scholarly journals Regulation of Lysosome-Associated Membrane Protein 3 (LAMP3) in Lung Epithelial Cells by Coronaviruses (SARS-CoV-1/2) and Type I Interferon Signaling

2021 ◽  
Author(s):  
Chilakamarti V. Ramana
Keyword(s):  
Epithelial Cells ◽  
Viral Entry ◽  
Human Lung ◽  
Type I Interferon ◽  
Respiratory Viruses ◽  
Lung Epithelial Cells ◽  
Type I ◽  
Type Ii ◽  
Interferon Signaling ◽  
Lung Epithelial

AbstractSevere acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection is a major risk factor for mortality and morbidity in critical care hospitals around the world. Lung epithelial type II cells play a major role in several physiological processes, including recognition and clearance of respiratory viruses as well as repair of lung injury in response to environmental toxicants. Gene expression profiling of lung epithelial type II-specific genes led to the identification of lysosomal-associated membrane protein 3 (LAMP3). Intracellular locations of LAMP3 include plasma membrane, endosomes, and lysosomes. These intracellular organelles are involved in vesicular transport and facilitate viral entry and release of the viral RNA into the host cell cytoplasm. In this study, regulation of LAMP3 expression in human lung epithelial cells by several respiratory viruses and type I interferon signaling was investigated. Coronaviruses including SARS-CoV-1 and SARS-CoV-2 significantly induced LAMP3 expression in lung epithelial cells within 24 hours after infection that required the presence of ACE2 viral entry receptor. Time-course experiments revealed that the induced expression of LAMP3 by SARS-CoV-2 was correlated with the induced expression of interferon-beta1 (IFNB1) and signal transducers and activator of transcription 1 (STAT1) mRNA levels. LAMP3 was also induced by direct IFN-beta treatment or by infection with influenza virus lacking the non-structural protein1(NS1) in NHBE bronchial epithelial cells. LAMP3 expression was induced in human lung epithelial cells by several respiratory viruses, including respiratory syncytial virus (RSV) and the human parainfluenza virus 3 (HPIV3). Location in lysosomes and endosomes as well as induction by respiratory viruses and type I Interferon suggests that LAMP3 may have an important role in inter-organellar regulation of innate immunity and a potential target for therapeutic modulation in health and disease. Furthermore, bioinformatics revealed that a subset of lung type II cell genes were differentially regulated in the lungs of COVID-19 patients.

scholarly journals Lung Epithelial Regulation of BCL2 Related Protein A1 (BCL2A1) by Coronaviruses (SARS-CoV) and Type I Interferon Signaling

2021 ◽  
Author(s):  
Ramana Chilakamarti
Keyword(s):  
Epithelial Cells ◽  
Human Lung ◽  
Type I Interferon ◽  
Respiratory Viruses ◽  
Lung Epithelial Cells ◽  
Type I ◽  
Related Protein ◽  
Interferon Signaling ◽  
Lung Epithelial ◽  
Human Lung Epithelial Cells

Highly pathogenic respiratory viruses such as 1918 influenza (HIN1) and coronavirus (SARS-CoV-2) induce significant lung injury with diffuse alveolar damage, capillary leak, and extensive cell death resulting in acute respiratory distress syndrome (ARDS). Direct effects of the virus, as well as host immune response such as proinflammatory cytokine production, contribute to programmed cell death or apoptosis. Alveolar lung epithelial type II (AT2) cells play a major role in the clearance of respiratory viruses, secretion of surfactant proteins and antimicrobial substances into the bronchoalveolar fluid as well as repair of lung injury. Gene expression in AT2 cells is regulated in a tissue and cell-specific manner and in a temporal fashion. The availability of tissue and cell-specific RNA datasets in Human Protein Atlas led to the identification of localized expression patterns of BCL-2 family members such as BCL2 related protein A1 (BCL2A1) in AT2 cells and immune cells of the lung. BCL2A1 expression was regulated by multiple stimuli including Toll-like receptor (TLR) ligands, interferons (IFNs), inflammatory cytokines, and inhibited by the steroid dexamethasone. In this study, regulation of BCL2A1 gene expression in human lung epithelial cells by several respiratory viruses and type I interferon signaling was investigated. SARS-CoV-2 infection significantly induced BCL2A1 expression in human lung epithelial cells within 24 hours that required the expression of Angiotensin-converting enzyme 2 (ACE2). BCL2A1 mRNA induction by SARS-CoV-2 was correlated with the induced expression of IFN-β and IFN-regulated transcription factor mRNA. BCL2A1 was induced by IFN-β treatment or by infection with influenza virus lacking the non-structural protein1(NS1) in NHBE cells. Furthermore, bioinformatics revealed that a subset of BCL-2 family members involved in the control of apoptosis and transcription such as BCL2A1, BCL2L14, BCL3, and BCL6 were regulated in the lung epithelial cells by coronaviruses and in the lung tissue samples of COVID-19 patients. Transcriptomic data also suggested that these genes were differentially regulated by the steroid drug dexamethasone.

scholarly journals Regulation of Indoleamine-3,5-dioxygenase 1 (IDO1) in Lung Epithelial Cells by Coronaviruses (SARS-CoV) and Cytokine Signaling

2021 ◽  
Author(s):  
Ramana Chilakamarti
Keyword(s):  
Gene Expression ◽  
Epithelial Cells ◽  
Inflammatory Cytokines ◽  
Proinflammatory Cytokines ◽  
Human Lung ◽  
Respiratory Viruses ◽  
Lung Epithelial Cells ◽  
Type I ◽  
Lung Epithelial ◽  
Rna Levels

Abstract Interferons (IFNs) and proinflammatory cytokines play an important role in the innate immune response to respiratory viruses, including coronaviruses (SARS-CoV). Metabolic profiling in the serum samples of coronavirus disease-19 (COVID-19) patients revealed altered cholesterol and tryptophan metabolism. Indoleamine-3,5-dioxygenase (IDO1) is the key enzyme involved in the tryptophan catabolism and induced by interferons and inflammatory cytokines. The regulation of IDO1 in immune cells and cancer was extensively studied. In this study, IDO1 regulation in human lung epithelial cells by coronaviruses and respiratory viruses as well as inflammatory cytokines was investigated. SARS-CoV-2 was a potent inducer of IFN–regulated metabolic enzymes such as IDO1, Cholesterol-25-hydroxylase (CH25H), Spermidine acetyltransferase (SAT1), and Sterile alpha motif and histidine/aspartic acid domain-containing protein (SAMHD1) at RNA levels in Calu-3 cells. Reconstitution of A549 lung epithelial cells with Angiotensin-converting enzyme 2 (ACE2) was necessary and sufficient to induce IDO1 at RNA levels. Influenza A virus (IAV) suppressed IDO1 RNA levels in a non-structural protein (NS1)-dependent manner in NHBE cells. In contrast, IDO1 RNA levels were dramatically induced in the lungs of mice infected with a reconstructed 1918 H1N1 influenza virus. Treatment of A549 cells with either type I or type II interferon induced IDO1 RNA levels. Furthermore, IDO1 levels were significantly higher in the lung tissues of COVID-19 patients in comparison with healthy controls. A mix of proinflammatory cytokines dramatically induced IDO1 and chemokine RNA levels in lung epithelial cells in a cell culture model, simulating the gene expression pattern in the lung tissue samples of COVID-19 patients. Furthermore, hypertonic saline solution (HTS) dramatically abrogated the gene expression induced by cytokine mix in human lung cells. The IDO1 protein interaction network included transcription factors STAT1 and STAT3. These studies suggest that IDO1 inhibition may be a potential therapeutic target in the treatment of viral and inflammatory diseases.

scholarly journals Profiling transcription factor sub-networks in type I interferon signaling and in response to SARS-CoV-2 infection

2021 ◽  
Author(s):  
Chilakamarti V. Ramana
Keyword(s):  
Gene Expression ◽  
Transcription Factor ◽  
Transcription Factors ◽  
Immune Modulation ◽  
Type I Interferon ◽  
Lung Epithelial Cells ◽  
Type I ◽  
Interferon Signaling ◽  
Lung Epithelial

AbstractType I interferons (IFN α/β) play a central role in innate immunity to respiratory viruses, including coronaviruses. Genetic defects in type I interferon signaling were reported in a significant proportion of critically ill CoOVID-19 patients. Extensive studies on interferon-induced intracellular signal transduction pathways led to the elucidation of the Jak-Stat pathway. Furthermore, advances in gene expression profiling by microarrays have revealed that type I interferon rapidly induced multiple transcription factor mRNA levels. In this study, transcription factor profiling in the transcriptome was used to gain novel insights into the role of inducible transcription factors in response to type I interferon signaling in immune cells and in lung epithelial cells after SARS-CoV-2 infection. Modeling the interferon-inducible transcription factor mRNA data in terms of distinct sub-networks based on biological functions such as antiviral response, immune modulation, and cell growth revealed enrichment of specific transcription factors in mouse and human immune cells. The evolutionarily conserved core type I interferon gene expression consists of the inducible transcriptional factor mRNA of the antiviral response sub-network and enriched in granulocytes. Analysis of the type I interferon-inducible transcription factor sub-networks as distinct protein-protein interaction pathways revealed insights into the role of critical hubs in signaling. Interrogation of multiple microarray datasets revealed that SARS-CoV-2 induced high levels of IFN-beta and interferon-inducible transcription factor mRNA in human lung epithelial cells. Transcription factor mRNA of the three major sub-networks regulating antiviral, immune modulation, and cell growth were differentially regulated in human lung epithelial cell lines after SARS-CoV-2 infection and in the tissue samples of COVID-19 patients. A subset of type I interferon-inducible transcription factors and inflammatory mediators were specifically enriched in the lungs and neutrophils of Covid-19 patients. The emerging complex picture of type I IFN transcriptional regulation consists of a rapid transcriptional switch mediated by the Jak-Stat cascade and a graded output of the inducible transcription factor activation that enables temporal regulation of gene expression.

scholarly journals Lung epithelial cells have virus-specific and shared gene expression responses to infection by diverse respiratory viruses

2016 ◽  
Author(s):  
James T. VanLeuven ◽  
Benjamin J. Ridenhour ◽  
Craig R. Miller ◽  
Tanya A. Miura
Keyword(s):  
Gene Expression ◽  
Epithelial Cells ◽  
Influenza A ◽  
Cellular Response ◽  
Respiratory Viruses ◽  
Lung Epithelial Cells ◽  
Interferon Response ◽  
Comparative Approach ◽  
Type I ◽  
Lung Epithelial

AbstractThe severity and outcome of respiratory viral infections is partially determined by the cellular response mounted by infected lung epithelial cells. Disease prevention and treatment is dependent on our understanding of the shared and unique responses elicited by diverse viruses, yet few studies compare host responses to different viruses while controlling other experimental parameters. We compared changes in gene expression of murine lung epithelial cells infected individually by three respiratory viruses causing mild (rhinovirus, RV1B), moderate (coronavirus, MHV-1), and severe (influenza A virus, PR8) disease in mice. RV1B infection caused numerous gene expression changes, but the differential effect peaked at 12 hours post-infection. PR8 altered an intermediate number of genes whose expression continued to change through 24 hours. MHV-1 had comparatively few effects on host gene expression. The viruses elicited highly overlapping responses in antiviral genes, though MHV-1 induced a lower type I interferon response than the other two viruses. Signature genes were identified for each virus and included host defense genes for PR8, tissue remodeling genes for RV1B, and transcription factors for MHV-1. Our comparative approach identified universal and specific transcriptional signatures of virus infection that can be used to discover mechanisms of pathogenesis in the respiratory tract.

TGF-β1 resistance is not associated with alterations in TGF-β type II receptors in immortalized human lung epithelial cells

1997 ◽  
Vol 113 (1-2) ◽  
pp. 65-70 ◽  
Author(s):  
Anne W. Hamburgera ◽  
Tamara Smith ◽  
Kathy Elliget ◽  
Koichi Hagiwara ◽  
Brenda I. Gerwin
Keyword(s):  
Epithelial Cells ◽  
Human Lung ◽  
Lung Epithelial Cells ◽  
Type Ii ◽  
Lung Epithelial ◽  
Tgf Β1 ◽  
Human Lung Epithelial Cells

scholarly journals Verification of SARS-CoV-2-Encoded small RNAs and contribution to Infection-Associated lung inflammation

2021 ◽  
Author(s):  
Cheng Zhang ◽  
Cheng Liu ◽  
Lin Jiang ◽  
Biao Lun Cui ◽  
Yu Chun Li ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Lung Inflammation ◽  
Small Rnas ◽  
Human Lung ◽  
Respiratory Illness ◽  
Lung Epithelial Cells ◽  
Type I ◽  
Viral Rnas ◽  
Lung Epithelial ◽  
Human Lung Epithelial Cells

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the virus that causes coronavirus disease 2019 (COVID-19), the respiratory illness responsible for the COVID-19 pandemic. SARS-CoV-2 is a positive-stranded RNA virus belongs to Coronaviridae family. The viral genome of SARS-CoV-2 contains around 29.8 kilobase with a 5′-cap structure and 3′-poly-A tail, and shows 79.2% nucleotide identity with human SARS-CoV-1, which caused the 2002-2004 SARS outbreak. As the successor to SARS-CoV-1, SARS-CoV-2 now has circulated across the globe. There is a growing understanding of SARS-CoV-2 in virology, epidemiology, and clinical management strategies. In this study, we verified the existence of two 18-22 nt small viral RNAs (svRNAs) derived from the same precursor in human specimens infected with SARS-CoV-2, including nasopharyngeal swabs and formalin-fixed paraffin-embedded (FFPE) explanted lungs from lung transplantation of COVID-19 patients. We then simulated and confirmed the formation of these two SARS-CoV-2-Encoded small RNAs in human lung epithelial cells. And the potential pro-inflammatory effects of the splicing and maturation process of these two svRNAs in human lung epithelial cells were also explored. By screening cytokine storm genes and the characteristic expression profiling of COVID-19 in the explanted lung tissues and the svRNAs precursor transfected human lung epithelial cells, we found that the maturation of these two small viral RNAs contributed significantly to the infection associated lung inflammation, mainly via the activation of the CXCL8, CXCL11 and type I interferon signaling pathway. Taken together, we discovered two SARS-CoV-2-Encoded small RNAs and investigated the pro-inflammatory effects during their maturation in human lung epithelial cells, which might provide new insight into the pathogenesis and possible treatment options for COVID-19.

scholarly journals Inducible Lung Epithelial Resistance Requires Multisource Reactive Oxygen Species Generation To Protect against Viral Infections

mBio ◽  
2018 ◽  
Vol 9 (3) ◽  
Author(s):  
Carson T. Kirkpatrick ◽  
Yongxing Wang ◽  
Miguel M. Leiva Juarez ◽  
Pooja Shivshankar ◽  
Jezreel Pantaleón García ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Epithelial Cells ◽  
Viral Infections ◽  
Type I Interferon ◽  
Reactive Oxygen ◽  
Lung Epithelial Cells ◽  
Type I ◽  
Oxygen Species ◽  
Inducible Resistance ◽  
Lung Epithelial

ABSTRACTViral pneumonias cause profound worldwide morbidity, necessitating novel strategies to prevent and treat these potentially lethal infections. Stimulation of intrinsic lung defenses via inhalation of synergistically acting Toll-like receptor (TLR) agonists protects mice broadly against pneumonia, including otherwise-lethal viral infections, providing a potential opportunity to mitigate infectious threats. As intact lung epithelial TLR signaling is required for the inducible resistance and as these cells are the principal targets of many respiratory viruses, the capacity of lung epithelial cells to be therapeutically manipulated to function as autonomous antiviral effectors was investigated. Our work revealed that mouse and human lung epithelial cells could be stimulated to generate robust antiviral responses that both reduce viral burden and enhance survival of isolated cells and intact animals. The antiviral protection required concurrent induction of epithelial reactive oxygen species (ROS) from both mitochondrial and dual oxidase sources, although neither type I interferon enrichment nor type I interferon signaling was required for the inducible protection. Taken together, these findings establish the sufficiency of lung epithelial cells to generate therapeutically inducible antiviral responses, reveal novel antiviral roles for ROS, provide mechanistic insights into inducible resistance, and may provide an opportunity to protect patients from viral pneumonia during periods of peak vulnerability.IMPORTANCEViruses are the most commonly identified causes of pneumonia and inflict unacceptable morbidity, despite currently available therapies. While lung epithelial cells are principal targets of respiratory viruses, they have also been recently shown to contribute importantly to therapeutically inducible antimicrobial responses. This work finds that lung cells can be stimulated to protect themselves against viral challenges, even in the absence of leukocytes, both reducing viral burden and improving survival. Further, it was found that the protection occurs via unexpected induction of reactive oxygen species (ROS) from spatially segregated sources without reliance on type I interferon signaling. Coordinated multisource ROS generation has not previously been described against viruses, nor has ROS generation been reported for epithelial cells against any pathogen. Thus, these findings extend the potential clinical applications for the strategy of inducible resistance to protect vulnerable people against viral infections and also provide new insights into the capacity of lung cells to protect against infections via novel ROS-dependent mechanisms.

scholarly journals Single-cell analysis of human lung epithelia reveals concomitant expression of the SARS-CoV-2 receptor ACE2 with multiple virus receptors and scavengers in alveolar type II cells

2020 ◽  
Author(s):  
Guangchun Han ◽  
Ansam Sinjab ◽  
Warapen Treekitkarnmongkol ◽  
Patrick Brennan ◽  
Kieko Hara ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Single Cell ◽  
Expression Patterns ◽  
Severe Pneumonia ◽  
Lung Epithelial Cells ◽  
Chronic Obstructive ◽  
Alveolar Type ◽  
Type I ◽  
Type Ii ◽  
Lung Epithelial

ABSTRACTThe novel coronavirus SARS-CoV-2 was identified as the causative agent of the ongoing pandemic COVID 19. COVID-19-associated deaths are mainly attributed to severe pneumonia and respiratory failure. Recent work demonstrated that SARS-CoV-2 binds to angiotensin converting enzyme 2 (ACE2) in the lung. To better understand ACE2 abundance and expression patterns in the lung we interrogated our in-house single-cell RNA-sequencing dataset containing 70,085 EPCAM+ lung epithelial cells from paired normal and lung adenocarcinoma tissues. Transcriptomic analysis revealed a diverse repertoire of airway lineages that included alveolar type I and II, bronchioalveolar, club/secretory, quiescent and proliferating basal, ciliated and malignant cells as well as rare populations such as ionocytes. While the fraction of lung epithelial cells expressing ACE2 was low (1.7% overall), alveolar type II (AT2, 2.2% ACE2+) cells exhibited highest levels of ACE2 expression among all cell subsets. Further analysis of the AT2 compartment (n = 27,235 cells) revealed a number of genes co-expressed with ACE2 that are important for lung pathobiology including those associated with chronic obstructive pulmonary disease (COPD; HHIP), pneumonia and infection (FGG and C4BPA) as well as malarial/bacterial (CD36) and viral (DMBT1) scavenging which, for the most part, were increased in smoker versus light or non-smoker cells. Notably, DMBT1 was highly expressed in AT2 cells relative to other lung epithelial subsets and its expression positively correlated with ACE2. We describe a population of ACE2-positive AT2 cells that co-express pathogen (including viral) receptors (e.g. DMBT1) with crucial roles in host defense thus comprising plausible phenotypic targets for treatment of COVID-19.

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