Enteroviral 3C protease activates the human NLRP1 inflammasome in airway epithelia

Science ◽  
2020 ◽  
Vol 370 (6521) ◽  
pp. eaay2002 ◽  
Author(s):  
Kim S. Robinson ◽  
Daniel Eng Thiam Teo ◽  
Kai Sen Tan ◽  
Gee Ann Toh ◽  
Hsiao Hui Ong ◽  
...  
Keyword(s):  
Inflammatory Diseases ◽  
Airway Epithelial Cells ◽  
Innate Immune ◽  
Inflammasome Activation ◽  
Airway Epithelial ◽  
Airway Epithelia ◽  
Nlrp1 Inflammasome ◽  
Terminal Fragment ◽  
Human Immune ◽  
Sensor Proteins

Immune sensor proteins are critical to the function of the human innate immune system. The full repertoire of cognate triggers for human immune sensors is not fully understood. Here, we report that human NACHT, LRR, and PYD domains-containing protein 1 (NLRP1) is activated by 3C proteases (3Cpros) of enteroviruses, such as human rhinovirus (HRV). 3Cpros directly cleave human NLRP1 at a single site between Glu130 and Gly131. This cleavage triggers N-glycine–mediated degradation of the autoinhibitory NLRP1 N-terminal fragment via the cullinZER1/ZYG11B complex, which liberates the activating C-terminal fragment. Infection of primary human airway epithelial cells by live human HRV triggers NLRP1-dependent inflammasome activation and interleukin-18 secretion. Our findings establish 3Cpros as a pathogen-derived trigger for the human NLRP1 inflammasome and suggest that NLRP1 may contribute to inflammatory diseases of the airway.

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 Pulmonary fibrosis distal airway epithelia are dynamically and structurally dysfunctional

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Ian T. Stancil ◽  
Jacob E. Michalski ◽  
Duncan Davis-Hall ◽  
Hong Wei Chu ◽  
Jin-Ah Park ◽  
...  
Keyword(s):  
Pulmonary Fibrosis ◽  
Airway Epithelium ◽  
Cell Types ◽  
Airway Epithelial Cells ◽  
Airway Epithelial ◽  
Airway Epithelia ◽  
Chronic Lung Diseases ◽  
Distal Airway ◽  
Signaling Axis

AbstractThe airway epithelium serves as the interface between the host and external environment. In many chronic lung diseases, the airway is the site of substantial remodeling after injury. While, idiopathic pulmonary fibrosis (IPF) has traditionally been considered a disease of the alveolus and lung matrix, the dominant environmental (cigarette smoking) and genetic (gain of function MUC5B promoter variant) risk factor primarily affect the distal airway epithelium. Moreover, airway-specific pathogenic features of IPF include bronchiolization of the distal airspace with abnormal airway cell-types and honeycomb cystic terminal airway-like structures with concurrent loss of terminal bronchioles in regions of minimal fibrosis. However, the pathogenic role of the airway epithelium in IPF is unknown. Combining biophysical, genetic, and signaling analyses of primary airway epithelial cells, we demonstrate that healthy and IPF airway epithelia are biophysically distinct, identifying pathologic activation of the ERBB-YAP axis as a specific and modifiable driver of prolongation of the unjammed-to-jammed transition in IPF epithelia. Furthermore, we demonstrate that this biophysical state and signaling axis correlates with epithelial-driven activation of the underlying mesenchyme. Our data illustrate the active mechanisms regulating airway epithelial-driven fibrosis and identify targets to modulate disease progression.

CF Monocyte Derived Macrophages Have an Attenuated Response to Extracellular Vesicles Secreted by Airway Epithelial Cells

2021 ◽  
Author(s):  
Katja Koeppen ◽  
Amanda B Nymon ◽  
Roxanna Barnaby ◽  
Zhongyou Li ◽  
Thomas H Hampton ◽  
...  
Keyword(s):  
Immune Response ◽  
Epithelial Cells ◽  
Bacterial Infection ◽  
Extracellular Vesicles ◽  
Cell Types ◽  
Airway Epithelial Cells ◽  
Innate Immune ◽  
Airway Epithelial ◽  
Immune Genes ◽  
Innate Immune Genes

Mutations in CFTR alter macrophage responses, for example, by reducing their ability to phagocytose and kill bacteria. Altered macrophage responses may facilitate bacterial infection and inflammation in the lungs, contributing to morbidity and mortality in cystic fibrosis (CF). Extracellular vesicles (EVs) are secreted by multiple cell types in the lungs and participate in the host immune response to bacterial infection, but the effect of EVs secreted by CF airway epithelial cells (AEC) on CF macrophages is unknown. This report examines the effect of EVs secreted by primary AEC on monocyte derived macrophages (MDM) and contrasts responses of CF and WT MDM. We found that EVs generally increase pro-inflammatory cytokine secretion and expression of innate immune genes in MDM, especially when EVs are derived from AEC exposed to Pseudomonas aeruginosa, and that this effect is attenuated in CF MDM. Specifically, EVs secreted by P. aeruginosa exposed AEC induced immune response genes and increased secretion of pro-inflammatory cytokines, chemoattractants and chemokines involved in tissue repair by WT MDM, but these effects were less robust in CF MDM. We attribute attenuated responses by CF MDM to differences between CF and WT macrophages because EVs secreted by CF AEC or WT AEC elicited similar responses in CF MDM. Our findings demonstrate the importance of AEC EVs in macrophage responses and show that the Phe508del mutation in CFTR attenuates the innate immune response of MDM to EVs.

IL-4/IL-13 upregulates Sonic hedgehog expression to induce allergic airway epithelial remodeling

2020 ◽  
Vol 318 (5) ◽  
pp. L888-L899 ◽  
Author(s):  
Xiangzhi Wang ◽  
Chengyun Xu ◽  
Junyan Ji ◽  
Yuqing Cai ◽  
Yingying Shu ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Sonic Hedgehog ◽  
Goblet Cell ◽  
Intratracheal Instillation ◽  
Allergic Airway Inflammation ◽  
Airway Epithelial Cells ◽  
Airway Epithelial ◽  
Airway Epithelia ◽  
Shh Signaling ◽  
Epithelial Remodeling

We have previously demonstrated that upregulation of Sonic hedgehog (SHH) expression in allergic airway epithelia essentially contributes to the goblet cell metaplasia and mucous hypersecretion. However, the mechanism underlying the upregulation of SHH expression remains completely unknown. In cultured human airway epithelial cells, IL-4/IL-13 but not IL-5 robustly induces the mRNA and protein expression of SHH and in turn activates SHH signaling by promoting the JAK/STAT6-controlling transcription of SHH gene. Moreover, intratracheal instillation of IL-4 and/or IL-13 robustly activates STAT6 and concomitantly upregulates SHH expression in mouse airway epithelia, whereas, in Club cell 10-kDa protein (CC10)-positive airway epithelial cells of children with asthma, activated STAT6 closely correlates with the increased expression of SHH and high activity of SHH signaling. Finally, intratracheal inhibition of STAT6 by AS-1517499 significantly diminished the allergen-induced upregulation of SHH expression, goblet cell phenotypes, and airway hyperresponsiveness, in an ovalbumin- or house dust mite-induced mouse model with allergic airway inflammation,. Together, upregulation of SHH expression by IL-4/IL-13-induced JAK/STAT6 signaling contributes to allergic airway epithelial remodeling, and this study thus provides insight into how morphogen signaling is coordinated with Th2 cytokine pathways to regulate tissue remodeling in chronic airway diseases.

scholarly journals Benzisothiazolinone upregulates the MUC5AC expression via ERK1/2, p38, and NF-κB pathways in airway epithelial cells

2019 ◽  
Vol 8 (5) ◽  
pp. 704-710
Author(s):  
Soyoung Kwak ◽  
Yoon Seok Choi ◽  
Hyung Gyun Na ◽  
Chang Hoon Bae ◽  
Si-Youn Song ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Inflammatory Diseases ◽  
Airway Epithelial Cells ◽  
Airway Epithelial ◽  
Mucus Hypersecretion ◽  
Human Airway ◽  
Airway Diseases ◽  
Extracellular Signal ◽  
Human Airway Epithelial Cells

Abstract Mucus plays an important role in protecting the respiratory tract from irritants. However, mucus hypersecretion is a major indicator of airway diseases. 1,2-Benzisothiazolin-3-one (BIT), as a microbicide, induces asthmatic inflammation. Therefore, we focused on the effects of BIT-related mucin secretion in airway epithelial cells. Our in vivo study showed increased mucus and MUC5AC expressions in the bronchioles of mice that inhaled BIT. For investigating the signaling pathways, we performed experiments in human airway epithelial cells. BIT induced the MUC5AC expression and significantly increased the phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2), p38, and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB). The specific inhibitors of ERK1/2, p38, and NF-κB blocked the BIT-induced MUC5AC expression. Therefore, these results suggest that BIT induces the MUC5AC expression via the ERK1/2, p38, and NF-κB pathways in human airway epithelial cells, which may be involved in mucus hypersecretion associated with airway inflammatory diseases.

scholarly journals Endotoxin responsiveness of human airway epithelia is limited by low expression of MD-2

2004 ◽  
Vol 287 (2) ◽  
pp. L428-L437 ◽  
Author(s):  
Hong Peng Jia ◽  
Joel N. Kline ◽  
Andrea Penisten ◽  
Michael A. Apicella ◽  
Theresa L. Gioannini ◽  
...  
Keyword(s):  
Primary Cultures ◽  
Airway Epithelial Cells ◽  
Response To Treatment ◽  
Airway Epithelial ◽  
Airway Epithelia ◽  
Human Airway ◽  
Tnf Α ◽  
Pulmonary Macrophages ◽  
Well Differentiated ◽  
Human Airway Epithelia

The expression of inducible antimicrobial peptides, such as human β-defensin-2 (HBD-2) by epithelia, comprises a component of innate pulmonary defenses. We hypothesized that HBD-2 induction in airway epithelia is linked to pattern recognition receptors such as the Toll-like receptors (TLRs). We found that primary cultures of well-differentiated human airway epithelia express the mRNA for TLR-4, but little or no MD-2 mRNA, and display little HBD-2 expression in response to treatment with purified endotoxin ± LPS binding protein (LBP) and soluble CD14. Expression of endogenous MD-2 by transduction of airway epithelial cells with an adenoviral vector encoding MD-2 or extracellular addition of recombinant MD-2 both increased the responses of airway epithelia to endotoxin + LBP and sCD14 by >100-fold, as measured by NF-κB-luciferase activity and HBD-2 mRNA expression. MD-2 mRNA could be induced in airway epithelia by exposure of these cells to specific bacterial or host products (e.g., killed Haemophilus influenzae, the P6 outer membrane protein from H. influenzae, or TNF-α + IFN-γ). These findings suggest that MD-2, either coexpressed with TLR-4 or secreted when produced in excess of TLR-4 from neighboring cells, is required for airway epithelia to respond sensitively to endotoxin. The regulation of MD-2 expression in airway epithelia and pulmonary macrophages may serve as a means to modify endotoxin responsiveness in the airway.

Paraoxonase-2 deficiency enhancesPseudomonas aeruginosaquorum sensing in murine tracheal epithelia

2007 ◽  
Vol 292 (4) ◽  
pp. L852-L860 ◽  
Author(s):  
David A. Stoltz ◽  
Egon A. Ozer ◽  
Carey J. Ng ◽  
Janet M. Yu ◽  
Srinivasa T. Reddy ◽  
...  
Keyword(s):  
Epithelial Cell ◽  
Epithelial Cells ◽  
Quorum Sensing ◽  
Airway Epithelial Cell ◽  
Airway Epithelial Cells ◽  
Airway Epithelial ◽  
Airway Epithelia ◽  
Tracheal Epithelial Cells ◽  
Human Airway ◽  
Tracheal Epithelial

Pseudomonas aeruginosa is an important cause of nosocomial infections and is frequently present in the airways of cystic fibrosis patients. Quorum sensing mediates P. aeruginosa's virulence and biofilm formation through density-dependent interbacterial signaling with autoinducers. N-3-oxododecanoyl homoserine lactone (3OC12-HSL) is the major autoinducer in P. aeruginosa. We have previously shown that human airway epithelia and paraoxonases (PONs) degrade 3OC12-HSL. This study investigated the role of PON1, PON2, and PON3 in airway epithelial cell inactivation of 3OC12-HSL. All three PONs were present in murine tracheal epithelial cells, with PON2 and PON3 expressed at the highest levels. Lysates of tracheal epithelial cells from PON2, but not PON1 or PON3, knockout mice had impaired 3OC12-HSL inactivation compared with wild-type mice. In contrast, PON1-, PON2-, or PON3-targeted deletions did not affect 3OC12-HSL degradation by intact epithelia. Overexpression of PON2 enhanced 3OC12-HSL degradation by human airway epithelial cell lysates but not by intact epithelia. Finally, using a quorum-sensing reporter strain of P. aeruginosa, we found that quorum sensing was enhanced in PON2-deficient airway epithelia. In summary, these results show that loss of PON2 impairs 3OC12-HSL degradation by airway epithelial cells and suggests that diffusion of 3OC12-HSL into the airway cells can be the rate-limiting step for degradation of the molecule.

Apical location of ferroportin 1 in airway epithelia and its role in iron detoxification in the lung

2005 ◽  
Vol 289 (1) ◽  
pp. L14-L23 ◽  
Author(s):  
Funmei Yang ◽  
David J. Haile ◽  
Xinchao Wang ◽  
Lisa A. Dailey ◽  
Jacqueline G. Stonehuerner ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Iron Homeostasis ◽  
Imaging Techniques ◽  
Basolateral Membrane ◽  
Airway Epithelial Cells ◽  
Dependent Manner ◽  
Airway Epithelial ◽  
Airway Epithelia ◽  
Ferroportin 1 ◽  
Immunofluorescence Labeling

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.

Contribution of innate immune cells to pathogenesis of severe influenza virus infection

2017 ◽  
Vol 131 (4) ◽  
pp. 269-283 ◽  
Author(s):  
Suzanne L. Cole ◽  
Ling-Pei Ho
Keyword(s):  
Immune Response ◽  
Influenza A ◽  
Influenza Virus Infection ◽  
Respiratory Illness ◽  
Airway Epithelial Cells ◽  
Innate Immune ◽  
Airway Epithelial ◽  
Cell Type ◽  
Influenza A Viruses ◽  
Effector Cells

Influenza A viruses (IAVs) cause respiratory illness of varying severity based on the virus strains, host predisposition and pre-existing immunity. Ultimately, outcome and recovery from infection rely on an effective immune response comprising both innate and adaptive components. The innate immune response provides the first line of defence and is crucial to the outcome of infection. Airway epithelial cells are the first cell type to encounter the virus in the lungs, providing antiviral and chemotactic molecules that shape the ensuing immune response by rapidly recruiting innate effector cells such as NK cells, monocytes and neutrophils. Each cell type has unique mechanisms to combat virus-infected cells and limit viral replication, however their actions may also lead to pathology. This review focuses how innate cells contribute to protection and pathology, and provides evidence for their involvement in immune pathology in IAV infections.

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