mock-infected airway epithelial cells (AECs). We also recovered more apoptotic neutrophils from RSV-infected cultures (>40%) than from mock-infected cultures (<5%) after 4 h. The results of this study could provide important insights into the role of neutrophils in host response in the airway. IMPORTANCE This study shows that the RSV-infected human airway drives changes in the behavior of human neutrophils, including increasing activation markers and delaying apoptosis, that result in greater airway damage and viral clearance.


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