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1.
ACS Infect Dis ; 8(7): 1265-1279, 2022 Jul 08.
Article in English | MEDLINE | ID: covidwho-1908084

ABSTRACT

There is a pressing need for host-directed therapeutics that elicit broad-spectrum antiviral activities to potentially address current and future viral pandemics. Apratoxin S4 (Apra S4) is a potent Sec61 inhibitor that prevents cotranslational translocation of secretory proteins into the endoplasmic reticulum (ER), leading to anticancer and antiangiogenic activity both in vitro and in vivo. Since Sec61 has been shown to be an essential host factor for viral proteostasis, we tested Apra S4 in cellular models of viral infection, including SARS-CoV-2, influenza A virus, and flaviviruses (Zika, West Nile, and Dengue virus). Apra S4 inhibited viral replication in a concentration-dependent manner and had high potency particularly against SARS-CoV-2 and influenza A virus, with subnanomolar activity in human cells. Characterization studies focused on SARS-CoV-2 revealed that Apra S4 impacted a post-entry stage of the viral life-cycle. Transmission electron microscopy revealed that Apra S4 blocked formation of stacked double-membrane vesicles, the sites of viral replication. Apra S4 reduced dsRNA formation and prevented viral protein production and trafficking of secretory proteins, especially the spike protein. Given the potent and broad-spectrum activity of Apra S4, further preclinical evaluation of Apra S4 and other Sec61 inhibitors as antivirals is warranted.


Subject(s)
COVID-19 , Influenza A virus , Zika Virus Infection , Zika Virus , Antiviral Agents/pharmacology , Antiviral Agents/therapeutic use , COVID-19/drug therapy , Depsipeptides , Humans , Pandemics , SARS-CoV-2 , Zika Virus Infection/drug therapy
2.
iScience ; 25(5): 104311, 2022 May 20.
Article in English | MEDLINE | ID: covidwho-1804381

ABSTRACT

Novel strategies are needed to identify drug targets and treatments for the COVID-19 pandemic. The altered gene expression of virus-infected host cells provides an opportunity to specifically inhibit viral propagation via targeting the synthetic lethal and synthetic dosage lethal (SL/SDL) partners of such altered host genes. Pursuing this disparate antiviral strategy, here we comprehensively analyzed multiple in vitro and in vivo bulk and single-cell RNA-sequencing datasets of SARS-CoV-2 infection to predict clinically relevant candidate antiviral targets that are SL/SDL with altered host genes. The predicted SL/SDL-based targets are highly enriched for infected cell inhibiting genes reported in four SARS-CoV-2 CRISPR-Cas9 genome-wide genetic screens. We further selected a focused subset of 26 genes that we experimentally tested in a targeted siRNA screen using human Caco-2 cells. Notably, as predicted, knocking down these targets reduced viral replication and cell viability only under the infected condition without harming noninfected healthy cells.

3.
EuropePMC; 2020.
Preprint in English | EuropePMC | ID: ppcovidwho-324816

ABSTRACT

COVID-19 pandemic is the third zoonotic coronavirus (CoV) outbreak of the century after severe acute respiratory syndrome (SARS) in 2003 and Middle East respiratory syndrome (MERS) since 2012. Treatment options for CoVs are largely lacking. Here, we show that clofazimine, an anti-leprosy drug with a favorable safety and pharmacokinetics profile, possesses pan-coronaviral inhibitory activity, and can antagonize SARS-CoV-2 replication in multiple in vitro systems, including the human embryonic stem cell-derived cardiomyocytes and ex vivo lung cultures. The FDA-approved molecule was found to inhibit multiple steps of viral replication, suggesting multiple underlying antiviral mechanisms. In a hamster model of SARS-CoV-2 pathogenesis, prophylactic or therapeutic administration of clofazimine significantly reduced viral load in the lung and fecal viral shedding, and also prevented cytokine storm associated with viral infection. Additionally, clofazimine exhibited synergy when administered with remdesivir. Since clofazimine is orally bioavailable and has a comparatively low manufacturing cost, it is an attractive clinical candidate for outpatient treatment and remdesivir-based combinatorial therapy for hospitalized COVID-19 patients, particularly in developing countries. Taken together, our data provide evidence that clofazimine may have a role in the control of the current pandemic SARS-CoV-2, endemic MERS-CoV in the Middle East, and, possibly most importantly, emerging CoVs of the future.

4.
Mol Syst Biol ; 17(11): e10260, 2021 11.
Article in English | MEDLINE | ID: covidwho-1488874

ABSTRACT

Tremendous progress has been made to control the COVID-19 pandemic caused by the SARS-CoV-2 virus. However, effective therapeutic options are still rare. Drug repurposing and combination represent practical strategies to address this urgent unmet medical need. Viruses, including coronaviruses, are known to hijack host metabolism to facilitate viral proliferation, making targeting host metabolism a promising antiviral approach. Here, we describe an integrated analysis of 12 published in vitro and human patient gene expression datasets on SARS-CoV-2 infection using genome-scale metabolic modeling (GEM), revealing complicated host metabolism reprogramming during SARS-CoV-2 infection. We next applied the GEM-based metabolic transformation algorithm to predict anti-SARS-CoV-2 targets that counteract the virus-induced metabolic changes. We successfully validated these targets using published drug and genetic screen data and by performing an siRNA assay in Caco-2 cells. Further generating and analyzing RNA-sequencing data of remdesivir-treated Vero E6 cell samples, we predicted metabolic targets acting in combination with remdesivir, an approved anti-SARS-CoV-2 drug. Our study provides clinical data-supported candidate anti-SARS-CoV-2 targets for future evaluation, demonstrating host metabolism targeting as a promising antiviral strategy.


Subject(s)
Adenosine Monophosphate/analogs & derivatives , Alanine/analogs & derivatives , Antiviral Agents/therapeutic use , COVID-19/metabolism , Metabolic Networks and Pathways/genetics , Pandemics , SARS-CoV-2/physiology , Adenosine Monophosphate/therapeutic use , Alanine/therapeutic use , Animals , COVID-19/drug therapy , COVID-19/virology , Caco-2 Cells , Chlorocebus aethiops , Datasets as Topic , Drug Development , Drug Repositioning , Host-Pathogen Interactions , Humans , RNA, Small Interfering , Sequence Analysis, RNA , Vero Cells
5.
PMC; 2020.
Preprint in English | PMC | ID: ppcovidwho-290515

ABSTRACT

We show that SARS-CoV-2 spike protein interacts with cell surface heparan sulfate and angiotensin converting enzyme 2 (ACE2) through its Receptor Binding Domain. Docking studies suggest a putative heparin/heparan sulfate-binding site adjacent to the domain that binds to ACE2. In vitro, binding of ACE2 and heparin to spike protein ectodomains occurs independently and a ternary complex can be generated using heparin as a template. Contrary to studies with purified components, spike protein binding to heparan sulfate and ACE2 on cells occurs codependently. Unfractionated heparin, non-anticoagulant heparin, treatment with heparin lyases, and purified lung heparan sulfate potently block spike protein binding and infection by spike protein-pseudotyped virus and SARS-CoV-2 virus. These findings support a model for SARS-CoV-2 infection in which viral attachment and infection involves formation of a complex between heparan sulfate and ACE2. Manipulation of heparan sulfate or inhibition of viral adhesion by exogenous heparin may represent new therapeutic opportunities. ### Competing Interest Statement J.D.E. is a co-founder of TEGA Therapeutics. J.D.E. and The Regents of the University of California have licensed a University invention to and have an equity interest in TEGA Therapeutics. The terms of this arrangement have been reviewed and approved by the University of California, San Diego in accordance with its conflict of interest policies. C.A.G and B.E.T are employees of TEGA Therapeutics.

6.
Mol Cell ; 81(12): 2656-2668.e8, 2021 06 17.
Article in English | MEDLINE | ID: covidwho-1179919

ABSTRACT

A deficient interferon (IFN) response to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has been implicated as a determinant of severe coronavirus disease 2019 (COVID-19). To identify the molecular effectors that govern IFN control of SARS-CoV-2 infection, we conducted a large-scale gain-of-function analysis that evaluated the impact of human IFN-stimulated genes (ISGs) on viral replication. A limited subset of ISGs were found to control viral infection, including endosomal factors inhibiting viral entry, RNA binding proteins suppressing viral RNA synthesis, and a highly enriched cluster of endoplasmic reticulum (ER)/Golgi-resident ISGs inhibiting viral assembly/egress. These included broad-acting antiviral ISGs and eight ISGs that specifically inhibited SARS-CoV-2 and SARS-CoV-1 replication. Among the broad-acting ISGs was BST2/tetherin, which impeded viral release and is antagonized by SARS-CoV-2 Orf7a protein. Overall, these data illuminate a set of ISGs that underlie innate immune control of SARS-CoV-2/SARS-CoV-1 infection, which will facilitate the understanding of host determinants that impact disease severity and offer potential therapeutic strategies for COVID-19.


Subject(s)
Antigens, CD/genetics , Host-Pathogen Interactions/genetics , Interferon Regulatory Factors/genetics , Interferon Type I/genetics , SARS-CoV-2/genetics , Viral Proteins/genetics , Animals , Antigens, CD/chemistry , Antigens, CD/immunology , Binding Sites , Cell Line, Tumor , Chlorocebus aethiops , Endoplasmic Reticulum/genetics , Endoplasmic Reticulum/immunology , Endoplasmic Reticulum/virology , GPI-Linked Proteins/chemistry , GPI-Linked Proteins/genetics , GPI-Linked Proteins/immunology , Gene Expression Regulation , Golgi Apparatus/genetics , Golgi Apparatus/immunology , Golgi Apparatus/virology , HEK293 Cells , Host-Pathogen Interactions/immunology , Humans , Immunity, Innate , Interferon Regulatory Factors/classification , Interferon Regulatory Factors/immunology , Interferon Type I/immunology , Molecular Docking Simulation , Protein Binding , Protein Conformation, alpha-Helical , Protein Conformation, beta-Strand , Protein Interaction Domains and Motifs , SARS-CoV-2/immunology , Signal Transduction , Vero Cells , Viral Proteins/chemistry , Viral Proteins/immunology , Virus Internalization , Virus Release/genetics , Virus Release/immunology , Virus Replication/genetics , Virus Replication/immunology
7.
Nature ; 593(7859): 418-423, 2021 05.
Article in English | MEDLINE | ID: covidwho-1137788

ABSTRACT

The COVID-19 pandemic is the third outbreak this century of a zoonotic disease caused by a coronavirus, following the emergence of severe acute respiratory syndrome (SARS) in 20031 and Middle East respiratory syndrome (MERS) in 20122. Treatment options for coronaviruses are limited. Here we show that clofazimine-an anti-leprosy drug with a favourable safety profile3-possesses inhibitory activity against several coronaviruses, and can antagonize the replication of SARS-CoV-2 and MERS-CoV in a range of in vitro systems. We found that this molecule, which has been approved by the US Food and Drug Administration, inhibits cell fusion mediated by the viral spike glycoprotein, as well as activity of the viral helicase. Prophylactic or therapeutic administration of clofazimine in a hamster model of SARS-CoV-2 pathogenesis led to reduced viral loads in the lung and viral shedding in faeces, and also alleviated the inflammation associated with viral infection. Combinations of clofazimine and remdesivir exhibited antiviral synergy in vitro and in vivo, and restricted viral shedding from the upper respiratory tract. Clofazimine, which is orally bioavailable and comparatively cheap to manufacture, is an attractive clinical candidate for the treatment of outpatients and-when combined with remdesivir-in therapy for hospitalized patients with COVID-19, particularly in contexts in which costs are an important factor or specialized medical facilities are limited. Our data provide evidence that clofazimine may have a role in the control of the current pandemic of COVID-19 and-possibly more importantly-in dealing with coronavirus diseases that may emerge in the future.


Subject(s)
Antiviral Agents/pharmacology , Clofazimine/pharmacology , Coronavirus/classification , Coronavirus/drug effects , SARS-CoV-2/drug effects , Adenosine Monophosphate/analogs & derivatives , Adenosine Monophosphate/pharmacology , Adenosine Monophosphate/therapeutic use , Alanine/analogs & derivatives , Alanine/pharmacology , Alanine/therapeutic use , Animals , Anti-Inflammatory Agents/pharmacokinetics , Anti-Inflammatory Agents/pharmacology , Anti-Inflammatory Agents/therapeutic use , Antiviral Agents/pharmacokinetics , Antiviral Agents/therapeutic use , Biological Availability , Cell Fusion , Cell Line , Clofazimine/pharmacokinetics , Clofazimine/therapeutic use , Coronavirus/growth & development , Coronavirus/pathogenicity , Cricetinae , DNA Helicases/antagonists & inhibitors , Drug Synergism , Female , Humans , Life Cycle Stages/drug effects , Male , Mesocricetus , Pre-Exposure Prophylaxis , SARS-CoV-2/growth & development , Species Specificity , Spike Glycoprotein, Coronavirus/antagonists & inhibitors , Transcription, Genetic/drug effects , Transcription, Genetic/genetics
8.
Optik ; 235:166644, 2021.
Article in English | ScienceDirect | ID: covidwho-1117415

ABSTRACT

Deep-ultraviolet (DUV) light devices are receiving widely attention due to their potential use in sterilization and water purification, in particularly, during the COVID-19 pandemic. Photoluminescence detectors that demonstrate the existence of DUV light invisible to our eyes are of importance. Herein, we propose a process intensified approach via high-gravity reactive precipitation combined with hydrothermal synthesis for production of Mn2+ doped zinc orthogermanate (Zn2GeO4: Mn2+) nanophosphors for deep-ultraviolet detecting. The rotating packed bed (RPB) was used as the reactor for process intensification of the reactive precipitation and the whole processing time was significantly reduced. The Zn2GeO4: Mn2+ phosphors show green emission upon ultraviolet or near ultraviolet excitation. In optimized conditions, the products show a sub-microrod morphology with average size of about 200 nm. Under the excitation of 254 nm light, the Zn2GeO4: Mn2+ nanophosphors exhibit bright green emission at peak wavelength of 535 nm.

9.
Cell Rep ; 34(2): 108628, 2021 01 12.
Article in English | MEDLINE | ID: covidwho-1036973

ABSTRACT

Recent studies have profiled the innate immune signatures in patients infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and suggest that cellular responses to viral challenge may affect disease severity. Yet the molecular events that underlie cellular recognition and response to SARS-CoV-2 infection remain to be elucidated. Here, we find that SARS-CoV-2 replication induces a delayed interferon (IFN) response in lung epithelial cells. By screening 16 putative sensors involved in sensing of RNA virus infection, we found that MDA5 and LGP2 primarily regulate IFN induction in response to SARS-CoV-2 infection. Further analyses revealed that viral intermediates specifically activate the IFN response through MDA5-mediated sensing. Additionally, we find that IRF3, IRF5, and NF-κB/p65 are the key transcription factors regulating the IFN response during SARS-CoV-2 infection. In summary, these findings provide critical insights into the molecular basis of the innate immune recognition and signaling response to SARS-CoV-2.


Subject(s)
Immunity, Innate , Interferon-Induced Helicase, IFIH1/metabolism , SARS-CoV-2/physiology , COVID-19/pathology , COVID-19/virology , Cell Line , Epithelial Cells/cytology , Epithelial Cells/immunology , Epithelial Cells/virology , Humans , Induced Pluripotent Stem Cells/cytology , Interferon Regulatory Factor-3/genetics , Interferon Regulatory Factor-3/metabolism , Interferon Regulatory Factors/genetics , Interferon Regulatory Factors/metabolism , Interferons/genetics , Interferons/metabolism , RNA Helicases/metabolism , RNA Interference , RNA, Double-Stranded/metabolism , RNA, Small Interfering/metabolism , SARS-CoV-2/immunology , SARS-CoV-2/isolation & purification , Signal Transduction , Transcription Factor RelA/metabolism , Virus Replication
10.
SSRN; 2020.
Preprint | SSRN | ID: ppcovidwho-5301

ABSTRACT

Recent studies profiling the innate immune signatures in patients infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) suggest that cellular responses to viral challenge impact disease severity. Yet, the molecular events that underlie cellular recognition and response to SARS-CoV-2 infection remains to be elucidated. Here, we find that SARS-CoV-2 replication induces a delayed interferon (IFN) response in lung epithelial cells. Through a survey of putative sensors involved in detection of RNA virus infection, we found that MDA5 and LGP2 primarily regulate IFN induction in response to SARS-CoV-2 infection. Additionally, we find that IRF-3, -5, and NF-kB/p65 are the key transcription factors regulating the IFN response during SARS-CoV-2 infection. In summary, these findings provide critical insights into the molecular basis of the innate immune recognition and signaling response to SARS-CoV-2. Funding: This work was supported by the following grants to the Sanford Burnham Prebys Medical Discovery Institute: DoD: W81XWH-20-1-0270;DHIPC: U19 AI118610;Fluomics/NOSI: U19 AI135972, as well as generous philanthropic donations from Dinah Ruch and Susan & James Blair. This work was additionally supported by the following grants to Northwestern University Feinberg School of Medicine: a CTSA supplement to NCATS: UL1 TR002389;a CTSA supplement to NUCATS with the generous support of the Dixon family: UL1 TR001422;and a Cancer Center supplement: P30 CA060553. Development and implementation of iPS cell technology for production of airway epithelial cells was supported by Incubation Program from Office of Society Academia Collaboration for Innovation, Kyoto University.

11.
Res Sq ; 2020 Oct 07.
Article in English | MEDLINE | ID: covidwho-869425

ABSTRACT

COVID-19 pandemic is the third zoonotic coronavirus (CoV) outbreak of the century after severe acute respiratory syndrome (SARS) in 2003 and Middle East respiratory syndrome (MERS) since 2012. Treatment options for CoVs are largely lacking. Here, we show that clofazimine, an anti-leprosy drug with a favorable safety and pharmacokinetics profile, possesses pan-coronaviral inhibitory activity, and can antagonize SARS-CoV-2 replication in multiple in vitro systems, including the human embryonic stem cell-derived cardiomyocytes and ex vivo lung cultures. The FDA-approved molecule was found to inhibit multiple steps of viral replication, suggesting multiple underlying antiviral mechanisms. In a hamster model of SARS-CoV-2 pathogenesis, prophylactic or therapeutic administration of clofazimine significantly reduced viral load in the lung and fecal viral shedding, and also prevented cytokine storm associated with viral infection. Additionally, clofazimine exhibited synergy when administered with remdesivir. Since clofazimine is orally bioavailable and has a comparatively low manufacturing cost, it is an attractive clinical candidate for outpatient treatment and remdesivir-based combinatorial therapy for hospitalized COVID-19 patients, particularly in developing countries. Taken together, our data provide evidence that clofazimine may have a role in the control of the current pandemic SARS-CoV-2, endemic MERS-CoV in the Middle East, and, possibly most importantly, emerging CoVs of the future.

13.
Cell ; 183(4): 1043-1057.e15, 2020 11 12.
Article in English | MEDLINE | ID: covidwho-756808

ABSTRACT

We show that SARS-CoV-2 spike protein interacts with both cellular heparan sulfate and angiotensin-converting enzyme 2 (ACE2) through its receptor-binding domain (RBD). Docking studies suggest a heparin/heparan sulfate-binding site adjacent to the ACE2-binding site. Both ACE2 and heparin can bind independently to spike protein in vitro, and a ternary complex can be generated using heparin as a scaffold. Electron micrographs of spike protein suggests that heparin enhances the open conformation of the RBD that binds ACE2. On cells, spike protein binding depends on both heparan sulfate and ACE2. Unfractionated heparin, non-anticoagulant heparin, heparin lyases, and lung heparan sulfate potently block spike protein binding and/or infection by pseudotyped virus and authentic SARS-CoV-2 virus. We suggest a model in which viral attachment and infection involves heparan sulfate-dependent enhancement of binding to ACE2. Manipulation of heparan sulfate or inhibition of viral adhesion by exogenous heparin presents new therapeutic opportunities.


Subject(s)
Betacoronavirus/physiology , Heparitin Sulfate/metabolism , Peptidyl-Dipeptidase A/metabolism , Spike Glycoprotein, Coronavirus/metabolism , Amino Acid Sequence , Angiotensin-Converting Enzyme 2 , Betacoronavirus/isolation & purification , Binding Sites , COVID-19 , Cell Line , Coronavirus Infections/pathology , Coronavirus Infections/virology , Heparin/chemistry , Heparin/metabolism , Heparitin Sulfate/chemistry , Humans , Kidney/metabolism , Lung/metabolism , Molecular Dynamics Simulation , Pandemics , Peptidyl-Dipeptidase A/chemistry , Pneumonia, Viral/pathology , Pneumonia, Viral/virology , Protein Binding , Protein Domains , Recombinant Proteins/biosynthesis , Recombinant Proteins/chemistry , Recombinant Proteins/isolation & purification , SARS-CoV-2 , Spike Glycoprotein, Coronavirus/chemistry , Spike Glycoprotein, Coronavirus/genetics , Virus Internalization
14.
Nature ; 586(7827): 113-119, 2020 10.
Article in English | MEDLINE | ID: covidwho-672174

ABSTRACT

The emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in 2019 has triggered an ongoing global pandemic of the severe pneumonia-like disease coronavirus disease 2019 (COVID-19)1. The development of a vaccine is likely to take at least 12-18 months, and the typical timeline for approval of a new antiviral therapeutic agent can exceed 10 years. Thus, repurposing of known drugs could substantially accelerate the deployment of new therapies for COVID-19. Here we profiled a library of drugs encompassing approximately 12,000 clinical-stage or Food and Drug Administration (FDA)-approved small molecules to identify candidate therapeutic drugs for COVID-19. We report the identification of 100 molecules that inhibit viral replication of SARS-CoV-2, including 21 drugs that exhibit dose-response relationships. Of these, thirteen were found to harbour effective concentrations commensurate with probable achievable therapeutic doses in patients, including the PIKfyve kinase inhibitor apilimod2-4 and the cysteine protease inhibitors MDL-28170, Z LVG CHN2, VBY-825 and ONO 5334. Notably, MDL-28170, ONO 5334 and apilimod were found to antagonize viral replication in human pneumocyte-like cells derived from induced pluripotent stem cells, and apilimod also demonstrated antiviral efficacy in a primary human lung explant model. Since most of the molecules identified in this study have already advanced into the clinic, their known pharmacological and human safety profiles will enable accelerated preclinical and clinical evaluation of these drugs for the treatment of COVID-19.


Subject(s)
Antiviral Agents/analysis , Antiviral Agents/pharmacology , Betacoronavirus/drug effects , Coronavirus Infections/drug therapy , Coronavirus Infections/virology , Drug Evaluation, Preclinical , Drug Repositioning , Pneumonia, Viral/drug therapy , Pneumonia, Viral/virology , Adenosine Monophosphate/analogs & derivatives , Adenosine Monophosphate/pharmacology , Alanine/analogs & derivatives , Alanine/pharmacology , Alveolar Epithelial Cells/cytology , Alveolar Epithelial Cells/drug effects , Betacoronavirus/growth & development , COVID-19 , Cell Line , Cysteine Proteinase Inhibitors/analysis , Cysteine Proteinase Inhibitors/pharmacology , Dose-Response Relationship, Drug , Drug Synergism , Gene Expression Regulation/drug effects , Humans , Hydrazones , Induced Pluripotent Stem Cells/cytology , Models, Biological , Morpholines/analysis , Morpholines/pharmacology , Pandemics , Pyrimidines , Reproducibility of Results , SARS-CoV-2 , Small Molecule Libraries/analysis , Small Molecule Libraries/pharmacology , Triazines/analysis , Triazines/pharmacology , Virus Internalization/drug effects , Virus Replication/drug effects
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