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1.
Int J Mol Sci ; 23(6)2022 Mar 10.
Article in English | MEDLINE | ID: covidwho-1742485

ABSTRACT

The B and T lymphocytes of the adaptive immune system are important for the control of most viral infections, including COVID-19. Identification of epitopes recognized by these cells is fundamental for understanding how the immune system detects and removes pathogens, and for antiviral vaccine design. Intriguingly, several cross-reactive T lymphocyte epitopes from SARS-CoV-2 with other betacoronaviruses responsible for the common cold have been identified. In addition, antibodies that cross-recognize the spike protein, but not the nucleoprotein (N protein), from different betacoronavirus have also been reported. Using a consensus of eight bioinformatic methods for predicting B-cell epitopes and the collection of experimentally detected epitopes for SARS-CoV and SARS-CoV-2, we identified four surface-exposed, conserved, and hypothetical antigenic regions that are exclusive of the N protein. These regions were analyzed using ELISA assays with two cohorts: SARS-CoV-2 infected patients and pre-COVID-19 samples. Here we describe four epitopes from SARS-CoV-2 N protein that are recognized by the humoral response from multiple individuals infected with COVID-19, and are conserved in other human coronaviruses. Three of these linear surface-exposed sequences and their peptide homologs in SARS-CoV-2 and HCoV-OC43 were also recognized by antibodies from pre-COVID-19 serum samples, indicating cross-reactivity of antibodies against coronavirus N proteins. Different conserved human coronaviruses (HCoVs) cross-reactive B epitopes against SARS-CoV-2 N protein are detected in a significant fraction of individuals not exposed to this pandemic virus. These results have potential clinical implications.


Subject(s)
Coronavirus Nucleocapsid Proteins/immunology , Coronavirus OC43, Human/immunology , Cross Reactions/immunology , Epitope Mapping/methods , Epitopes, B-Lymphocyte/immunology , SARS-CoV-2/immunology , Adult , Amino Acid Sequence , COVID-19/immunology , COVID-19/virology , Cohort Studies , Coronavirus Nucleocapsid Proteins/chemistry , Coronavirus Nucleocapsid Proteins/genetics , Coronavirus OC43, Human/genetics , Coronavirus OC43, Human/physiology , Cross Reactions/genetics , Enzyme-Linked Immunosorbent Assay/methods , Epitopes, B-Lymphocyte/metabolism , HEK293 Cells , Health Personnel/statistics & numerical data , Humans , Protein Domains , SARS-CoV-2/genetics , SARS-CoV-2/physiology , Sequence Homology, Amino Acid , Spike Glycoprotein, Coronavirus/genetics , Spike Glycoprotein, Coronavirus/immunology
2.
Viruses ; 13(12)2021 12 17.
Article in English | MEDLINE | ID: covidwho-1580427

ABSTRACT

The COVID-19 pandemic has resulted in a huge number of deaths from 2020 to 2021; however, effective antiviral drugs against SARS-CoV-2 are currently under development. Recent studies have demonstrated that green tea polyphenols, particularly EGCG, inhibit coronavirus enzymes as well as coronavirus replication in vitro. Herein, we examined the inhibitory effect of green tea polyphenols on coronavirus replication in a mouse model. We used epigallocatechin gallate (EGCG) and green tea polyphenols containing more than 60% catechin (GTP60) and human coronavirus OC43 (HCoV-OC43) as a surrogate for SARS-CoV-2. Scanning electron microscopy analysis results showed that HCoV-OC43 infection resulted in virion particle production in infected cells. EGCG and GTP60 treatment reduced coronavirus protein and virus production in the cells. Finally, EGCG- and GTP60-fed mice exhibited reduced levels of coronavirus RNA in mouse lungs. These results demonstrate that green tea polyphenol treatment is effective in decreasing the level of coronavirus in vivo.


Subject(s)
Antiviral Agents/pharmacology , Catechin/analogs & derivatives , Coronavirus Infections/drug therapy , Polyphenols/pharmacology , Tea/chemistry , Virus Replication/drug effects , Animals , Antiviral Agents/chemistry , Antiviral Agents/therapeutic use , Catechin/pharmacology , Catechin/therapeutic use , Cell Line , Coronavirus Infections/virology , Coronavirus OC43, Human/drug effects , Coronavirus OC43, Human/physiology , Disease Models, Animal , Humans , Mice , Polyphenols/chemistry , Polyphenols/therapeutic use
3.
Cells ; 10(11)2021 10 29.
Article in English | MEDLINE | ID: covidwho-1488496

ABSTRACT

Human coronavirus (HCoV) similar to other viruses rely on host cell machinery for both replication and to spread. The p97/VCP ATPase is associated with diverse pathways that may favor HCoV replication. In this study, we assessed the role of p97 and associated host responses in human lung cell line H1299 after HCoV-229E or HCoV-OC43 infection. Inhibition of p97 function by small molecule inhibitors shows antiviral activity, particularly at early stages of the virus life cycle, during virus uncoating and viral RNA replication. Importantly, p97 activity inhibition protects human cells against HCoV-induced cytopathic effects. The p97 knockdown also inhibits viral production in infected cells. Unbiased quantitative proteomics analyses reveal that HCoV-OC43 infection resulted in proteome changes enriched in cellular senescence and DNA repair during virus replication. Further analysis of protein changes between infected cells with control and p97 shRNA identifies cell cycle pathways for both HCoV-229E and HCoV-OC43 infection. Together, our data indicate a role for the essential host protein p97 in supporting HCoV replication, suggesting that p97 is a therapeutic target to treat HCoV infection.


Subject(s)
Coronavirus 229E, Human/physiology , Coronavirus OC43, Human/physiology , Valosin Containing Protein/metabolism , Virus Replication/physiology , Antiviral Agents/pharmacology , Cell Cycle/drug effects , Cell Line , Coronavirus 229E, Human/drug effects , Coronavirus OC43, Human/drug effects , Cytopathogenic Effect, Viral/drug effects , Humans , Proteome/drug effects , Proteome/metabolism , RNA, Small Interfering/genetics , RNA, Viral/biosynthesis , Valosin Containing Protein/antagonists & inhibitors , Valosin Containing Protein/genetics , Virus Replication/drug effects , Virus Uncoating/drug effects
4.
Sci Rep ; 11(1): 19930, 2021 10 07.
Article in English | MEDLINE | ID: covidwho-1462026

ABSTRACT

Transmission of SARS-CoV-2 by aerosols has played a significant role in the rapid spread of COVID-19 across the globe. Indoor environments with inadequate ventilation pose a serious infection risk. Whilst vaccines suppress transmission, they are not 100% effective and the risk from variants and new viruses always remains. Consequently, many efforts have focused on ways to disinfect air. One such method involves use of minimally hazardous 222 nm far-UVC light. Whilst a small number of controlled experimental studies have been conducted, determining the efficacy of this approach is difficult because chamber or room geometry, and the air flow within them, influences both far-UVC illumination and aerosol dwell times. Fortunately, computational multiphysics modelling allows the inadequacy of dose-averaged assessment of viral inactivation to be overcome in these complex situations. This article presents the first validation of the WYVERN radiation-CFD code for far-UVC air-disinfection against survival fraction measurements, and the first measurement-informed modelling approach to estimating far-UVC susceptibility of viruses in air. As well as demonstrating the reliability of the code, at circa 70% higher, our findings indicate that aerosolized human coronaviruses are significantly more susceptible to far-UVC than previously thought.


Subject(s)
Coronavirus 229E, Human/radiation effects , Coronavirus Infections/prevention & control , Coronavirus OC43, Human/radiation effects , Disinfection/methods , Ultraviolet Rays , Virus Inactivation/radiation effects , Aerosols/isolation & purification , Air Microbiology , COVID-19/prevention & control , Computer Simulation , Coronavirus 229E, Human/isolation & purification , Coronavirus 229E, Human/physiology , Coronavirus OC43, Human/isolation & purification , Coronavirus OC43, Human/physiology , Disinfection/instrumentation , Equipment Design , Humans , Models, Biological
5.
Virology ; 564: 33-38, 2021 12.
Article in English | MEDLINE | ID: covidwho-1447220

ABSTRACT

Endemic seasonal coronaviruses cause morbidity and mortality in a subset of patients, but no specific treatment is available. Molnupiravir is a promising pipeline antiviral drug for treating SARS-CoV-2 infection potentially by targeting RNA-dependent RNA polymerase (RdRp). This study aims to evaluate the potential of repurposing molnupiravir for treating seasonal human coronavirus (HCoV) infections. Molecular docking revealed that the active form of molnupiravir, ß-D-N4-hydroxycytidine (NHC), has similar binding affinity to RdRp of SARS-CoV-2 and seasonal HCoV-NL63, HCoV-OC43 and HCoV-229E. In cell culture models, treatment of molnupiravir effectively inhibited viral replication and production of infectious viruses of the three seasonal coronaviruses. A time-of-drug-addition experiment indicates the specificity of molnupiravir in inhibiting viral components. Furthermore, combining molnupiravir with the protease inhibitor GC376 resulted in enhanced antiviral activity. Our findings highlight that the great potential of repurposing molnupiravir for treating seasonal coronavirus infected patients.


Subject(s)
Coronavirus 229E, Human/genetics , Coronavirus Infections/drug therapy , Coronavirus NL63, Human/genetics , Coronavirus OC43, Human/genetics , Cytidine/analogs & derivatives , Hydroxylamines/pharmacology , Antiviral Agents/chemistry , Antiviral Agents/metabolism , Antiviral Agents/pharmacology , Common Cold/drug therapy , Coronavirus 229E, Human/drug effects , Coronavirus 229E, Human/physiology , Coronavirus NL63, Human/drug effects , Coronavirus NL63, Human/physiology , Coronavirus OC43, Human/drug effects , Coronavirus OC43, Human/physiology , Cytidine/pharmacology , Humans , Molecular Docking Simulation , Protein Binding/drug effects , Pyrrolidines/pharmacology , RNA-Dependent RNA Polymerase/chemistry , RNA-Dependent RNA Polymerase/genetics , RNA-Dependent RNA Polymerase/metabolism , Seasons , Sulfonic Acids/pharmacology , Virus Replication/drug effects , Virus Replication/genetics
6.
Viruses ; 13(8)2021 08 23.
Article in English | MEDLINE | ID: covidwho-1367925

ABSTRACT

An escalating pandemic of the novel SARS-CoV-2 virus is impacting global health, and effective antivirals are needed. Umifenovir (Arbidol) is an indole-derivative molecule, licensed in Russia and China for prophylaxis and treatment of influenza and other respiratory viral infections. It has been shown that umifenovir has broad spectrum activity against different viruses. We evaluated the sensitivity of different coronaviruses, including the novel SARS-CoV-2 virus, to umifenovir using in vitro assays. Using a plaque assay, we revealed an antiviral effect of umifenovir against seasonal HCoV-229E and HCoV-OC43 coronaviruses in Vero E6 cells, with estimated 50% effective concentrations (EC50) of 10.0 ± 0.5 µM and 9.0 ± 0.4 µM, respectively. Umifenovir at 90 µM significantly suppressed plaque formation in CMK-AH-1 cells infected with SARS-CoV. Umifenovir also inhibited the replication of SARS-CoV-2 virus, with EC50 values ranging from 15.37 ± 3.6 to 28.0 ± 1.0 µM. In addition, 21-36 µM of umifenovir significantly suppressed SARS-CoV-2 virus titers (≥2 log TCID50/mL) in the first 24 h after infection. Repurposing of antiviral drugs is very helpful in fighting COVID-19. A safe, pan-antiviral drug such as umifenovir could be extremely beneficial in combating the early stages of a viral pandemic.


Subject(s)
Antiviral Agents/pharmacology , Coronavirus 229E, Human/drug effects , Coronavirus OC43, Human/drug effects , Indoles/pharmacology , SARS Virus/drug effects , SARS-CoV-2/drug effects , Animals , Antiviral Agents/administration & dosage , Cell Survival/drug effects , Chlorocebus aethiops , Coronavirus 229E, Human/physiology , Coronavirus OC43, Human/physiology , Cytopathogenic Effect, Viral/drug effects , Humans , Indoles/administration & dosage , Microbial Sensitivity Tests , SARS Virus/physiology , SARS-CoV-2/physiology , Vero Cells , Viral Load/drug effects , Viral Plaque Assay , Virus Replication/drug effects
7.
J Photochem Photobiol B ; 222: 112282, 2021 Sep.
Article in English | MEDLINE | ID: covidwho-1347724

ABSTRACT

Emerging evidence suggests that blue light has the potential to inactivate viruses. Therefore, we investigated the effect of 405 nm, 410 nm, 425 nm and 450 nm pulsed blue light (PBL) on human alpha coronavirus HCoV-229 E and human beta coronavirus HCoV-OC43, using Qubit fluorometry and RT-LAMP to quantitate the amount of nucleic acid in irradiated and control samples. Like SARS-CoV-2, HCoV-229E and HCoV-OC43 are single stranded RNA viruses transmitted by air and direct contact; they have similar genomic sizes as SARS-CoV-2, and are used as surrogates for SARS-CoV-2. Irradiation was carried out either at 32.4 J cm-2 using 3 mW cm-2 irradiance or at 130 J cm-2 using 12 mW cm-2 irradiance. Results: (1) At each wavelength tested, PBL was antiviral against both coronaviruses. (2) 405 nm light gave the best result, yielding 52.3% (2.37 log10) inactivation against HCoV-OC43 (p < .0001), and a significant 1.46 log 10 (44%) inactivation of HCoV-229E (p < .01). HCoV-OC43, which like SARS-CoV-2 is a beta coronavirus, was more susceptible to PBL irradiation than alpha coronavirus HCoV-229E. The latter finding suggests that PBL is potentially antiviral against multiple coronavirus strains, and that, while its potency may vary from one virus to another, it seems more antiviral against beta coronaviruses, such as HCoV-OC43. (3) Further, the antiviral effect of PBL was better at a higher irradiance than a lower irradiance, and this indicates that with further refinement, a protocol capable of yielding 100% inactivation of viruses is attainable.


Subject(s)
Coronavirus 229E, Human/radiation effects , Coronavirus OC43, Human/radiation effects , Low-Level Light Therapy/methods , SARS-CoV-2/radiation effects , Coronavirus 229E, Human/physiology , Coronavirus OC43, Human/physiology , Dose-Response Relationship, Radiation , Humans , SARS-CoV-2/physiology
8.
Viruses ; 13(8)2021 08 10.
Article in English | MEDLINE | ID: covidwho-1348697

ABSTRACT

The novel coronavirus SARS-CoV-2 is the seventh identified human coronavirus. Understanding the extent of pre-existing immunity induced by seropositivity to endemic seasonal coronaviruses and the impact of cross-reactivity on COVID-19 disease progression remains a key research question in immunity to SARS-CoV-2 and the immunopathology of COVID-2019 disease. This paper describes a panel of lentiviral pseudotypes bearing the spike (S) proteins for each of the seven human coronaviruses (HCoVs), generated under similar conditions optimized for high titre production allowing a high-throughput investigation of antibody neutralization breadth. Optimal production conditions and most readily available permissive target cell lines were determined for spike-mediated entry by each HCoV pseudotype: SARS-CoV-1, SARS-CoV-2 and HCoV-NL63 best transduced HEK293T/17 cells transfected with ACE2 and TMPRSS2, HCoV-229E and MERS-CoV preferentially entered HUH7 cells, and CHO cells were most permissive for the seasonal betacoronavirus HCoV-HKU1. Entry of ACE2 using pseudotypes was enhanced by ACE2 and TMPRSS2 expression in target cells, whilst TMPRSS2 transfection rendered HEK293T/17 cells permissive for HCoV-HKU1 and HCoV-OC43 entry. Additionally, pseudotype viruses were produced bearing additional coronavirus surface proteins, including the SARS-CoV-2 Envelope (E) and Membrane (M) proteins and HCoV-OC43/HCoV-HKU1 Haemagglutinin-Esterase (HE) proteins. This panel of lentiviral pseudotypes provides a safe, rapidly quantifiable and high-throughput tool for serological comparison of pan-coronavirus neutralizing responses; this can be used to elucidate antibody dynamics against individual coronaviruses and the effects of antibody cross-reactivity on clinical outcome following natural infection or vaccination.


Subject(s)
Antibodies, Viral/immunology , Broadly Neutralizing Antibodies/immunology , COVID-19/immunology , Coronavirus/immunology , SARS-CoV-2/immunology , Spike Glycoprotein, Coronavirus/immunology , Animals , Antibodies, Viral/blood , Broadly Neutralizing Antibodies/blood , Cell Line , Coronavirus 229E, Human/immunology , Coronavirus 229E, Human/physiology , Coronavirus NL63, Human/immunology , Coronavirus NL63, Human/physiology , Coronavirus OC43, Human/immunology , Coronavirus OC43, Human/physiology , Cross Reactions , Humans , Lentivirus/genetics , Middle East Respiratory Syndrome Coronavirus/immunology , Middle East Respiratory Syndrome Coronavirus/physiology , Neutralization Tests , Plasmids , SARS-CoV-2/physiology , Transfection , Virus Internalization
9.
Genes Dev ; 35(13-14): 1005-1019, 2021 07 01.
Article in English | MEDLINE | ID: covidwho-1334329

ABSTRACT

N6-methyladenosine (m6A) is an abundant internal RNA modification, influencing transcript fate and function in uninfected and virus-infected cells. Installation of m6A by the nuclear RNA methyltransferase METTL3 occurs cotranscriptionally; however, the genomes of some cytoplasmic RNA viruses are also m6A-modified. How the cellular m6A modification machinery impacts coronavirus replication, which occurs exclusively in the cytoplasm, is unknown. Here we show that replication of SARS-CoV-2, the agent responsible for the COVID-19 pandemic, and a seasonal human ß-coronavirus HCoV-OC43, can be suppressed by depletion of METTL3 or cytoplasmic m6A reader proteins YTHDF1 and YTHDF3 and by a highly specific small molecule METTL3 inhibitor. Reduction of infectious titer correlates with decreased synthesis of viral RNAs and the essential nucleocapsid (N) protein. Sites of m6A modification on genomic and subgenomic RNAs of both viruses were mapped by methylated RNA immunoprecipitation sequencing (meRIP-seq). Levels of host factors involved in m6A installation, removal, and recognition were unchanged by HCoV-OC43 infection; however, nuclear localization of METTL3 and cytoplasmic m6A readers YTHDF1 and YTHDF2 increased. This establishes that coronavirus RNAs are m6A-modified and host m6A pathway components control ß-coronavirus replication. Moreover, it illustrates the therapeutic potential of targeting the m6A pathway to restrict coronavirus reproduction.


Subject(s)
Coronavirus OC43, Human/physiology , RNA Processing, Post-Transcriptional/genetics , SARS-CoV-2/physiology , Virus Replication/genetics , Adenosine/analogs & derivatives , Adenosine/genetics , Adenosine/metabolism , Cell Line , Coronavirus Infections/metabolism , Coronavirus Infections/virology , Gene Expression Regulation/drug effects , Host-Pathogen Interactions/drug effects , Humans , Methyltransferases/antagonists & inhibitors , Methyltransferases/metabolism , Nucleocapsid Proteins , RNA, Viral/metabolism , RNA-Binding Proteins/metabolism , Virus Replication/drug effects
10.
Science ; 373(6557): 931-936, 2021 08 20.
Article in English | MEDLINE | ID: covidwho-1319369

ABSTRACT

There is an urgent need for antiviral agents that treat severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. We screened a library of 1900 clinically safe drugs against OC43, a human beta coronavirus that causes the common cold, and evaluated the top hits against SARS-CoV-2. Twenty drugs significantly inhibited replication of both viruses in cultured human cells. Eight of these drugs inhibited the activity of the SARS-CoV-2 main protease, 3CLpro, with the most potent being masitinib, an orally bioavailable tyrosine kinase inhibitor. X-ray crystallography and biochemistry show that masitinib acts as a competitive inhibitor of 3CLpro. Mice infected with SARS-CoV-2 and then treated with masitinib showed >200-fold reduction in viral titers in the lungs and nose, as well as reduced lung inflammation. Masitinib was also effective in vitro against all tested variants of concern (B.1.1.7, B.1.351, and P.1).


Subject(s)
Antiviral Agents/pharmacology , COVID-19/drug therapy , Coronavirus 3C Proteases/antagonists & inhibitors , Coronavirus OC43, Human/drug effects , Cysteine Proteinase Inhibitors/pharmacology , SARS-CoV-2/drug effects , Thiazoles/pharmacology , A549 Cells , Animals , Antiviral Agents/chemistry , Antiviral Agents/metabolism , Antiviral Agents/therapeutic use , Benzamides , COVID-19/virology , Catalytic Domain , Coronavirus 3C Proteases/chemistry , Coronavirus 3C Proteases/metabolism , Coronavirus OC43, Human/physiology , Cysteine Proteinase Inhibitors/chemistry , Cysteine Proteinase Inhibitors/metabolism , HEK293 Cells , Humans , Inhibitory Concentration 50 , Mice , Mice, Transgenic , Microbial Sensitivity Tests , Piperidines , Pyridines , SARS-CoV-2/enzymology , SARS-CoV-2/physiology , Thiazoles/chemistry , Thiazoles/metabolism , Thiazoles/therapeutic use , Viral Load/drug effects , Virus Replication/drug effects
11.
mSphere ; 6(3)2021 05 12.
Article in English | MEDLINE | ID: covidwho-1230164

ABSTRACT

Human coronavirus (HCoV)-OC43 rarely shows a cytopathic effect (CPE) after infection of various cell lines, and the indirect immunoperoxidase assay (IPA), a relatively complex procedure, has long been used as an alternative assay. Because HCoV-OC43 uses cell-surface transmembrane protease serine 2 (TMPRSS2) for cell entry, VeroE6 cells expressing TMPRSS2 may show a clear CPE after HCoV-OC43 infection. The aim of this study was to construct a 50% tissue culture infectious dose (TCID50) assay for HCoV-OC43 based on CPE evaluation using VeroE6/TMPRSS2 cells. VeroE6/TMPRSS2 cells showed clear CPEs 3 to 4 days after low-titer HCoV-OC43 infection. Evaluation of viral kinetics indicated that the viral titer in the culture supernatant of VeroE6/TMPRSS2 cells in the early stages of infection was higher than that of other cells. In comparison, between the CPE-based and the IPA-based (i.e., the reference titer) methods, the titer measured with CPE evaluation 4 to 5 days after infection using VeroE6/TMPRSS2 cells showed a much smaller difference from the reference titer than that measured using other cells. Thus, the TCID50 assay using CPE evaluation with VeroE6/TMPRSS2 cells provides the correct titer value and will greatly contribute to future research on HCoV-OC43.IMPORTANCE HCoV-OC43 rarely shows a cytopathic effect (CPE) in infected cell lines, and thus the plaque and TCID50 assays by CPE observation are not applicable for titration; the indirect immunoperoxidase assay (IPA) is used instead. However, the IPA is relatively complex, time-consuming, costly, and not suitable for simultaneous titration of many samples. We developed a TCID50 assay using CPE evaluation with TMPRSS2-expressing VeroE6/TMPRSS2 cells that provides the same accuracy as the conventional IPA-based viral titration and does not require any staining procedures using antibodies or substrates. This titration method will greatly contribute to future research on HCoV-OC43 by allowing simple, low-cost, and accurate titration of this virus.


Subject(s)
Coronavirus OC43, Human/physiology , Cytopathogenic Effect, Viral , Receptors, Virus/metabolism , Serine Endopeptidases/metabolism , Viral Load/methods , Animals , Cell Line, Tumor , Chlorocebus aethiops , Coronavirus OC43, Human/isolation & purification , Humans , Immunoenzyme Techniques , Receptors, Virus/genetics , Recombinant Proteins/genetics , Recombinant Proteins/metabolism , Serine Endopeptidases/genetics , Vero Cells/virology , Virus Cultivation , Virus Internalization , Virus Replication
12.
Biochem Biophys Res Commun ; 547: 23-28, 2021 04 02.
Article in English | MEDLINE | ID: covidwho-1077785

ABSTRACT

COVID-19 pandemic results in record high deaths in many countries. Although a vaccine for SARS-CoV-2 is now available, effective antiviral drugs to treat coronavirus diseases are not available yet. Recently, EGCG, a green tea polyphenol, was reported to inhibit SARS-CoV-2 3CL-protease, however the effect of EGCG on coronavirus replication is unknown. In this report, human coronavirus HCoV-OC43 (beta coronavirus) and HCoV-229E (alpha coronavirus) were used to examine the effect of EGCG on coronavirus. EGCG treatment decreases 3CL-protease activity of HCoV-OC43 and HCoV-229E. Moreover, EGCG treatment decreased HCoV-OC43-induced cytotoxicity. Finally, we found that EGCG treatment decreased the levels of coronavirus RNA and protein in infected cell media. These results indicate that EGCG inhibits coronavirus replication.


Subject(s)
Coronavirus 229E, Human/drug effects , Coronavirus OC43, Human/drug effects , Polyphenols/pharmacology , Tea/chemistry , Virus Replication/drug effects , Amino Acid Sequence , Cell Line, Tumor , Coronavirus 229E, Human/physiology , Coronavirus 3C Proteases/antagonists & inhibitors , Coronavirus OC43, Human/physiology , Humans , SARS-CoV-2/drug effects , SARS-CoV-2/physiology
13.
Cell ; 184(1): 120-132.e14, 2021 01 07.
Article in English | MEDLINE | ID: covidwho-1064914

ABSTRACT

The coronavirus disease 2019 (COVID-19) pandemic has claimed the lives of over one million people worldwide. The causative agent, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is a member of the Coronaviridae family of viruses that can cause respiratory infections of varying severity. The cellular host factors and pathways co-opted during SARS-CoV-2 and related coronavirus life cycles remain ill defined. To address this gap, we performed genome-scale CRISPR knockout screens during infection by SARS-CoV-2 and three seasonal coronaviruses (HCoV-OC43, HCoV-NL63, and HCoV-229E). These screens uncovered host factors and pathways with pan-coronavirus and virus-specific functional roles, including major dependency on glycosaminoglycan biosynthesis, sterol regulatory element-binding protein (SREBP) signaling, bone morphogenetic protein (BMP) signaling, and glycosylphosphatidylinositol biosynthesis, as well as a requirement for several poorly characterized proteins. We identified an absolute requirement for the VMP1, TMEM41, and TMEM64 (VTT) domain-containing protein transmembrane protein 41B (TMEM41B) for infection by SARS-CoV-2 and three seasonal coronaviruses. This human coronavirus host factor compendium represents a rich resource to develop new therapeutic strategies for acute COVID-19 and potential future coronavirus pandemics.


Subject(s)
Coronavirus Infections/genetics , Genome-Wide Association Study , SARS-CoV-2/physiology , A549 Cells , Cell Line , Clustered Regularly Interspaced Short Palindromic Repeats , Coronavirus 229E, Human/physiology , Coronavirus Infections/virology , Coronavirus NL63, Human/physiology , Coronavirus OC43, Human/physiology , Gene Knockout Techniques , HEK293 Cells , Host-Pathogen Interactions/drug effects , Humans , Membrane Proteins/metabolism , Metabolic Networks and Pathways/drug effects , Protein Interaction Mapping
14.
Viruses ; 13(2)2021 02 03.
Article in English | MEDLINE | ID: covidwho-1060766

ABSTRACT

The long-term control strategy of SARS-CoV-2 and other major respiratory viruses needs to include antivirals to treat acute infections, in addition to the judicious use of effective vaccines. Whilst COVID-19 vaccines are being rolled out for mass vaccination, the modest number of antivirals in use or development for any disease bears testament to the challenges of antiviral development. We recently showed that non-cytotoxic levels of thapsigargin (TG), an inhibitor of the sarcoplasmic/endoplasmic reticulum (ER) Ca2+ ATPase pump, induces a potent host innate immune antiviral response that blocks influenza A virus replication. Here we show that TG is also highly effective in blocking the replication of respiratory syncytial virus (RSV), common cold coronavirus OC43, SARS-CoV-2 and influenza A virus in immortalized or primary human cells. TG's antiviral performance was significantly better than remdesivir and ribavirin in their respective inhibition of OC43 and RSV. Notably, TG was just as inhibitory to coronaviruses (OC43 and SARS-CoV-2) and influenza viruses (USSR H1N1 and pdm 2009 H1N1) in separate infections as in co-infections. Post-infection oral gavage of acid-stable TG protected mice against a lethal influenza virus challenge. Together with its ability to inhibit the different viruses before or during active infection, and with an antiviral duration of at least 48 h post-TG exposure, we propose that TG (or its derivatives) is a promising broad-spectrum inhibitor against SARS-CoV-2, OC43, RSV and influenza virus.


Subject(s)
Antiviral Agents/pharmacology , Betacoronavirus/drug effects , Coronavirus OC43, Human/drug effects , Influenza A Virus, H1N1 Subtype/drug effects , Respiratory Syncytial Virus, Human/drug effects , SARS-CoV-2/drug effects , Thapsigargin/pharmacology , Animals , Antiviral Agents/therapeutic use , Betacoronavirus/physiology , Cell Line , Cell Line, Tumor , Cells, Cultured , Coronavirus OC43, Human/physiology , Endoplasmic Reticulum Stress , Humans , Influenza A Virus, H1N1 Subtype/physiology , Mice , Microbial Sensitivity Tests , Orthomyxoviridae Infections/drug therapy , Orthomyxoviridae Infections/virology , Respiratory Syncytial Virus, Human/physiology , Ribavirin/pharmacology , SARS-CoV-2/physiology , Thapsigargin/therapeutic use , Virus Replication/drug effects
15.
Antiviral Res ; 173: 104646, 2020 01.
Article in English | MEDLINE | ID: covidwho-829317

ABSTRACT

Human coronaviruses (HCoVs) are important pathogens that cause upper respiratory tract infections and have neuroinvasive abilities; however, little is known about the dynamic infection process of CoVs in vivo, and there are currently no specific antiviral drugs to prevent or treat HCoV infection. Here, we verified the replication ability and pathogenicity of a reporter HCoV-OC43 strain expressing Renilla luciferase (Rluc; rOC43-ns2DelRluc) in mice with different genetic backgrounds (C57BL/6 and BALB/c). Additionally, we monitored the spatial and temporal progression of HCoV-OC43 through the central nervous system (CNS) of live BALB/c mice after intranasal or intracerebral inoculation with rOC43-ns2DelRluc. We found that rOC43-ns2DelRluc was fatal to suckling mice after intranasal inoculation, and that viral titers and Rluc expression were detected in the brains and spinal cords of mice infected with rOC43-ns2DelRluc. Moreover, viral replication was initially observed in the brain by non-invasive bioluminescence imaging before the infection spread to the spinal cord of BALB/c mice, consistent with its tropism in the CNS. Furthermore, the Rluc readout correlated with the HCoV replication ability and protein expression, which allowed quantification of antiviral activity in live mice. Additionally, we validated that chloroquine strongly inhibited rOC43-ns2DelRluc replication in vivo. These results provide new insights into the temporal and spatial dissemination of HCoV-OC43 in the CNS, and our methods provide an extremely sensitive platform for evaluating the efficacy of antiviral therapies to treat neuroinvasive HCoVs in live mice.


Subject(s)
Central Nervous System/virology , Coronavirus Infections/virology , Coronavirus OC43, Human/physiology , Animals , Antiviral Agents/administration & dosage , Brain/diagnostic imaging , Brain/virology , Central Nervous System/diagnostic imaging , Chloroquine/administration & dosage , Coronavirus Infections/diagnostic imaging , Coronavirus Infections/drug therapy , Coronavirus OC43, Human/genetics , Genes, Reporter , Humans , Luciferases, Renilla/genetics , Luciferases, Renilla/metabolism , Mice , Mice, Inbred BALB C , Mice, Inbred C57BL , Molecular Imaging , Virus Replication/drug effects
16.
Proc Natl Acad Sci U S A ; 117(41): 25759-25770, 2020 10 13.
Article in English | MEDLINE | ID: covidwho-807358

ABSTRACT

Human coronaviruses OC43 and HKU1 are respiratory pathogens of zoonotic origin that have gained worldwide distribution. OC43 apparently emerged from a bovine coronavirus (BCoV) spillover. All three viruses attach to 9-O-acetylated sialoglycans via spike protein S with hemagglutinin-esterase (HE) acting as a receptor-destroying enzyme. In BCoV, an HE lectin domain promotes esterase activity toward clustered substrates. OC43 and HKU1, however, lost HE lectin function as an adaptation to humans. Replaying OC43 evolution, we knocked out BCoV HE lectin function and performed forced evolution-population dynamics analysis. Loss of HE receptor binding selected for second-site mutations in S, decreasing S binding affinity by orders of magnitude. Irreversible HE mutations led to cooperativity in virus swarms with low-affinity S minority variants sustaining propagation of high-affinity majority phenotypes. Salvageable HE mutations induced successive second-site substitutions in both S and HE. Apparently, S and HE are functionally interdependent and coevolve to optimize the balance between attachment and release. This mechanism of glycan-based receptor usage, entailing a concerted, fine-tuned activity of two envelope protein species, is unique among CoVs, but reminiscent of that of influenza A viruses. Apparently, general principles fundamental to virion-sialoglycan interactions prompted convergent evolution of two important groups of human and animal pathogens.


Subject(s)
Coronavirus/physiology , Hemagglutinins, Viral/genetics , Spike Glycoprotein, Coronavirus/genetics , Viral Fusion Proteins/genetics , Virion/metabolism , Animals , Biological Evolution , Cell Line , Coronavirus/genetics , Coronavirus/metabolism , Coronavirus Infections/virology , Coronavirus OC43, Human/genetics , Coronavirus OC43, Human/metabolism , Coronavirus OC43, Human/physiology , Coronavirus, Bovine/genetics , Coronavirus, Bovine/metabolism , Coronavirus, Bovine/physiology , Hemagglutinins, Viral/chemistry , Hemagglutinins, Viral/metabolism , Humans , Lectins/genetics , Lectins/metabolism , Mice , Mutation , Protein Binding , Protein Domains , Receptors, Virus/metabolism , Selection, Genetic , Sialic Acids/metabolism , Spike Glycoprotein, Coronavirus/chemistry , Spike Glycoprotein, Coronavirus/metabolism , Viral Fusion Proteins/chemistry , Viral Fusion Proteins/metabolism , Virion/genetics , Virus Attachment , Virus Release
17.
Science ; 368(6493): 860-868, 2020 05 22.
Article in English | MEDLINE | ID: covidwho-57045

ABSTRACT

It is urgent to understand the future of severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) transmission. We used estimates of seasonality, immunity, and cross-immunity for human coronavirus OC43 (HCoV-OC43) and HCoV-HKU1 using time-series data from the United States to inform a model of SARS-CoV-2 transmission. We projected that recurrent wintertime outbreaks of SARS-CoV-2 will probably occur after the initial, most severe pandemic wave. Absent other interventions, a key metric for the success of social distancing is whether critical care capacities are exceeded. To avoid this, prolonged or intermittent social distancing may be necessary into 2022. Additional interventions, including expanded critical care capacity and an effective therapeutic, would improve the success of intermittent distancing and hasten the acquisition of herd immunity. Longitudinal serological studies are urgently needed to determine the extent and duration of immunity to SARS-CoV-2. Even in the event of apparent elimination, SARS-CoV-2 surveillance should be maintained because a resurgence in contagion could be possible as late as 2024.


Subject(s)
Betacoronavirus/physiology , Coronavirus Infections/virology , Models, Biological , Pneumonia, Viral/virology , Betacoronavirus/immunology , COVID-19 , Coronavirus Infections/epidemiology , Coronavirus Infections/transmission , Coronavirus OC43, Human/physiology , Disease Outbreaks , Disease Transmission, Infectious , Humans , Pandemics , Pneumonia, Viral/epidemiology , Pneumonia, Viral/transmission , SARS-CoV-2 , Seasons
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