SARS-CoV-2 drives JAK1/2-dependent local complement hyperactivation

Patients with coronavirus disease 2019 (COVID-19) present a wide range of acute clinical manifestations affecting the lungs, liver, kidneys and gut. Angiotensin converting enzyme (ACE) 2, the best-characterized entry receptor for the disease-causing virus SARS-CoV-2, is highly expressed in the aforementioned tissues. However, the pathways that underlie the disease are still poorly understood. Here, we unexpectedly found that the complement system was one of the intracellular pathways most highly induced by SARS-CoV-2 infection in lung epithelial cells. Infection of respiratory epithelial cells with SARS-CoV-2 generated activated complement component C3a and could be blocked by a cell-permeable inhibitor of complement factor B (CFBi), indicating the presence of an inducible cell-intrinsic C3 convertase in respiratory epithelial cells. Within cells of the bronchoalveolar lavage of patients, distinct signatures of complement activation in myeloid, lymphoid and epithelial cells tracked with disease severity. Genes induced by SARS-CoV-2 and the drugs that could normalize these genes both implicated the interferon-JAK1/2-STAT1 signaling system and NF-κB as the main drivers of their expression. Ruxolitinib, a JAK1/2 inhibitor, normalized interferon signature genes and all complement gene transcripts induced by SARS-CoV-2 in lung epithelial cell lines, but did not affect NF-κB-regulated genes. Ruxolitinib, alone or in combination with the antiviral remdesivir, inhibited C3a protein produced by infected cells. Together, we postulate that combination therapy with JAK inhibitors and drugs that normalize NF-κB-signaling could potentially have clinical application for severe COVID-19.

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Bioassay of a tracheal smooth muscle-constricting factor released by respiratory epithelial cells

AJP Lung Cellular and Molecular Physiology ◽

10.1152/ajplung.1992.263.1.l137 ◽

1992 ◽

Vol 263 (1) ◽

pp. L137-L141 ◽

Cited By ~ 5

Author(s):

J. H. Wilkens ◽

A. Becker ◽

H. Wilkens ◽

M. Emura ◽

M. Riebe-Imre ◽

...

Keyword(s):

Smooth Muscle ◽

Epithelial Cell ◽

Epithelial Cells ◽

Muscle Tone ◽

Lung Epithelial Cells ◽

Epithelial Cell Line ◽

Cell Column ◽

Respiratory Epithelial Cells ◽

Lung Epithelial ◽

Respiratory Epithelial

Epithelium-derived factors of unknown identity have been proposed to modulate airway smooth muscle tone. We developed a novel sensitive bioassay system that allows serial perfusion of cultured respiratory epithelial cells and guinea pig trachea (GPT). GPT responses were assessed as diameter changes by computerized video microscopy (resolution, 15 microns). A permanent hamster lung epithelial cell line was grown on microcarrier beads and perfused in a cell column. When the outflow tubing from the epithelial cell column was connected to the inflow cannula, the detector GPT contracted, reaching 28 +/- 6% of the maximum methacholine (100 microM)-induced contraction (n = 12, P less than 0.001). Perfusion of the cell column with diclofenac (10 microM) or lysin-mono-acetylsalicylic acid (100 microM) abolished the GPT contraction, whereas selective perfusion of the detector GPT with either agent did not block the contraction. Analysis of the effluent of the epithelial cell column demonstrated a significant basal release of prostaglandins F2 alpha and E2 (PGF2 alpha and PGE2) and 6-ketoprostaglandin F1 alpha, whereas only marginal amounts of thromboxane B2 were detected. When given exogenously, PGF2 alpha, PGE2, PGI2, and U-46619 all contracted the GPT. It is concluded that lung epithelial cells can contract GPT by releasing a transferable factor. This factor is likely to be a constrictor cyclooxygenase product that is not produced in epithelium-denuded GPT.

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Regulation of Proinflammatory Cytokines in Human Lung Epithelial Cells Infected with Mycoplasma pneumoniae

Infection and Immunity ◽

10.1128/iai.70.7.3649-3655.2002 ◽

2002 ◽

Vol 70 (7) ◽

pp. 3649-3655 ◽

Cited By ~ 85

Author(s):

Jun Yang ◽

W. Craig Hooper ◽

Donald J. Phillips ◽

Deborah F. Talkington

Keyword(s):

Protein Synthesis ◽

Epithelial Cells ◽

Mycoplasma Pneumoniae ◽

Proinflammatory Cytokines ◽

Human Lung ◽

Lung Epithelial Cells ◽

Cytokine Gene Expression ◽

Respiratory Epithelial Cells ◽

Lung Epithelial ◽

Respiratory Epithelial

ABSTRACT Mycoplasma pneumoniae is a small bacterium without a cell wall that causes tracheobronchitis and atypical pneumonia in humans. It has also been associated with chronic conditions, such as arthritis, and extrapulmonary complications, such as encephalitis. Although the interaction of mycoplasmas with respiratory epithelial cells is a critical early phase of pathogenesis, little is known about the cascade of events initiated by infection of respiratory epithelial cells by mycoplasmas. Previous studies have shown that M. pneumoniae can induce proinflammatory cytokines in several different study systems including cultured murine and human monocytes. In this study, we demonstrate that M. pneumoniae infection also induces proinflammatory cytokine expression in A549 human lung carcinoma cells. Infection of A549 cells resulted in increased levels of interleukin-8 (IL-8) and tumor necrosis factor alpha mRNA, and both proteins were secreted into culture medium. IL-1β mRNA also increased after infection and IL-1β protein was synthesized, but it remained intracellular. In contrast, levels of IL-6 and gamma interferon mRNA and protein remained unchanged or undetectable. Using protease digestion and antibody blocking methods, we found that M. pneumoniae cytadherence is important for the induction of cytokines. On the other hand, while M. pneumoniae protein synthesis and DNA synthesis do not appear to be prerequisites for the induction of cytokine gene expression, A549 cellular de novo protein synthesis is responsible for the increased cytokine protein levels. These results suggest a novel role for lung epithelial cells in the pathogenesis of M. pneumoniae infection and provide a better understanding of M. pneumoniae pathology at the cellular level.

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Role of Pht Proteins in Attachment of Streptococcus pneumoniae to Respiratory Epithelial Cells

Infection and Immunity ◽

10.1128/iai.00699-13 ◽

2014 ◽

Vol 82 (4) ◽

pp. 1683-1691 ◽

Cited By ~ 30

Author(s):

Anna Kallio ◽

Kirsi Sepponen ◽

Philippe Hermand ◽

Philippe Denoël ◽

Fabrice Godfroid ◽

...

Keyword(s):

Epithelial Cells ◽

Bacterial Attachment ◽

Surface Proteins ◽

Lung Epithelial Cells ◽

Host Cells ◽

Respiratory Epithelial Cells ◽

Relative Significance ◽

Mucosal Surfaces ◽

Respiratory Epithelial

ABSTRACTPneumococcal adherence to mucosal surfaces is a critical step in nasopharyngeal colonization, but so far few pneumococcal adhesins involved in the interaction with host cells have been identified. PhtA, PhtB, PhtD, and PhtE are conserved pneumococcal surface proteins that have proven promising as vaccine candidates. One suggested virulence function of Pht proteins is to mediate adherence at the respiratory mucosa. In this study, we assessed the role of Pht proteins in pneumococcal binding to respiratory epithelial cells. Pneumococci were incubated with human nasopharyngeal epithelial cells (Detroit-562) and lung epithelial cells (A549 and NCI-H292), and the proportion of bound bacteria was measured by plating viable counts. Strains R36A (unencapsulated), D39 (serotype 2), 43 (serotype 3), 4-CDC (serotype 4), and 2737 (serotype 19F) with one or more of the four homologous Pht proteins deleted were compared with their wild-type counterparts. Also, the effect of anti-PhtD antibodies on the adherence of strain 2737 to the respiratory epithelial cells was studied. Our results suggest that Pht proteins play a role in pneumococcal adhesion to the respiratory epithelium. We also found that antibody to PhtD is able to inhibit bacterial attachment to the cells, suggesting that antibodies against PhtD present at mucosal surfaces might protect from pneumococcal attachment and subsequent colonization. However, the relative significance of Pht proteins to the ability of pneumococci to bindin vitroto epithelial cells depends on the genetic background and the capsular serotype of the strain.

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Zinc chelators inhibit eotaxin, RANTES, and MCP-1 production in stimulated human airway epithelium and fibroblasts

AJP Lung Cellular and Molecular Physiology ◽

10.1152/ajplung.00406.2002 ◽

2003 ◽

Vol 285 (3) ◽

pp. L719-L729 ◽

Cited By ~ 35

Author(s):

Martin Richter ◽

André M. Cantin ◽

Claudia Beaulieu ◽

Alexandre Cloutier ◽

Pierre Larivée

Keyword(s):

Epithelial Cells ◽

Airway Epithelium ◽

Rnase Protection Assay ◽

Zinc Content ◽

Lung Epithelial Cells ◽

Respiratory Epithelial Cells ◽

Rnase Protection ◽

Human Airway Epithelium ◽

Zinc Chelator ◽

Respiratory Epithelial

Asthma is characterized by an increased production of eosinophil-active C-C chemokines by the airway epithelium. Recent studies have identified the presence of important quantities of labile zinc in the conducting airways. We hypothesized that modulation of this labile zinc could influence the production of proinflammatory chemokines in respiratory epithelial cells. The zinc chelator N,N,N′ ,N′-tetrakis(2-pyridylmethyl)ethylenediamine (TPEN) and the heavy metal chelator 2,3-dimercapto-1-propanesulfonic acid (DMPS) were used to reduce the labile zinc content of A549, BEAS-2B, and HFL-1 cells. Northern blot analysis and RNase protection assay were used to study the effects of the zinc chelators on mRNA expression. DMPS and TPEN specifically inhibited the production of eotaxin, regulated on activation, normal T-cell expressed, and presumably secreted, and monocyte chemotactic protein-1 in TNF-α-stimulated respiratory epithelial cells and fibroblasts through labile zinc chelation. The inhibitory effects of DMPS and TPEN were associated with the decreased binding of the zinc-finger transcription factor GATA-1, whereas no change in NF-κB activation was observed. Together these results demonstrate that modulation of the labile pool of zinc can regulate gene expression and protein synthesis of C-C chemokines in lung epithelial cells and fibroblasts.

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Evaluation of miR-155 Expression in Cystic Fibrosis Patients

Journal of Comprehensive Pediatrics ◽

10.5812/compreped.100938 ◽

2020 ◽

Vol 11 (4) ◽

Author(s):

Somayeh Yasseri ◽

Maryam Hassanzad ◽

Poopak Farnia ◽

Jalaledin Ghanavi ◽

Mohammadreza Boloursaz ◽

...

Keyword(s):

Cystic Fibrosis ◽

Epithelial Cells ◽

Genetic Disorder ◽

Clinical Manifestations ◽

Lung Epithelial Cells ◽

Influential Factor ◽

Expression Level ◽

Expression Levels ◽

Significant Difference ◽

Lung Epithelial

Background: Cystic Fibrosis (CF) is the most fatal genetic disorder among white populations. It is a multi-system disease with various symptoms, which causes many different complications. miRNAs are a class of endogenous small non-coding RNAs of 19-22 nt that regulate mRNAs post-transcriptionally. Different types of miRNAs, including miR-155, are expressed in CF lung epithelial cells. The elevated expression level of miR-155 contributes to the pro-inflammatory expression of IL-8 in CF lung epithelial cells. Therefore, miR-155 may play an important role in the activation of IL-8 in CF. Objectives: The present study aimed to investigate the relationship between miR-155 expression level and the clinical manifestations of CF patients. Methods: The participants of this cross-sectional study included 30 CF patients (according to sweat test and < F508 in the genetic study) with age ranging from 5 to 27 years (M = 17, F = 13) and 30 healthy individuals with age ranging from 8 to 28 (M = 17, F = 13). Using RNA purification Kit, microRNAs, we extracted microRNAs from serum samples, and cDNA was synthesized via the cDNA synthesis kit. Then, the levels of miR-155 were measured by real-time PCR, and the expression levels were compared in different groups of CF patients according to the Shwachman-Kulczycki scoring system. Results: The expression level of miR-155 was elevated in CF patients compared to healthy controls (Fold change: 1.41, P value = 0.056). Interestingly, the elevated level of miR-155 in severe and moderate patients (according to Shwachman-Kulczycki score) showed a significant difference compared to the other patients, where age and sex were not an influential factor. Conclusions: Serum expression levels of miR-155 are different in CF patients, along with the severity of the disease. By suppressing the expression of miR-155, more investigations might lead to the development of new treatment strategies for CF.

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Inactivation of a Two-Component Signal Transduction System, SaeRS, Eliminates Adherence and Attenuates Virulence of Staphylococcus aureus

Infection and Immunity ◽

10.1128/iai.00322-06 ◽

2006 ◽

Vol 74 (8) ◽

pp. 4655-4665 ◽

Cited By ~ 86

Author(s):

Xudong Liang ◽

Chuanxin Yu ◽

Junsong Sun ◽

Hong Liu ◽

Christina Landwehr ◽

...

Keyword(s):

Signal Transduction ◽

Staphylococcus Aureus ◽

Epithelial Cells ◽

Binding Proteins ◽

Lung Epithelial Cells ◽

Complement Factor ◽

Signal Transduction System ◽

Lung Epithelial ◽

Two Component ◽

Two Component Signal Transduction

ABSTRACTStaphylococcus aureusis a major human and animal pathogen. During infection, this organism not only is able to attach to and enter host cells by using its cell surface-associated factors but also exports toxins to induce apoptosis and kill invaded cells. In this study, we identified the regulon of a two-component signal transduction system, SaeRS, and demonstrated that the SaeRS system is required forS. aureusto cause infection both in vitro and in vivo. Using microarray and real-time reverse transcriptase PCR analyses, we found that SaeRS regulates the expression of genes involved in adhesion and invasion (such as those encoding fibronectin-binding proteins and fibrinogen-binding proteins) and genes encoding α-, β-, and γ-hemolysins. Surprisingly, we found that SaeRS represses the Agr regulatory system since the mutation ofsaeSup-regulatesagrAexpression, which was confirmed by using anagrpromoter-reporter fusion system. More importantly, we demonstrated that inactivation of the SaeRS system significantly decreases the bacterium-induced apoptosis and/or death of lung epithelial cells (A549) and attenuates virulence in a murine infection model. Moreover, we found that inactivation of the SaeRS system eliminates staphylococcal adhesion and internalization of lung epithelial cells. We also found that both a novel hypothetical protein (the SA1000 protein) and a bifunctional protein (Efb), which binds to extracellular fibrinogen and complement factor C3, might partially contribute to bacterial adhesion to and invasion of epithelial cells. Our results indicate that activation of the SaeRS system may be required forS. aureusto adhere to and invade epithelial cells.

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Lung epithelial MyD88 drives early pulmonary clearance of Pseudomonas aeruginosa by a flagellin dependent mechanism

AJP Lung Cellular and Molecular Physiology ◽

10.1152/ajplung.00078.2016 ◽

2016 ◽

Vol 311 (2) ◽

pp. L219-L228 ◽

Cited By ~ 15

Author(s):

Adam A. Anas ◽

Miriam H. P. van Lieshout ◽

Theodora A. M. Claushuis ◽

Alex F. de Vos ◽

Sandrine Florquin ◽

...

Keyword(s):

Bone Marrow ◽

Pseudomonas Aeruginosa ◽

Epithelial Cells ◽

Lung Epithelial Cells ◽

Chimeric Mice ◽

Lung Epithelial ◽

Parenchymal Cells ◽

Respiratory Epithelial ◽

Myeloid Differentiation Factor

Pseudomonas aeruginosa is a flagellated pathogen frequently causing pneumonia in hospitalized patients and sufferers of chronic lung disease. Here we investigated the role of the common Toll-like receptor (TLR) adaptor myeloid differentiation factor (MyD)88 in myeloid vs. lung epithelial cells in clearance of P. aeruginosa from the airways. Mice deficient for MyD88 in lung epithelial cells (Sftpccre -MyD88-lox mice) or myeloid cells (LysMcre- MyD88-lox mice) and bone marrow chimeric mice deficient for TLR5 (the receptor recognizing Pseudomonas flagellin) in either parenchymal or hematopoietic cells were infected with P. aeruginosa via the airways. Sftpccre -MyD88-lox mice demonstrated a reduced influx of neutrophils into the bronchoalveolar space and an impaired early antibacterial defense after infection with P. aeruginosa, whereas the response of LysMcre- MyD88-lox mice did not differ from control mice. The immune-enhancing role of epithelial MyD88 was dependent on recognition of pathogen-derived flagellin by epithelial TLR5, as demonstrated by an unaltered clearance of mutant P. aeruginosa lacking flagellin from the lungs of Sftpccre -MyD88-lox mice and an impaired bacterial clearance in bone marrow chimeric mice lacking TLR5 in parenchymal cells. These data indicate that early clearance of P. aeruginosa from the airways is dependent on flagellin-TLR5-MyD88-dependent signaling in respiratory epithelial cells.

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Graphene oxide nanoparticle attachment and its toxicity on living lung epithelial cells

RSC Advances ◽

10.1039/c5ra09351a ◽

2015 ◽

Vol 5 (73) ◽

pp. 59447-59457 ◽

Cited By ~ 4

Author(s):

Linnea Ahlinder ◽

Jiří Henych ◽

Susanne Wiklund Lindström ◽

Barbro Ekstrand-Hammarström ◽

Václav Stengl ◽

...

Keyword(s):

Graphene Oxide ◽

Epithelial Cells ◽

Lung Epithelial Cells ◽

Wide Range ◽

Lung Epithelial ◽

Oxide Nanoparticle

Since its discovery graphene and its oxidized form graphene oxide have attracted interest in a wide range of applications, which calls for scrutinized studies about their possible toxicity.

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