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1.
EuropePMC; 2022.
Preprint in English | EuropePMC | ID: ppcovidwho-336025

ABSTRACT

Vaccines are a cornerstone in COVID-19 pandemic management. Here, we compare immune responses to and preclinical efficacy of the mRNA vaccine BNT162b2, an adenovirus-vectored spike vaccine, and the live-attenuated-virus vaccine candidate sCPD9 after single and double vaccination in Syrian hamsters. All regimens containing sCPD9 showed superior efficacy. The robust immunity elicited by sCPD9 was evident in a wide range of immune parameters after challenge with heterologous SARS-CoV-2 including rapid viral clearance, reduced tissue damage, fast differentiation of pre-plasmablasts, strong systemic and mucosal humoral responses, and rapid recall of memory T cells from lung tissue. Our results demonstrate that use of live-attenuated vaccines may offer advantages over available COVID-19 vaccines, specifically when applied as booster, and may provide a solution for containment of the COVID-19 pandemic.

2.
Mol Ther ; 30(5): 1952-1965, 2022 May 04.
Article in English | MEDLINE | ID: covidwho-1783847

ABSTRACT

For coronavirus disease 2019 (COVID-19), effective and well-understood treatment options are still scarce. Since vaccine efficacy is challenged by novel variants, short-lasting immunity, and vaccine hesitancy, understanding and optimizing therapeutic options remains essential. We aimed at better understanding the effects of two standard-of-care drugs, dexamethasone and anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibodies, on infection and host responses. By using two COVID-19 hamster models, pulmonary immune responses were analyzed to characterize effects of single or combinatorial treatments. Pulmonary viral burden was reduced by anti-SARS-CoV-2 antibody treatment and unaltered or increased by dexamethasone alone. Dexamethasone exhibited strong anti-inflammatory effects and prevented fulminant disease in a severe disease model. Combination therapy showed additive benefits with both anti-viral and anti-inflammatory potency. Bulk and single-cell transcriptomic analyses confirmed dampened inflammatory cell recruitment into lungs upon dexamethasone treatment and identified a specifically responsive subpopulation of neutrophils, thereby indicating a potential mechanism of action. Our analyses confirm the anti-inflammatory properties of dexamethasone and suggest possible mechanisms, validate anti-viral effects of anti-SARS-CoV-2 antibody treatment, and reveal synergistic effects of a combination therapy, thus informing more effective COVID-19 therapies.


Subject(s)
COVID-19 , Animals , Anti-Inflammatory Agents/pharmacology , Anti-Inflammatory Agents/therapeutic use , Antibodies, Viral , Antiviral Agents , COVID-19/drug therapy , Cricetinae , Dexamethasone/pharmacology , SARS-CoV-2 , Transcriptome
3.
EuropePMC; 2021.
Preprint in English | EuropePMC | ID: ppcovidwho-318102

ABSTRACT

In COVID-19, immune responses are key in determining disease severity. However, cellular mechanisms at the onset of inflammatory lung injury in SARS-CoV-2 infection, particularly involving endothelial cells, remain ill-defined. Using Syrian hamsters as model for moderate COVID-19, we conducted a detailed longitudinal analysis of systemic and pulmonary cellular responses, and corroborated it with datasets from COVID-19 patients. Monocyte-derived macrophages in lungs exerted the earliest and strongest transcriptional response to infection, including induction of pro-inflammatory genes, while epithelial cells showed weak activation. Without evidence for productive infection, endothelial cells reacted, depending on cell subtypes, by strong and early expression of anti-viral, pro-inflammatory, and T cell recruiting genes. Recruitment of cytotoxic T cells as well as emergence of IgM antibodies preceded viral clearance at day 5 post infection. Investigating SARS-CoV-2 infected Syrian hamsters can thus identify cell type-specific effector functions, provide detailed insights into pathomechanisms of COVID-19, and inform therapeutic strategies.

4.
EuropePMC;
Preprint in English | EuropePMC | ID: ppcovidwho-327696

ABSTRACT

Cell-intrinsic responses mounted in vivo in PBMCs during mild and severe COVID-19 differ quantitatively and qualitatively. Whether they are triggered by signals emitted by productively infected cells of the respiratory tract or are, at least partially, resulting from physical interaction with virus particles, remains unclear. Here, we analyzed susceptibility and expression profiles of PBMCs from healthy donors upon ex vivo exposure to SARS-CoV and SARS-CoV-2. In line with the absence of detectable ACE2 receptor expression, human PBMCs were refractory to productive infection. Bulk and single cell RNA-sequencing revealed JAK/STAT-dependent induction of interferon-stimulated genes, but not pro-inflammatory cytokines. This SARS-CoV-2-specific response was most pronounced in monocytes. SARS-CoV-2-RNA-positive monocytes displayed a lower ISG signature as compared to bystander cells of the identical culture. This suggests a preferential invasion of cells with a low ISG base-line profile or delivery of a SARS-CoV-2-specific sensing antagonist upon efficient particle internalization. Together, non-productive physical interaction of PBMCs with SARS-CoV-2- but not SARS-CoV particles stimulates JAK/STAT-dependent, monocyte-accentuated innate immune responses that resemble those detected in vivo in patients with mild COVID-19.

5.
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
6.
Nat Commun ; 12(1): 4869, 2021 08 11.
Article in English | MEDLINE | ID: covidwho-1354100

ABSTRACT

In COVID-19, immune responses are key in determining disease severity. However, cellular mechanisms at the onset of inflammatory lung injury in SARS-CoV-2 infection, particularly involving endothelial cells, remain ill-defined. Using Syrian hamsters as a model for moderate COVID-19, we conduct a detailed longitudinal analysis of systemic and pulmonary cellular responses, and corroborate it with datasets from COVID-19 patients. Monocyte-derived macrophages in lungs exert the earliest and strongest transcriptional response to infection, including induction of pro-inflammatory genes, while epithelial cells show weak alterations. Without evidence for productive infection, endothelial cells react, depending on cell subtypes, by strong and early expression of anti-viral, pro-inflammatory, and T cell recruiting genes. Recruitment of cytotoxic T cells as well as emergence of IgM antibodies precede viral clearance at day 5 post infection. Investigating SARS-CoV-2 infected Syrian hamsters thus identifies cell type-specific effector functions, providing detailed insights into pathomechanisms of COVID-19 and informing therapeutic strategies.


Subject(s)
COVID-19/immunology , Disease Models, Animal , Alveolar Epithelial Cells/immunology , Animals , Cricetinae , Cytokines/genetics , Cytokines/immunology , Endothelial Cells/immunology , Humans , Immunoglobulin M/immunology , Inflammation , Lung/immunology , Macrophages/immunology , Mesocricetus , Monocytes/immunology , SARS-CoV-2/immunology , Signal Transduction , T-Lymphocytes, Cytotoxic/immunology , Toll-Like Receptors/immunology
7.
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
8.
Nat Biotechnol ; 39(6): 705-716, 2021 06.
Article in English | MEDLINE | ID: covidwho-997913

ABSTRACT

In coronavirus disease 2019 (COVID-19), hypertension and cardiovascular diseases are major risk factors for critical disease progression. However, the underlying causes and the effects of the main anti-hypertensive therapies-angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs)-remain unclear. Combining clinical data (n = 144) and single-cell sequencing data of airway samples (n = 48) with in vitro experiments, we observed a distinct inflammatory predisposition of immune cells in patients with hypertension that correlated with critical COVID-19 progression. ACEI treatment was associated with dampened COVID-19-related hyperinflammation and with increased cell intrinsic antiviral responses, whereas ARB treatment related to enhanced epithelial-immune cell interactions. Macrophages and neutrophils of patients with hypertension, in particular under ARB treatment, exhibited higher expression of the pro-inflammatory cytokines CCL3 and CCL4 and the chemokine receptor CCR1. Although the limited size of our cohort does not allow us to establish clinical efficacy, our data suggest that the clinical benefits of ACEI treatment in patients with COVID-19 who have hypertension warrant further investigation.


Subject(s)
COVID-19/drug therapy , Chemokine CCL3/genetics , Chemokine CCL4/genetics , Hypertension/drug therapy , Receptors, CCR1/genetics , Adult , Angiotensin Receptor Antagonists/administration & dosage , Angiotensin Receptor Antagonists/adverse effects , Angiotensin-Converting Enzyme Inhibitors/administration & dosage , Angiotensin-Converting Enzyme Inhibitors/adverse effects , COVID-19/complications , COVID-19/genetics , COVID-19/virology , Disease Progression , Female , Gene Expression Regulation/drug effects , Humans , Hypertension/complications , Hypertension/genetics , Hypertension/pathology , Inflammation/complications , Inflammation/drug therapy , Inflammation/genetics , Inflammation/virology , Male , Middle Aged , RNA-Seq , Respiratory System/drug effects , Respiratory System/pathology , Respiratory System/virology , Risk Factors , SARS-CoV-2/pathogenicity , Single-Cell Analysis
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