Your browser doesn't support javascript.
Show: 20 | 50 | 100
Results 1 - 9 de 9
Filter
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.
Emerg Microbes Infect ; 10(1): 2151-2168, 2021 Dec.
Article in English | MEDLINE | ID: covidwho-1541485

ABSTRACT

Infection by (re-)emerging RNA arboviruses including Chikungunya virus (CHIKV) and Mayaro virus primarily cause acute febrile disease and transient polyarthralgia. However, in a significant subset of infected individuals, debilitating arthralgia persists for weeks over months up to years. The underlying immunopathogenesis of chronification of arthralgia upon primary RNA-viral infection remains unclear. Here, we analysed cell-intrinsic responses to ex vivo arthritogenic alphaviral infection of primary human synovial fibroblasts isolated from knee joints, one the most affected joint types during acute and chronic CHIKV disease. Synovial fibroblasts were susceptible and permissive to alphaviral infection. Base-line and exogenously added type I interferon (IFN) partially and potently restricted infection, respectively. RNA-seq revealed a CHIKV infection-induced transcriptional profile that comprised upregulation of expression of several hundred IFN-stimulated and arthralgia-mediating genes. Single-cell virus-inclusive RNA-seq uncovered a fine-tuned switch from induction to repression of cell-intrinsic immune responses depending on the abundance of viral RNA in an individual cell. Specifically, responses were most pronounced in cells displaying low-to-intermediate amounts of viral RNA and absence of virus-encoded, fluorescent reporter protein expression, arguing for efficient counteraction of innate immunity in cells expressing viral antagonists at sufficient quantities. In summary, cell-intrinsic sensing of viral RNA that potentially persists or replicates at low levels in synovial fibroblasts and other target cell types in vivo may contribute to the chronic arthralgia induced by alphaviral infections. Our findings might advance our understanding of the immunopathophysiology of long-term pathogenesis of RNA-viral infections.


Subject(s)
Arbovirus Infections/virology , Arboviruses/physiology , Arthralgia/virology , Immunity, Innate , RNA, Viral/genetics , Synovial Fluid/immunology , Arbovirus Infections/genetics , Arbovirus Infections/immunology , Arboviruses/genetics , Arthralgia/genetics , Arthralgia/immunology , Cells, Cultured , Fibroblasts/immunology , Fibroblasts/virology , Humans , RNA, Viral/metabolism , Single-Cell Analysis , Synovial Fluid/cytology , Virus Replication
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.
Lancet Microbe ; 2(5): e210-e218, 2021 05.
Article in English | MEDLINE | ID: covidwho-1117258

ABSTRACT

BACKGROUND: The COVID-19 agent, SARS-CoV-2, is conspecific with SARS-CoV, the causal agent of the severe acute respiratory syndrome epidemic in 2002-03. Although the viruses share a completely homologous repertoire of proteins and use the same cellular entry receptor, their transmission efficiencies and pathogenetic traits differ. We aimed to compare interferon antagonism by SARS-CoV and SARS-CoV-2. METHODS: For this functional study, we infected Vero E6 and Calu-3 cells with strains of SARS-CoV and SARS-CoV-2. We studied differences in cell line-specific replication (Vero E6 vs Calu-3 cells) and analysed these differences in relation to TMPRSS2-dependent cell entry based on inhibition with the drug camostat mesilate. We evaluated viral sensitivity towards type I interferon treatment and assessed cytokine induction and type I interferon signalling in the host cells by RT-PCR and analysis of transcription factor activation and nuclear translocation. Based on reverse genetic engineering of SARS-CoV, we investigated the contribution of open reading frame 6 (ORF6) to the observed phenotypic differences in interferon signalling, because ORF6 encodes an interferon signalling antagonist. We did a luciferase-based interferon-stimulated response element promotor activation assay to evaluate the antagonistic capacity of SARS-CoV-2 wild-type ORF6 constructs and three mutants (Gln51Glu, Gln56Glu, or both) that represent amino acid substitutions between SARS-CoV and SARS-CoV-2 protein 6 in the carboxy-terminal domain. FINDINGS: Overall, replication was higher for SARS-CoV in Vero E6 cells and for SARS-CoV-2 in Calu-3 cells. SARS-CoV-2 was reliant on TMPRSS2, found only in Calu-3 cells, for more efficient entry. SARS-CoV-2 was more sensitive to interferon treatment, less efficient in suppressing cytokine induction via IRF3 nuclear translocation, and permissive of a higher level of induction of interferon-stimulated genes MX1 and ISG56. SARS-CoV-2 ORF6 expressed in the context of a fully replicating SARS-CoV backbone suppressed MX1 gene induction, but this suppression was less efficient than that by SARS-CoV ORF6. Mutagenesis showed that charged amino acids in residues 51 and 56 shift the phenotype towards more efficient interferon antagonism, as seen in SARS-CoV. INTERPRETATION: SARS-CoV-2 ORF6 interferes less efficiently with human interferon induction and interferon signalling than SARS-CoV ORF6. Because of the homology of the genes, onward selection for fitness could involve functional optimisation of interferon antagonism. Charged amino acids at positions 51 and 56 in ORF6 should be monitored for potential adaptive changes. FUNDING: Bundesministerium für Bildung und Forschung, EU RECOVER project.


Subject(s)
COVID-19 , Interferon Type I , SARS Virus , Amino Acids/genetics , Antiviral Agents/pharmacology , COVID-19/drug therapy , Humans , Interferon Type I/genetics , Reverse Genetics , SARS Virus/genetics , SARS-CoV-2/genetics , Viral Proteins/chemistry
8.
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
9.
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
SELECTION OF CITATIONS
SEARCH DETAIL