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1.
EMBO Rep ; 23(6): e54305, 2022 Jun 07.
Article in English | MEDLINE | ID: covidwho-1836040

ABSTRACT

The severe-acute-respiratory-syndrome-coronavirus-2 (SARS-CoV-2) is the causative agent of COVID-19, but host cell factors contributing to COVID-19 pathogenesis remain only partly understood. We identify the host metalloprotease ADAM17 as a facilitator of SARS-CoV-2 cell entry and the metalloprotease ADAM10 as a host factor required for lung cell syncytia formation, a hallmark of COVID-19 pathology. ADAM10 and ADAM17, which are broadly expressed in the human lung, cleave the SARS-CoV-2 spike protein (S) in vitro, indicating that ADAM10 and ADAM17 contribute to the priming of S, an essential step for viral entry and cell fusion. ADAM protease-targeted inhibitors severely impair lung cell infection by the SARS-CoV-2 variants of concern alpha, beta, delta, and omicron and also reduce SARS-CoV-2 infection of primary human lung cells in a TMPRSS2 protease-independent manner. Our study establishes ADAM10 and ADAM17 as host cell factors for viral entry and syncytia formation and defines both proteases as potential targets for antiviral drug development.


Subject(s)
COVID-19 , SARS-CoV-2 , ADAM10 Protein/genetics , ADAM17 Protein , Amyloid Precursor Protein Secretases/genetics , Angiotensin-Converting Enzyme 2 , Cell Fusion , Humans , Lung , Membrane Proteins/genetics , Membrane Proteins/metabolism , Metalloproteases , Spike Glycoprotein, Coronavirus/genetics , Spike Glycoprotein, Coronavirus/metabolism , Virus Internalization
2.
EuropePMC; 2020.
Preprint in English | EuropePMC | ID: ppcovidwho-305488

ABSTRACT

A promising approach to tackle the Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) could be small interfering (si)RNAs. The proof of concept that SARS-CoV-2 can be inhibited with siRNAs, however, is missing. Here, we report that siRNAs can target genomic RNA (gRNA) of SARS-CoV-2 after cell entry, terminating replication before start of transcription and preventing cytopathic effects. Coronaviruses replicate via negative sense intermediate transcripts using a unique discontinuous transcription process. As a result, each viral RNA contains identical sequences at the 5’ and 3’ end. Surprisingly, siRNAs were not active against intermediate negative sense transcripts. Targeting sequences shared by different viral transcripts allowed simultaneous suppression of gRNA and subgenomic (sg)RNAs by a single siRNA. The most effective suppression of viral replication and spread, however, was achieved by siRNAs targeting open reading frame 1 (ORF1) which is solely part of gRNA. We propose two independent mechanisms for this: An increased accessibility of translational-active ORF1 before the start of transcription, as well as highly abundant sgRNAs out-competing siRNAs that target common sequences of transcripts. Our work encourages the development of siRNA-based therapies for COVID-19 and suggests that an early therapy start, together with targeting ORF1, might be key for high antiviral efficacy.

3.
EuropePMC; 2020.
Preprint in English | EuropePMC | ID: ppcovidwho-320468

ABSTRACT

Coronavirus Disease-2019 (COVID-19) is an infectious disease caused by the SARS-CoV-2 virus. It was first identified in Wuhan, China, and has since spread causing a global pandemic. Various studies have been performed to understand the molecular mechanisms of viral infection for predicting drug repurposing candidates. However, such information is spread across many publications and it is very time-consuming to access, integrate, explore, and exploit. We developed CoVex, the first interactive online platform for SARS-CoV-2 and SARS-CoV-1 host interactome exploration and drug (target) identification. CoVex integrates 1) experimentally validated virus-human protein interactions, 2) human protein-protein interactions and 3) drug-target interactions. The web interface allows user-friendly visual exploration of the virus-host interactome and implements systems medicine algorithms for network-based prediction of drugs. Thus, CoVex is an important resource, not only to understand the molecular mechanisms involved in SARS-CoV-2 and SARS-CoV-1 pathogenicity, but also in clinical research for the identification and prioritization of candidate therapeutics. We apply CoVex to investigate recent hypotheses on a systems biology level and to systematically explore the molecular mechanisms driving the virus life cycle. Furthermore, we extract and discuss drug repurposing candidates involved in these mechanisms. CoVex renders COVID-19 drug research systems-medicine-ready by giving the scientific community direct access to network medicine algorithms integrating virus-host-drug interactions. It is available at https://exbio.wzw.tum.de/covex/.

4.
Nucleic Acids Res ; 50(1): 333-349, 2022 01 11.
Article in English | MEDLINE | ID: covidwho-1591186

ABSTRACT

A promising approach to tackle the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) could be small interfering (si)RNAs. So far it is unclear, which viral replication steps can be efficiently inhibited with siRNAs. Here, we report that siRNAs can target genomic RNA (gRNA) of SARS-CoV-2 after cell entry, and thereby terminate replication before start of transcription and prevent virus-induced cell death. Coronaviruses replicate via negative sense RNA intermediates using a unique discontinuous transcription process. As a result, each viral RNA contains identical sequences at the 5' and 3' end. Surprisingly, siRNAs were not active against intermediate negative sense transcripts. Targeting common sequences shared by all viral transcripts allowed simultaneous suppression of gRNA and subgenomic (sg)RNAs by a single siRNA. The most effective suppression of viral replication and spread, however, was achieved by siRNAs that targeted open reading frame 1 (ORF1) which only exists in gRNA. In contrast, siRNAs that targeted the common regions of transcripts were outcompeted by the highly abundant sgRNAs leading to an impaired antiviral efficacy. Verifying the translational relevance of these findings, we show that a chemically modified siRNA that targets a highly conserved region of ORF1, inhibited SARS-CoV-2 replication ex vivo in explants of the human lung. Our work encourages the development of siRNA-based therapies for COVID-19 and suggests that early therapy start, or prophylactic application, together with specifically targeting gRNA, might be key for high antiviral efficacy.


Subject(s)
COVID-19/virology , Lung/virology , RNA, Small Interfering , RNA, Viral , SARS-CoV-2/genetics , Virus Replication , 3' Untranslated Regions , Animals , Antiviral Agents/pharmacology , COVID-19/drug therapy , Cell Survival , Databases, Genetic , HEK293 Cells , Humans , Nucleic Acid Conformation , Oligonucleotides , Open Reading Frames , RNA, Small Interfering/metabolism
5.
Cell Rep ; 38(2): 110214, 2022 01 11.
Article in English | MEDLINE | ID: covidwho-1588141

ABSTRACT

T cell immunity is crucial for control of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and has been studied widely on a quantitative level. However, the quality of responses, in particular of CD8+ T cells, has only been investigated marginally so far. Here, we isolate T cell receptor (TCR) repertoires specific for immunodominant SARS-CoV-2 epitopes restricted to common human Leukocyte antigen (HLA) class I molecules in convalescent individuals. SARS-CoV-2-specific CD8+ T cells are detected up to 12 months after infection. TCR repertoires are diverse, with heterogeneous functional avidity and cytotoxicity toward virus-infected cells, as demonstrated for TCR-engineered T cells. High TCR functionality correlates with gene signatures that, remarkably, could be retrieved for each epitope:HLA combination analyzed. Overall, our data demonstrate that polyclonal and highly functional CD8+ TCRs-classic features of protective immunity-are recruited upon mild SARS-CoV-2 infection, providing tools to assess the quality of and potentially restore functional CD8+ T cell immunity.


Subject(s)
CD8-Positive T-Lymphocytes/immunology , COVID-19/immunology , Receptors, Antigen, T-Cell/immunology , SARS-CoV-2/immunology , Adult , Cells, Cultured , Cross Reactions/immunology , Epitopes, T-Lymphocyte/immunology , Female , Humans , Immunodominant Epitopes/immunology , Leukocytes, Mononuclear/immunology , Leukocytes, Mononuclear/virology , Male , Spike Glycoprotein, Coronavirus/immunology , T-Lymphocytes, Cytotoxic/immunology
6.
FASEB J ; 35(6): e21651, 2021 06.
Article in English | MEDLINE | ID: covidwho-1388031

ABSTRACT

The SARS-CoV-2 pandemic imposed a large burden on health and society. Therapeutics targeting different components and processes of the viral infection replication cycle are being investigated, particularly to repurpose already approved drugs. Spike protein is an important target for both vaccines and therapeutics. Insights into the mechanisms of spike-ACE2 binding and cell fusion could support the identification of compounds with inhibitory effects. Here, we demonstrate that the integrity of disulfide bonds within the receptor-binding domain (RBD) plays an important role in the membrane fusion process although their disruption does not prevent binding of spike protein to ACE2. Several reducing agents and thiol-reactive compounds are able to inhibit viral entry. N-acetyl cysteine amide, L-ascorbic acid, JTT-705, and auranofin prevented syncytia formation, viral entry into cells, and infection in a mouse model, supporting disulfides of the RBD as a therapeutically relevant target.


Subject(s)
Acetylcysteine/analogs & derivatives , Amides/pharmacology , Ascorbic Acid/pharmacology , Auranofin/pharmacology , COVID-19 , Disulfides/metabolism , Esters/pharmacology , SARS-CoV-2/metabolism , Spike Glycoprotein, Coronavirus/metabolism , Sulfhydryl Compounds/pharmacology , Virus Internalization/drug effects , Acetylcysteine/pharmacology , COVID-19/drug therapy , COVID-19/metabolism , COVID-19/pathology , HEK293 Cells , Humans
7.
Nat Commun ; 12(1): 4515, 2021 07 26.
Article in English | MEDLINE | ID: covidwho-1327196

ABSTRACT

The in vivo phenotypic profile of T cells reactive to severe acute respiratory syndrome (SARS)-CoV-2 antigens remains poorly understood. Conventional methods to detect antigen-reactive T cells require in vitro antigenic re-stimulation or highly individualized peptide-human leukocyte antigen (pHLA) multimers. Here, we use single-cell RNA sequencing to identify and profile SARS-CoV-2-reactive T cells from Coronavirus Disease 2019 (COVID-19) patients. To do so, we induce transcriptional shifts by antigenic stimulation in vitro and take advantage of natural T cell receptor (TCR) sequences of clonally expanded T cells as barcodes for 'reverse phenotyping'. This allows identification of SARS-CoV-2-reactive TCRs and reveals phenotypic effects introduced by antigen-specific stimulation. We characterize transcriptional signatures of currently and previously activated SARS-CoV-2-reactive T cells, and show correspondence with phenotypes of T cells from the respiratory tract of patients with severe disease in the presence or absence of virus in independent cohorts. Reverse phenotyping is a powerful tool to provide an integrated insight into cellular states of SARS-CoV-2-reactive T cells across tissues and activation states.


Subject(s)
COVID-19/immunology , Gene Expression Profiling/methods , Sequence Analysis, RNA/methods , Single-Cell Analysis/methods , T-Lymphocytes/metabolism , Aged , Aged, 80 and over , CD4-Positive T-Lymphocytes/metabolism , CD4-Positive T-Lymphocytes/virology , COVID-19/epidemiology , COVID-19/virology , Cells, Cultured , Cohort Studies , Female , Humans , Male , Middle Aged , Pandemics , Receptors, Antigen, T-Cell/genetics , Receptors, Antigen, T-Cell/immunology , Receptors, Antigen, T-Cell/metabolism , SARS-CoV-2/physiology , T-Lymphocytes/virology
8.
Nature ; 594(7862): 246-252, 2021 06.
Article in English | MEDLINE | ID: covidwho-1180252

ABSTRACT

The emergence and global spread of SARS-CoV-2 has resulted in the urgent need for an in-depth understanding of molecular functions of viral proteins and their interactions with the host proteome. Several individual omics studies have extended our knowledge of COVID-19 pathophysiology1-10. Integration of such datasets to obtain a holistic view of virus-host interactions and to define the pathogenic properties of SARS-CoV-2 is limited by the heterogeneity of the experimental systems. Here we report a concurrent multi-omics study of SARS-CoV-2 and SARS-CoV. Using state-of-the-art proteomics, we profiled the interactomes of both viruses, as well as their influence on the transcriptome, proteome, ubiquitinome and phosphoproteome of a lung-derived human cell line. Projecting these data onto the global network of cellular interactions revealed crosstalk between the perturbations taking place upon infection with SARS-CoV-2 and SARS-CoV at different levels and enabled identification of distinct and common molecular mechanisms of these closely related coronaviruses. The TGF-ß pathway, known for its involvement in tissue fibrosis, was specifically dysregulated by SARS-CoV-2 ORF8 and autophagy was specifically dysregulated by SARS-CoV-2 ORF3. The extensive dataset (available at https://covinet.innatelab.org ) highlights many hotspots that could be targeted by existing drugs and may be used to guide rational design of virus- and host-directed therapies, which we exemplify by identifying inhibitors of kinases and matrix metalloproteases with potent antiviral effects against SARS-CoV-2.


Subject(s)
COVID-19/metabolism , Host-Pathogen Interactions , Proteome/metabolism , Proteomics , SARS Virus/pathogenicity , SARS-CoV-2/pathogenicity , Severe Acute Respiratory Syndrome/metabolism , Animals , Antiviral Agents/pharmacology , Autophagy/drug effects , COVID-19/immunology , COVID-19/virology , Cell Line , Datasets as Topic , Drug Evaluation, Preclinical , Host-Pathogen Interactions/immunology , Humans , Matrix Metalloproteinase Inhibitors/pharmacology , Phosphorylation , Protein Interaction Maps , Protein Kinase Inhibitors/pharmacology , Protein Processing, Post-Translational , Proteome/chemistry , SARS Virus/immunology , SARS-CoV-2/immunology , Severe Acute Respiratory Syndrome/immunology , Severe Acute Respiratory Syndrome/virology , Transforming Growth Factor beta/metabolism , Ubiquitination , Viral Proteins/chemistry , Viral Proteins/metabolism , Viroporin Proteins/metabolism
9.
Nat Commun ; 11(1): 3518, 2020 07 14.
Article in English | MEDLINE | ID: covidwho-646906

ABSTRACT

Coronavirus Disease-2019 (COVID-19) is an infectious disease caused by the SARS-CoV-2 virus. Various studies exist about the molecular mechanisms of viral infection. However, such information is spread across many publications and it is very time-consuming to integrate, and exploit. We develop CoVex, an interactive online platform for SARS-CoV-2 host interactome exploration and drug (target) identification. CoVex integrates virus-human protein interactions, human protein-protein interactions, and drug-target interactions. It allows visual exploration of the virus-host interactome and implements systems medicine algorithms for network-based prediction of drug candidates. Thus, CoVex is a resource to understand molecular mechanisms of pathogenicity and to prioritize candidate therapeutics. We investigate recent hypotheses on a systems biology level to explore mechanistic virus life cycle drivers, and to extract drug repurposing candidates. CoVex renders COVID-19 drug research systems-medicine-ready by giving the scientific community direct access to network medicine algorithms. It is available at https://exbio.wzw.tum.de/covex/.


Subject(s)
Antiviral Agents/therapeutic use , Betacoronavirus/drug effects , Coronavirus Infections/drug therapy , Drug Repositioning/methods , Host Microbial Interactions/physiology , Pneumonia, Viral/drug therapy , Algorithms , COVID-19 , Computer Simulation , Humans , Internet , Pandemics , Protein Interaction Maps , SARS-CoV-2 , Virus Attachment/drug effects
10.
Mol Cell Proteomics ; 19(9): 1503-1522, 2020 09.
Article in English | MEDLINE | ID: covidwho-616588

ABSTRACT

As the COVID-19 pandemic continues to spread, thousands of scientists around the globe have changed research direction to understand better how the virus works and to find out how it may be tackled. The number of manuscripts on preprint servers is soaring and peer-reviewed publications using MS-based proteomics are beginning to emerge. To facilitate proteomic research on SARS-CoV-2, the virus that causes COVID-19, this report presents deep-scale proteomes (10,000 proteins; >130,000 peptides) of common cell line models, notably Vero E6, Calu-3, Caco-2, and ACE2-A549 that characterize their protein expression profiles including viral entry factors such as ACE2 or TMPRSS2. Using the 9 kDa protein SRP9 and the breast cancer oncogene BRCA1 as examples, we show how the proteome expression data can be used to refine the annotation of protein-coding regions of the African green monkey and the Vero cell line genomes. Monitoring changes of the proteome on viral infection revealed widespread expression changes including transcriptional regulators, protease inhibitors, and proteins involved in innate immunity. Based on a library of 98 stable-isotope labeled synthetic peptides representing 11 SARS-CoV-2 proteins, we developed PRM (parallel reaction monitoring) assays for nano-flow and micro-flow LC-MS/MS. We assessed the merits of these PRM assays using supernatants of virus-infected Vero E6 cells and challenged the assays by analyzing two diagnostic cohorts of 24 (+30) SARS-CoV-2 positive and 28 (+9) negative cases. In light of the results obtained and including recent publications or manuscripts on preprint servers, we critically discuss the merits of MS-based proteomics for SARS-CoV-2 research and testing.


Subject(s)
Betacoronavirus/genetics , Coronavirus Infections/genetics , Host-Pathogen Interactions/genetics , Pneumonia, Viral/genetics , Proteomics/methods , Viral Proteins/genetics , A549 Cells , Amino Acid Sequence , Angiotensin-Converting Enzyme 2 , Animals , BRCA1 Protein/genetics , BRCA1 Protein/metabolism , Betacoronavirus/pathogenicity , COVID-19 , Caco-2 Cells , Case-Control Studies , Chlorocebus aethiops , Coronavirus Infections/pathology , Coronavirus Infections/virology , Gene Expression Regulation , Gene Ontology , Humans , Indicators and Reagents , Molecular Sequence Annotation , Open Reading Frames , Pandemics , Peptidyl-Dipeptidase A/genetics , Peptidyl-Dipeptidase A/metabolism , Pneumonia, Viral/pathology , Pneumonia, Viral/virology , Proteomics/instrumentation , SARS-CoV-2 , Serine Endopeptidases/genetics , Serine Endopeptidases/metabolism , Signal Recognition Particle/genetics , Signal Recognition Particle/metabolism , Signal Transduction , Vero Cells , Viral Proteins/classification , Viral Proteins/metabolism , Virus Internalization
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