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1.
Int J Mol Sci ; 22(16)2021 Aug 23.
Article in English | MEDLINE | ID: covidwho-1662694

ABSTRACT

Polyethyleneimine (PEI) induced immune responses were investigated in human bronchial epithelial (hBE) cells and mice. PEI rapidly induced ATP release from hBE cells and pretreatment with glutathione (GSH) blocked the response. PEI activated two conductive pathways, VDAC-1 and pannexin 1, which completely accounted for ATP efflux across the plasma membrane. Moreover, PEI increased intracellular Ca2+ concentration ([Ca2+]i), which was reduced by the pannexin 1 inhibitor, 10Panx (50 µM), the VDAC-1 inhibitor, DIDS (100 µM), and was nearly abolished by pretreatment with GSH (5 mM). The increase in [Ca2+]i involved Ca2+ uptake through two pathways, one blocked by oxidized ATP (oATP, 300 µM) and another that was blocked by the TRPV-1 antagonist A784168 (100 nM). PEI stimulation also increased IL-33 mRNA expression and protein secretion. In vivo experiments showed that acute (4.5 h) PEI exposure stimulated secretion of Th2 cytokines (IL-5 and IL-13) into bronchoalveolar lavage (BAL) fluid. Conjugation of PEI with ovalbumin also induced eosinophil recruitment and secretion of IL-5 and IL-13 into BAL fluid, which was inhibited in IL-33 receptor (ST2) deficient mice. In conclusion, PEI-induced oxidative stress stimulated type 2 immune responses by activating ATP-dependent Ca2+ uptake leading to IL-33 secretion, similar to allergens derived from Alternaria.


Subject(s)
Adenosine Triphosphate/immunology , Epithelial Cells/drug effects , Epithelial Cells/immunology , Immunity/drug effects , Nanoparticles/administration & dosage , Oxidative Stress/drug effects , Polyethyleneimine/pharmacology , Allergens/immunology , Animals , Calcium/immunology , Cells, Cultured , Cytokines/immunology , Female , Humans , Immunity/immunology , Mice , Mice, Inbred BALB C , Oxidative Stress/immunology , RNA, Messenger/immunology , Respiratory Mucosa/drug effects , Respiratory Mucosa/immunology
2.
Front Immunol ; 12: 800074, 2021.
Article in English | MEDLINE | ID: covidwho-1662584

ABSTRACT

Collapsing glomerulopathy represents a special variant of the proteinuric kidney disease focal segmental glomerulosclerosis (FSGS). Histologically, the collapsing form of FSGS (cFSGS) is characterized by segmental or global condensation and obliteration of glomerular capillaries, the appearance of hyperplastic and hypertrophic podocytes and severe tubulointerstitial damage. Clinically, cFSGS patients present with acute kidney injury, nephrotic-range proteinuria and are at a high risk of rapid progression to irreversible kidney failure. cFSGS can be attributed to numerous etiologies, namely, viral infections like HIV, cytomegalovirus, Epstein-Barr-Virus, and parvovirus B19 and also drugs and severe ischemia. Risk variants of the APOL1 gene, predominantly found in people of African descent, increase the risk of developing cFSGS. Patients infected with the new Corona-Virus SARS-CoV-2 display an increased rate of acute kidney injury (AKI) in severe cases of COVID-19. Besides hemodynamic instability, cytokine mediated injury and direct viral entry and infection of renal epithelial cells contributing to AKI, there are emerging reports of cFSGS associated with SARS-CoV-2 infection in patients of mainly African ethnicity. The pathogenesis of cFSGS is proposed to be linked with direct viral infection of podocytes, as described for HIV-associated glomerulopathy. Nevertheless, there is growing evidence that the systemic inflammatory cascade, activated in acute viral infections like COVID-19, is a major contributor to the impairment of basic cellular functions in podocytes. This mini review will summarize the current knowledge on cFSGS associated with viral infections with a special focus on the influence of systemic immune responses and potential mechanisms propagating the development of cFSGS.


Subject(s)
COVID-19/complications , Glomerulosclerosis, Focal Segmental/etiology , Kidney Glomerulus/virology , Animals , COVID-19/immunology , COVID-19/virology , Epithelial Cells/immunology , Epithelial Cells/virology , Glomerulosclerosis, Focal Segmental/immunology , Glomerulosclerosis, Focal Segmental/virology , Humans , Immunity/immunology , Kidney Glomerulus/immunology , Podocytes/immunology , Podocytes/virology , Proteinuria/etiology , Proteinuria/immunology , Proteinuria/virology , SARS-CoV-2/immunology
3.
Aging Cell ; 21(2): e13544, 2022 02.
Article in English | MEDLINE | ID: covidwho-1621824

ABSTRACT

Coronavirus disease 2019 (COVID-19) is especially severe in aged patients, defined as 65 years or older, for reasons that are currently unknown. To investigate the underlying basis for this vulnerability, we performed multimodal data analyses on immunity, inflammation, and COVID-19 incidence and severity as a function of age. Our analysis leveraged age-specific COVID-19 mortality and laboratory testing from a large COVID-19 registry, along with epidemiological data of ~3.4 million individuals, large-scale deep immune cell profiling data, and single-cell RNA-sequencing data from aged COVID-19 patients across diverse populations. We found that decreased lymphocyte count and elevated inflammatory markers (C-reactive protein, D-dimer, and neutrophil-lymphocyte ratio) are significantly associated with age-specific COVID-19 severities. We identified the reduced abundance of naïve CD8 T cells with decreased expression of antiviral defense genes (i.e., IFITM3 and TRIM22) in aged severe COVID-19 patients. Older individuals with severe COVID-19 displayed type I and II interferon deficiencies, which is correlated with SARS-CoV-2 viral load. Elevated expression of SARS-CoV-2 entry factors and reduced expression of antiviral defense genes (LY6E and IFNAR1) in the secretory cells are associated with critical COVID-19 in aged individuals. Mechanistically, we identified strong TGF-beta-mediated immune-epithelial cell interactions (i.e., secretory-non-resident macrophages) in aged individuals with critical COVID-19. Taken together, our findings point to immuno-inflammatory factors that could be targeted therapeutically to reduce morbidity and mortality in aged COVID-19 patients.


Subject(s)
Aging , COVID-19/immunology , COVID-19/physiopathology , Inflammation , Severity of Illness Index , Adolescent , Adult , Aged , CD8-Positive T-Lymphocytes/immunology , COVID-19/epidemiology , Cell Communication , Epithelial Cells/immunology , Female , Humans , Immune System , Interferons/metabolism , Leukocytes, Mononuclear/metabolism , Male , Middle Aged , Nasal Mucosa/virology , Odds Ratio , RNA-Seq , Registries , SARS-CoV-2 , Viral Load , Young Adult
4.
Proc Natl Acad Sci U S A ; 119(1)2022 01 04.
Article in English | MEDLINE | ID: covidwho-1595265

ABSTRACT

Infection by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) provokes a potentially fatal pneumonia with multiorgan failure, and high systemic inflammation. To gain mechanistic insight and ferret out the root of this immune dysregulation, we modeled, by in vitro coculture, the interactions between infected epithelial cells and immunocytes. A strong response was induced in monocytes and B cells, with a SARS-CoV-2-specific inflammatory gene cluster distinct from that seen in influenza A or Ebola virus-infected cocultures, and which reproduced deviations reported in blood or lung myeloid cells from COVID-19 patients. A substantial fraction of the effect could be reproduced after individual transfection of several SARS-CoV-2 proteins (Spike and some nonstructural proteins), mediated by soluble factors, but not via transcriptional induction. This response was greatly muted in monocytes from healthy children, perhaps a clue to the age dependency of COVID-19. These results suggest that the inflammatory malfunction in COVID-19 is rooted in the earliest perturbations that SARS-CoV-2 induces in epithelia.


Subject(s)
COVID-19/immunology , Epithelial Cells/immunology , Monocytes/immunology , SARS-CoV-2/pathogenicity , Adult , B-Lymphocytes/immunology , COVID-19/pathology , Child , Coculture Techniques , Ebolavirus/pathogenicity , Epithelial Cells/virology , Gene Expression Profiling , Humans , Inflammation , Influenza A virus/pathogenicity , Lung/immunology , Myeloid Cells/immunology , Species Specificity , Viral Proteins/immunology
5.
PLoS Biol ; 19(12): e3001065, 2021 12.
Article in English | MEDLINE | ID: covidwho-1594053

ABSTRACT

The pandemic spread of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), the etiological agent of Coronavirus Disease 2019 (COVID-19), represents an ongoing international health crisis. A key symptom of SARS-CoV-2 infection is the onset of fever, with a hyperthermic temperature range of 38 to 41°C. Fever is an evolutionarily conserved host response to microbial infection that can influence the outcome of viral pathogenicity and regulation of host innate and adaptive immune responses. However, it remains to be determined what effect elevated temperature has on SARS-CoV-2 replication. Utilizing a three-dimensional (3D) air-liquid interface (ALI) model that closely mimics the natural tissue physiology of SARS-CoV-2 infection in the respiratory airway, we identify tissue temperature to play an important role in the regulation of SARS-CoV-2 infection. Respiratory tissue incubated at 40°C remained permissive to SARS-CoV-2 entry but refractory to viral transcription, leading to significantly reduced levels of viral RNA replication and apical shedding of infectious virus. We identify tissue temperature to play an important role in the differential regulation of epithelial host responses to SARS-CoV-2 infection that impact upon multiple pathways, including intracellular immune regulation, without disruption to general transcription or epithelium integrity. We present the first evidence that febrile temperatures associated with COVID-19 inhibit SARS-CoV-2 replication in respiratory epithelia. Our data identify an important role for tissue temperature in the epithelial restriction of SARS-CoV-2 independently of canonical interferon (IFN)-mediated antiviral immune defenses.


Subject(s)
Epithelial Cells/immunology , Hot Temperature , Immunity, Innate/immunology , Interferons/immunology , Respiratory Mucosa/immunology , SARS-CoV-2/immunology , Virus Replication/immunology , Adolescent , Animals , COVID-19/genetics , COVID-19/immunology , COVID-19/virology , Chlorocebus aethiops , Epithelial Cells/metabolism , Epithelial Cells/virology , Female , Gene Expression Profiling/methods , Host-Pathogen Interactions/genetics , Host-Pathogen Interactions/immunology , Humans , Immunity, Innate/genetics , Interferons/genetics , Interferons/metabolism , Male , Middle Aged , Models, Biological , RNA-Seq/methods , Respiratory Mucosa/metabolism , Respiratory Mucosa/virology , SARS-CoV-2/genetics , SARS-CoV-2/physiology , Tissue Culture Techniques , Vero Cells , Virus Replication/genetics , Virus Replication/physiology
6.
Nature ; 602(7896): 321-327, 2022 02.
Article in English | MEDLINE | ID: covidwho-1585831

ABSTRACT

It is not fully understood why COVID-19 is typically milder in children1-3. Here, to examine the differences between children and adults in their response to SARS-CoV-2 infection, we analysed paediatric and adult patients with COVID-19 as well as healthy control individuals (total n = 93) using single-cell multi-omic profiling of matched nasal, tracheal, bronchial and blood samples. In the airways of healthy paediatric individuals, we observed cells that were already in an interferon-activated state, which after SARS-CoV-2 infection was further induced especially in airway immune cells. We postulate that higher paediatric innate interferon responses restrict viral replication and disease progression. The systemic response in children was characterized by increases in naive lymphocytes and a depletion of natural killer cells, whereas, in adults, cytotoxic T cells and interferon-stimulated subpopulations were significantly increased. We provide evidence that dendritic cells initiate interferon signalling in early infection, and identify epithelial cell states associated with COVID-19 and age. Our matching nasal and blood data show a strong interferon response in the airways with the induction of systemic interferon-stimulated populations, which were substantially reduced in paediatric patients. Together, we provide several mechanisms that explain the milder clinical syndrome observed in children.


Subject(s)
COVID-19/blood , COVID-19/immunology , Dendritic Cells/immunology , Interferons/immunology , Killer Cells, Natural/immunology , SARS-CoV-2/immunology , T-Lymphocytes, Cytotoxic/immunology , Adult , Bronchi/immunology , Bronchi/virology , COVID-19/pathology , Chicago , Cohort Studies , Disease Progression , Epithelial Cells/cytology , Epithelial Cells/immunology , Epithelial Cells/virology , Female , Humans , Immunity, Innate , London , Male , Nasal Mucosa/immunology , Nasal Mucosa/virology , SARS-CoV-2/growth & development , Single-Cell Analysis , Trachea/virology , Young Adult
7.
Genes (Basel) ; 13(1)2021 12 23.
Article in English | MEDLINE | ID: covidwho-1580896

ABSTRACT

ADAR1-mediated deamination of adenosines in long double-stranded RNAs plays an important role in modulating the innate immune response. However, recent investigations based on metatranscriptomic samples of COVID-19 patients and SARS-COV-2-infected Vero cells have recovered contrasting findings. Using RNAseq data from time course experiments of infected human cell lines and transcriptome data from Vero cells and clinical samples, we prove that A-to-G changes observed in SARS-COV-2 genomes represent genuine RNA editing events, likely mediated by ADAR1. While the A-to-I editing rate is generally low, changes are distributed along the entire viral genome, are overrepresented in exonic regions, and are (in the majority of cases) nonsynonymous. The impact of RNA editing on virus-host interactions could be relevant to identify potential targets for therapeutic interventions.


Subject(s)
Adenosine Deaminase/genetics , COVID-19/genetics , Genome, Viral , Host-Pathogen Interactions/genetics , RNA Editing , RNA, Viral/genetics , RNA-Binding Proteins/genetics , SARS-CoV-2/genetics , Adenosine/metabolism , Adenosine Deaminase/immunology , Animals , COVID-19/metabolism , COVID-19/virology , Cell Line, Tumor , Chlorocebus aethiops , DEAD Box Protein 58/genetics , DEAD Box Protein 58/immunology , Deamination , Epithelial Cells/immunology , Epithelial Cells/virology , Host-Pathogen Interactions/immunology , Humans , Immunity, Innate , Inosine/metabolism , Interferon-Induced Helicase, IFIH1/genetics , Interferon-Induced Helicase, IFIH1/immunology , Interferon-beta/genetics , Interferon-beta/immunology , RNA, Double-Stranded/genetics , RNA, Double-Stranded/immunology , RNA, Viral/immunology , RNA-Binding Proteins/immunology , Receptors, Immunologic/genetics , Receptors, Immunologic/immunology , SARS-CoV-2/metabolism , SARS-CoV-2/pathogenicity , Transcriptome , Vero Cells
8.
Nat Commun ; 12(1): 7092, 2021 12 07.
Article in English | MEDLINE | ID: covidwho-1561304

ABSTRACT

The nasal epithelium is a plausible entry point for SARS-CoV-2, a site of pathogenesis and transmission, and may initiate the host response to SARS-CoV-2. Antiviral interferon (IFN) responses are critical to outcome of SARS-CoV-2. Yet little is known about the interaction between SARS-CoV-2 and innate immunity in this tissue. Here we apply single-cell RNA sequencing and proteomics to a primary cell model of human nasal epithelium differentiated at air-liquid interface. SARS-CoV-2 demonstrates widespread tropism for nasal epithelial cell types. The host response is dominated by type I and III IFNs and interferon-stimulated gene products. This response is notably delayed in onset relative to viral gene expression and compared to other respiratory viruses. Nevertheless, once established, the paracrine IFN response begins to impact on SARS-CoV-2 replication. When provided prior to infection, recombinant IFNß or IFNλ1 induces an efficient antiviral state that potently restricts SARS-CoV-2 viral replication, preserving epithelial barrier integrity. These data imply that the IFN-I/III response to SARS-CoV-2 initiates in the nasal airway and suggest nasal delivery of recombinant IFNs to be a potential chemoprophylactic strategy.


Subject(s)
Epithelial Cells/virology , Interferon Type I/immunology , Interferons/immunology , Nasal Mucosa/virology , SARS-CoV-2/physiology , Antiviral Agents/immunology , Antiviral Agents/pharmacology , COVID-19/immunology , COVID-19/virology , Cells, Cultured , Epithelial Cells/cytology , Epithelial Cells/immunology , Humans , Immunity, Innate , Kinetics , Nasal Mucosa/cytology , Nasal Mucosa/immunology , SARS-CoV-2/drug effects , Signal Transduction/drug effects , Viral Tropism , Virus Replication/drug effects
9.
J Allergy Clin Immunol ; 149(3): 923-933.e6, 2022 03.
Article in English | MEDLINE | ID: covidwho-1560006

ABSTRACT

BACKGROUND: Treatments for coronavirus disease 2019, which is caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), are urgently needed but remain limited. SARS-CoV-2 infects cells through interactions of its spike (S) protein with angiotensin-converting enzyme 2 (ACE2) and transmembrane protease serine 2 (TMPRSS2) on host cells. Multiple cells and organs are targeted, particularly airway epithelial cells. OM-85, a standardized lysate of human airway bacteria with strong immunomodulating properties and an impeccable safety profile, is widely used to prevent recurrent respiratory infections. We found that airway OM-85 administration inhibits Ace2 and Tmprss2 transcription in the mouse lung, suggesting that OM-85 might hinder SARS-CoV-2/host cell interactions. OBJECTIVES: We sought to investigate whether and how OM-85 treatment protects nonhuman primate and human epithelial cells against SARS-CoV-2. METHODS: ACE2 and TMPRSS2 mRNA and protein expression, cell binding of SARS-CoV-2 S1 protein, cell entry of SARS-CoV-2 S protein-pseudotyped lentiviral particles, and SARS-CoV-2 cell infection were measured in kidney, lung, and intestinal epithelial cell lines, primary human bronchial epithelial cells, and ACE2-transfected HEK293T cells treated with OM-85 in vitro. RESULTS: OM-85 significantly downregulated ACE2 and TMPRSS2 transcription and surface ACE2 protein expression in epithelial cell lines and primary bronchial epithelial cells. OM-85 also strongly inhibited SARS-CoV-2 S1 protein binding to, SARS-CoV-2 S protein-pseudotyped lentivirus entry into, and SARS-CoV-2 infection of epithelial cells. These effects of OM-85 appeared to depend on SARS-CoV-2 receptor downregulation. CONCLUSIONS: OM-85 inhibits SARS-CoV-2 epithelial cell infection in vitro by downregulating SARS-CoV-2 receptor expression. Further studies are warranted to assess whether OM-85 may prevent and/or reduce the severity of coronavirus disease 2019.


Subject(s)
Adjuvants, Immunologic/administration & dosage , COVID-19/prevention & control , Cell Extracts/administration & dosage , Receptors, Virus/antagonists & inhibitors , Receptors, Virus/immunology , SARS-CoV-2/immunology , Angiotensin-Converting Enzyme 2/antagonists & inhibitors , Angiotensin-Converting Enzyme 2/genetics , Angiotensin-Converting Enzyme 2/immunology , Animals , COVID-19/immunology , COVID-19/virology , Caco-2 Cells , Cell Extracts/immunology , Cells, Cultured , Chlorocebus aethiops , Down-Regulation/drug effects , Epithelial Cells/drug effects , Epithelial Cells/immunology , Epithelial Cells/virology , HEK293 Cells , Host Microbial Interactions/drug effects , Host Microbial Interactions/immunology , Humans , In Vitro Techniques , Lung/drug effects , Lung/immunology , Lung/virology , Mice , Mice, Inbred BALB C , Serine Endopeptidases/drug effects , Serine Endopeptidases/genetics , Serine Endopeptidases/immunology , Transcription, Genetic/drug effects , Transcription, Genetic/immunology , Vero Cells
10.
J Photochem Photobiol B ; 226: 112357, 2022 Jan.
Article in English | MEDLINE | ID: covidwho-1510060

ABSTRACT

Mitochondrial antiviral signaling (MAVS) protein mediates innate antiviral responses, including responses to certain coronaviruses such as severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). We have previously shown that ultraviolet-A (UVA) therapy can prevent virus-induced cell death in human ciliated tracheal epithelial cells (HTEpC) infected with coronavirus-229E (CoV-229E), and results in increased intracellular levels of MAVS. In this study, we explored the mechanisms by which UVA light can activate MAVS, and whether local UVA light application can activate MAVS at locations distant from the light source (e.g. via cell-to-cell communication). MAVS levels were compared in HTEpC exposed to 2 mW/cm2 narrow band (NB)-UVA for 20 min and in unexposed controls at 30-40% and at 100% confluency, and in unexposed HTEpC treated with supernatants or lysates from UVA-exposed cells or from unexposed controls. MAVS was also assessed in different sections of confluent monolayer plates where only one section was exposed to NB-UVA. Our results showed that UVA increases the expression of MAVS protein. Further, cells in a confluent monolayer exposed to UVA conferred an elevation in MAVS in cells adjacent to the exposed section, and also in cells in the most distant sections which were not exposed to UVA. In this study, human ciliated tracheal epithelial cells exposed to UVA demonstrate increased MAVS protein, and also appear to transmit this influence to confluent cells not exposed to UVA, likely via cell-cell signaling.


Subject(s)
Adaptor Proteins, Signal Transducing/metabolism , Adaptor Proteins, Signal Transducing/radiation effects , Ultraviolet Rays , Adaptor Proteins, Signal Transducing/immunology , COVID-19/immunology , COVID-19/radiotherapy , COVID-19/virology , Cell Communication/immunology , Cell Communication/radiation effects , Cells, Cultured , Epithelial Cells/immunology , Epithelial Cells/radiation effects , Host Microbial Interactions/immunology , Host Microbial Interactions/radiation effects , Humans , Immunity, Innate/radiation effects , Photobiology , SARS-CoV-2/immunology , SARS-CoV-2/pathogenicity , Signal Transduction/immunology , Signal Transduction/radiation effects , Trachea/cytology , Ultraviolet Therapy
11.
mBio ; 12(6): e0275621, 2021 12 21.
Article in English | MEDLINE | ID: covidwho-1494976

ABSTRACT

Outbreaks of emerging viral pathogens like severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are a major medical challenge. There is a pressing need for antivirals that can be rapidly deployed to curb infection and dissemination. We determined the efficacy of interferon lambda-1 (IFN-λ) as a broad-spectrum antiviral agent to inhibit SARS-CoV-2 infection and reduce pathology in a mouse model of disease. IFN-λ significantly limited SARS-CoV-2 production in primary human bronchial epithelial cells in culture. Pretreatment of human lung cells with IFN-λ completely blocked infectious virus production, and treatment with IFN-λ at the time of infection inhibited virus production more than 10-fold. To interrogate the protective effects of IFN-λ in response to SARS-CoV-2 infection, transgenic mice expressing the human angiotensin-converting enzyme 2 (ACE-2) were tested. One dose of IFN-λ administered intranasally was found to reduce animal morbidity and mortality. Our study with SARS-CoV-2 also revealed a sex differential in disease outcome. Male mice had higher mortality, reflecting the more severe symptoms and mortality found in male patients infected with SARS-CoV-2. The results indicate that IFN-λ potentially can treat early stages of SARS-CoV-2 infection and decrease pathology, and this murine model can be used to investigate the sex differential documented in COVID-19. IMPORTANCE The COVID-19 pandemic has claimed millions of lives worldwide. In this report, we used a preclinical mouse model to investigate the prophylactic and therapeutic value of intranasal IFN-λ for this acute respiratory disease. Specific vaccines have been responsible for curbing the transmission of SARS-CoV-2 in developed nations. However, vaccines require time to generate and keep pace with antigenic variants. There is a need for broad-spectrum prophylactic and therapeutic agents to combat new emerging viral pathogens. Our mouse model suggests IFN-λ has clinical utility, and it reflects the well-documented finding that male COVID-19 patients manifest more severe symptoms and mortality. Understanding this sex bias is critical for considering therapeutic approaches to COVID-19.


Subject(s)
Antiviral Agents/therapeutic use , COVID-19/immunology , COVID-19/therapy , Epithelial Cells/drug effects , Interferons/immunology , Interferons/pharmacology , SARS-CoV-2/immunology , Administration, Intranasal , Angiotensin-Converting Enzyme 2/genetics , Animals , Antiviral Agents/pharmacology , Bronchi/cytology , Disease Models, Animal , Epithelial Cells/immunology , Epithelial Cells/virology , Female , HEK293 Cells , Humans , Interferons/classification , Lung/drug effects , Lung/pathology , Lung/virology , Male , Mice , Mice, Transgenic , Risk Factors , SARS-CoV-2/drug effects , Sex Factors
12.
PLoS Comput Biol ; 17(10): e1008874, 2021 10.
Article in English | MEDLINE | ID: covidwho-1484838

ABSTRACT

Respiratory viruses present major public health challenges, as evidenced by the 1918 Spanish Flu, the 1957 H2N2, 1968 H3N2, and 2009 H1N1 influenza pandemics, and the ongoing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic. Severe RNA virus respiratory infections often correlate with high viral load and excessive inflammation. Understanding the dynamics of the innate immune response and its manifestations at the cell and tissue levels is vital to understanding the mechanisms of immunopathology and to developing strain-independent treatments. Here, we present a novel spatialized multicellular computational model of RNA virus infection and the type-I interferon-mediated antiviral response that it induces within lung epithelial cells. The model is built using the CompuCell3D multicellular simulation environment and is parameterized using data from influenza virus-infected cell cultures. Consistent with experimental observations, it exhibits either linear radial growth of viral plaques or arrested plaque growth depending on the local concentration of type I interferons. The model suggests that modifying the activity of signaling molecules in the JAK/STAT pathway or altering the ratio of the diffusion lengths of interferon and virus in the cell culture could lead to plaque growth arrest. The dependence of plaque growth arrest on diffusion lengths highlights the importance of developing validated spatial models of cytokine signaling and the need for in vitro measurement of these diffusion coefficients. Sensitivity analyses under conditions leading to continuous or arrested plaque growth found that plaque growth is more sensitive to variations of most parameters and more likely to have identifiable model parameters when conditions lead to plaque arrest. This result suggests that cytokine assay measurements may be most informative under conditions leading to arrested plaque growth. The model is easy to extend to include SARS-CoV-2-specific mechanisms or to use as a component in models linking epithelial cell signaling to systemic immune models.


Subject(s)
Host-Pathogen Interactions/immunology , Interferons , RNA Virus Infections , RNA Viruses , Virus Replication , Cells, Cultured , Computational Biology , Epithelial Cells/immunology , Humans , Immunity, Innate/immunology , Interferons/immunology , Interferons/metabolism , Lung/cytology , Lung/immunology , Models, Biological , RNA Virus Infections/immunology , RNA Virus Infections/virology , RNA Viruses/immunology , RNA Viruses/physiology , Virus Replication/immunology , Virus Replication/physiology
13.
Int Immunopharmacol ; 101(Pt B): 108201, 2021 Dec.
Article in English | MEDLINE | ID: covidwho-1440134

ABSTRACT

One of the major clinical features of COVID-19 is a hyperinflammatory state, which is characterized by high expression of cytokines (such as IL-6 and TNF-α), chemokines (such as IL-8) and growth factors and is associated with severe forms of COVID-19. For this reason, the control of the "cytokine storm" represents a key issue in the management of COVID-19 patients. In this study we report evidence that the release of key proteins of the COVID-19 "cytokine storm" can be inhibited by mimicking the biological activity of microRNAs. The major focus of this report is on IL-8, whose expression can be modified by the employment of a molecule mimicking miR-93-5p, which is able to target the IL-8 RNA transcript and modulate its activity. The results obtained demonstrate that the production of IL-8 protein is enhanced in bronchial epithelial IB3-1 cells by treatment with the SARS-CoV-2 Spike protein and that IL-8 synthesis and extracellular release can be strongly reduced using an agomiR molecule mimicking miR-93-5p.


Subject(s)
Epithelial Cells/immunology , Interleukin-8/immunology , MicroRNAs , Spike Glycoprotein, Coronavirus/immunology , Bronchi/cytology , Cell Line , Humans , Interleukin-8/genetics
14.
Immunology ; 163(3): 239-249, 2021 07.
Article in English | MEDLINE | ID: covidwho-1434725

ABSTRACT

Communication between stromal and immune cells is essential to maintain tissue homeostasis, mount an effective immune response and promote tissue repair. This 'crosstalk' occurs in both the steady state and following a variety of insults, for example, in response to local injury, at sites of infection or cancer. What do we mean by crosstalk between cells? Reciprocal activation and/or regulation occurs between immune and stromal cells, by direct cell contact and indirect mechanisms, including the release of soluble cytokines. Moving beyond cell-to-cell contact, this review investigates the complexity of 'cross-space' cellular communication. We highlight different examples of cellular communication by a variety of lung stromal and immune cells following tissue insults. This review examines how the 'geography of the lung microenvironment' is altered in various disease states; more specifically, we investigate how this influences lung epithelial cells and fibroblasts via their communication with immune cells and each other.


Subject(s)
CD8-Positive T-Lymphocytes/immunology , Epithelial Cells/immunology , Fibroblasts/immunology , Lung/pathology , Stromal Cells/immunology , Animals , Cell Communication , Cellular Microenvironment , Humans , Immunity, Cellular
15.
Signal Transduct Target Ther ; 5(1): 221, 2020 10 06.
Article in English | MEDLINE | ID: covidwho-1387195
16.
Nat Biotechnol ; 40(3): 319-324, 2022 03.
Article in English | MEDLINE | ID: covidwho-1364597

ABSTRACT

Children have reduced severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection rates and a substantially lower risk for developing severe coronavirus disease 2019 compared with adults. However, the molecular mechanisms underlying protection in younger age groups remain unknown. Here we characterize the single-cell transcriptional landscape in the upper airways of SARS-CoV-2-negative (n = 18) and age-matched SARS-CoV-2-positive (n = 24) children and corresponding samples from adults (n = 44), covering an age range of 4 weeks to 77 years. Children displayed higher basal expression of relevant pattern recognition receptors such as MDA5 (IFIH1) and RIG-I (DDX58) in upper airway epithelial cells, macrophages and dendritic cells, resulting in stronger innate antiviral responses upon SARS-CoV-2 infection than in adults. We further detected distinct immune cell subpopulations including KLRC1 (NKG2A)+ cytotoxic T cells and a CD8+ T cell population with a memory phenotype occurring predominantly in children. Our study provides evidence that the airway immune cells of children are primed for virus sensing, resulting in a stronger early innate antiviral response to SARS-CoV-2 infection than in adults.


Subject(s)
Bronchi/immunology , Bronchi/virology , COVID-19/immunology , COVID-19/virology , Immunity, Innate , SARS-CoV-2/immunology , Adolescent , Adult , Aged , CD8-Positive T-Lymphocytes/immunology , Child , Child, Preschool , DEAD Box Protein 58/metabolism , Dendritic Cells/immunology , Epithelial Cells/immunology , Epithelial Cells/virology , Female , Humans , Infant , Infant, Newborn , Interferon-Induced Helicase, IFIH1/metabolism , Macrophages/immunology , Male , Middle Aged , Receptors, Immunologic/metabolism , Single-Cell Analysis , T-Lymphocytes, Cytotoxic/immunology , Young Adult
17.
Viruses ; 13(8)2021 08 12.
Article in English | MEDLINE | ID: covidwho-1355052

ABSTRACT

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) is the causative agent of coronavirus disease 2019 (COVID-19), a global pandemic characterized by an exaggerated immune response and respiratory illness. Age (>60 years) is a significant risk factor for developing severe COVID-19. To better understand the host response of the aged airway epithelium to SARS-CoV-2 infection, we performed an in vitro study using primary human bronchial epithelial cells from donors >67 years of age differentiated on an air-liquid interface culture. We demonstrate that SARS-CoV-2 infection leads to early induction of a proinflammatory response and a delayed interferon response. In addition, we observed changes in the genes and pathways associated with cell death and senescence throughout infection. In summary, our study provides new and important insights into the temporal kinetics of the airway epithelial innate immune response to SARS-CoV-2 in older individuals.


Subject(s)
Bronchi/immunology , Bronchi/virology , Immunity, Innate , Respiratory Mucosa/immunology , Respiratory Mucosa/virology , SARS-CoV-2/immunology , Aged , Aging/immunology , Bronchi/cytology , Bronchi/metabolism , COVID-19/immunology , Cell Death/genetics , Cells, Cultured , Cellular Senescence/genetics , Cytokines/biosynthesis , Cytokines/genetics , Epithelial Cells/immunology , Epithelial Cells/metabolism , Epithelial Cells/virology , Female , Humans , Inflammation , Interferons/biosynthesis , Interferons/genetics , Male , RNA-Seq , Respiratory Mucosa/cytology , Respiratory Mucosa/metabolism , SARS-CoV-2/physiology , Signal Transduction/genetics
18.
Microbiol Spectr ; 9(1): e0077421, 2021 09 03.
Article in English | MEDLINE | ID: covidwho-1352543

ABSTRACT

The primary target organ of coronavirus disease 2019 (COVID-19) infection is the respiratory tract. Currently, there is limited information on the ability of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) to infect and regulate innate immunity in human immune cells and lung epithelial cells. Here, we compared the ability of four Finnish isolates of SARS-CoV-2 from COVID-19 patients to replicate and induce interferons (IFNs) and other cytokines in different human cells. All isolates failed to replicate in dendritic cells, macrophages, monocytes, and lymphocytes, and no induction of cytokine gene expression was seen. However, most of the isolates replicated in Calu-3 cells, and they readily induced type I and type III IFN gene expression. The hCoV-19/Finland/FIN-25/2020 isolate, originating from a traveler from Milan in March 2020, showed better ability to replicate and induce IFN and inflammatory responses in Calu-3 cells than other isolates of SARS-CoV-2. Our data increase the knowledge on the pathogenesis and antiviral mechanisms of SARS-CoV-2 infection in human cell systems. IMPORTANCE With the rapid spread of the coronavirus disease 2019 (COVID-19) pandemic, information on the replication of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and regulation of innate immunity in human immune cells and lung epithelial cells is needed. In the present study, we show that SARS-CoV-2 failed to productively infect human immune cells, but different isolates of SARS-CoV-2 showed differential ability to replicate and regulate innate interferon responses in human lung epithelial Calu-3 cells. These findings will open up the way for further studies on the mechanisms of pathogenesis of SARS-CoV-2 in human cells.


Subject(s)
COVID-19/immunology , Epithelial Cells/immunology , Immunity, Innate , Lung/immunology , SARS-CoV-2/isolation & purification , Virus Replication/physiology , Angiotensin-Converting Enzyme 2 , Antiviral Agents/pharmacology , Cytokines/genetics , Epithelial Cells/virology , Gene Expression , Humans , Interferon Type I/genetics , Interferons/genetics , Kinetics , Lung/virology , Phylogeny , RNA, Viral , SARS-CoV-2/classification , SARS-CoV-2/drug effects , SARS-CoV-2/genetics , Spike Glycoprotein, Coronavirus , Trypsin
19.
Theranostics ; 11(16): 8076-8091, 2021.
Article in English | MEDLINE | ID: covidwho-1337802

ABSTRACT

Rationale: Pulmonary vascular endotheliitis, perivascular inflammation, and immune activation are observed in COVID-19 patients. While the initial SARS-CoV-2 infection mainly infects lung epithelial cells, whether it also infects endothelial cells (ECs) and to what extent SARS-CoV-2-mediated pulmonary vascular endotheliitis is associated with immune activation remain to be determined. Methods: To address these questions, we studied SARS-CoV-2-infected K18-hACE2 (K18) mice, a severe COVID-19 mouse model, as well as lung samples from SARS-CoV-2-infected nonhuman primates (NHP) and patient deceased from COVID-19. We used immunostaining, RNAscope, and electron microscopy to analyze the organs collected from animals and patient. We conducted bulk and single cell (sc) RNA-seq analyses, and cytokine profiling of lungs or serum of the severe COVID-19 mice. Results: We show that SARS-CoV-2-infected K18 mice develop severe COVID-19, including progressive body weight loss and fatality at 7 days, severe lung interstitial inflammation, edema, hemorrhage, perivascular inflammation, systemic lymphocytopenia, and eosinopenia. Body weight loss in K18 mice correlated with the severity of pneumonia, but not with brain infection. We also observed endothelial activation and dysfunction in pulmonary vessels evidenced by the up-regulation of VCAM1 and ICAM1 and the downregulation of VE-cadherin. We detected SARS-CoV-2 in capillary ECs, activation and adhesion of platelets and immune cells to the vascular wall of the alveolar septa, and increased complement deposition in the lungs, in both COVID-19-murine and NHP models. We also revealed that pathways of coagulation, complement, K-ras signaling, and genes of ICAM1 and VCAM1 related to EC dysfunction and injury were upregulated, and were associated with massive immune activation in the lung and circulation. Conclusion: Together, our results indicate that SARS-CoV-2 causes endotheliitis via both infection and infection-mediated immune activation, which may contribute to the pathogenesis of severe COVID-19 disease.


Subject(s)
COVID-19/immunology , COVID-19/pathology , Animals , COVID-19/metabolism , Disease Models, Animal , Endothelial Cells/immunology , Endothelial Cells/virology , Epithelial Cells/immunology , Epithelial Cells/virology , Lung/pathology , Mice , Mice, Inbred Strains , Mice, Transgenic , SARS-CoV-2/isolation & purification
20.
EBioMedicine ; 70: 103500, 2021 Aug.
Article in English | MEDLINE | ID: covidwho-1322074

ABSTRACT

BACKGROUND: The outbreak of Coronavirus disease 2019 (COVID-19) caused by SARS-CoV-2 infection has become a global health emergency. We aim to decipher SARS-CoV-2 infected cell types, the consequent host immune response and their interplay in lung of COVID-19 patients. METHODS: We analyzed single-cell RNA sequencing (scRNA-seq) data of bronchoalveolar lavage fluid (BALF) samples from 10 healthy donors, 6 severe COVID-19 patients and 3 mild recovered patients. The expressions of SARS-CoV-2 receptors (ACE2 and TMPRSS2) were examined among different cell types. The immune cells infiltration patterns, their expression profiles, and interplays between immune cells and SARS-CoV-2 target cells were further investigated. FINDINGS: Compared to healthy controls, ACE2 and TMPRSS2 expressions were significantly higher in lung epithelial cells of COVID-19 patients, in particular club and ciliated cells. SARS-CoV-2 activated pro-inflammatory genes and interferon/cytokine signaling in these cells. In severe COVID-19 patients, significantly higher neutrophil, but lower macrophage in lung was observed along with markedly increased cytokines expression compared with healthy controls and mild patients. By contrast, neutrophil and macrophage returned to normal level whilst more T and NK cells accumulation were observed in mild patients. Moreover, SARS-CoV-2 infection altered the community interplays of lung epithelial and immune cells: interactions between the club and immune cells were higher in COVID-19 patients compared to healthy donors; on the other hand, immune-immune cells interactions appeared the strongest in mild patients. INTERPRETATION: SARS-CoV-2 could infect lung epithelium, alter communication patterns between lung epithelial cells and immune system, and drive dysregulated host immune response in COVID-19 patients. FUNDING: This project was supported by National Key R&D Program of China (No. 2018YFC1315000/2018YFC1315004), Science and Technology Program Grant Shenzhen (JCYJ20170413161534162), HMRF Hong Kong (17160862), RGC-CRF Hong Kong (C4039-19G), RGC-GRF Hong Kong (14163817), Vice-Chancellor's Discretionary Fund CUHK and CUHK direct grant, Shenzhen Virtual University Park Support Scheme to CUHK Shenzhen Research Institute.


Subject(s)
COVID-19/immunology , Epithelial Cells/immunology , Inflammation/immunology , Lung/immunology , SARS-CoV-2/immunology , Signal Transduction/immunology , A549 Cells , Angiotensin-Converting Enzyme 2/immunology , COVID-19/virology , Case-Control Studies , Cell Line , Cell Line, Tumor , Cytokines/immunology , Humans , Inflammation/virology , Killer Cells, Natural/immunology , Lung/virology , Macrophages/immunology , Neutrophils/immunology , Respiratory Mucosa/immunology , Respiratory Mucosa/virology , Serine Endopeptidases/immunology , T-Lymphocytes/immunology
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