scholarly journals Alveolar Type II Epithelial Cells Contribute to the Anti-Influenza A Virus Response in the Lung by Integrating Pathogen- and Microenvironment-Derived Signals

mBio ◽  
2016 ◽  
Vol 7 (3) ◽  
Author(s):  
S. Stegemann-Koniszewski ◽  
Andreas Jeron ◽  
Marcus Gereke ◽  
Robert Geffers ◽  
Andrea Kröger ◽  
...  
Keyword(s):  
Transcriptional Regulation ◽  
Epithelial Cells ◽  
Influenza A Virus ◽  
Lung Tissue ◽  
Influenza A ◽  
Ex Vivo ◽  
Type Ii ◽  
Pathogen Recognition ◽  
Cell Recruitment

ABSTRACT Influenza A virus (IAV) periodically causes substantial morbidity and mortality in the human population. In the lower lung, the primary targets for IAV replication are type II alveolar epithelial cells (AECII), which are increasingly recognized for their immunological potential. So far, little is known about their reaction to IAV and their contribution to respiratory antiviral immunity in vivo . Therefore, we characterized the AECII response during early IAV infection by analyzing transcriptional regulation in cells sorted from the lungs of infected mice. We detected rapid and extensive regulation of gene expression in AECII following in vivo IAV infection. The comparison to transcriptional regulation in lung tissue revealed a strong contribution of AECII to the respiratory response. IAV infection triggered the expression of a plethora of antiviral factors and immune mediators in AECII with a high prevalence for interferon-stimulated genes. Functional pathway analyses revealed high activity in pathogen recognition, immune cell recruitment, and antigen presentation. Ultimately, our analyses of transcriptional regulation in AECII and lung tissue as well as interferon I/III levels and cell recruitment indicated AECII to integrate signals provided by direct pathogen recognition and surrounding cells. Ex vivo analysis of AECII proved a powerful tool to increase our understanding of their role in respiratory immune responses, and our results clearly show that AECII need to be considered a part of the surveillance and effector system of the lower respiratory tract. IMPORTANCE In order to confront the health hazard posed by IAV, we need to complete our understanding of its pathogenesis. AECII are primary targets for IAV replication in the lung, and while we are beginning to understand their importance for respiratory immunity, the in vivo AECII response during IAV infection has not been analyzed. In contrast to studies addressing the response of AECII infected with IAV ex vivo , we have performed detailed gene transcriptional profiling of AECII isolated from the lungs of infected mice. Thereby, we have identified an exceptionally rapid and versatile response to IAV infection that is shaped by pathogen-derived as well as microenvironment-derived signals and aims at the induction of antiviral measures and the recruitment and activation of immune cells. In conclusion, our study presents AECII as active players in antiviral defense in vivo that need to be considered part of the sentinel and effector immune system of the lung.

scholarly journals Influenza A Virus Infection Induces Apical Redistribution of Na+, K+-ATPase in Lung Epithelial Cells In Vitro and In Vivo

2019 ◽  
Vol 61 (3) ◽  
pp. 395-398
Author(s):  
Christin Peteranderl ◽  
Irina Kuznetsova ◽  
Jessica Schulze ◽  
Martin Hardt ◽  
Emilia Lecuona ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Virus Infection ◽  
Influenza A Virus ◽  
Influenza A ◽  
Lung Epithelial Cells ◽  
Lung Epithelial ◽  
Influenza A Virus Infection

scholarly journals Bcl-2 overexpression in type II epithelial cells does not prevent hyperoxia-induced acute lung injury in mice

2010 ◽  
Vol 299 (3) ◽  
pp. L312-L322 ◽  
Author(s):  
Isabelle Métrailler-Ruchonnet ◽  
Alessandra Pagano ◽  
Stéphanie Carnesecchi ◽  
Karim Khatib ◽  
Pedro Herrera ◽  
...  
Keyword(s):  
Cell Death ◽  
Epithelial Cells ◽  
Lung Injury ◽  
Ex Vivo ◽  
Lung Damage ◽  
Type Ii Cells ◽  
Type Ii ◽  
Lung Weight

Bcl-2 is an anti-apoptotic molecule preventing oxidative stress damage and cell death. We have previously shown that Bcl-2 is able to prevent hyperoxia-induced cell death when overexpressed in a murine fibrosarcoma cell line L929. We hypothesized that its specific overexpression in pulmonary epithelial type II cells could prevent hyperoxia-induced lung injury by protecting the epithelial side of the alveolo-capillary barrier. In the present work, we first showed that in vitro Bcl-2 can rescue murine pulmonary epithelial cells (MLE12) from oxygen-induced cell apoptosis, as shown by analysis of LDH release, annexin V/propidium staining, and caspase-3 activity. We then generated transgenic mice overexpressing specifically Bcl-2 in lung epithelial type II cells under surfactant protein C (SP-C) promoter (Tg-Bcl-2) and exposed them to hyperoxia. Bcl-2 did not hinder hyperoxia-induced mitochondria and DNA oxidative damage of type II cell in vivo. Accordingly, lung damage was identical in both Tg-Bcl-2 and littermate mice strains, as measured by lung weight, bronchoalveolar lavage, and protein content. Nevertheless, we observed a significant lower number of TUNEL-positive cells in type II cells isolated from Tg-Bcl-2 mice exposed to hyperoxia compared with cells isolated from littermate mice. In summary, these results show that although Bcl-2 overexpression is able to prevent hyperoxia-induced cell death at single cell level in vitro and ex vivo, it is not sufficient to prevent cell death of parenchymal cells and to protect the lung from acute damage in mice.

scholarly journals Mitogenic stimulation accelerates influenza-induced mortality by increasing susceptibility of alveolar type II cells to infection

2017 ◽  
Vol 114 (32) ◽  
pp. E6613-E6622 ◽  
Author(s):  
Nikolaos M. Nikolaidis ◽  
John G. Noel ◽  
Lori B. Pitstick ◽  
Jason C. Gardner ◽  
Yasuaki Uehara ◽  
...  
Keyword(s):  
Viral Infection ◽  
Influenza A ◽  
Ex Vivo ◽  
Keratinocyte Growth Factor ◽  
Alveolar Epithelium ◽  
Host Susceptibility ◽  
Alveolar Type ◽  
Type Ii ◽  
Mitogenic Stimulation

Development of pneumonia is the most lethal consequence of influenza, increasing mortality more than 50-fold compared with uncomplicated infection. The spread of viral infection from conducting airways to the alveolar epithelium is therefore a pivotal event in influenza pathogenesis. We found that mitogenic stimulation with keratinocyte growth factor (KGF) markedly accelerated mortality after infectious challenge with influenza A virus (IAV). Coadministration of KGF with IAV markedly accelerated the spread of viral infection from the airways to alveoli compared with challenge with IAV alone, based on spatial and temporal analyses of viral nucleoprotein staining of lung tissue sections and dissociated lung cells. To better define the temporal relationship between KGF administration and susceptibility to IAV infection in vivo, we administered KGF 120, 48, 24, and 0 h before intrapulmonary IAV challenge and assessed the percentages of proliferating and IAV-infected, alveolar type II (AECII) cells in dispersed lung cell populations. Peak AECII infectivity coincided with the timing of KGF administration that also induced peak AECII proliferation. AECII from mice that were given intrapulmonary KGF before isolation and then infected with IAV ex vivo exhibited the same temporal pattern of proliferation and infectious susceptibility. KGF-induced increases in mortality, AECII proliferation, and enhanced IAV susceptibility were all reversed by pretreatment of the animals with the mTOR inhibitor rapamycin before mitogenic stimulation. Taken together, these data suggest mTOR signaling-dependent, mitogenic conditioning of AECII is a determinant of host susceptibility to infection with IAV.

scholarly journals Influenza a virus NS1 resembles a TRAF3-interacting motif to target the RNA sensing-TRAF3-type I IFN axis and impair antiviral innate immunity

2021 ◽  
Vol 28 (1) ◽  
Author(s):  
Chun-Yang Lin ◽  
Meng-Cen Shih ◽  
Hung-Chun Chang ◽  
Kuan-Jung Lin ◽  
Lin-Fang Chen ◽  
...  
Keyword(s):  
Influenza A Virus ◽  
Influenza A ◽  
Ex Vivo ◽  
Antiviral Response ◽  
Mutant Virus ◽  
Luciferase Reporter ◽  
Common Mechanism ◽  
Type I ◽  
Type I Ifn

Abstract Background Influenza A virus (IAV) evolves strategies to counteract the host antiviral defense for establishing infection. The influenza A virus (IAV) non-structural protein 1 (NS1) is a key viral factor shown to counteract type I IFN antiviral response mainly through targeting RIG-I signaling. Growing evidence suggests that viral RNA sensors RIG-I, TLR3, and TLR7 function to detect IAV RNA in different cell types to induce type I IFN antiviral response to IAV infection. Yet, it remains unclear if IAV NS1 can exploit a common mechanism to counteract these RNA sensing pathways to type I IFN production at once, then promoting viral propagation in the host. Methods Luciferase reporter assays were conducted to determine the effect of NS1 and its mutants on the RIG-I and TLR3 pathways to the activation of the IFN-β and NF-κB promoters. Coimmunoprecipitation and confocal microscopic analyses were used to the interaction and colocalization between NS1 and TRAF3. Ubiquitination assays were performed to study the effect of NS1 and its mutants on TRAF3 ubiquitination. A recombinant mutant virus carrying NS1 E152A/E153A mutations was generated by reverse genetics for biochemical, ex vivo, and in vivo analyses to explore the importance of NS1 E152/E153 residues in targeting the RNA sensing-TRAF3-type I IFN axis and IAV pathogenicity. Results Here we report that NS1 subverts the RIG-I, TLR3, and TLR7 pathways to type I IFN production through targeting TRAF3 E3 ubiquitin ligase. NS1 harbors a conserved FTEE motif (a.a. 150-153), in which the E152/E153 residues are critical for binding TRAF3 to block TRAF3 ubiquitination and type I IFN production by these RNA sensing pathways. A recombinant mutant virus carrying NS1 E152A/E153A mutations induces higher type I IFN production ex vivo and in vivo, and exhibits the attenuated phenotype in infected mice, indicating the importance of E152/E153 residues in IAV pathogenicity. Conclusions Together our work uncovers a novel mechanism of IAV NS1-mediated immune evasion to promote viral infection through targeting the RNA sensing-TRAF3-type I IFN axis.

scholarly journals Deficiency of HIF-1α enhances influenza A virus replication by promoting autophagy in alveolar type II epithelial cells

2020 ◽  
Vol 9 (1) ◽  
pp. 691-706 ◽  
Author(s):  
Caiqi Zhao ◽  
Jie Chen ◽  
Lianping Cheng ◽  
Kaifeng Xu ◽  
Yiyu Yang ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Influenza A Virus ◽  
Virus Replication ◽  
Influenza A ◽  
Alveolar Type ◽  
Type Ii

scholarly journals SARS-CoV-2 launches a unique transcriptional signature from in vitro, ex vivo, and in vivo systems

2020 ◽  
Author(s):  
Daniel Blanco-Melo ◽  
Benjamin E. Nilsson-Payant ◽  
Wen-Chun Liu ◽  
Rasmus Møller ◽  
Maryline Panis ◽  
...  
Keyword(s):  
Influenza A Virus ◽  
Influenza A ◽  
Ex Vivo ◽  
Influenza Viruses ◽  
Model Systems ◽  
Type I ◽  
Transcriptional Signature ◽  
Syncytial Virus

ABSTRACTOne of the greatest threats to humanity is the emergence of a pandemic virus. Among those with the greatest potential for such an event include influenza viruses and coronaviruses. In the last century alone, we have observed four major influenza A virus pandemics as well as the emergence of three highly pathogenic coronaviruses including SARS-CoV-2, the causative agent of the ongoing COVID-19 pandemic. As no effective antiviral treatments or vaccines are presently available against SARS-CoV-2, it is important to understand the host response to this virus as this may guide the efforts in development towards novel therapeutics. Here, we offer the first in-depth characterization of the host transcriptional response to SARS-CoV-2 and other respiratory infections through in vitro, ex vivo, and in vivo model systems. Our data demonstrate the each virus elicits both core antiviral components as well as unique transcriptional footprints. Compared to the response to influenza A virus and respiratory syncytial virus, SARS-CoV-2 elicits a muted response that lacks robust induction of a subset of cytokines including the Type I and Type III interferons as well as a numerous chemokines. Taken together, these data suggest that the unique transcriptional signature of this virus may be responsible for the development of COVID-19.

Hypoxia decreases proteins involved in epithelial electrolyte transport in A549 cells and rat lung

2000 ◽  
Vol 279 (6) ◽  
pp. L1110-L1119 ◽  
Author(s):  
Ralf Wodopia ◽  
Hyun Soo Ko ◽  
Javiera Billian ◽  
Rudolf Wiesner ◽  
Peter Bärtsch ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Lung Tissue ◽  
A549 Cells ◽  
Alveolar Epithelial Cells ◽  
Alveolar Type ◽  
Type Ii Cells ◽  
Type Ii ◽  
Alveolar Type Ii Cells ◽  
Alveolar Epithelial

Fluid reabsorption from alveolar space is driven by active Na reabsorption via epithelial Na channels (ENaCs) and Na-K-ATPase. Both are inhibited by hypoxia. Here we tested whether hypoxia decreases Na transport by decreasing the number of copies of transporters in alveolar epithelial cells and in lungs of hypoxic rats. Membrane fractions were prepared from A549 cells exposed to hypoxia (3% O2) as well as from whole lung tissue and alveolar type II cells from rats exposed to hypoxia. Transport proteins were measured by Western blot analysis. In A549 cells, α1- and β1-Na-K-ATPase, Na/K/2Cl cotransport, and ENaC proteins decreased during hypoxia. In whole lung tissue, α1-Na-K-ATPase and Na/K/2Cl cotransport decreased. α- and β-ENaC mRNAs also decreased in hypoxic lungs. Similar results were seen in alveolar type II cells from hypoxic rats. These results indicate a slow decrease in the amount of Na-transporting proteins in alveolar epithelial cells during exposure to hypoxia that also occurs in vivo in lungs from hypoxic animals. The reduced number of transporters might account for the decreased transport activity and impaired edema clearance in hypoxic lungs.

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.

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