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1.
J Infect Dis ; 2021 Oct 15.
Article in English | MEDLINE | ID: covidwho-1575544

ABSTRACT

The upper respiratory tract (URT) is the primary entry site for SARS-CoV-2 and other respiratory viruses, but its involvement in viral amplification and pathogenesis remains incompletely understood. Here we investigated primary nasal epithelial cultures, as well as vital explanted tissues to scrutinize the tropism of wild-type SARS-CoV-2 and the recently emerged B.1.1.7 variant. Our analyses revealed a widespread replication competence of SARS-CoV-2 in polarized nasal epithelium as well as in the examined URT and salivary gland tissues, which was also shared by the B.1.1.7 virus thereby highlighting the active role of these anatomic sites in COVID-19.

2.
Cell ; 184(26): 6243-6261.e27, 2021 12 22.
Article in English | MEDLINE | ID: covidwho-1536467

ABSTRACT

COVID-19-induced "acute respiratory distress syndrome" (ARDS) is associated with prolonged respiratory failure and high mortality, but the mechanistic basis of lung injury remains incompletely understood. Here, we analyze pulmonary immune responses and lung pathology in two cohorts of patients with COVID-19 ARDS using functional single-cell genomics, immunohistology, and electron microscopy. We describe an accumulation of CD163-expressing monocyte-derived macrophages that acquired a profibrotic transcriptional phenotype during COVID-19 ARDS. Gene set enrichment and computational data integration revealed a significant similarity between COVID-19-associated macrophages and profibrotic macrophage populations identified in idiopathic pulmonary fibrosis. COVID-19 ARDS was associated with clinical, radiographic, histopathological, and ultrastructural hallmarks of pulmonary fibrosis. Exposure of human monocytes to SARS-CoV-2, but not influenza A virus or viral RNA analogs, was sufficient to induce a similar profibrotic phenotype in vitro. In conclusion, we demonstrate that SARS-CoV-2 triggers profibrotic macrophage responses and pronounced fibroproliferative ARDS.


Subject(s)
COVID-19/pathology , COVID-19/virology , Idiopathic Pulmonary Fibrosis/pathology , Idiopathic Pulmonary Fibrosis/virology , Macrophages/pathology , Macrophages/virology , SARS-CoV-2/physiology , Antigens, CD/metabolism , Antigens, Differentiation, Myelomonocytic/metabolism , COVID-19/diagnostic imaging , Cell Communication , Cohort Studies , Fibroblasts/pathology , Gene Expression Regulation , Humans , Idiopathic Pulmonary Fibrosis/diagnostic imaging , Idiopathic Pulmonary Fibrosis/genetics , Mesenchymal Stem Cells/pathology , Phenotype , Proteome/metabolism , Receptors, Cell Surface/metabolism , Respiratory Distress Syndrome/diagnostic imaging , Respiratory Distress Syndrome/pathology , Respiratory Distress Syndrome/virology , Tomography, X-Ray Computed , Transcription, Genetic
3.
J Infect Dis ; 2021 Oct 15.
Article in English | MEDLINE | ID: covidwho-1470155

ABSTRACT

The upper respiratory tract (URT) is the primary entry site for SARS-CoV-2 and other respiratory viruses, but its involvement in viral amplification and pathogenesis remains incompletely understood. Here we investigated primary nasal epithelial cultures, as well as vital explanted tissues to scrutinize the tropism of wild-type SARS-CoV-2 and the recently emerged B.1.1.7 variant. Our analyses revealed a widespread replication competence of SARS-CoV-2 in polarized nasal epithelium as well as in the examined URT and salivary gland tissues, which was also shared by the B.1.1.7 virus thereby highlighting the active role of these anatomic sites in COVID-19.

5.
Nat Commun ; 12(1): 3818, 2021 06 21.
Article in English | MEDLINE | ID: covidwho-1279876

ABSTRACT

Viruses manipulate cellular metabolism and macromolecule recycling processes like autophagy. Dysregulated metabolism might lead to excessive inflammatory and autoimmune responses as observed in severe and long COVID-19 patients. Here we show that SARS-CoV-2 modulates cellular metabolism and reduces autophagy. Accordingly, compound-driven induction of autophagy limits SARS-CoV-2 propagation. In detail, SARS-CoV-2-infected cells show accumulation of key metabolites, activation of autophagy inhibitors (AKT1, SKP2) and reduction of proteins responsible for autophagy initiation (AMPK, TSC2, ULK1), membrane nucleation, and phagophore formation (BECN1, VPS34, ATG14), as well as autophagosome-lysosome fusion (BECN1, ATG14 oligomers). Consequently, phagophore-incorporated autophagy markers LC3B-II and P62 accumulate, which we confirm in a hamster model and lung samples of COVID-19 patients. Single-nucleus and single-cell sequencing of patient-derived lung and mucosal samples show differential transcriptional regulation of autophagy and immune genes depending on cell type, disease duration, and SARS-CoV-2 replication levels. Targeting of autophagic pathways by exogenous administration of the polyamines spermidine and spermine, the selective AKT1 inhibitor MK-2206, and the BECN1-stabilizing anthelmintic drug niclosamide inhibit SARS-CoV-2 propagation in vitro with IC50 values of 136.7, 7.67, 0.11, and 0.13 µM, respectively. Autophagy-inducing compounds reduce SARS-CoV-2 propagation in primary human lung cells and intestinal organoids emphasizing their potential as treatment options against COVID-19.


Subject(s)
COVID-19/metabolism , COVID-19/virology , SARS-CoV-2/metabolism , Animals , Antinematodal Agents/pharmacology , Autophagosomes/metabolism , Autophagy , Autophagy-Related Proteins/metabolism , COVID-19/drug therapy , COVID-19/pathology , Cells, Cultured , Chlorocebus aethiops , Cricetinae , Disease Models, Animal , Humans , Lung/metabolism , Lung/pathology , Lung/virology , Metabolome , Niclosamide/pharmacology , Organoids , SARS-CoV-2/isolation & purification , Spermidine/pharmacology , Spermine/pharmacology
6.
The FASEB Journal ; 35(S1), 2021.
Article in English | Wiley | ID: covidwho-1233934

ABSTRACT

Study objective Endothelial dysfunction and increased microvascular permeability are hallmarks of severe COVID-19. At present, the extent of endothelial barrier failure and its underlying mechanisms in COVID?19 remain unclear. We hypothesized that endothelial leak results from bioactive mediators released in COVID-19 rather than direct endothelial infection and can thus be recapitulated ex vivo by treating endothelial cells with patient plasma, thus providing a personalized screening platform for barrier-protective interventions in COVID-19. Methods Citrate plasma was sampled as part of the Pa-COVID-19 cohort study (ethics approval EA2/066/20) in patients with moderate (hospitalized, no invasive ventilation;WHO severity score: 3-4) and severe (high flow O2 or intubated and mechanically ventilated;WHO severity score: 5-7) COVID?19. Plasma samples were diluted to 10% (v/v) in cell culture medium without FCS and tested for their ability to disrupt barrier integrity of primary human pulmonary microvascular endothelial cells (HPMEC) monolayers by electrical cell-substrate impedance sensing (ECIS), immunofluorescence for endothelial VE-cadherin and F-actin, and real-time Ca2+ imaging. Plasma from healthy donors served as control. Results COVID-19 plasma was virus-free but caused endothelial barrier disruption as measured by ECIS and gap formation in HPMEC monolayers. The extent of barrier disruption increased with disease severity but varied considerably between endothelial cells from different microvascular beds (lung/heart >> skin). The TRPV4-antagonist HC-067047 prevented the endothelial Ca2+ response to COVID-19 plasma and protected endothelial barrier integrity in lung microvascular cells. Conclusion Here, we identify TRPV4 as critical regulator of microvascular permeability in COVID?19. Targeting TRPV4-mediated endothelial barrier failure may present a promising adjunctive therapy in COVID-19.

7.
Nat Rev Mater ; : 1-3, 2021 Mar 17.
Article in English | MEDLINE | ID: covidwho-1145059

ABSTRACT

Scientists worldwide struggle to identify suitable animal models to study SARS-CoV-2 infections. Interspecies-related differences, such as host specificity, divergent immune responses, or the unavailability of species-specific reagents hamper the research. Human-based models, such as micro-engineered multi-organs-on-chip, may hold the solution.

8.
iScience ; 24(3): 102151, 2021 Mar 19.
Article in English | MEDLINE | ID: covidwho-1065235

ABSTRACT

Detailed knowledge of the molecular biology of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is crucial for understanding of viral replication, host responses, and disease progression. Here, we report gene expression profiles of three SARS-CoV- and SARS-CoV-2-infected human cell lines. SARS-CoV-2 elicited an approximately two-fold higher stimulation of the innate immune response compared to SARS-CoV in the human epithelial cell line Calu-3, including induction of miRNA-155. Single-cell RNA sequencing of infected cells showed that genes induced by virus infections were broadly upregulated, whereas interferon beta/lambda genes, a pro-inflammatory cytokines such as IL-6, were expressed only in small subsets of infected cells. Temporal analysis suggested that transcriptional activities of interferon regulatory factors precede those of nuclear factor κB. Lastly, we identified heat shock protein 90 (HSP90) as a protein relevant for the infection. Inhibition of the HSP90 activity resulted in a reduction of viral replication and pro-inflammatory cytokine expression in primary human airway epithelial cells.

10.
Nat Biotechnol ; 38(8): 970-979, 2020 08.
Article in English | MEDLINE | ID: covidwho-1023942

ABSTRACT

To investigate the immune response and mechanisms associated with severe coronavirus disease 2019 (COVID-19), we performed single-cell RNA sequencing on nasopharyngeal and bronchial samples from 19 clinically well-characterized patients with moderate or critical disease and from five healthy controls. We identified airway epithelial cell types and states vulnerable to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. In patients with COVID-19, epithelial cells showed an average three-fold increase in expression of the SARS-CoV-2 entry receptor ACE2, which correlated with interferon signals by immune cells. Compared to moderate cases, critical cases exhibited stronger interactions between epithelial and immune cells, as indicated by ligand-receptor expression profiles, and activated immune cells, including inflammatory macrophages expressing CCL2, CCL3, CCL20, CXCL1, CXCL3, CXCL10, IL8, IL1B and TNF. The transcriptional differences in critical cases compared to moderate cases likely contribute to clinical observations of heightened inflammatory tissue damage, lung injury and respiratory failure. Our data suggest that pharmacologic inhibition of the CCR1 and/or CCR5 pathways might suppress immune hyperactivation in critical COVID-19.


Subject(s)
Coronavirus Infections/pathology , Coronavirus Infections/physiopathology , Pneumonia, Viral/pathology , Pneumonia, Viral/physiopathology , Respiratory System/pathology , Single-Cell Analysis , Transcriptome , Adult , Aged , Angiotensin-Converting Enzyme 2 , Bronchoalveolar Lavage Fluid/virology , COVID-19 , Cell Communication , Cell Differentiation , Coronavirus Infections/virology , Epithelial Cells/pathology , Epithelial Cells/virology , Female , Humans , Immune System/pathology , Inflammation/immunology , Inflammation/pathology , Longitudinal Studies , Male , Middle Aged , Nasopharynx/virology , Pandemics , Peptidyl-Dipeptidase A/genetics , Pneumonia, Viral/virology , Respiratory System/immunology , Respiratory System/virology , Severity of Illness Index
12.
Cell ; 183(4): 1058-1069.e19, 2020 11 12.
Article in English | MEDLINE | ID: covidwho-785287

ABSTRACT

The emergence of SARS-CoV-2 led to pandemic spread of coronavirus disease 2019 (COVID-19), manifesting with respiratory symptoms and multi-organ dysfunction. Detailed characterization of virus-neutralizing antibodies and target epitopes is needed to understand COVID-19 pathophysiology and guide immunization strategies. Among 598 human monoclonal antibodies (mAbs) from 10 COVID-19 patients, we identified 40 strongly neutralizing mAbs. The most potent mAb, CV07-209, neutralized authentic SARS-CoV-2 with an IC50 value of 3.1 ng/mL. Crystal structures of two mAbs in complex with the SARS-CoV-2 receptor-binding domain at 2.55 and 2.70 Å revealed a direct block of ACE2 attachment. Interestingly, some of the near-germline SARS-CoV-2-neutralizing mAbs reacted with mammalian self-antigens. Prophylactic and therapeutic application of CV07-209 protected hamsters from SARS-CoV-2 infection, weight loss, and lung pathology. Our results show that non-self-reactive virus-neutralizing mAbs elicited during SARS-CoV-2 infection are a promising therapeutic strategy.


Subject(s)
Antibodies, Monoclonal/immunology , Antibodies, Viral/immunology , Betacoronavirus/metabolism , Coronavirus Infections/pathology , Pneumonia, Viral/pathology , Angiotensin-Converting Enzyme 2 , Animals , Antibodies, Monoclonal/therapeutic use , Antibodies, Neutralizing/immunology , Antibodies, Viral/therapeutic use , Antigen-Antibody Reactions , Betacoronavirus/immunology , Betacoronavirus/pathogenicity , Binding Sites , COVID-19 , Coronavirus Infections/drug therapy , Coronavirus Infections/virology , Cricetinae , Crystallography, X-Ray , Disease Models, Animal , Humans , Kinetics , Lung/immunology , Lung/metabolism , Lung/pathology , Mice , Mice, Inbred C57BL , Molecular Dynamics Simulation , Pandemics , Peptidyl-Dipeptidase A/chemistry , Peptidyl-Dipeptidase A/metabolism , Pneumonia, Viral/drug therapy , Pneumonia, Viral/virology , Protein Binding , SARS-CoV-2 , Spike Glycoprotein, Coronavirus/chemistry , Spike Glycoprotein, Coronavirus/immunology , Spike Glycoprotein, Coronavirus/metabolism
13.
Cell ; 182(6): 1419-1440.e23, 2020 09 17.
Article in English | MEDLINE | ID: covidwho-694631

ABSTRACT

Coronavirus disease 2019 (COVID-19) is a mild to moderate respiratory tract infection, however, a subset of patients progress to severe disease and respiratory failure. The mechanism of protective immunity in mild forms and the pathogenesis of severe COVID-19 associated with increased neutrophil counts and dysregulated immune responses remain unclear. In a dual-center, two-cohort study, we combined single-cell RNA-sequencing and single-cell proteomics of whole-blood and peripheral-blood mononuclear cells to determine changes in immune cell composition and activation in mild versus severe COVID-19 (242 samples from 109 individuals) over time. HLA-DRhiCD11chi inflammatory monocytes with an interferon-stimulated gene signature were elevated in mild COVID-19. Severe COVID-19 was marked by occurrence of neutrophil precursors, as evidence of emergency myelopoiesis, dysfunctional mature neutrophils, and HLA-DRlo monocytes. Our study provides detailed insights into the systemic immune response to SARS-CoV-2 infection and reveals profound alterations in the myeloid cell compartment associated with severe COVID-19.


Subject(s)
Coronavirus Infections/immunology , Myeloid Cells/immunology , Myelopoiesis , Pneumonia, Viral/immunology , Adult , Aged , CD11 Antigens/genetics , CD11 Antigens/metabolism , COVID-19 , Cells, Cultured , Coronavirus Infections/blood , Coronavirus Infections/pathology , Female , HLA-DR Antigens/genetics , HLA-DR Antigens/metabolism , Humans , Male , Middle Aged , Myeloid Cells/cytology , Pandemics , Pneumonia, Viral/blood , Pneumonia, Viral/pathology , Proteome/genetics , Proteome/metabolism , Proteomics , Single-Cell Analysis
14.
Nature ; 587(7833): 270-274, 2020 11.
Article in English | MEDLINE | ID: covidwho-684778

ABSTRACT

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused the rapidly unfolding coronavirus disease 2019 (COVID-19) pandemic1,2. Clinical manifestations of COVID-19 vary, ranging from asymptomatic infection to respiratory failure. The mechanisms that determine such variable outcomes remain unresolved. Here we investigated CD4+ T cells that are reactive against the spike glycoprotein of SARS-CoV-2 in the peripheral blood of patients with COVID-19 and SARS-CoV-2-unexposed healthy donors. We detected spike-reactive CD4+ T cells not only in 83% of patients with COVID-19 but also in 35% of healthy donors. Spike-reactive CD4+ T cells in healthy donors were primarily active against C-terminal epitopes in the spike protein, which show a higher homology to spike glycoproteins of human endemic coronaviruses, compared with N-terminal epitopes. Spike-protein-reactive T cell lines generated from SARS-CoV-2-naive healthy donors responded similarly to the C-terminal region of the spike proteins of the human endemic coronaviruses 229E and OC43, as well as that of SARS-CoV-2. This results indicate that spike-protein cross-reactive T cells are present, which were probably generated during previous encounters with endemic coronaviruses. The effect of pre-existing SARS-CoV-2 cross-reactive T cells on clinical outcomes remains to be determined in larger cohorts. However, the presence of spike-protein cross-reactive T cells in a considerable fraction of the general population may affect the dynamics of the current pandemic, and has important implications for the design and analysis of upcoming trials investigating COVID-19 vaccines.


Subject(s)
Betacoronavirus/immunology , CD4-Positive T-Lymphocytes/immunology , Coronavirus Infections/immunology , Pneumonia, Viral/immunology , Spike Glycoprotein, Coronavirus/immunology , Adult , Aged , Aged, 80 and over , COVID-19 , Cell Line , Coronavirus 229E, Human/immunology , Coronavirus NL63, Human/immunology , Coronavirus OC43, Human/immunology , Cross Reactions , Epitopes, T-Lymphocyte/immunology , Female , Healthy Volunteers , Humans , Lymphocyte Activation , Male , Middle Aged , Pandemics , SARS-CoV-2
15.
Infection ; 48(4): 619-626, 2020 Aug.
Article in English | MEDLINE | ID: covidwho-597401

ABSTRACT

PURPOSE: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has spread worldwide causing a global health emergency. Pa-COVID-19 aims to provide comprehensive data on clinical course, pathophysiology, immunology and outcome of COVID-19, to identify prognostic biomarkers, clinical scores, and therapeutic targets for improved clinical management and preventive interventions. METHODS: Pa-COVID-19 is a prospective observational cohort study of patients with confirmed SARS-CoV-2 infection treated at Charité - Universitätsmedizin Berlin. We collect data on epidemiology, demography, medical history, symptoms, clinical course, and pathogen testing and treatment. Systematic, serial blood sampling will allow deep molecular and immunological phenotyping, transcriptomic profiling, and comprehensive biobanking. Longitudinal data and sample collection during hospitalization will be supplemented by long-term follow-up. RESULTS: Outcome measures include the WHO clinical ordinal scale on day 15 and clinical, functional, and health-related quality-of-life assessments at discharge and during follow-up. We developed a scalable dataset to (i) suit national standards of care, (ii) facilitate comprehensive data collection in medical care facilities with varying resources, and (iii) allow for rapid implementation of interventional trials based on the standardized study design and data collection. We propose this scalable protocol as blueprint for harmonized data collection and deep phenotyping in COVID-19 in Germany. CONCLUSION: We established a basic platform for harmonized, scalable data collection, pathophysiological analysis, and deep phenotyping of COVID-19, which enables rapid generation of evidence for improved medical care and identification of candidate therapeutic and preventive strategies. The electronic database accredited for interventional trials allows fast trial implementation for candidate therapeutic agents. TRIAL REGISTRATION: Registered at the German registry for clinical studies (DRKS00021688).


Subject(s)
Coronavirus Infections/physiopathology , Pneumonia, Viral/physiopathology , Registries , Berlin/epidemiology , Betacoronavirus , Biological Specimen Banks , COVID-19 , Coronavirus Infections/epidemiology , Disease Management , Humans , Observational Studies as Topic , Pandemics , Phenotype , Pneumonia, Viral/epidemiology , Prospective Studies , Risk Assessment , Risk Factors , SARS-CoV-2 , Time Factors , Treatment Outcome , World Health Organization
16.
Cell Syst ; 11(1): 11-24.e4, 2020 07 22.
Article in English | MEDLINE | ID: covidwho-459007

ABSTRACT

The COVID-19 pandemic is an unprecedented global challenge, and point-of-care diagnostic classifiers are urgently required. Here, we present a platform for ultra-high-throughput serum and plasma proteomics that builds on ISO13485 standardization to facilitate simple implementation in regulated clinical laboratories. Our low-cost workflow handles up to 180 samples per day, enables high precision quantification, and reduces batch effects for large-scale and longitudinal studies. We use our platform on samples collected from a cohort of early hospitalized cases of the SARS-CoV-2 pandemic and identify 27 potential biomarkers that are differentially expressed depending on the WHO severity grade of COVID-19. They include complement factors, the coagulation system, inflammation modulators, and pro-inflammatory factors upstream and downstream of interleukin 6. All protocols and software for implementing our approach are freely available. In total, this work supports the development of routine proteomic assays to aid clinical decision making and generate hypotheses about potential COVID-19 therapeutic targets.


Subject(s)
Blood Proteins/metabolism , Coronavirus Infections/blood , Pneumonia, Viral/blood , Proteomics/methods , Adult , Aged , Aged, 80 and over , Betacoronavirus/isolation & purification , Biomarkers/blood , Blood Proteins/analysis , COVID-19 , Coronavirus Infections/classification , Coronavirus Infections/pathology , Coronavirus Infections/virology , Female , Humans , Male , Middle Aged , Pandemics/classification , Pneumonia, Viral/classification , Pneumonia, Viral/pathology , Pneumonia, Viral/virology , SARS-CoV-2 , Young Adult
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