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1.
Viruses ; 14(2)2022 02 18.
Article in English | MEDLINE | ID: covidwho-1707748

ABSTRACT

In the current context of the COVID-19 pandemic, it appears that our scientific resources and the medical community are not sufficiently developed to combat rapid viral spread all over the world. A number of viruses causing epidemics have already disseminated across the world in the last few years, such as the dengue or chinkungunya virus, the Ebola virus, and other coronavirus families such as Middle East respiratory syndrome (MERS-CoV) and severe acute respiratory syndrome (SARS-CoV). The outbreaks of these infectious diseases have demonstrated the difficulty of treating an epidemic before the creation of vaccine. Different antiviral drugs already exist. However, several of them cause side effects or have lost their efficiency because of virus mutations. It is essential to develop new antiviral strategies, but ones that rely on more natural compounds to decrease the secondary effects. Polysaccharides, which have come to be known in recent years for their medicinal properties, including antiviral activities, are an excellent alternative. They are essential for the metabolism of plants, microorganisms, and animals, and are directly extractible. Polysaccharides have attracted more and more attention due to their therapeutic properties, low toxicity, and availability, and seem to be attractive candidates as antiviral drugs of tomorrow.


Subject(s)
Antiviral Agents/chemistry , Antiviral Agents/pharmacology , Polysaccharides/chemistry , Polysaccharides/pharmacology , Viruses/drug effects , Animals , Disease Outbreaks/prevention & control , Ebolavirus/drug effects , Humans , SARS-CoV-2/drug effects , Virus Diseases/drug therapy , Virus Replication/drug effects , Viruses/classification , Viruses/pathogenicity
2.
Biomed Pharmacother ; 147: 112682, 2022 Mar.
Article in English | MEDLINE | ID: covidwho-1664682

ABSTRACT

Viral infections have a great impact on human health. The urgent need to find a cure against different viruses led us to investigations in a vast range of drugs. Azithromycin (AZT), classified as a macrolide, showed various effects on different known viruses such as severe acute respiratory syndrome coronavirus (SARS-CoV), Zika, Ebola, Enterovirus (EVs) and Rhinoviruses (RVs), and Influenza A previously; namely, these viruses, which caused global concerns, are considered as targets for AZT different actions. Due to AZT background in the treatment of known viral infections mentioned above (which is described in this study), in the early stages of COVID-19 (a new zoonotic disease caused by a novel coronavirus called severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)) development, AZT drew attention to itself due to its antiviral and immunomodulatory effects as a valuable candidate for COVID-19 treatment. AZT usage instructions for treating different viral infections have always been under observation, and COVID-19 is no exception. There are still debates about the use of AZT in COVID-19 treatment. However, eventually, novel researches convinced WHO to announce the discontinuation of AZT use (alone or in combination with hydroxychloroquine) in treating SARS-CoV-2 infection. This research aims to study the structure of all of the viruses mentioned above and the molecular and clinical effects of AZT against the virus.


Subject(s)
Antiviral Agents/therapeutic use , Azithromycin/therapeutic use , COVID-19/drug therapy , Anti-Bacterial Agents , Antiviral Agents/pharmacology , Azithromycin/pharmacology , Ebolavirus/drug effects , Humans , Influenza A virus/drug effects , SARS Virus/drug effects , SARS-CoV-2/drug effects , Zika Virus/drug effects
3.
Sci Rep ; 11(1): 19458, 2021 09 30.
Article in English | MEDLINE | ID: covidwho-1447326

ABSTRACT

Efficacious therapeutics for Ebola virus disease are in great demand. Ebola virus infections mediated by mucosal exposure, and aerosolization in particular, present a novel challenge due to nontypical massive early infection of respiratory lymphoid tissues. We performed a randomized and blinded study to compare outcomes from vehicle-treated and remdesivir-treated rhesus monkeys in a lethal model of infection resulting from aerosolized Ebola virus exposure. Remdesivir treatment initiated 4 days after exposure was associated with a significant survival benefit, significant reduction in serum viral titer, and improvements in clinical pathology biomarker levels and lung histology compared to vehicle treatment. These observations indicate that remdesivir may have value in countering aerosol-induced Ebola virus disease.


Subject(s)
Adenosine Monophosphate/analogs & derivatives , Alanine/analogs & derivatives , Antiviral Agents/pharmacology , Ebolavirus/drug effects , Hemorrhagic Fever, Ebola/drug therapy , Adenosine Monophosphate/administration & dosage , Adenosine Monophosphate/pharmacology , Administration, Intravenous , Aerosols , Alanine/administration & dosage , Alanine/pharmacology , Animals , Antiviral Agents/administration & dosage , Disease Models, Animal , Female , Hemorrhagic Fever, Ebola/blood , Kaplan-Meier Estimate , Liver/drug effects , Liver/virology , Lung/pathology , Lung/virology , Lymph Nodes/drug effects , Lymph Nodes/pathology , Lymph Nodes/virology , Macaca mulatta , Male , Random Allocation , Systemic Inflammatory Response Syndrome/drug therapy , Systemic Inflammatory Response Syndrome/virology , Viral Load/drug effects , Viremia/drug therapy
4.
Front Immunol ; 12: 721328, 2021.
Article in English | MEDLINE | ID: covidwho-1435991

ABSTRACT

The unprecedented 2013-2016 West Africa Ebola outbreak accelerated several medical countermeasures (MCMs) against Ebola virus disease (EVD). Several investigational products (IPs) were used throughout the outbreak but were not conclusive for efficacy results. Only the Randomized Controlled Trial (RCT) on ZMapp was promising but inconclusive. More recently, during the second-largest Ebola outbreak in North Kivu and Ituri provinces, Democratic Republic of the Congo (DRC), four IPs, including one small molecule (Remdesivir), two monoclonal antibody (mAb) cocktails (ZMapp and REGN-EB3) and a single mAb (mAb114), were evaluated in an RCT, the Pamoja Tulinde Maisha (PALM) study. Two products (REGN-EB3 and mAb114) demonstrated efficacy as compared to the control arm, ZMapp. There were remarkably few side effects recorded in the trial. The FDA approved both medications in this scientifically sound study, marking a watershed moment in the field of EVD therapy. These products can be produced relatively inexpensively and can be stockpiled. The administration of mAbs in EVD patients appears to be safe and effective, while several critical knowledge gaps remain; the impact of early administration of Ebola-specific mAbs on developing a robust immune response for future Ebola virus exposure is unknown. The viral mutation escape, leading to resistance, presents a potential limitation for single mAb therapy; further improvements need to be explored. Understanding the contribution of Fc-mediated antibody functions such as antibody-dependent cellular cytotoxicity (ADCC) of those approved mAbs is still critical. The potential merit of combination therapy and post-exposure prophylaxis (PEP) need to be demonstrated. Furthermore, the PALM trial has accounted for 30% of mortality despite the administration of specific treatments. The putative role of EBOV soluble Glycoprotein (sGP) as a decoy to the immune system, the virus persistence, and relapses might be investigated for treatment failure. The development of pan-filovirus or pan-species mAbs remains essential for protection. The interaction between FDA-approved mAbs and vaccines remains unclear and needs to be investigated. In this review, we summarize the efficacy and safety results of the PALM study and review current research questions for the further development of mAbs in pre-exposure or emergency post-exposure use.


Subject(s)
Antibodies, Monoclonal/therapeutic use , Antiviral Agents/therapeutic use , Ebolavirus/drug effects , Hemorrhagic Fever, Ebola/drug therapy , Hemorrhagic Fever, Ebola/virology , Animals , Antibodies, Monoclonal/pharmacology , Antigens, Viral/immunology , Antiviral Agents/pharmacology , Clinical Studies as Topic , Drug Approval , Drug Evaluation, Preclinical , Ebola Vaccines , Ebolavirus/immunology , Hemorrhagic Fever, Ebola/mortality , Hemorrhagic Fever, Ebola/prevention & control , Humans , Prognosis , Treatment Failure , Treatment Outcome , United States , United States Food and Drug Administration , Vaccination
5.
Eur J Med Chem ; 226: 113862, 2021 Dec 15.
Article in English | MEDLINE | ID: covidwho-1433178

ABSTRACT

We report here the synthesis, purification, and characterization of mono- and di-fatty acyl conjugates of remdesivir (RDV) and their in vitro antiviral activity against SAR-CoV-2, an Ebola virus transcription- and replication-competent virus-like particle (trVLP) system, and infectious Ebola virus. The most potent monofatty acyl conjugate was 4b, containing a 4-oxatetradecanolyl at the 3' position. Monofatty acyl conjugates, 3'-O-tetradecanoyl (4a) (IC50(VeroE6) = 2.3 µM; IC50(Calu3) = 0.24 µM), 3'-O-4-oxatetradodecanoyl (4b) (IC50(VeroE6) = 2.0 µM; IC50(Calu3) = 0.18 µM), and 3'-O-(12-ethylthiododecanoyl) (4e) (IC50(VeroE6) = 2.4 µM; IC50(Calu3) = 0.25 µM) derivatives exhibited less activity than RDV (IC50(VeroE6) = 0.85 µM; IC50(Calu3) = 0.06 µM) in both VeroE6 and Calu3 cells. Difatty acylation led to a significant reduction in the antiviral activity of RDV (as shown in conjugates 5a and 5b) against SARS-CoV-2 when compared with monofatty acylation (3a-e and 4a-e). About 77.9% of 4c remained intact after 4 h incubation with human plasma while only 47% of parent RDV was observed at the 2 h time point. The results clearly indicate the effectiveness of fatty acylation to improve the half-life of RDV. The antiviral activities of a number of monofatty acyl conjugates of RDV, such as 3b, 3e, and 4b, were comparable with RDV against the Ebola trVLP system. Meanwhile, the corresponding physical mixtures of RDV and fatty acids 6a and 6b showed 1.6 to 2.2 times less antiviral activity than the corresponding conjugates, 4a and 4c, respectively, against SARS-CoV-2 in VeroE6 cells. A significant reduction in viral RNA synthesis was observed for selected compounds 3a and 4b consistent with the IC50 results. These studies indicate the potential of these compounds as long-acting antiviral agents or prodrugs of RDV.


Subject(s)
Adenosine Monophosphate/analogs & derivatives , Alanine/analogs & derivatives , Antiviral Agents/chemical synthesis , Antiviral Agents/pharmacology , COVID-19/virology , Ebolavirus/drug effects , Fatty Acids/chemistry , SARS-CoV-2/drug effects , Adenosine Monophosphate/chemical synthesis , Adenosine Monophosphate/chemistry , Adenosine Monophosphate/pharmacology , Alanine/chemical synthesis , Alanine/chemistry , Alanine/pharmacology , Antiviral Agents/chemistry , Humans , SARS-CoV-2/isolation & purification
6.
Biochemistry ; 60(24): 1869-1875, 2021 06 22.
Article in English | MEDLINE | ID: covidwho-1387102

ABSTRACT

Remdesivir is an antiviral drug initially designed against the Ebola virus. The results obtained with it both in biochemical studies in vitro and in cell line assays in vivo were very promising, but it proved to be ineffective in clinical trials. Remdesivir exhibited far better efficacy when repurposed against SARS-CoV-2. The chemistry that accounts for this difference is the subject of this study. Here, we examine the hypothesis that remdesivir monophosphate (RMP)-containing RNA functions as a template at the polymerase site for the second run of RNA synthesis, and as mRNA at the decoding center for protein synthesis. Our hypothesis is supported by the observation that RMP can be incorporated into RNA by the RNA-dependent RNA polymerases (RdRps) of both viruses, although some of the incorporated RMPs are subsequently removed by exoribonucleases. Furthermore, our hypothesis is consistent with the fact that RdRp of SARS-CoV-2 selects RMP for incorporation over AMP by 3-fold in vitro, and that RMP-added RNA can be rapidly extended, even though primer extension is often paused when the added RMP is translocated at the i + 3 position (with i the nascent base pair at an initial insertion site of RMP) or when the concentrations of the subsequent nucleoside triphosphates (NTPs) are below their physiological concentrations. These observations have led to the hypothesis that remdesivir might be a delayed chain terminator. However, that hypothesis is challenged under physiological concentrations of NTPs by the observation that approximately three-quarters of RNA products efficiently overrun the pause.


Subject(s)
Adenosine Monophosphate/analogs & derivatives , Alanine/analogs & derivatives , Coronavirus RNA-Dependent RNA Polymerase/genetics , Ebolavirus/drug effects , SARS-CoV-2/drug effects , Virus Replication/drug effects , Adenosine Monophosphate/genetics , Adenosine Monophosphate/metabolism , Alanine/genetics , Alanine/metabolism , Antiviral Agents/metabolism , Base Pairing , Coronavirus RNA-Dependent RNA Polymerase/antagonists & inhibitors , Coronavirus RNA-Dependent RNA Polymerase/metabolism , Enzyme Inhibitors/metabolism , Models, Molecular , Protein Biosynthesis/drug effects , RNA/genetics , RNA/metabolism , RNA, Messenger/genetics , RNA, Messenger/metabolism , RNA, Viral/genetics , RNA, Viral/metabolism
7.
Biochemistry ; 60(24): 1869-1875, 2021 06 22.
Article in English | MEDLINE | ID: covidwho-1263454

ABSTRACT

Remdesivir is an antiviral drug initially designed against the Ebola virus. The results obtained with it both in biochemical studies in vitro and in cell line assays in vivo were very promising, but it proved to be ineffective in clinical trials. Remdesivir exhibited far better efficacy when repurposed against SARS-CoV-2. The chemistry that accounts for this difference is the subject of this study. Here, we examine the hypothesis that remdesivir monophosphate (RMP)-containing RNA functions as a template at the polymerase site for the second run of RNA synthesis, and as mRNA at the decoding center for protein synthesis. Our hypothesis is supported by the observation that RMP can be incorporated into RNA by the RNA-dependent RNA polymerases (RdRps) of both viruses, although some of the incorporated RMPs are subsequently removed by exoribonucleases. Furthermore, our hypothesis is consistent with the fact that RdRp of SARS-CoV-2 selects RMP for incorporation over AMP by 3-fold in vitro, and that RMP-added RNA can be rapidly extended, even though primer extension is often paused when the added RMP is translocated at the i + 3 position (with i the nascent base pair at an initial insertion site of RMP) or when the concentrations of the subsequent nucleoside triphosphates (NTPs) are below their physiological concentrations. These observations have led to the hypothesis that remdesivir might be a delayed chain terminator. However, that hypothesis is challenged under physiological concentrations of NTPs by the observation that approximately three-quarters of RNA products efficiently overrun the pause.


Subject(s)
Adenosine Monophosphate/analogs & derivatives , Alanine/analogs & derivatives , Coronavirus RNA-Dependent RNA Polymerase/genetics , Ebolavirus/drug effects , SARS-CoV-2/drug effects , Virus Replication/drug effects , Adenosine Monophosphate/genetics , Adenosine Monophosphate/metabolism , Alanine/genetics , Alanine/metabolism , Antiviral Agents/metabolism , Base Pairing , Coronavirus RNA-Dependent RNA Polymerase/antagonists & inhibitors , Coronavirus RNA-Dependent RNA Polymerase/metabolism , Enzyme Inhibitors/metabolism , Models, Molecular , Protein Biosynthesis/drug effects , RNA/genetics , RNA/metabolism , RNA, Messenger/genetics , RNA, Messenger/metabolism , RNA, Viral/genetics , RNA, Viral/metabolism
8.
FEBS Open Bio ; 11(5): 1452-1464, 2021 05.
Article in English | MEDLINE | ID: covidwho-1168813

ABSTRACT

Human pathogenic RNA viruses are threats to public health because they are prone to escaping the human immune system through mutations of genomic RNA, thereby causing local outbreaks and global pandemics of emerging or re-emerging viral diseases. While specific therapeutics and vaccines are being developed, a broad-spectrum therapeutic agent for RNA viruses would be beneficial for targeting newly emerging and mutated RNA viruses. In this study, we conducted a screen of repurposed drugs using Sendai virus (an RNA virus of the family Paramyxoviridae), with human-induced pluripotent stem cells (iPSCs) to explore existing drugs that may present anti-RNA viral activity. Selected hit compounds were evaluated for their efficacy against two important human pathogens: Ebola virus (EBOV) using Huh7 cells and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) using Vero E6 cells. Selective estrogen receptor modulators (SERMs), including raloxifene, exhibited antiviral activities against EBOV and SARS-CoV-2. Pioglitazone, a PPARγ agonist, also exhibited antiviral activities against SARS-CoV-2, and both raloxifene and pioglitazone presented a synergistic antiviral effect. Finally, we demonstrated that SERMs blocked entry steps of SARS-CoV-2 into host cells. These findings suggest that the identified FDA-approved drugs can modulate host cell susceptibility against RNA viruses.


Subject(s)
Antiviral Agents/pharmacology , Drug Repositioning , RNA Viruses/drug effects , RNA, Viral/antagonists & inhibitors , SARS-CoV-2/drug effects , Animals , COVID-19/drug therapy , Cell Line , Chlorocebus aethiops , Drug Repositioning/methods , Ebolavirus/drug effects , Ebolavirus/physiology , Humans , Induced Pluripotent Stem Cells/virology , Microbial Sensitivity Tests/methods , Pioglitazone/pharmacology , RNA Viruses/physiology , Raloxifene Hydrochloride/pharmacology , SARS-CoV-2/physiology , Selective Estrogen Receptor Modulators/pharmacology , Sendai virus/drug effects , Sendai virus/physiology , Vero Cells
9.
Antiviral Res ; 186: 104990, 2021 02.
Article in English | MEDLINE | ID: covidwho-1064808

ABSTRACT

The endocytic pathway is a common strategy that several highly pathogenic viruses use to enter into the cell. To demonstrate the usefulness of this pathway as a common target for the development of broad-spectrum antivirals, the inhibitory effect of drug compounds targeting endosomal membrane proteins were investigated. This study entailed direct comparison of drug effectiveness against animal and human pathogenic viruses, namely Ebola (EBOV), African swine fever virus (ASFV), and the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). A panel of experimental and FDA-approved compounds targeting calcium channels and PIKfyve at the endosomal membrane caused potent reductions of entry up to 90% in SARS-CoV-2 S-protein pseudotyped retrovirus. Similar inhibition was observed against transduced EBOV glycoprotein pseudovirus and ASFV. SARS-CoV-2 infection was potently inhibited by selective estrogen receptor modulators in cells transduced with pseudovirus, among them Raloxifen inhibited ASFV with very low 50% inhibitory concentration. Finally, the mechanism of the inhibition caused by the latter in ASFV infection was analyzed. Overall, this work shows that cellular proteins related to the endocytic pathway can constitute suitable cellular targets for broad range antiviral compounds.


Subject(s)
African Swine Fever Virus/drug effects , Antiviral Agents/pharmacology , Ebolavirus/drug effects , Endosomes/drug effects , SARS-CoV-2/drug effects , Virus Internalization/drug effects , African Swine Fever Virus/physiology , Animals , Calcium/metabolism , Calcium Channel Blockers/pharmacology , Cell Line , Cell Line, Tumor , Chlorocebus aethiops , Cholesterol/metabolism , Dose-Response Relationship, Drug , Drug Evaluation, Preclinical , Ebolavirus/physiology , Endocytosis/drug effects , Endosomes/metabolism , Humans , Membrane Proteins/antagonists & inhibitors , Membrane Proteins/metabolism , Phosphatidylinositol 3-Kinases/metabolism , Phosphoinositide-3 Kinase Inhibitors/pharmacology , Raloxifene Hydrochloride/pharmacology , Receptors, Estrogen/metabolism , SARS-CoV-2/physiology , Selective Estrogen Receptor Modulators/pharmacology , Vero Cells
10.
Viruses ; 12(12)2020 12 10.
Article in English | MEDLINE | ID: covidwho-969583

ABSTRACT

Recent RNA virus outbreaks such as Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and Ebola virus (EBOV) have caused worldwide health emergencies highlighting the urgent need for new antiviral strategies. Targeting host cell pathways supporting viral replication is an attractive approach for development of antiviral compounds, especially with new, unexplored viruses where knowledge of virus biology is limited. Here, we present a strategy to identify host-targeted small molecule inhibitors using an image-based phenotypic antiviral screening assay followed by extensive target identification efforts revealing altered cellular pathways upon antiviral compound treatment. The newly discovered antiviral compounds showed broad-range antiviral activity against pathogenic RNA viruses such as SARS-CoV-2, EBOV and Crimean-Congo hemorrhagic fever virus (CCHFV). Target identification of the antiviral compounds by thermal protein profiling revealed major effects on proteostasis pathways and disturbance in interactions between cellular HSP70 complex and viral proteins, illustrating the supportive role of HSP70 on many RNA viruses across virus families. Collectively, this strategy identifies new small molecule inhibitors with broad antiviral activity against pathogenic RNA viruses, but also uncovers novel virus biology urgently needed for design of new antiviral therapies.


Subject(s)
Antiviral Agents/pharmacology , Host-Pathogen Interactions/drug effects , RNA Viruses/drug effects , Virus Replication/drug effects , Animals , Cell Line , Ebolavirus/drug effects , Ebolavirus/physiology , HSP70 Heat-Shock Proteins/metabolism , Hemorrhagic Fever Virus, Crimean-Congo/drug effects , Hemorrhagic Fever Virus, Crimean-Congo/physiology , Humans , Protein Binding/drug effects , Protein Stability , Proteome/drug effects , Proteostasis/drug effects , RNA Virus Infections/metabolism , RNA Virus Infections/virology , RNA Viruses/physiology , SARS-CoV-2/drug effects , SARS-CoV-2/physiology , Small Molecule Libraries/pharmacology , Viral Proteins/metabolism
11.
Clin Microbiol Rev ; 34(1)2020 12 16.
Article in English | MEDLINE | ID: covidwho-962931

ABSTRACT

Patients and physicians worldwide are facing tremendous health care hazards that are caused by the ongoing severe acute respiratory distress syndrome coronavirus 2 (SARS-CoV-2) pandemic. Remdesivir (GS-5734) is the first approved treatment for severe coronavirus disease 2019 (COVID-19). It is a novel nucleoside analog with a broad antiviral activity spectrum among RNA viruses, including ebolavirus (EBOV) and the respiratory pathogens Middle East respiratory syndrome coronavirus (MERS-CoV), SARS-CoV, and SARS-CoV-2. First described in 2016, the drug was derived from an antiviral library of small molecules intended to target emerging pathogenic RNA viruses. In vivo, remdesivir showed therapeutic and prophylactic effects in animal models of EBOV, MERS-CoV, SARS-CoV, and SARS-CoV-2 infection. However, the substance failed in a clinical trial on ebolavirus disease (EVD), where it was inferior to investigational monoclonal antibodies in an interim analysis. As there was no placebo control in this study, no conclusions on its efficacy in EVD can be made. In contrast, data from a placebo-controlled trial show beneficial effects for patients with COVID-19. Remdesivir reduces the time to recovery of hospitalized patients who require supplemental oxygen and may have a positive impact on mortality outcomes while having a favorable safety profile. Although this is an important milestone in the fight against COVID-19, approval of this drug will not be sufficient to solve the public health issues caused by the ongoing pandemic. Further scientific efforts are needed to evaluate the full potential of nucleoside analogs as treatment or prophylaxis of viral respiratory infections and to develop effective antivirals that are orally bioavailable.


Subject(s)
Adenosine Monophosphate/analogs & derivatives , Alanine/analogs & derivatives , Antiviral Agents/pharmacology , Coronavirus Infections/drug therapy , Hemorrhagic Fever, Ebola/drug therapy , Pneumonia, Viral/drug therapy , Severe Acute Respiratory Syndrome/drug therapy , Adenosine Monophosphate/pharmacokinetics , Adenosine Monophosphate/pharmacology , Alanine/pharmacokinetics , Alanine/pharmacology , Antiviral Agents/pharmacokinetics , Betacoronavirus/drug effects , Betacoronavirus/growth & development , Betacoronavirus/pathogenicity , COVID-19 , Clinical Trials as Topic , Compassionate Use Trials/methods , Coronavirus Infections/mortality , Coronavirus Infections/pathology , Coronavirus Infections/virology , Drug Administration Schedule , Ebolavirus/drug effects , Ebolavirus/growth & development , Ebolavirus/pathogenicity , Hemorrhagic Fever, Ebola/mortality , Hemorrhagic Fever, Ebola/pathology , Hemorrhagic Fever, Ebola/virology , Humans , Middle East Respiratory Syndrome Coronavirus/drug effects , Middle East Respiratory Syndrome Coronavirus/growth & development , Middle East Respiratory Syndrome Coronavirus/pathogenicity , Pandemics , Patient Safety , Pneumonia, Viral/mortality , Pneumonia, Viral/pathology , Pneumonia, Viral/virology , SARS Virus/drug effects , SARS Virus/growth & development , SARS Virus/pathogenicity , SARS-CoV-2 , Severe Acute Respiratory Syndrome/mortality , Severe Acute Respiratory Syndrome/pathology , Severe Acute Respiratory Syndrome/virology , Survival Analysis , Treatment Outcome
13.
Proc Natl Acad Sci U S A ; 117(43): 26946-26954, 2020 10 27.
Article in English | MEDLINE | ID: covidwho-841854

ABSTRACT

Remdesivir is a broad-spectrum antiviral nucleotide prodrug that has been clinically evaluated in Ebola virus patients and recently received emergency use authorization (EUA) for treatment of COVID-19. With approvals from the Federal Select Agent Program and the Centers for Disease Control and Prevention's Institutional Biosecurity Board, we characterized the resistance profile of remdesivir by serially passaging Ebola virus under remdesivir selection; we generated lineages with low-level reduced susceptibility to remdesivir after 35 passages. We found that a single amino acid substitution, F548S, in the Ebola virus polymerase conferred low-level reduced susceptibility to remdesivir. The F548 residue is highly conserved in filoviruses but should be subject to specific surveillance among novel filoviruses, in newly emerging variants in ongoing outbreaks, and also in Ebola virus patients undergoing remdesivir therapy. Homology modeling suggests that the Ebola virus polymerase F548 residue lies in the F-motif of the polymerase active site, a region that was previously identified as susceptible to resistance mutations in coronaviruses. Our data suggest that molecular surveillance of this region of the polymerase in remdesivir-treated COVID-19 patients is also warranted.


Subject(s)
Adenosine Monophosphate/analogs & derivatives , Alanine/analogs & derivatives , Antiviral Agents/pharmacology , Betacoronavirus/enzymology , Ebolavirus/enzymology , RNA-Dependent RNA Polymerase/chemistry , Viral Nonstructural Proteins/chemistry , Adenosine Monophosphate/pharmacology , Alanine/pharmacology , Betacoronavirus/chemistry , Cell Line , Drug Tolerance/genetics , Ebolavirus/drug effects , Ebolavirus/genetics , Humans , Models, Molecular , Mutation , RNA-Dependent RNA Polymerase/genetics , SARS-CoV-2 , Viral Nonstructural Proteins/genetics , Virus Replication/drug effects
14.
Proc Natl Acad Sci U S A ; 117(34): 20803-20813, 2020 08 25.
Article in English | MEDLINE | ID: covidwho-695945

ABSTRACT

Virus entry is a multistep process. It initiates when the virus attaches to the host cell and ends when the viral contents reach the cytosol. Genetically unrelated viruses can subvert analogous subcellular mechanisms and use similar trafficking pathways for successful entry. Antiviral strategies targeting early steps of infection are therefore appealing, particularly when the probability for successful interference through a common step is highest. We describe here potent inhibitory effects on content release and infection by chimeric vesicular stomatitis virus (VSV) containing the envelope proteins of Zaire ebolavirus (VSV-ZEBOV) or severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) (VSV-SARS-CoV-2) elicited by Apilimod and Vacuolin-1, small-molecule inhibitors of the main endosomal phosphatidylinositol-3-phosphate/phosphatidylinositol 5-kinase, PIKfyve. We also describe potent inhibition of SARS-CoV-2 strain 2019-nCoV/USA-WA1/2020 by Apilimod. These results define tools for studying the intracellular trafficking of pathogens elicited by inhibition of PIKfyve kinase and suggest the potential for targeting this kinase in developing small-molecule antivirals against SARS-CoV-2.


Subject(s)
Betacoronavirus/drug effects , Ebolavirus/drug effects , Heterocyclic Compounds, 4 or More Rings/pharmacology , Morpholines/pharmacology , Phosphatidylinositol 3-Kinases , Triazines/pharmacology , Virus Internalization/drug effects , Animals , Betacoronavirus/physiology , COVID-19 , Cells, Cultured , Coronavirus Infections , Ebolavirus/physiology , Gene Editing , Humans , Hydrazones , Pandemics , Phosphoinositide-3 Kinase Inhibitors/pharmacology , Pneumonia, Viral , Pyrimidines , SARS-CoV-2 , Viral Envelope Proteins/genetics
15.
Rev Med Virol ; 30(6): 1-13, 2020 11.
Article in English | MEDLINE | ID: covidwho-688978

ABSTRACT

Since the emergence of coronavirus disease 2019 (Covid-19), many studies have been performed to characterize severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and find the optimum way to combat this virus. After suggestions and assessments of several therapeutic options, remdesivir (GS-5734), a direct-acting antiviral drug previously tested against Ebola virus disease, was found to be moderately effective and probably safe for inhibiting SARS-CoV-2 replication. Finally, on 1 May 2020, remdesivir (GS-5734) was granted emergency use authorization as an investigational drug for the treatment of Covid-19 by the Food and Drug Administration. However, without a doubt, there are challenging days ahead. Here, we provide a review of the latest findings (based on preprints, post-prints, and news releases in scientific websites) related to remdesivir efficacy and safety for the treatment of Covid-19, along with covering remdesivir history from bench-to-bedside, as well as an overview of its mechanism of action. In addition, active clinical trials, as well as challenging issues related to the future of remdesivir in Covid-19, are covered. Up to the date of writing this review (19 May 2020), there is one finished randomized clinical trial and two completed non-randomized studies, in addition to some ongoing studies, including three observational studies, two expanded access studies, and seven active clinical trials registered on the clinicaltrials.gov and isrctn.com websites. Based on these studies, it seems that remdesivir could be an effective and probably safe treatment option for Covid-19. However, more randomized controlled studies are required.


Subject(s)
Adenosine Monophosphate/analogs & derivatives , Alanine/analogs & derivatives , Antiviral Agents/pharmacology , Antiviral Agents/therapeutic use , COVID-19/drug therapy , COVID-19/virology , Hemorrhagic Fever, Ebola/drug therapy , Hemorrhagic Fever, Ebola/virology , Adenosine Monophosphate/pharmacology , Adenosine Monophosphate/therapeutic use , Alanine/pharmacology , Alanine/therapeutic use , Clinical Trials as Topic , Ebolavirus/drug effects , Ebolavirus/physiology , Humans , SARS-CoV-2/drug effects , SARS-CoV-2/physiology , Treatment Outcome , Virus Replication/drug effects
16.
Trends Biotechnol ; 38(9): 943-947, 2020 09.
Article in English | MEDLINE | ID: covidwho-597298

ABSTRACT

Vaccine solutions rarely reach the public until after an outbreak abates; an Ebola vaccine was approved 5 years after peak outbreak and SARS, MERS, and Zika vaccines are still in clinical development. Despite massive leaps forward in rapid science, other regulatory bottlenecks are hamstringing the global effort for pandemic vaccines.


Subject(s)
Coronavirus Infections/prevention & control , Drug Approval/organization & administration , Hemorrhagic Fever, Ebola/prevention & control , Influenza, Human/prevention & control , Pandemics/prevention & control , Pneumonia, Viral/prevention & control , Viral Vaccines/biosynthesis , Betacoronavirus/drug effects , Betacoronavirus/immunology , Betacoronavirus/pathogenicity , COVID-19 , COVID-19 Vaccines , Coronavirus Infections/epidemiology , Coronavirus Infections/immunology , Coronavirus Infections/virology , Ebola Vaccines/administration & dosage , Ebola Vaccines/biosynthesis , Ebolavirus/drug effects , Ebolavirus/immunology , Ebolavirus/pathogenicity , Europe/epidemiology , Global Health/trends , Government Regulation , Hemorrhagic Fever, Ebola/epidemiology , Hemorrhagic Fever, Ebola/immunology , Hemorrhagic Fever, Ebola/virology , Humans , Influenza A Virus, H1N1 Subtype/genetics , Influenza A Virus, H1N1 Subtype/immunology , Influenza Vaccines/administration & dosage , Influenza Vaccines/biosynthesis , Influenza, Human/epidemiology , Influenza, Human/immunology , Influenza, Human/virology , Middle East Respiratory Syndrome Coronavirus/drug effects , Middle East Respiratory Syndrome Coronavirus/immunology , Middle East Respiratory Syndrome Coronavirus/pathogenicity , Pneumonia, Viral/epidemiology , Pneumonia, Viral/immunology , Pneumonia, Viral/virology , SARS Virus/drug effects , SARS Virus/immunology , SARS Virus/pathogenicity , SARS-CoV-2 , Severe Acute Respiratory Syndrome/epidemiology , Severe Acute Respiratory Syndrome/immunology , Severe Acute Respiratory Syndrome/prevention & control , Severe Acute Respiratory Syndrome/virology , United States/epidemiology , Viral Vaccines/administration & dosage , Zika Virus/drug effects , Zika Virus/immunology , Zika Virus/pathogenicity , Zika Virus Infection/epidemiology , Zika Virus Infection/immunology , Zika Virus Infection/prevention & control , Zika Virus Infection/virology
17.
Autophagy ; 16(12): 2267-2270, 2020 12.
Article in English | MEDLINE | ID: covidwho-592167

ABSTRACT

At a time when the world faces an emotional breakdown, crushing our dreams, if not, taking our lives, we realize that together we must fight the war against the COVID-19 outbreak even if almost the majority of the scientific community finds itself confined at home. Every day, we, scientists, listen to the latest news with its promises and announcements. Across the world, a surge of clinical trials trying to cure or slow down the coronavirus pandemic has been launched to bring hope instead of fear and despair. One first proposed clinical trial has drawn worldwide hype to the benefit of chloroquine (CQ), in the treatment of patients infected by the recently emerged deadly coronavirus (SARS-CoV-2). We should consider this information in light of the long-standing anti-inflammatory and anti-viral properties of CQ-related drugs. Yet, none of the articles promoting the use of CQ in the current pandemic evoked a possible molecular or cellular mechanism of action that could account for any efficacy. Here, given the interaction of viruses with macroautophagy (hereafter referred to as autophagy), a CQ-sensitive anti-viral safeguard pathway, we would like to discuss the pros, but also the cons concerning the current therapeutic options targeting this process.


Subject(s)
Anti-Inflammatory Agents/therapeutic use , Autophagy/drug effects , COVID-19/drug therapy , Chloroquine/therapeutic use , SARS-CoV-2/drug effects , Anti-Inflammatory Agents/pharmacology , Antiviral Agents/pharmacology , Antiviral Agents/therapeutic use , Autophagy/physiology , COVID-19/epidemiology , COVID-19/immunology , COVID-19/pathology , Chloroquine/analogs & derivatives , Chloroquine/pharmacology , Disease Eradication/methods , Drug Repositioning/methods , Drug Repositioning/trends , Drug-Related Side Effects and Adverse Reactions/epidemiology , Ebolavirus/drug effects , HIV/drug effects , History, 21st Century , Humans , Hydroxychloroquine/pharmacology , Hydroxychloroquine/therapeutic use , Malaria/drug therapy , Pandemics , Plasmodium malariae/drug effects , SARS-CoV-2/immunology , SARS-CoV-2/pathogenicity , Signal Transduction/drug effects , Signal Transduction/immunology
18.
J Cell Mol Med ; 24(12): 6988-6999, 2020 06.
Article in English | MEDLINE | ID: covidwho-186413

ABSTRACT

Outbreaks of infections with viruses like Sars-CoV-2, Ebola virus and Zika virus lead to major global health and economic problems because of limited treatment options. Therefore, new antiviral drug candidates are urgently needed. The promising new antiviral drug candidate silvestrol effectively inhibited replication of Corona-, Ebola-, Zika-, Picorna-, Hepatis E and Chikungunya viruses. Besides a direct impact on pathogens, modulation of the host immune system provides an additional facet to antiviral drug development because suitable immune modulation can boost innate defence mechanisms against the pathogens. In the present study, silvestrol down-regulated several pro- and anti-inflammatory cytokines (IL-6, IL-8, IL-10, CCL2, CCL18) and increased TNF-α during differentiation and activation of M1-macrophages, suggesting that the effects of silvestrol might cancel each other out. However, silvestrol amplified the anti-inflammatory potential of M2-macrophages by increasing expression of anti-inflammatory surface markers CD206, TREM2 and reducing release of pro-inflammatory IL-8 and CCL2. The differentiation of dendritic cells in the presence of silvestrol is characterized by down-regulation of several surface markers and cytokines indicating that differentiation is impaired by silvestrol. In conclusion, silvestrol influences the inflammatory status of immune cells depending on the cell type and activation status.


Subject(s)
Antiviral Agents/pharmacology , Betacoronavirus/drug effects , Cytokines/genetics , Dendritic Cells/drug effects , Immunologic Factors/pharmacology , Macrophages/drug effects , Triterpenes/pharmacology , Betacoronavirus/growth & development , Betacoronavirus/immunology , Cell Differentiation/drug effects , Chikungunya virus/drug effects , Chikungunya virus/growth & development , Chikungunya virus/immunology , Cytokines/classification , Cytokines/immunology , Dendritic Cells/immunology , Dendritic Cells/virology , Ebolavirus/drug effects , Ebolavirus/growth & development , Ebolavirus/immunology , Gene Expression Profiling , Gene Expression Regulation/drug effects , Hepatitis E virus/drug effects , Hepatitis E virus/growth & development , Hepatitis E virus/immunology , Humans , Immunity, Innate/drug effects , Macrophages/immunology , Macrophages/virology , Organ Specificity , Picornaviridae/drug effects , Picornaviridae/growth & development , Picornaviridae/immunology , Primary Cell Culture , SARS-CoV-2 , Signal Transduction , Zika Virus/drug effects , Zika Virus/growth & development , Zika Virus/immunology
19.
Pharm Res ; 37(4): 71, 2020 Mar 25.
Article in English | MEDLINE | ID: covidwho-18423

ABSTRACT

For the last 50 years we have known of a broad-spectrum agent tilorone dihydrochloride (Tilorone). This is a small-molecule orally bioavailable drug that was originally discovered in the USA and is currently used clinically as an antiviral in Russia and the Ukraine. Over the years there have been numerous clinical and non-clinical reports of its broad spectrum of antiviral activity. More recently we have identified additional promising antiviral activities against Middle East Respiratory Syndrome, Chikungunya, Ebola and Marburg which highlights that this old drug may have other uses against new viruses. This may in turn inform the types of drugs that we need for virus outbreaks such as for the new coronavirus severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Tilorone has been long neglected by the west in many respects but it deserves further reassessment in light of current and future needs for broad-spectrum antivirals.


Subject(s)
Antiviral Agents/pharmacology , Betacoronavirus/drug effects , Tilorone/pharmacology , Animals , COVID-19 , Chikungunya virus/drug effects , Coronavirus Infections/drug therapy , Ebolavirus/drug effects , Humans , Marburgvirus/drug effects , Middle East Respiratory Syndrome Coronavirus/drug effects , Pandemics , Pneumonia, Viral/drug therapy , SARS-CoV-2
20.
Antimicrob Agents Chemother ; 64(5)2020 04 21.
Article in English | MEDLINE | ID: covidwho-13986

ABSTRACT

Tilorone is a 50-year-old synthetic small-molecule compound with antiviral activity that is proposed to induce interferon after oral administration. This drug is used as a broad-spectrum antiviral in several countries of the Russian Federation. We have recently described activity in vitro and in vivo against the Ebola virus. After a broad screening of additional viruses, we now describe in vitro activity against Chikungunya virus (CHIK) and Middle Eastern respiratory syndrome coronavirus (MERS-CoV).


Subject(s)
Antiviral Agents/pharmacology , Chikungunya virus/drug effects , Communicable Diseases, Emerging/drug therapy , Coronavirus/drug effects , Ebolavirus/drug effects , Middle East Respiratory Syndrome Coronavirus/drug effects , Tilorone/pharmacology , Humans
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