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2.
Signal Transduct Target Ther ; 7(1): 7, 2022 01 04.
Article in English | MEDLINE | ID: covidwho-1606287

ABSTRACT

Activation-induced cytidine deaminase (AID) initiates class-switch recombination and somatic hypermutation (SHM) in antibody genes. Protein expression and activity are tightly controlled by various mechanisms. However, it remains unknown whether a signal from the extracellular environment directly affects the AID activity in the nucleus where it works. Here, we demonstrated that a deubiquitinase USP10, which specifically stabilizes nuclear AID protein, can translocate into the nucleus after AKT-mediated phosphorylation at its T674 within the NLS domain. Interestingly, the signals from BCR and TLR1/2 synergistically promoted this phosphorylation. The deficiency of USP10 in B cells significantly decreased AID protein levels, subsequently reducing neutralizing antibody production after immunization with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) or human immunodeficiency virus type 1 (HIV-1) nanoparticle vaccines. Collectively, we demonstrated that USP10 functions as an integrator for both BCR and TLR signals and directly regulates nuclear AID activity. Its manipulation could be used for the development of vaccines and adjuvants.


Subject(s)
AIDS Vaccines/immunology , B-Cell Activating Factor/immunology , COVID-19 Vaccines/immunology , Cytidine Deaminase/immunology , HIV-1/immunology , Nanoparticles , SARS-CoV-2/immunology , Signal Transduction/immunology , Ubiquitin Thiolesterase/immunology , Ubiquitination/immunology , AIDS Vaccines/genetics , Animals , B-Cell Activating Factor/genetics , COVID-19 Vaccines/genetics , Cytidine Deaminase/genetics , HEK293 Cells , HIV-1/genetics , Humans , Mice , Mice, Knockout , SARS-CoV-2/genetics , Signal Transduction/genetics , Ubiquitin Thiolesterase/genetics
4.
Front Immunol ; 12: 784028, 2021.
Article in English | MEDLINE | ID: covidwho-1581324

ABSTRACT

Background: Extracellular vesicles (EVs) are mediators of cell-to-cell communication in inflammatory lung diseases. They function as carriers for miRNAs which regulate mRNA transcripts and signaling pathways after uptake into recipient cells. We investigated whether miRNAs associated with circulating EVs regulate immunologic processes in COVID-19. Methods: We prospectively studied 20 symptomatic patients with COVID-19 pneumonia, 20 mechanically ventilated patients with severe COVID-19 (severe acute respiratory corona virus-2 syndrome, ARDS) and 20 healthy controls. EVs were isolated by precipitation, total RNA was extracted, profiled by small RNA sequencing and evaluated by differential gene expression analysis (DGE). Differentially regulated miRNAs between groups were bioinformatically analyzed, mRNA target transcripts identified and signaling networks constructed, thereby comparing COVID-19 pneumonia to the healthy state and pneumonia to severe COVID-19 ARDS. Results: DGE revealed 43 significantly and differentially expressed miRNAs (25 downregulated) in COVID-19 pneumonia when compared to controls, and 20 miRNAs (15 downregulated) in COVID-19 ARDS patients in comparison to those with COVID-19 pneumonia. Network analysis for comparison of COVID-19 pneumonia to healthy controls showed upregulated miR-3168 (log2FC=2.28, padjusted<0.001), among others, targeting interleukin-6 (IL6) (25.1, 15.2 - 88.2 pg/ml in COVID-19 pneumonia) and OR52N2, an olfactory smell receptor in the nasal epithelium. In contrast, miR-3168 was significantly downregulated in COVID-19 ARDS (log2FC=-2.13, padjusted=0.003) and targeted interleukin-8 (CXCL8) in a completely activated network. Toll-like receptor 4 (TLR4) was inhibited in COVID-19 pneumonia by miR-146a-5p and upregulated in ARDS by let-7e-5p. Conclusion: EV-derived miRNAs might have important regulative functions in the pathophysiology of COVID-19: CXCL8 regulates neutrophil recruitment into the lung causing epithelial damage whereas activated TLR4, to which SARS-CoV-2 spike protein binds strongly, increases cell surface ACE2 expression and destroys type II alveolar cells that secrete pulmonary surfactants; both resulting in pulmonary-capillary leakage and ARDS. These miRNAs may serve as biomarkers or as possible therapeutic targets.


Subject(s)
Biomarkers/blood , COVID-19/immunology , Extracellular Vesicles/immunology , MicroRNAs/immunology , Aged , Aged, 80 and over , COVID-19/pathology , Disease Progression , Female , Humans , Male , Middle Aged , Pneumonia/immunology , Pneumonia/pathology , SARS-CoV-2 , Signal Transduction/immunology
5.
Int J Mol Sci ; 22(24)2021 Dec 15.
Article in English | MEDLINE | ID: covidwho-1572496

ABSTRACT

In humans, over-activation of innate immunity in response to viral or bacterial infections often causes severe illness and death. Furthermore, similar mechanisms related to innate immunity can cause pathogenesis and death in sepsis, massive trauma (including surgery and burns), ischemia/reperfusion, some toxic lesions, and viral infections including COVID-19. Based on the reviewed observations, we suggest that such severe outcomes may be manifestations of a controlled suicidal strategy protecting the entire population from the spread of pathogens and from dangerous pathologies rather than an aberrant hyperstimulation of defense responses. We argue that innate immunity may be involved in the implementation of an altruistic programmed death of an organism aimed at increasing the well-being of the whole community. We discuss possible ways to suppress this atavistic program by interfering with innate immunity and suggest that combating this program should be a major goal of future medicine.


Subject(s)
Altruism , Apoptosis/immunology , Immunity, Innate/immunology , Animals , COVID-19/immunology , Cell Death/immunology , Cytokine Release Syndrome/immunology , Cytokine Release Syndrome/mortality , Humans , Inflammasomes/immunology , Inflammation/immunology , SARS-CoV-2/immunology , SARS-CoV-2/pathogenicity , Signal Transduction/immunology
6.
Antioxid Redox Signal ; 35(16): 1376-1392, 2021 12.
Article in English | MEDLINE | ID: covidwho-1510864

ABSTRACT

Significance: It is estimated that close to 50 million cases of sepsis result in over 11 million annual fatalities worldwide. The pathognomonic feature of sepsis is a dysregulated inflammatory response arising from viral, bacterial, or fungal infections. Immune recognition of pathogen-associated molecular patterns is a hallmark of the host immune defense to combat microbes and to prevent the progression to sepsis. Mitochondrial antiviral signaling protein (MAVS) is a ubiquitous adaptor protein located at the outer mitochondrial membrane, which is activated by the cytosolic pattern recognition receptors, retinoic acid-inducible gene I (RIG-I) and melanoma differentiation associated gene 5 (MDA5), following binding of viral RNA agonists. Recent Advances: Substantial progress has been made in deciphering the activation of the MAVS pathway with its interacting proteins, downstream signaling events (interferon [IFN] regulatory factors, nuclear factor kappa B), and context-dependent type I/III IFN response. Critical Issues: In the evolutionary race between pathogens and the host, viruses have developed immune evasion strategies for cleavage, degradation, or blockade of proteins in the MAVS pathway. For example, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) M protein and ORF9b protein antagonize MAVS signaling and a protective type I IFN response. Future Directions: The role of MAVS as a sensor for nonviral pathogens, host cell injury, and metabolic perturbations awaits better characterization in the future. New technical advances in multidimensional single-cell analysis and single-molecule methods will accelerate the rate of new discoveries. The ultimate goal is to manipulate MAVS activities in the form of immune-modulatory therapies to combat infections and sepsis. Antioxid. Redox Signal. 35, 1376-1392.


Subject(s)
Adaptor Proteins, Signal Transducing/immunology , Sepsis/immunology , Signal Transduction/immunology , Virus Diseases/immunology , Animals , Host-Pathogen Interactions/immunology , Humans , Immune Evasion/immunology , Sepsis/virology
7.
Aging (Albany NY) ; 13(21): 23913-23935, 2021 11 03.
Article in English | MEDLINE | ID: covidwho-1502964

ABSTRACT

LianHuaQingWen (LHQW) improves clinical symptoms and alleviates the severity of COVID-19, but the mechanism is unclear. This study aimed to investigate the potential molecular targets and mechanisms of LHQW in treating COVID-19 using a network pharmacology-based approach and molecular docking analysis. The main active ingredients, therapeutic targets of LHQW, and the pathogenic targets of COVID-19 were screened using the TCMSP, UniProt, STRING, and GeneCards databases. According to the "Drug-Ingredients-Targets-Disease" network, Interleukin 6 (IL6) was identified as the core target, and quercetin, luteolin, and wogonin as the active ingredients of LHQW associated with IL6. The response to lipopolysaccharide was the most significant biological process identified by gene ontology enrichment analysis, and AGE-RAGE signaling pathway activation was prominent based on the interaction between LHQW and COVID-19. Protein-protein docking analysis showed that IL6 receptor (IL6R)/IL6/IL6 receptor subunit beta (IL6ST) and Spike protein were mainly bound via conventional hydrogen bonds. Furthermore, protein-small molecule docking showed that all three active ingredients could bind stably in the binding model of IL6R/IL6 and IL6ST. Our findings suggest that LHQW may inhibit the lipopolysaccharide-mediated inflammatory response and regulate the AGE-RAGE signaling pathway through IL6. In addition, the N-terminal domain of the S protein of COVID-19 has a good binding activity to IL6ST, and quercetin and wogonin in LHQW may affect IL6ST-mediated IL6 signal transduction and a large number of signaling pathways downstream to other cytokines by directly affecting protein-protein interaction. These findings suggest the potential molecular mechanism by which LHQW inhibits COVID-19 through the regulation of IL6R/IL6/IL6ST.


Subject(s)
COVID-19 , Drugs, Chinese Herbal/pharmacology , Glycation End Products, Advanced/metabolism , Interleukin-6/metabolism , Receptor for Advanced Glycation End Products/metabolism , SARS-CoV-2 , Antiviral Agents/pharmacology , COVID-19/drug therapy , COVID-19/immunology , Cytokine Receptor gp130/metabolism , Flavanones/pharmacology , Humans , Luteolin/pharmacology , Molecular Docking Simulation , Quercetin/pharmacology , Receptors, Interleukin-6/metabolism , SARS-CoV-2/drug effects , SARS-CoV-2/physiology , Signal Transduction/drug effects , Signal Transduction/immunology , Spike Glycoprotein, Coronavirus/metabolism
8.
Immunology ; 164(3): 541-554, 2021 11.
Article in English | MEDLINE | ID: covidwho-1488214

ABSTRACT

IL-33 and ATP are alarmins, which are released upon damage of cellular barriers or are actively secreted upon cell stress. Due to high-density expression of the IL-33 receptor T1/ST2 (IL-33R), and the ATP receptor P2X7, mast cells (MCs) are one of the first highly sensitive sentinels recognizing released IL-33 or ATP in damaged peripheral tissues. Whereas IL-33 induces the MyD88-dependent activation of the TAK1-IKK2-NF-κB signalling, ATP induces the Ca2+ -dependent activation of NFAT. Thereby, each signal alone only induces a moderate production of pro-inflammatory cytokines and lipid mediators (LMs). However, MCs, which simultaneously sense (co-sensing) IL-33 and ATP, display an enhanced and prolonged activation of the TAK1-IKK2-NF-κB signalling pathway. This resulted in a massive production of pro-inflammatory cytokines such as IL-2, IL-4, IL-6 and GM-CSF as well as of arachidonic acid-derived cyclooxygenase (COX)-mediated pro-inflammatory prostaglandins (PGs) and thromboxanes (TXs), hallmarks of strong MC activation. Collectively, these data show that co-sensing of ATP and IL-33 results in hyperactivation of MCs, which resembles to MC activation induced by IgE-mediated crosslinking of the FcεRI. Therefore, the IL-33/IL-33R and/or the ATP/P2X7 signalling axis are attractive targets for therapeutical intervention of diseases associated with the loss of integrity of cellular barriers such as allergic and infectious respiratory reactions.


Subject(s)
Adenosine Triphosphate/metabolism , Hypersensitivity/immunology , Interleukin-33/metabolism , Mast Cells/immunology , Animals , Anti-Allergic Agents/pharmacology , Anti-Allergic Agents/therapeutic use , Cell Degranulation/drug effects , Cytokines/metabolism , Disease Models, Animal , Eicosanoids/metabolism , Humans , Hypersensitivity/drug therapy , Interleukin-1 Receptor-Like 1 Protein/antagonists & inhibitors , Interleukin-1 Receptor-Like 1 Protein/metabolism , Interleukin-33/antagonists & inhibitors , Lipidomics , Mast Cells/drug effects , Mast Cells/metabolism , Mice , Mice, Knockout , NFATC Transcription Factors/genetics , Primary Cell Culture , Receptors, Purinergic P2X7/metabolism , Signal Transduction/drug effects , Signal Transduction/immunology
9.
Front Immunol ; 12: 687397, 2021.
Article in English | MEDLINE | ID: covidwho-1477818

ABSTRACT

Severe COVID-19 is characterized by acute respiratory distress syndrome (ARDS)-like hyperinflammation and endothelial dysfunction, that can lead to respiratory and multi organ failure and death. Interstitial lung diseases (ILD) and pulmonary fibrosis confer an increased risk for severe disease, while a subset of COVID-19-related ARDS surviving patients will develop a fibroproliferative response that can persist post hospitalization. Autotaxin (ATX) is a secreted lysophospholipase D, largely responsible for the extracellular production of lysophosphatidic acid (LPA), a pleiotropic signaling lysophospholipid with multiple effects in pulmonary and immune cells. In this review, we discuss the similarities of COVID-19, ARDS and ILDs, and suggest ATX as a possible pathologic link and a potential common therapeutic target.


Subject(s)
COVID-19/pathology , Phosphoric Diester Hydrolases/metabolism , Pulmonary Fibrosis/pathology , Respiratory Distress Syndrome/pathology , Anti-Inflammatory Agents/therapeutic use , COVID-19/blood , Dexamethasone/therapeutic use , Humans , Lung/pathology , Lysophospholipids/metabolism , Phosphoric Diester Hydrolases/blood , Pulmonary Fibrosis/blood , Respiratory Distress Syndrome/blood , SARS-CoV-2 , Signal Transduction/immunology
10.
Signal Transduct Target Ther ; 6(1): 367, 2021 10 20.
Article in English | MEDLINE | ID: covidwho-1475287

ABSTRACT

Cytokine release syndrome (CRS) embodies a mixture of clinical manifestations, including elevated circulating cytokine levels, acute systemic inflammatory symptoms and secondary organ dysfunction, which was first described in the context of acute graft-versus-host disease after allogeneic hematopoietic stem-cell transplantation and was later observed in pandemics of influenza, SARS-CoV and COVID-19, immunotherapy of tumor, after chimeric antigen receptor T (CAR-T) therapy, and in monogenic disorders and autoimmune diseases. Particularly, severe CRS is a very significant and life-threatening complication, which is clinically characterized by persistent high fever, hyperinflammation, and severe organ dysfunction. However, CRS is a double-edged sword, which may be both helpful in controlling tumors/viruses/infections and harmful to the host. Although a high incidence and high levels of cytokines are features of CRS, the detailed kinetics and specific mechanisms of CRS in human diseases and intervention therapy remain unclear. In the present review, we have summarized the most recent advances related to the clinical features and management of CRS as well as cutting-edge technologies to elucidate the mechanisms of CRS. Considering that CRS is the major adverse event in human diseases and intervention therapy, our review delineates the characteristics, kinetics, signaling pathways, and potential mechanisms of CRS, which shows its clinical relevance for achieving both favorable efficacy and low toxicity.


Subject(s)
Cytokine Release Syndrome , Signal Transduction/immunology , Acute Disease , Autoimmune Diseases/complications , Autoimmune Diseases/immunology , Autoimmune Diseases/therapy , COVID-19/complications , COVID-19/immunology , COVID-19/therapy , Cytokine Release Syndrome/etiology , Cytokine Release Syndrome/immunology , Cytokine Release Syndrome/therapy , Graft vs Host Disease/complications , Graft vs Host Disease/immunology , Graft vs Host Disease/therapy , Hematopoietic Stem Cell Transplantation , Humans , Immunotherapy, Adoptive/adverse effects , Influenza, Human/complications , Influenza, Human/immunology , Neoplasms/complications , Neoplasms/immunology , Neoplasms/therapy , SARS Virus/immunology , SARS-CoV-2/immunology , Severe Acute Respiratory Syndrome/complications , Severe Acute Respiratory Syndrome/immunology , Severe Acute Respiratory Syndrome/therapy
11.
Viruses ; 13(10)2021 10 14.
Article in English | MEDLINE | ID: covidwho-1470993

ABSTRACT

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a member of the Coronaviridae family, which is responsible for the COVID-19 pandemic followed by unprecedented global societal and economic disruptive impact. The innate immune system is the body's first line of defense against invading pathogens and is induced by a variety of cellular receptors that sense viral components. However, various strategies are exploited by SARS-CoV-2 to disrupt the antiviral innate immune responses. Innate immune dysfunction is characterized by the weak generation of type I interferons (IFNs) and the hypersecretion of pro-inflammatory cytokines, leading to mortality and organ injury in patients with COVID-19. This review summarizes the existing understanding of the mutual effects between SARS-CoV-2 and the type I IFN (IFN-α/ß) responses, emphasizing the relationship between host innate immune signaling and viral proteases with an insight on tackling potential therapeutic targets.


Subject(s)
COVID-19/immunology , Immune Evasion/immunology , Immunity, Innate/immunology , Interferon Type I/immunology , SARS-CoV-2/immunology , Antiviral Agents/therapeutic use , COVID-19/drug therapy , COVID-19/pathology , Cytokines/metabolism , Drug Combinations , Humans , Interferon Type I/biosynthesis , Lopinavir/therapeutic use , Ribavirin/therapeutic use , Ritonavir/therapeutic use , Signal Transduction/immunology
12.
Med Sci Monit ; 26: e922281, 2020 Mar 31.
Article in English | MEDLINE | ID: covidwho-1453382

ABSTRACT

BACKGROUND Acute respiratory distress syndrome (ARDS) is a sudden and serious disease with increasing morbidity and mortality rates. Phosphodiesterase 4 (PDE4) is a novel target for inflammatory disease, and ibudilast (IBU), a PDE4 inhibitor, inhibits inflammatory response. Our study investigated the effect of IBU on the pathogenesis of neonatal ARDS and the underlying mechanism related to it. MATERIAL AND METHODS Western blotting was performed to analyze the expression levels of PDE4, CXCR4, SDF-1, CXCR5, CXCL1, inflammatory cytokines, and proteins related to cell apoptosis. Hematoxylin-eosin staining was performed to observe the pathological morphology of lung tissue. Pulmonary edema score was used to assess the degree of lung water accumulation after pulmonary injury. Enzyme-linked immunosorbent assay (ELISA) was used to assess levels of inflammatory factors (TNF-alpha, IL-1ß, IL-6, and MCP-1) in serum. TUNEL assay was used to detect apoptotic cells. RESULTS Increased expression of PDE4 was observed in an LPS-induced neonatal ARDS mouse model, and IBU ameliorated LPS-induced pathological manifestations and pulmonary edema in lung tissue. In addition, IBU attenuated the secretion of inflammatory cytokines by inactivating the chemokine axis in the LPS-induced neonatal ARDS mouse model. Finally, IBU significantly reduced LPS-induced cell apoptosis in lung tissue. CONCLUSIONS IBU, a PDE4 inhibitor, protected against ARDS by interfering with pulmonary inflammation and apoptosis. Our findings provide a novel and promising strategy to regulate pulmonary inflammation in ARDS.


Subject(s)
Cyclic Nucleotide Phosphodiesterases, Type 4/metabolism , Inflammation/drug therapy , Phosphodiesterase 4 Inhibitors/pharmacology , Pyridines/pharmacology , Respiratory Distress Syndrome, Newborn/drug therapy , Animals , Animals, Newborn , Apoptosis/drug effects , Apoptosis/immunology , Bronchoalveolar Lavage Fluid , Disease Models, Animal , Humans , Inflammation/diagnosis , Inflammation/immunology , Inflammation/pathology , Injections, Intraperitoneal , Lipopolysaccharides/immunology , Lung/drug effects , Lung/immunology , Lung/pathology , Mice , Phosphodiesterase 4 Inhibitors/therapeutic use , Pyridines/therapeutic use , Respiratory Distress Syndrome, Newborn/diagnosis , Respiratory Distress Syndrome, Newborn/immunology , Respiratory Distress Syndrome, Newborn/pathology , Signal Transduction/drug effects , Signal Transduction/immunology
13.
Nutrients ; 13(10)2021 Sep 29.
Article in English | MEDLINE | ID: covidwho-1444284

ABSTRACT

There is an ongoing need for new therapeutic modalities against SARS-CoV-2 infection. Mast cell histamine has been implicated in the pathophysiology of COVID-19 as a regulator of proinflammatory, fibrotic, and thrombogenic processes. Consequently, mast cell histamine and its receptors represent promising pharmacological targets. At the same time, nutritional modulation of immune system function has been proposed and is being investigated for the prevention of COVID-19 or as an adjunctive strategy combined with conventional therapy. Several studies indicate that several immunonutrients can regulate mast cell activity to reduce the de novo synthesis and/or release of histamine and other mediators that are considered to mediate, at least in part, the complex pathophysiology present in COVID-19. This review summarizes the effects on mast cell histamine of common immunonutrients that have been investigated for use in COVID-19.


Subject(s)
COVID-19/immunology , Histamine/immunology , Immune System/immunology , Mast Cells/immunology , Nutritional Physiological Phenomena/immunology , Signal Transduction/immunology , Humans , SARS-CoV-2
14.
Curr Issues Mol Biol ; 43(3): 1212-1225, 2021 Sep 22.
Article in English | MEDLINE | ID: covidwho-1438531

ABSTRACT

The coronavirus SARS-CoV-2 is the cause of the ongoing COVID-19 pandemic. Most SARS-CoV-2 infections are mild or even asymptomatic. However, a small fraction of infected individuals develops severe, life-threatening disease, which is caused by an uncontrolled immune response resulting in hyperinflammation. However, the factors predisposing individuals to severe disease remain poorly understood. Here, we show that levels of CD47, which is known to mediate immune escape in cancer and virus-infected cells, are elevated in SARS-CoV-2-infected Caco-2 cells, Calu-3 cells, and air-liquid interface cultures of primary human bronchial epithelial cells. Moreover, SARS-CoV-2 infection increases SIRPalpha levels, the binding partner of CD47, on primary human monocytes. Systematic literature searches further indicated that known risk factors such as older age and diabetes are associated with increased CD47 levels. High CD47 levels contribute to vascular disease, vasoconstriction, and hypertension, conditions that may predispose SARS-CoV-2-infected individuals to COVID-19-related complications such as pulmonary hypertension, lung fibrosis, myocardial injury, stroke, and acute kidney injury. Hence, age-related and virus-induced CD47 expression is a candidate mechanism potentially contributing to severe COVID-19, as well as a therapeutic target, which may be addressed by antibodies and small molecules. Further research will be needed to investigate the potential involvement of CD47 and SIRPalpha in COVID-19 pathology. Our data should encourage other research groups to consider the potential relevance of the CD47/ SIRPalpha axis in their COVID-19 research.


Subject(s)
Antigens, Differentiation/metabolism , CD47 Antigen/metabolism , COVID-19/epidemiology , COVID-19/metabolism , Pandemics , Receptors, Immunologic/metabolism , SARS-CoV-2/metabolism , Severity of Illness Index , Signal Transduction/immunology , Blood Donors , Blotting, Western/methods , Bronchi/cytology , COVID-19/pathology , COVID-19/virology , Caco-2 Cells , Epithelial Cells/metabolism , Epithelial Cells/virology , Healthy Volunteers , Humans , Monocytes/metabolism , Monocytes/virology , Polymerase Chain Reaction/methods , RNA, Viral/genetics , SARS-CoV-2/genetics , SARS-CoV-2/isolation & purification
15.
Int J Mol Sci ; 22(18)2021 Sep 16.
Article in English | MEDLINE | ID: covidwho-1409704

ABSTRACT

Autotaxin (ATX; ENPP2) is a secreted lysophospholipase D catalyzing the extracellular production of lysophosphatidic acid (LPA), a pleiotropic signaling phospholipid. Genetic and pharmacologic studies have previously established a pathologic role for ATX and LPA signaling in pulmonary injury, inflammation, and fibrosis. Here, increased ENPP2 mRNA levels were detected in immune cells from nasopharyngeal swab samples of COVID-19 patients, and increased ATX serum levels were found in severe COVID-19 patients. ATX serum levels correlated with the corresponding increased serum levels of IL-6 and endothelial damage biomarkers, suggesting an interplay of the ATX/LPA axis with hyperinflammation and the associated vascular dysfunction in COVID-19. Accordingly, dexamethasone (Dex) treatment of mechanically ventilated patients reduced ATX levels, as shown in two independent cohorts, indicating that the therapeutic benefits of Dex include the suppression of ATX. Moreover, large scale analysis of multiple single cell RNA sequencing datasets revealed the expression landscape of ENPP2 in COVID-19 and further suggested a role for ATX in the homeostasis of dendritic cells, which exhibit both numerical and functional deficits in COVID-19. Therefore, ATX has likely a multifunctional role in COVID-19 pathogenesis, suggesting that its pharmacological targeting might represent an additional therapeutic option, both during and after hospitalization.


Subject(s)
COVID-19/diagnosis , Dendritic Cells/immunology , Phosphodiesterase Inhibitors/therapeutic use , Phosphoric Diester Hydrolases/blood , SARS-CoV-2/immunology , Adult , Aged , Aged, 80 and over , Biomarkers/blood , COVID-19/blood , COVID-19/immunology , COVID-19/therapy , Cohort Studies , Datasets as Topic , Dendritic Cells/drug effects , Dexamethasone/pharmacology , Dexamethasone/therapeutic use , Endothelium, Vascular/immunology , Endothelium, Vascular/pathology , Female , Humans , Interleukin-6/blood , Interleukin-6/metabolism , Male , Middle Aged , Phosphodiesterase Inhibitors/pharmacology , Phosphoric Diester Hydrolases/metabolism , RNA-Seq , Respiration, Artificial , SARS-CoV-2/isolation & purification , Severity of Illness Index , Signal Transduction/drug effects , Signal Transduction/immunology , Single-Cell Analysis
16.
Signal Transduct Target Ther ; 6(1): 331, 2021 09 01.
Article in English | MEDLINE | ID: covidwho-1392811

ABSTRACT

The recently emerged severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which is the causative agent of ongoing global pandemic of COVID-19, may trigger immunosuppression in the early stage and overactive immune response in the late stage of infection; However, the underlying mechanisms are not well understood. Here we demonstrated that the SARS-CoV-2 nucleocapsid (N) protein dually regulated innate immune responses, i.e., the low-dose N protein suppressed type I interferon (IFN-I) signaling and inflammatory cytokines, whereas high-dose N protein promoted IFN-I signaling and inflammatory cytokines. Mechanistically, the SARS-CoV-2 N protein dually regulated the phosphorylation and nuclear translocation of IRF3, STAT1, and STAT2. Additionally, low-dose N protein combined with TRIM25 could suppress the ubiquitination and activation of retinoic acid-inducible gene I (RIG-I). Our findings revealed a regulatory mechanism of innate immune responses by the SARS-CoV-2 N protein, which would contribute to understanding the pathogenesis of SARS-CoV-2 and other SARS-like coronaviruses, and development of more effective strategies for controlling COVID-19.


Subject(s)
COVID-19/immunology , Coronavirus Nucleocapsid Proteins/immunology , Immunity, Innate , SARS-CoV-2/immunology , Signal Transduction/immunology , A549 Cells , COVID-19/pathology , Caco-2 Cells , HEK293 Cells , Hep G2 Cells , Humans , Interferon Type I/immunology , Phosphoproteins/immunology
17.
Int J Med Sci ; 18(12): 2561-2569, 2021.
Article in English | MEDLINE | ID: covidwho-1389722

ABSTRACT

SARS-CoV-2 infection poses a global challenge to human health. Upon viral infection, host cells initiate the innate antiviral response, which primarily involves type I interferons (I-IFNs), to enable rapid elimination of the invading virus. Previous studies revealed that SARS-CoV-2 infection limits the expression of I-IFNs in vitro and in vivo, but the underlying mechanism remains incompletely elucidated. In the present study, we performed data mining and longitudinal data analysis using SARS-CoV-2-infected normal human bronchial epithelial (NHBE) cells and ferrets, and the results confirmed the strong inhibitory effect of SARS-CoV-2 on the induction of I-IFNs. Moreover, we identified genes that are negatively correlated with IFNB1 expression in vitro and in vivo based on Pearson correlation analysis. We found that SARS-CoV-2 activates numerous intrinsic pathways, such as the circadian rhythm, phosphatidylinositol signaling system, peroxisome, and TNF signaling pathways, to inhibit I-IFNs. These intrinsic inhibitory pathways jointly facilitate the successful immune evasion of SARS-CoV-2. Our study elucidates the underlying mechanism by which SARS-CoV-2 evades the host innate antiviral response in vitro and in vivo, providing theoretical evidence for targeting these immune evasion-associated pathways to combat SARS-CoV-2 infection.


Subject(s)
COVID-19/immunology , Host-Pathogen Interactions/immunology , Interferon-gamma/metabolism , SARS-CoV-2/immunology , Animals , Bronchi/cytology , COVID-19/virology , Cell Line , Datasets as Topic , Disease Models, Animal , Epithelial Cells , Ferrets , Gene Expression Regulation/immunology , Host-Pathogen Interactions/genetics , Humans , Immunity, Innate , Interferon-gamma/immunology , RNA-Seq , Respiratory Mucosa/cytology , Signal Transduction/genetics , Signal Transduction/immunology
19.
Clin Rev Allergy Immunol ; 60(2): 259-270, 2021 Apr.
Article in English | MEDLINE | ID: covidwho-1384600

ABSTRACT

Ultraviolet blood irradiation (UBI) was used with success in the 1930s and 1940s for a variety of diseases. Despite the success, the lack of understanding of the detailed mechanisms of actions, and the achievements of antibiotics, phased off the use of UBI from the 1950s. The emergence of novel viral infections, from HIV/AIDS to Ebola, from SARS and MERS, and SARS-CoV-2, bring back the attention to this therapeutical opportunity. UBI has a complex virucidal activity, mostly acting on the immune system response. It has effects on lymphocytes (T-cells and B-cells), macrophages, monocytes, dendritic cells, low-density lipoprotein (LDL), and lipids. The Knott technique was applied for bacterial infections such as tuberculosis to viral infections such as hepatitis or influenza. The more complex extracorporeal photopheresis (ECP) is also being applied to hematological cancers such as T-cell lymphomas. Further studies of UBI may help to create a useful device that may find applications for novel viruses that are resistant to known antivirals or vaccines, or also bacteria that are resistant to known antibiotics.


Subject(s)
COVID-19/therapy , Photopheresis/methods , SARS-CoV-2/radiation effects , Ultraviolet Rays , Bacteria/radiation effects , Bacterial Infections/microbiology , Bacterial Infections/therapy , COVID-19/virology , Cytokines/metabolism , Dendritic Cells/immunology , Dendritic Cells/radiation effects , Humans , Lymphocytes/immunology , Lymphocytes/radiation effects , Macrophages/immunology , Macrophages/radiation effects , Monocytes/immunology , Monocytes/radiation effects , Signal Transduction/immunology , Signal Transduction/radiation effects , Treatment Outcome
20.
Front Immunol ; 12: 705080, 2021.
Article in English | MEDLINE | ID: covidwho-1389187

ABSTRACT

Respiratory viral infections have been a long-standing global burden ranging from seasonal recurrences to the unexpected pandemics. The yearly hospitalizations from seasonal viruses such as influenza can fluctuate greatly depending on the circulating strain(s) and the congruency with the predicted strains used for the yearly vaccine formulation, which often are not predicted accurately. While antiviral agents are available against influenza, efficacy is limited due to a temporal disconnect between the time of infection and symptom development and viral resistance. Uncontrolled, influenza infections can lead to a severe inflammatory response initiated by pathogen-associated molecular patterns (PAMPs) or host-derived danger-associated molecular patterns (DAMPs) that ultimately signal through pattern recognition receptors (PRRs). Overall, these pathogen-host interactions result in a local cytokine storm leading to acute lung injury (ALI) or the more severe acute respiratory distress syndrome (ARDS) with concomitant systemic involvement and more severe, life threatening consequences. In addition to traditional antiviral treatments, blocking the host's innate immune response may provide a more viable approach to combat these infectious pathogens. The SARS-CoV-2 pandemic illustrates a critical need for novel treatments to counteract the ALI and ARDS that has caused the deaths of millions worldwide. This review will examine how antagonizing TLR4 signaling has been effective experimentally in ameliorating ALI and lethal infection in challenge models triggered not only by influenza, but also by other ALI-inducing viruses.


Subject(s)
Acute Lung Injury/immunology , COVID-19/immunology , SARS-CoV-2/immunology , Signal Transduction/immunology , Toll-Like Receptor 4/immunology , Acute Lung Injury/prevention & control , Acute Lung Injury/virology , Antiviral Agents/therapeutic use , COVID-19/epidemiology , COVID-19/virology , Cytokine Release Syndrome/immunology , Cytokine Release Syndrome/metabolism , Cytokine Release Syndrome/prevention & control , Humans , Lung/drug effects , Lung/immunology , Lung/virology , Pandemics , SARS-CoV-2/physiology , Signal Transduction/drug effects , Toll-Like Receptor 4/metabolism
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