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2.
Clin Infect Dis ; 73(11): e3978-e3979, 2021 Dec 06.
Article in English | MEDLINE | ID: covidwho-1575770
4.
J Infect Dis ; 224(3): 415-419, 2021 08 02.
Article in English | MEDLINE | ID: covidwho-1526165

ABSTRACT

Mutagenic ribonucleosides can act as broad-based antiviral agents. They are metabolized to the active ribonucleoside triphosphate form and concentrate in genomes of RNA viruses during viral replication. ß-d-N4-hydroxycytidine (NHC, initial metabolite of molnupiravir) is >100-fold more active than ribavirin or favipiravir against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), with antiviral activity correlated to the level of mutagenesis in virion RNA. However, NHC also displays host mutational activity in an animal cell culture assay, consistent with RNA and DNA precursors sharing a common intermediate of a ribonucleoside diphosphate. These results indicate highly active mutagenic ribonucleosides may hold risk for the host.


Subject(s)
Antiviral Agents/pharmacology , Cytidine/analogs & derivatives , Mutagens/pharmacology , SARS-CoV-2/drug effects , Animals , Antiviral Agents/adverse effects , CHO Cells/drug effects , Cells, Cultured , Cricetulus , Cytidine/adverse effects , Cytidine/pharmacology , Dose-Response Relationship, Drug , Mutagenesis/drug effects , Mutagens/adverse effects , SARS-CoV-2/genetics , Virus Replication/drug effects
5.
J Clin Microbiol ; 59(12): e0144621, 2021 11 18.
Article in English | MEDLINE | ID: covidwho-1522905

ABSTRACT

To provide an accessible and inexpensive method to surveil for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) mutations, we developed a multiplex real-time reverse transcription-PCR (rRT-PCR) assay, the Spike single-nucleotide polymorphism (SNP) assay, to detect specific mutations in the spike receptor binding domain. A single primer pair was designed to amplify a 348-bp region of spike, and probes were initially designed to detect K417, E484K, and N501Y. The assay was evaluated using characterized variant sample pools and residual nasopharyngeal samples. Variant calls were confirmed by SARS-CoV-2 genome sequencing in a subset of samples. Subsequently, a fourth probe was designed to detect L452R. The lower limit of 95% detection was 2.46 to 2.48 log10 genome equivalents (GE)/ml for the three initial targets (∼1 to 2 GE/reaction). Among 253 residual nasopharyngeal swabs with detectable SARS-CoV-2 RNA, the Spike SNP assay was positive in 238 (94.1%) samples. All 220 samples with threshold cycle (CT) values of <30 for the SARS-CoV-2 N2 target were detected, whereas 18/33 samples with N2 CT values of ≥30 were detected. Spike SNP results were confirmed by sequencing in 50/50 samples (100%). Addition of the 452R probe did not affect performance for the original targets. The Spike SNP assay accurately identifies SARS-CoV-2 mutations in the receptor binding domain, and it can be quickly modified to detect new mutations that emerge.


Subject(s)
COVID-19 , SARS-CoV-2 , Humans , Mutation , RNA, Viral/genetics , Real-Time Polymerase Chain Reaction , Reverse Transcription
6.
J Nat Prod ; 84(11): 3001-3007, 2021 11 26.
Article in English | MEDLINE | ID: covidwho-1483081

ABSTRACT

The pressing need for SARS-CoV-2 controls has led to a reassessment of strategies to identify and develop natural product inhibitors of zoonotic, highly virulent, and rapidly emerging viruses. This review article addresses how contemporary approaches involving computational chemistry, natural product (NP) and protein databases, and mass spectrometry (MS) derived target-ligand interaction analysis can be utilized to expedite the interrogation of NP structures while minimizing the time and expense of extraction, purification, and screening in BioSafety Laboratories (BSL)3 laboratories. The unparalleled structural diversity and complexity of NPs is an extraordinary resource for the discovery and development of broad-spectrum inhibitors of viral genera, including Betacoronavirus, which contains MERS, SARS, SARS-CoV-2, and the common cold. There are two key technological advances that have created unique opportunities for the identification of NP prototypes with greater efficiency: (1) the application of structural databases for NPs and target proteins and (2) the application of modern MS techniques to assess protein-ligand interactions directly from NP extracts. These approaches, developed over years, now allow for the identification and isolation of unique antiviral ligands without the immediate need for BSL3 facilities. Overall, the goal is to improve the success rate of NP-based screening by focusing resources on source materials with a higher likelihood of success, while simultaneously providing opportunities for the discovery of novel ligands to selectively target proteins involved in viral infection.


Subject(s)
Antiviral Agents/pharmacology , Betacoronavirus/drug effects , Biological Products/pharmacology , Drug Discovery , Computational Biology , Databases, Chemical , Databases, Protein , Ligands , Mass Spectrometry , Protein Interaction Mapping , SARS-CoV-2/drug effects
7.
Emerg Infect Dis ; 27(11): 2887-2891, 2021 11.
Article in English | MEDLINE | ID: covidwho-1369635

ABSTRACT

Among symptomatic outpatients, subgenomic RNA of severe acute respiratory syndrome coronavirus 2 in nasal midturbinate swab specimens was concordant with antigen detection but remained detectable in 13 (82.1%) of 16 nasopharyngeal swab specimens from antigen-negative persons. Subgenomic RNA in midturbinate swab specimens might be useful for routine diagnostics to identify active virus replication.


Subject(s)
COVID-19 , SARS-CoV-2 , Diagnostic Tests, Routine , Humans , Nasopharynx , RNA
8.
Curr Res Pharmacol Drug Discov ; 2: 100045, 2021.
Article in English | MEDLINE | ID: covidwho-1351596

ABSTRACT

Remdesivir, a monophosphate prodrug of nucleoside analog GS-441524, is widely used for the treatment of moderate to severe COVID-19. It has been suggested to use GS-441524 instead of remdesivir in the clinic and in new inhalation formulations. Thus, we compared the anti-SARS-CoV-2 activity of remdesivir and GS-441524 in Vero E6, Vero CCL-81, Calu-3, Caco-2 â€‹cells, and anti-HCoV-OC43 activity in Huh-7 â€‹cells. We also compared the cellular pharmacology of these two compounds in Vero E6, Vero CCL-81, Calu-3, Caco-2, Huh-7, 293T, BHK-21, 3T3 and human airway epithelial (HAE) cells. Overall, remdesivir exhibited greater potency and superior intracellular metabolism than GS-441524 except in Vero E6 and Vero CCL-81 â€‹cells.

9.
Sci Rep ; 11(1): 14604, 2021 07 16.
Article in English | MEDLINE | ID: covidwho-1315611

ABSTRACT

While there has been significant progress in the development of rapid COVID-19 diagnostics, as the pandemic unfolds, new challenges have emerged, including whether these technologies can reliably detect the more infectious variants of concern and be viably deployed in non-clinical settings as "self-tests". Multidisciplinary evaluation of the Abbott BinaxNOW COVID-19 Ag Card (BinaxNOW, a widely used rapid antigen test, included limit of detection, variant detection, test performance across different age-groups, and usability with self/caregiver-administration. While BinaxNOW detected the highly infectious variants, B.1.1.7 (Alpha) first identified in the UK, B.1.351 (Beta) first identified in South Africa, P.1 (Gamma) first identified in Brazil, B.1.617.2 (Delta) first identified in India and B.1.2, a non-VOC, test sensitivity decreased with decreasing viral loads. Moreover, BinaxNOW sensitivity trended lower when devices were performed by patients/caregivers themselves compared to trained clinical staff, despite universally high usability assessments following self/caregiver-administration among different age groups. Overall, these data indicate that while BinaxNOW accurately detects the new viral variants, as rapid COVID-19 tests enter the home, their already lower sensitivities compared to RT-PCR may decrease even more due to user error.


Subject(s)
COVID-19 Serological Testing , COVID-19/diagnosis , Point-of-Care Systems , Self-Testing , Humans , Limit of Detection , SARS-CoV-2 , Sensitivity and Specificity
10.
J Biol Chem ; 297(1): 100770, 2021 07.
Article in English | MEDLINE | ID: covidwho-1225273

ABSTRACT

The RNA-dependent RNA polymerase of the severe acute respiratory syndrome coronavirus 2 is an important target in current drug development efforts for the treatment of coronavirus disease 2019. Molnupiravir is a broad-spectrum antiviral that is an orally bioavailable prodrug of the nucleoside analogue ß-D-N4-hydroxycytidine (NHC). Molnupiravir or NHC can increase G to A and C to U transition mutations in replicating coronaviruses. These increases in mutation frequencies can be linked to increases in antiviral effects; however, biochemical data of molnupiravir-induced mutagenesis have not been reported. Here we studied the effects of the active compound NHC 5'-triphosphate (NHC-TP) against the purified severe acute respiratory syndrome coronavirus 2 RNA-dependent RNA polymerase complex. The efficiency of incorporation of natural nucleotides over the efficiency of incorporation of NHC-TP into model RNA substrates followed the order GTP (12,841) > ATP (424) > UTP (171) > CTP (30), indicating that NHC-TP competes predominantly with CTP for incorporation. No significant inhibition of RNA synthesis was noted as a result of the incorporated monophosphate in the RNA primer strand. When embedded in the template strand, NHC-monophosphate supported the formation of both NHC:G and NHC:A base pairs with similar efficiencies. The extension of the NHC:G product was modestly inhibited, but higher nucleotide concentrations could overcome this blockage. In contrast, the NHC:A base pair led to the observed G to A (G:NHC:A) or C to U (C:G:NHC:A:U) mutations. Together, these biochemical data support a mechanism of action of molnupiravir that is primarily based on RNA mutagenesis mediated via the template strand.


Subject(s)
Antiviral Agents/pharmacology , COVID-19/virology , Cytidine/analogs & derivatives , Hydroxylamines/pharmacology , RNA, Viral/genetics , SARS-CoV-2/drug effects , SARS-CoV-2/genetics , Cytidine/pharmacology , Humans , Mutagenesis , Point Mutation/drug effects , SARS-CoV-2/metabolism
11.
J Infect Dis ; 224(3): 415-419, 2021 08 02.
Article in English | MEDLINE | ID: covidwho-1221478

ABSTRACT

Mutagenic ribonucleosides can act as broad-based antiviral agents. They are metabolized to the active ribonucleoside triphosphate form and concentrate in genomes of RNA viruses during viral replication. ß-d-N4-hydroxycytidine (NHC, initial metabolite of molnupiravir) is >100-fold more active than ribavirin or favipiravir against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), with antiviral activity correlated to the level of mutagenesis in virion RNA. However, NHC also displays host mutational activity in an animal cell culture assay, consistent with RNA and DNA precursors sharing a common intermediate of a ribonucleoside diphosphate. These results indicate highly active mutagenic ribonucleosides may hold risk for the host.


Subject(s)
Antiviral Agents/pharmacology , Cytidine/analogs & derivatives , Mutagens/pharmacology , SARS-CoV-2/drug effects , Animals , Antiviral Agents/adverse effects , CHO Cells/drug effects , Cells, Cultured , Cricetulus , Cytidine/adverse effects , Cytidine/pharmacology , Dose-Response Relationship, Drug , Mutagenesis/drug effects , Mutagens/adverse effects , SARS-CoV-2/genetics , Virus Replication/drug effects
12.
Microorganisms ; 9(5)2021 Apr 22.
Article in English | MEDLINE | ID: covidwho-1201125

ABSTRACT

Coronavirus Disease 2019 (COVID-19) is a deadly emerging infectious disease caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). Because SARS-CoV-2 is easily transmitted through the air and has a relatively long incubation time, COVID-19 has rapidly developed into a global pandemic. As there are no antiviral agents for the prevention and treatment of this severe pathogen except for remdesivir, development of antiviral therapies to treat infected individuals remains highly urgent. Here, we showed that baicalein and baicalin exhibited significant antiviral activity against SARS-CoV-2, the causative agent of COVID-19 through in vitro studies. Our data through cell-based and biochemical studies showed that both compounds act as SARS-CoV-2 RNA-dependent RNA polymerase (RdRp) inhibitors directly and inhibit the activity of the SARS-CoV-2 RdRp, but baicalein was more potent. We also showed specific binding of baicalein to the SARS-CoV-2 RdRp, making it a potential candidate for further studies towards therapeutic development for COVID-19 as a selective non-nucleoside polymerase inhibitor.

13.
Clin Infect Dis ; 72(7): 1247-1250, 2021 04 08.
Article in English | MEDLINE | ID: covidwho-1174886

ABSTRACT

Hyperinflammation is associated with increased mortality in coronavirus disease 2019 (COVID-19). In this retrospective, uncontrolled patient cohort with moderate -severe COVID-19, treatment with baricitinib plus hydroxychloroquine was associated with recovery in 11 of 15 patients. Baricitinib for the treatment of COVID-19 should be further investigated in randomized, controlled clinical trials.


Subject(s)
COVID-19 , Antiviral Agents/therapeutic use , Azetidines , COVID-19/drug therapy , Humans , Purines , Pyrazoles , Retrospective Studies , SARS-CoV-2 , Sulfonamides , Treatment Outcome
14.
Molecules ; 26(5)2021 Mar 09.
Article in English | MEDLINE | ID: covidwho-1143539

ABSTRACT

A series of hitherto unknown (1,4-disubstituted-1,2,3-triazol)-(E)-2-methyl-but-2-enyl nucleosides phosphonate prodrugs bearing 4-substituted-1,2,3-triazoles were prepared in a straight approach through an olefin acyclic cross metathesis as the key synthetic step. All novel compounds were evaluated for their antiviral activities against HBV, HIV and SARS-CoV-2. Among these molecules, only compound 15j, a hexadecyloxypropyl (HDP)/(isopropyloxycarbonyl-oxymethyl)-ester (POC) prodrug, showed activity against HBV in Huh7 cell cultures with 62% inhibition at 10 µM, without significant cytotoxicity (IC50 = 66.4 µM in HepG2 cells, IC50 = 43.1 µM in HepG2 cells) at 10 µM.


Subject(s)
Antiviral Agents/chemical synthesis , Antiviral Agents/pharmacology , Azo Compounds/chemistry , Nucleosides/chemistry , Organophosphonates/chemistry , Prodrugs/chemical synthesis , Prodrugs/pharmacology , Alkenes/chemistry , Animals , Cell Line, Tumor , Chlorocebus aethiops , HIV-1/drug effects , Hepatitis B virus/drug effects , Humans , Magnetic Resonance Spectroscopy , Methylation , SARS-CoV-2/drug effects , Structure-Activity Relationship , Triazoles/chemistry , Vero Cells
15.
Antimicrob Agents Chemother ; 65(1)2020 12 16.
Article in English | MEDLINE | ID: covidwho-1015593

ABSTRACT

Coronavirus disease 2019 (COVID-19) is a serious illness caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2 or CoV-2). Some reports claimed certain nucleoside analogs to be active against CoV-2 and thus needed confirmation. Here, we evaluated a panel of compounds and identified novel nucleoside analogs with antiviral activity against CoV-2 and HCoV-OC43 while ruling out others. Of significance, sofosbuvir demonstrated no antiviral effect against CoV-2, and its triphosphate did not inhibit CoV-2 RNA polymerase.


Subject(s)
Antiviral Agents/pharmacology , Drug Repositioning/methods , Nucleosides/pharmacology , SARS-CoV-2/drug effects , Animals , Antiviral Agents/chemistry , Antiviral Agents/toxicity , Cell Line , Chlorocebus aethiops , Coronavirus OC43, Human/drug effects , Drug Evaluation, Preclinical , Humans , Nucleosides/chemistry , Nucleosides/toxicity , Propanolamines/pharmacology , Sofosbuvir/pharmacology , Vero Cells
16.
Am J Hematol ; 96(2): 174-178, 2021 02 01.
Article in English | MEDLINE | ID: covidwho-954382
17.
Cell ; 184(2): 460-475.e21, 2021 01 21.
Article in English | MEDLINE | ID: covidwho-917237

ABSTRACT

SARS-CoV-2-induced hypercytokinemia and inflammation are critically associated with COVID-19 severity. Baricitinib, a clinically approved JAK1/JAK2 inhibitor, is currently being investigated in COVID-19 clinical trials. Here, we investigated the immunologic and virologic efficacy of baricitinib in a rhesus macaque model of SARS-CoV-2 infection. Viral shedding measured from nasal and throat swabs, bronchoalveolar lavages, and tissues was not reduced with baricitinib. Type I interferon (IFN) antiviral responses and SARS-CoV-2-specific T cell responses remained similar between the two groups. Animals treated with baricitinib showed reduced inflammation, decreased lung infiltration of inflammatory cells, reduced NETosis activity, and more limited lung pathology. Importantly, baricitinib-treated animals had a rapid and remarkably potent suppression of lung macrophage production of cytokines and chemokines responsible for inflammation and neutrophil recruitment. These data support a beneficial role for, and elucidate the immunological mechanisms underlying, the use of baricitinib as a frontline treatment for inflammation induced by SARS-CoV-2 infection.


Subject(s)
Anti-Inflammatory Agents/administration & dosage , Azetidines/administration & dosage , COVID-19/drug therapy , COVID-19/immunology , Macaca mulatta , Neutrophil Infiltration/drug effects , Purines/administration & dosage , Pyrazoles/administration & dosage , Sulfonamides/administration & dosage , Animals , COVID-19/physiopathology , Cell Death/drug effects , Cell Degranulation/drug effects , Disease Models, Animal , Inflammation/drug therapy , Inflammation/genetics , Inflammation/immunology , Janus Kinases/antagonists & inhibitors , Lung/drug effects , Lung/immunology , Lung/pathology , Lymphocyte Activation/drug effects , Macrophages, Alveolar/immunology , SARS-CoV-2/physiology , Severity of Illness Index , T-Lymphocytes/immunology , Virus Replication/drug effects
19.
J Hepatol ; 74(1): 168-184, 2021 01.
Article in English | MEDLINE | ID: covidwho-837362

ABSTRACT

Coronavirus disease 2019 (COVID-19) started as an epidemic in Wuhan in 2019, and has since become a pandemic. Groups from China identified and sequenced the virus responsible for COVID-19, named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and determined that it was a novel coronavirus sharing high sequence identity with bat- and pangolin-derived SARS-like coronaviruses, suggesting a zoonotic origin. SARS-CoV-2 is a member of the Coronaviridae family of enveloped, positive-sense, single-stranded RNA viruses that infect a broad range of vertebrates. The rapid release of the sequence of the virus has enabled the development of diagnostic tools. Additionally, serological tests can now identify individuals who have been infected. SARS-CoV-2 infection is associated with a fatality rate of around 1-3%, which is commonly linked to the development of acute respiratory distress syndrome (ARDS), likely resulting from uncontrolled immune activation, the so called "cytokine storm". Risk factors for mortality include advanced age, obesity, diabetes, and hypertension. Drug repurposing has been used to rapidly identify potential treatments for COVID-19, which could move quickly to phase III. Better knowledge of the virus and its enzymes will aid the development of more potent and specific direct-acting antivirals. In the long term, a vaccine to prevent infection is crucial; however, even if successful, it might not be available before 2021-22. To date, except for intravenous remdesivir and dexamethasone, which have modest effects in moderate to severe COVID-19, no strong clinical evidence supports the efficacy of any other drugs against SARS-CoV-2. The aim of this review is to provide insights on the discovery of SARS-CoV-2, its virology, diagnostic tools, and the ongoing drug discovery effort.


Subject(s)
Antiviral Agents/pharmacology , Drug Development , Drug Discovery , SARS-CoV-2/drug effects , COVID-19/diagnosis , COVID-19/drug therapy , COVID-19/physiopathology , Drug Repositioning , Genome, Viral , Humans , Immunity, Innate , Pandemics , Respiratory Distress Syndrome/virology , Risk Factors , SARS-CoV-2/genetics
20.
bioRxiv ; 2020 Sep 16.
Article in English | MEDLINE | ID: covidwho-807103

ABSTRACT

Effective therapeutics aimed at mitigating COVID-19 symptoms are urgently needed. SARS-CoV-2 induced hypercytokinemia and systemic inflammation are associated with disease severity. Baricitinib, a clinically approved JAK1/2 inhibitor with potent anti-inflammatory properties is currently being investigated in COVID-19 human clinical trials. Recent reports suggest that baricitinib may also have antiviral activity in limiting viral endocytosis. Here, we investigated the immunologic and virologic efficacy of baricitinib in a rhesus macaque model of SARS-CoV-2 infection. Viral shedding measured from nasal and throat swabs, bronchoalveolar lavages and tissues was not reduced with baricitinib. Type I IFN antiviral responses and SARS-CoV-2 specific T cell responses remained similar between the two groups. Importantly, however, animals treated with baricitinib showed reduced immune activation, decreased infiltration of neutrophils into the lung, reduced NETosis activity, and more limited lung pathology. Moreover, baricitinib treated animals had a rapid and remarkably potent suppression of alveolar macrophage derived production of cytokines and chemokines responsible for inflammation and neutrophil recruitment. These data support a beneficial role for, and elucidate the immunological mechanisms underlying, the use of baricitinib as a frontline treatment for severe inflammation induced by SARS-CoV-2 infection.

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