scholarly journals Human Metapneumovirus Impairs Apoptosis of Nasal Epithelial Cells in Asthma via HSP70

2016 ◽  
Vol 9 (1) ◽  
pp. 52-64 ◽  
Author(s):  
Engin Baturcam ◽  
Natale Snape ◽  
Tiong Han Yeo ◽  
Johanna Schagen ◽  
Emma Thomas ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Viral Infections ◽  
Airway Epithelial Cells ◽  
Human Metapneumovirus ◽  
Airway Epithelial ◽  
Caspase Activation ◽  
Nasal Epithelial Cells ◽  
Hmpv Infection ◽  
Syncytial Virus

Asthmatics are highly susceptible to respiratory viral infections, possibly due to impaired innate immunity. However, the exact mechanisms of susceptibility are likely to differ amongst viruses. Therefore, we infected primary nasal epithelial cells (NECs) from adults with mild-to-moderate asthma, with respiratory syncytial virus (RSV) or human metapneumovirus (hMPV) in vitro and investigated the antiviral response. NECs from these asthmatics supported elevated hMPV but not RSV infection, compared to non-asthmatic controls. This correlated with reduced apoptosis and reduced activation of caspase-9 and caspase-3/7 in response to hMPV, but not RSV. The expression of heat shock protein 70 (HSP70), a known inhibitor of caspase activation and subsequent apoptosis, was amplified in response to hMPV infection. Chemical inhibition of HSP70 function restored caspase activation and reduced hMPV infection in NECs from asthmatic subjects. There was no impairment in the production of IFN by NECs from asthmatics in response to either hMPV or RSV, demonstrating that increased infection of asthmatic airway cells by hMPV is IFN-independent. This study demonstrates, for the first time, a mechanism for elevated hMPV infection in airway epithelial cells from adult asthmatics and identifies HSP70 as a potential target for antiviral and asthma therapies.

Alpha 1-adrenergic signaling in human airway epithelial cells involves inositol lipid and phosphate metabolism

1992 ◽  
Vol 262 (2) ◽  
pp. L183-L191 ◽  
Author(s):  
C. M. Liedtke
Keyword(s):  
Epithelial Cells ◽  
Inositol Phosphates ◽  
Inositol Phosphate ◽  
Airway Epithelial Cells ◽  
Airway Epithelial ◽  
Nasal Epithelial Cells ◽  
Human Airway ◽  
Adrenergic Antagonist ◽  
Human Airway Epithelial Cells

A role for phospholipase C (PLC) hydrolysis of phosphatidylinositol 4,5-bisphosphate (PIP2) as a mechanism of alpha 1-adrenergic signal transduction in human airway epithelial cells (AEC) was investigated in isolated normal tracheal and cystic fibrosis (CF) nasal epithelial cells grown in in vitro culture and prelabeled with 3 muCi myo-[3H]inositol/ml for 72 h. Breakdown of polyphosphoinositides was measured using thin-layer chromatography to detect phosphatidylinositol, phosphatidylinositol 4-phosphate (PIP), and PIP2. Inositol phosphates were separated by ion-exchange column chromatography. In normal AEC, the addition of the endogenous catecholamine l-epinephrine produced a rapid, transient accumulation of inositol 1,4,5-trisphosphate (IP3) and inositol 1,4-bisphosphate (IP2) and breakdown of PIP and PIP2. IP3 increased 1.7-fold and IP2 1.6-fold after 20 and 40 s, respectively. A maximal decrease of 35% PIP2 and 30% PIP is observed after 20 and 40 s, respectively. The effects of l-epinephrine were not blocked by the beta-adrenergic antagonist dl-propranolol but were mimicked by the alpha 1-adrenergic agonist methoxamine. Prazosin, an alpha 1-adrenergic antagonist, and pertussis toxin (PTX) blocked the effects of l-epinephrine and methoxamine. Addition of l-epinephrine and methoxamine to CF nasal epithelial cells also induced prazosin-sensitive polyphosphoinositide breakdown and inositol phosphate accumulation. A 2.2-fold accumulation of IP3 was observed after 10 s and 2.0-fold increase in IP2 after 20 s. Maximal decreases of 32% PIP2 and 23% PIP levels were observed after 20-s incubation with l-epinephrine. PTX reduced the effects of l-epinephrine and significantly blocked the effects of methoxamine.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Role of retinoic acid inducible gene-I in human metapneumovirus-induced cellular signalling

2008 ◽  
Vol 89 (8) ◽  
pp. 1978-1986 ◽  
Author(s):  
S. Liao ◽  
X. Bao ◽  
T. Liu ◽  
S. Lai ◽  
K. Li ◽  
...  
Keyword(s):  
Retinoic Acid ◽  
Epithelial Cells ◽  
Gene Transcription ◽  
Airway Epithelial Cells ◽  
Human Metapneumovirus ◽  
Airway Epithelial ◽  
Cellular Signalling ◽  
Hmpv Infection ◽  
Inducible Gene

Human metapneumovirus (HMPV) is a recently discovered pathogen that causes a significant proportion of respiratory infections in young infants, the elderly and immunocompromised patients. Very little is known regarding the cellular signalling elicited by this virus in airway epithelial cells, the target of HMPV infection. In this study, we investigated the role of the RNA helicases retinoic acid inducible gene-I (RIG-I) and melanoma differentiation-associated gene-5 (MDA-5) as the main pattern recognition receptors (PRRs) involved in viral detection and subsequent expression of proinflammatory and antiviral genes. HMPV infection readily induced RIG-I and MDA-5 gene and protein expression in A549 cells, a type II-like alveolar epithelial cell line. Expression of dominant-negative (DN) RIG-I or downregulation of RIG-I gene expression using small interfering RNA (siRNA) significantly decreased HMPV-induced beta interferon (IFN-β), interleukin (IL)-8 and RANTES gene transcription, by inhibiting viral-induced activation of nuclear factor (NF)-κB and interferon regulatory factor (IRF), leading to enhanced viral replication. On the other hand, MDA-5 did not seem to play a significant role in HMPV-induced cellular responses. Mitochondrial antiviral signalling protein (MAVS), an adaptor protein linking both RIG-I and MDA-5 to downstream activation of IRF-3 and NF-κB, was also necessary for HMPV-induced cellular signalling. Expression of a DN MAVS significantly reduced IFN-β and chemokine gene transcription, by inhibiting NF-κB- and IRF-dependent gene transcription, in response to HMPV infection. Our results show that HMPV activates the RIG-I–MAVS signalling pathway in airway epithelial cells, leading to the expression of important proinflammatory and antiviral molecules involved in the innate immune response to viruses.

Nitrogen dioxide exposure: effects on airway and blood cells

2002 ◽  
Vol 282 (1) ◽  
pp. L155-L165 ◽  
Author(s):  
Mark W. Frampton ◽  
Joseph Boscia ◽  
Norbert J. Roberts ◽  
Mitra Azadniv ◽  
Alfonso Torres ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Nitrogen Dioxide ◽  
Airway Inflammation ◽  
Blood Cells ◽  
Respiratory Viruses ◽  
Airway Epithelial Cells ◽  
Airway Epithelial ◽  
Air Exposure ◽  
Syncytial Virus

This study examined the effects of nitrogen dioxide (NO2) exposure on airway inflammation, blood cells, and antiviral respiratory defense. Twenty-one healthy volunteers were exposed on separate occasions to air and 0.6 and 1.5 ppm NO2for 3 h with intermittent moderate exercise. Phlebotomy and bronchoscopy were performed 3.5 h after each exposure, and recovered cells were challenged with respiratory viruses in vitro. Blood studies revealed a 4.1% NO2dose-related decrease in hematocrit ( P = 0.003). Circulating total lymphocytes ( P = 0.024) and T lymphocytes ( P = 0.049) decreased with NO2exposure. Exposure to NO2increased the blood lymphocyte CD4+-to-CD8+ratio from 1.74 ± 0.11 to 1.85 ± 0.12 in males but decreased it from 1.88 ± 0.19 to 1.78 ± 0.19 in females ( P < 0.001 for gender difference). Polymorphonuclear leukocytes in bronchial lavage increased with NO2exposure ( P = 0.003). Bronchial epithelial cells obtained after exposure to 1.5 ppm NO2released 40% more lactate dehydrogenase after challenge with respiratory syncytial virus than with air exposure ( P = 0.024). In healthy subjects, exposures to NO2at levels found indoors cause mild airway inflammation, effects on blood cells, and increased susceptibility of airway epithelial cells to injury from respiratory viruses.

A Toolbox for Studying Respiratory Viral Infections Using Air-Liquid Interface Cultures of Human Airway Epithelial Cells

2021 ◽  
Author(s):  
Aubrey Nicole Michi ◽  
David Proud
Keyword(s):  
Epithelial Cells ◽  
Cell Lines ◽  
Viral Infections ◽  
Airway Epithelial Cells ◽  
Airway Epithelial ◽  
Human Airway ◽  
Respiratory Viral Infections ◽  
Air Liquid Interface ◽  
Human Airway Epithelial Cells

Submerged cultures of primary human airway epithelial cells, or human airway epithelial cell lines have been a mainstay of airway epithelial biology research for decades due to their robust in vitro proliferative capacity, relatively low maintenance culture conditions, and clinically translatable results to nasal or bronchial brushings. With the development and improvement of air-liquid interface (ALI) cultures of human airway epithelial cells, such cultures have been considered superior to immortalized cell lines and primary cell monolayers as such cultures effectively recapitulate in vivo epithelial architecture and cell types. Although ALI culture growth protocols are well-established and widely available, many researchers have avoided their use, as ALI cultures not only take longer to grow but also present technical challenges and limitations that make in vitro intracellular and structural assays taxing. Challenges arise relating to their complex structure, requirements for air exposure, the constraints of transwell growth apparatus, and interference in assays caused by mucus secretion. Although few publications briefly describe technical adaptations for some assays, there is still considerable trial and error required for researchers to establish consistent and reliable assay adaptations, often becoming a deterrent for pursuing mechanistic investigation. We have created a user-friendly toolbox detailing comprehensive protocols for numerous techniques and assay adaptations, particularly focusing on respiratory virus infections. By expanding the repertoire of ALI culture-adapted in vitro assays, we hope to facilitate the widespread adoption of this valuable culture system for mechanistic investigations of respiratory viral infections or other epithelial-pathogen models.

scholarly journals Human metapneumovirus induces autophagy through JNK and MEK/ERK pathway

2019 ◽  
Author(s):  
Pan Zhang ◽  
Suhua Chen ◽  
Hui Yang ◽  
Bin Tan ◽  
Yao Zhao
Keyword(s):  
Airway Epithelial Cells ◽  
Human Metapneumovirus ◽  
Host Cells ◽  
Respiratory Pathogen ◽  
Erk Pathway ◽  
Airway Epithelial ◽  
Host Interaction ◽  
Hmpv Infection ◽  
Lc3 Puncta

Abstract Background: Human metapneumovirus (hMPV) is a ubiquitous respiratory pathogen, especially in infants and young children. Virus-host interaction affects viral replication and host immune responses. Autophagy plays an important role in virus-host interaction. Airway epithelial cells serve as the first line in host to against respiratory virus infection. However, it is still unknown whether autophagy is activated in human metapneumovirus (hMPV) infected host cells. Methods: In this study, we demonstrated the occurrence of autophagy through some autophagic features including the conversion of GFP-RFP-LC3 plasmid, RFP-LC3 puncta and expression of autophagic-related gene. The pathways involved in autophagy were detected by Western Blot and verified by specific pathway inhibitors. The relationship between the replication of hMPV and autophagy was tested by Rapamycin, 3-MA, siRNA-LC3 and pathway inhibitors. We also used BALB/c mice to verified the autophagy and pathways in hMPV infection. Results: We found that the GFP-RFP-LC3 plasmid, RFP-LC3 puncta and expression of ATG5, ATG7, Becllin1, LC3 were increased in hMPV group in vitro . JNK and MEK/ERK signaling pathway are activated in hMPV induced-autophagy and we confirmed the two pathways with specific inhibitors SP600125 and PD98059. Furthermore, we found that rapamycin suppressed hMPV infection significantly, but reversed when treated with autophagy inhibitor 3-MA, siRNA-LC3 and pathway inhibitors. hMPV infected mice also induce autophagy through JNK and MEK/ERK pathways. Conclusion: Taken together, our results show strong evidence that autophagy involved in hMPV infection through JNK, MEK/ERK pathway which plays an antiviral role in the process of hMPV infection.

scholarly journals Comparative primary paediatric nasal epithelial cell culture differentiation and RSV-induced cytopathogenesis following culture in two commercial media

2020 ◽  
Author(s):  
Lindsay Broadbent ◽  
Sheerien Manzoor ◽  
Maria Zarcone ◽  
Judit Barabas ◽  
Mike Shields ◽  
...  
Keyword(s):  
Cell Culture ◽  
Epithelial Cell ◽  
Epithelial Cells ◽  
Airway Epithelial Cells ◽  
Airway Epithelial ◽  
Nasal Epithelial Cell ◽  
Human Airway ◽  
Syncytial Virus ◽  
Human Airway Epithelial Cells

AbstractThe culture of differentiated human airway epithelial cells allows the study of pathogen-host interactions and innate immune responses in a physiologically relevant in vitro model. As the use of primary cell culture has gained popularity the availability of the reagents needed to generate these cultures has increased. In this study we assessed two different media, Promocell and PneumaCult, during the differentiation and maintenance of well-differentiated primary nasal epithelial cell cultures (WD-PNECs). We compared and contrasted the consequences of these media on WD-PNEC morphological and physiological characteristics and their responses to respiratory syncytial virus (RSV) infection. We found that cultures generated using PneumaCult resulted in greater total numbers of smaller, tightly packed, pseudostratified cells. However, cultures from both media resulted in similar proportions of ciliated and goblet cells. There were no differences in RSV growth kinetics, although more ciliated cells were infected in the PneumaCult cultures. There was also significantly more IL-29/IFNλ1 secreted from PneumaCult compared to Promocell cultures. In conclusion, the type of medium used for the differentiation of primary human airway epithelial cells impacts experimental results.

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.

Sign in / Sign up

Export Citation Format

Share Document