scholarly journals Novel and potent inhibitors targeting DHODH, a rate-limiting enzyme in de novo pyrimidine biosynthesis, are broad-spectrum antiviral against RNA viruses including newly emerged coronavirus SARS-CoV-2

2020 ◽  
Author(s):  
Rui Xiong ◽  
Leike Zhang ◽  
Shiliang Li ◽  
Yuan Sun ◽  
Minyi Ding ◽  
...  
Keyword(s):  
Broad Spectrum ◽  
Influenza A ◽  
Ebola Virus ◽  
De Novo ◽  
Rna Viruses ◽  
Direct Acting Antiviral ◽  
Novel Coronavirus ◽  
Direct Acting ◽  
Viral Mutagenesis

AbstractEmerging and re-emerging RNA viruses occasionally cause epidemics and pandemics worldwide, such as the on-going outbreak of coronavirus SARS-CoV-2. Existing direct-acting antiviral (DAA) drugs cannot be applied immediately to new viruses because of virus-specificity, and the development of new DAA drugs from the beginning is not timely for outbreaks. Thus, host-targeting antiviral (HTA) drugs have many advantages to fight against a broad spectrum of viruses, by blocking the viral replication and overcoming the potential viral mutagenesis simultaneously. Herein, we identified two potent inhibitors of DHODH, S312 and S416, with favorable drug-like and pharmacokinetic profiles, which all showed broad-spectrum antiviral effects against various RNA viruses, including influenza A virus (H1N1, H3N2, H9N2), Zika virus, Ebola virus, and particularly against the recent novel coronavirus SARS-CoV-2. Our results are the first to validate that DHODH is an attractive host target through high antiviral efficacy in vivo and low virus replication in DHODH knocking-out cells. We also proposed the drug combination of DAA and HTA was a promising strategy for anti-virus treatment and proved that S312 showed more advantageous than Oseltamivir to treat advanced influenza diseases in severely infected animals. Notably, S416 is reported to be the most potent inhibitor with an EC50 of 17nM and SI value >5882 in SARS-CoV-2-infected cells so far. This work demonstrates that both our self-designed candidates and old drugs (Leflunomide/Teriflunomide) with dual actions of antiviral and immuno-repression may have clinical potentials not only to influenza but also to COVID-19 circulating worldwide, no matter such viruses mutate or not.

scholarly journals Novel and potent inhibitors targeting DHODH are broad-spectrum antivirals against RNA viruses including newly-emerged coronavirus SARS-CoV-2

2020 ◽  
Vol 11 (10) ◽  
pp. 723-739 ◽  
Author(s):  
Rui Xiong ◽  
Leike Zhang ◽  
Shiliang Li ◽  
Yuan Sun ◽  
Minyi Ding ◽  
...  
Keyword(s):  
Broad Spectrum ◽  
Influenza A ◽  
Ebola Virus ◽  
Rna Viruses ◽  
The Novel ◽  
Knock Out ◽  
Infected Cells ◽  
Virus Zika ◽  
Novel Coronavirus

Abstract Emerging and re-emerging RNA viruses occasionally cause epidemics and pandemics worldwide, such as the on-going outbreak of the novel coronavirus SARS-CoV-2. Herein, we identified two potent inhibitors of human DHODH, S312 and S416, with favorable drug-likeness and pharmacokinetic profiles, which all showed broad-spectrum antiviral effects against various RNA viruses, including influenza A virus, Zika virus, Ebola virus, and particularly against SARS-CoV-2. Notably, S416 is reported to be the most potent inhibitor so far with an EC50 of 17 nmol/L and an SI value of 10,505.88 in infected cells. Our results are the first to validate that DHODH is an attractive host target through high antiviral efficacy in vivo and low virus replication in DHODH knock-out cells. This work demonstrates that both S312/S416 and old drugs (Leflunomide/Teriflunomide) with dual actions of antiviral and immuno-regulation may have clinical potentials to cure SARS-CoV-2 or other RNA viruses circulating worldwide, no matter such viruses are mutated or not.

A review on Remdesivir: A broad-spectrum antiviral molecule for possible COVID-19 treatment

2021 ◽  
Vol 21 ◽  
Author(s):  
Jabeena Khazir ◽  
Tariq Maqbool ◽  
Bilal Ahmad Mir
Keyword(s):  
Clinical Trials ◽  
Broad Spectrum ◽  
Ebola Virus ◽  
Controlled Trial ◽  
In Vivo Studies ◽  
Therapeutic Drug ◽  
Viral Agent ◽  
Double Blind

: Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), a novel coronavirus strain and the causative agent of COVID-19 was identified to have emerged in Wuhan, China, in December 2019 [1]. This pandemic situation and magnitude of suffering has led to global effort to find out effective measures for discovery of new specific drugs and vaccines to combat this deadly disease. In addition to many initiatives to develop vaccines for protective immunity against SARS-CoV-2, some of which are at various stages of clinical trials researchers worldwide are currently using available conventional therapeutic drugs with potential to combat the disease effectively in other viral infections and it is believed that these antiviral drugs could act as a promising immediate alternative. Remdesivir (RDV), a broad-spectrum anti-viral agent, initially developed for the treatment of Ebola virus (EBOV) and known to show promising efficiency in in vitro and in vivo studies against SARS and MERS coronaviruses, is now being investigated against SARS-CoV-2. On May 1, 2020, The U.S. Food and Drug Administration (FDA) granted Emergency Use Authorization (EUA) for RDV to treat COVID-19 patients [2]. A number of multicentre clinical trials are on-going to check the safety and efficacy of RDV for the treatment of COVID-19. Results of published double blind, and placebo-controlled trial on RDV against SARS-CoV-2, showed that RDV administration led to faster clinical improvement in severe COVID-19 patients compared to placebo. This review highlights the available knowledge about RDV as a therapeutic drug for coronaviruses and its preclinical and clinical trials against COVID-19.

scholarly journals Viruses harness YxxØ motif to interact with host AP2M1 for replication: A vulnerable broad-spectrum antiviral target

2020 ◽  
Vol 6 (35) ◽  
pp. eaba7910
Author(s):  
Shuofeng Yuan ◽  
Hin Chu ◽  
Jingjing Huang ◽  
Xiaoyu Zhao ◽  
Zi-Wei Ye ◽  
...  
Keyword(s):  
Broad Spectrum ◽  
Influenza A ◽  
Host Protein ◽  
Influenza A Viruses ◽  
Protein Protein Interaction ◽  
Enterovirus A71 ◽  
Evolutionarily Conserved ◽  
Immunodeficiency Virus

Targeting a universal host protein exploited by most viruses would be a game-changing strategy that offers broad-spectrum solution and rapid pandemic control including the current COVID-19. Here, we found a common YxxØ-motif of multiple viruses that exploits host AP2M1 for intracellular trafficking. A library chemical, N-(p-amylcinnamoyl)anthranilic acid (ACA), was identified to interrupt AP2M1-virus interaction and exhibit potent antiviral efficacy against a number of viruses in vitro and in vivo, including the influenza A viruses (IAVs), Zika virus (ZIKV), human immunodeficiency virus, and coronaviruses including MERS-CoV and SARS-CoV-2. YxxØ mutation, AP2M1 depletion, or disruption by ACA causes incorrect localization of viral proteins, which is exemplified by the failure of nuclear import of IAV nucleoprotein and diminished endoplasmic reticulum localization of ZIKV-NS3 and enterovirus-A71-2C proteins, thereby suppressing viral replication. Our study reveals an evolutionarily conserved mechanism of protein-protein interaction between host and virus that can serve as a broad-spectrum antiviral target.

scholarly journals Remdesivir is a direct-acting antiviral that inhibits RNA-dependent RNA polymerase from severe acute respiratory syndrome coronavirus 2 with high potency

2020 ◽  
Vol 295 (20) ◽  
pp. 6785-6797 ◽  
Author(s):  
Calvin J. Gordon ◽  
Egor P. Tchesnokov ◽  
Emma Woolner ◽  
Jason K. Perry ◽  
Joy Y. Feng ◽  
...  
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Rna Polymerase ◽  
Rna Synthesis ◽  
Ebola Virus ◽  
Lassa Virus ◽  
Nonstructural Proteins ◽  
Rna Dependent Rna Polymerase ◽  
Direct Acting Antiviral ◽  
Nucleotide Analogue ◽  
Direct Acting

Effective treatments for coronavirus disease 2019 (COVID-19) are urgently needed to control this current pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Replication of SARS-CoV-2 depends on the viral RNA-dependent RNA polymerase (RdRp), which is the likely target of the investigational nucleotide analogue remdesivir (RDV). RDV shows broad-spectrum antiviral activity against RNA viruses, and previous studies with RdRps from Ebola virus and Middle East respiratory syndrome coronavirus (MERS-CoV) have revealed that delayed chain termination is RDV's plausible mechanism of action. Here, we expressed and purified active SARS-CoV-2 RdRp composed of the nonstructural proteins nsp8 and nsp12. Enzyme kinetics indicated that this RdRp efficiently incorporates the active triphosphate form of RDV (RDV-TP) into RNA. Incorporation of RDV-TP at position i caused termination of RNA synthesis at position i+3. We obtained almost identical results with SARS-CoV, MERS-CoV, and SARS-CoV-2 RdRps. A unique property of RDV-TP is its high selectivity over incorporation of its natural nucleotide counterpart ATP. In this regard, the triphosphate forms of 2′-C-methylated compounds, including sofosbuvir, approved for the management of hepatitis C virus infection, and the broad-acting antivirals favipiravir and ribavirin, exhibited significant deficits. Furthermore, we provide evidence for the target specificity of RDV, as RDV-TP was less efficiently incorporated by the distantly related Lassa virus RdRp, and termination of RNA synthesis was not observed. These results collectively provide a unifying, refined mechanism of RDV-mediated RNA synthesis inhibition in coronaviruses and define this nucleotide analogue as a direct-acting antiviral.

scholarly journals Role of Initiating Nucleoside Triphosphate Concentrations in the Regulation of Influenza Virus Replication and Transcription

2008 ◽  
Vol 82 (14) ◽  
pp. 6902-6910 ◽  
Author(s):  
Frank T. Vreede ◽  
Hugh Gifford ◽  
George G. Brownlee
Keyword(s):  
Influenza Virus ◽  
Virus Replication ◽  
Influenza A ◽  
De Novo ◽  
Nucleoside Triphosphate ◽  
Ribonucleoprotein Complexes ◽  
Influenza Virus Replication ◽  
High Concentrations

ABSTRACT The mechanisms regulating the synthesis of mRNA, cRNA, and viral genomic RNA (vRNA) by the influenza A virus RNA-dependent RNA polymerase are not fully understood. Previous studies in our laboratory have shown that virion-derived viral ribonucleoprotein complexes synthesize both mRNA and cRNA in vitro and early in the infection cycle in vivo. Our continued studies showed that de novo synthesis of cRNA in vitro is more sensitive to the concentrations of ATP, CTP, and GTP than capped-primer-dependent synthesis of mRNA. Using rescued recombinant influenza A/WSN/33 viruses, we now demonstrate that the 3′-terminal sequence of the vRNA promoter dictates the requirement for a high nucleoside triphosphate (NTP) concentration during de novo-initiated replication to cRNA, whereas this is not the case for the extension of capped primers during transcription to mRNA. In contrast to some other viral polymerases, for which only the initiating NTP is required at high concentrations, influenza virus polymerase requires high concentrations of the first three NTPs. In addition, we show that base pair mutations in the vRNA promoter can lead to nontemplated dead-end mutations during replication to cRNA in vivo. Based on our observations, we propose a new model for the de novo initiation of influenza virus replication.

scholarly journals Targeting viral genome synthesis as broad-spectrum approach against RNA virus infections

2020 ◽  
Vol 28 ◽  
pp. 204020662097678
Author(s):  
Johanna Huchting
Keyword(s):  
Broad Spectrum ◽  
Viral Genome ◽  
De Novo ◽  
Rna Viruses ◽  
Rna Virus ◽  
Antiviral Drug ◽  
Building Blocks ◽  
Structural Features ◽  
Pathogen Transmission ◽  
Nucleotide Synthesis

Zoonotic spillover, i.e. pathogen transmission from animal to human, has repeatedly introduced RNA viruses into the human population. In some cases, where these viruses were then efficiently transmitted between humans, they caused large disease outbreaks such as the 1918 flu pandemic or, more recently, outbreaks of Ebola and Coronavirus disease. These examples demonstrate that RNA viruses pose an immense burden on individual and public health with outbreaks threatening the economy and social cohesion within and across borders. And while emerging RNA viruses are introduced more frequently as human activities increasingly disrupt wild-life eco-systems, therapeutic or preventative medicines satisfying the “one drug-multiple bugs”-aim are unavailable. As one central aspect of preparedness efforts, this review digs into the development of broadly acting antivirals via targeting viral genome synthesis with host- or virus-directed drugs centering around nucleotides, the genomes’ universal building blocks. Following the first strategy, selected examples of host de novo nucleotide synthesis inhibitors are presented that ultimately interfere with viral nucleic acid synthesis, with ribavirin being the most prominent and widely used example. For directly targeting the viral polymerase, nucleoside and nucleotide analogues (NNAs) have long been at the core of antiviral drug development and this review illustrates different molecular strategies by which NNAs inhibit viral infection. Highlighting well-known as well as recent, clinically promising compounds, structural features and mechanistic details that may confer broad-spectrum activity are discussed. The final part addresses limitations of NNAs for clinical development such as low efficacy or mitochondrial toxicity and illustrates strategies to overcome these.

scholarly journals Reduced Nucleoprotein availability impairs negative-sense RNA virus replication and promotes host recognition

2021 ◽  
Author(s):  
Benjamin E. Nilsson-Payant ◽  
Daniel Blanco-Melo ◽  
Skyler Uhl ◽  
Beatriz Escudero-Pérez ◽  
Silke Olschewski ◽  
...  
Keyword(s):  
Host Response ◽  
Measles Virus ◽  
Influenza A ◽  
Ebola Virus ◽  
Rna Viruses ◽  
Viral Rna ◽  
Genome Replication ◽  
Replication Machinery ◽  
Molecular Patterns ◽  
Negative Sense

Negative-sense RNA viruses (NSVs) rely on prepackaged viral RNA-dependent RNA polymerases (RdRp) to replicate and transcribe their viral genomes. Their replication machinery consists of an RdRp bound to viral RNA which is wound around a nucleoprotein (NP) scaffold, forming a viral ribonucleoprotein complex. NSV NP is known to regulate transcription and replication of genomic RNA, however its role in maintaining and protecting the viral genetic material is unknown. Here, we exploited host microRNA expression to target NP of influenza A virus and Sendai virus to ascertain how this would impact genomic levels and the host response to infection. We find that in addition to inducing a drastic decrease in genome replication, the antiviral host response in the absence of NP is dramatically enhanced. Additionally, our data shows that insufficient levels of NP prevent the replication machinery of these NSVs to process full-length genomes, resulting in aberrant replication products which form pathogen-associated molecular patterns in the process. These dynamics facilitate immune recognition by cellular pattern recognition receptors leading to a strong host antiviral response. Moreover, we observe that the consequences of limiting NP levels are universal amongst NSVs including Ebola virus, Lassa virus and Measles virus. Overall, these results provide new insights into viral genome replication of negative-sense RNA viruses and highlight novel avenues towards developing effective antiviral strategies, adjuvants, and/or live-attenuated vaccines. IMPORTANCE Negative-sense RNA viruses comprise some of the most important known human pathogens, including influenza A virus, measles virus and Ebola virus. These viruses possess RNA genomes that are unreadable to the host as they require specific viral RNA dependent RNA polymerases in conjunction with other viral proteins such as nucleoprotein to be replicated and transcribed. As this process generates a significant amount of pathogen-associated molecular patterns, this phylum of viruses can result in a robust induction of the intrinsic host cellular response. To circumvent these defenses, these viruses form tightly regulated ribonucleoprotein replication complexes in order to protect their genomes from detection and to prevent excessive aberrant replication. Here we demonstrate the balance that negative-sense RNA viruses must achieve to both replicate efficiently and to avoid induction of the host defenses.

De-novo versus recurrent hepatocellular carcinoma following direct-acting antiviral therapy for hepatitis C virus

2018 ◽  
Vol 30 (1) ◽  
pp. 39-43 ◽  
Author(s):  
Ashraf O. Abdelaziz ◽  
Mohamed M. Nabil ◽  
Ahmed H. Abdelmaksoud ◽  
Hend I. Shousha ◽  
Ahmed A. Cordie ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Antiviral Therapy ◽  
De Novo ◽  
Direct Acting Antiviral ◽  
Recurrent Hepatocellular Carcinoma ◽  
Direct Acting

scholarly journals HCC in the Era of Direct-Acting Antiviral Agents (DAAs): Surgical and Other Curative or Palliative Strategies in the Elderly

Cancers ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 3025
Author(s):  
Stefania Brozzetti ◽  
Marsia Tancredi ◽  
Simone Bini ◽  
Chiara De Lucia ◽  
Jessica Antimi ◽  
...  
Keyword(s):  
De Novo ◽  
Antiviral Agents ◽  
Sustained Viral Response ◽  
Incidence Rates ◽  
Liver Malignancies ◽  
Direct Acting Antiviral ◽  
Significant Difference ◽  
Historical Group ◽  
Direct Acting ◽  
Direct Acting Antiviral Agents

Hepatocellular carcinoma (HCC) accounts for 75–85% of primary liver malignancies, and elderlies have the highest incidence rates. Direct-acting antiviral agents (DAAs) have shown satisfying results in terms of HCV sustained viral response (SVR). However, data regarding HCC risk post-DAA-SVR is still conflicting. This study aims to consider HCC onset in moderate underlying liver disease. We conducted a retrospective study on 227 chronically infected patients (cHCV), treated with DAAs. Patients were divided into three groups: “de novo occurrent HCC”, “recurrent HCC”, and “without HCC”. Fifty-six patients aged <65 years (yDAA) were studied separately. HCC patients aged ≥65 years (DAA-HCC) were compared to a historical group of 100 elderly HCC patients, treated with peginterferon (Peg-IFN) ± ribavirin antiviral agents, non-SVR (hHCC). The HCC prevalence in DAA patients was 32.75%: “de novo occurrent’’ 18.13% and “recurrent’’ 14.62%, despite 42.85% of them having no fibrosis to mild or moderate fibrosis (F0-F1-F2). yDAA showed 5.36% “de novo occurrent” HCC. Curative procedure rates were compared between DAA-HCC and hHCC at the first and at recurrent presentation (22 (39.29%) vs. 72 (72%); 17 (30.36%) vs. 70 (70%), respectively (p < 0.001)). No significant difference was found in 3-year OS (p = 0.6). However, in cause-specific mortality analysis, HCC-related death was higher in the DAA-treated group, whereas cirrhosis-related death was more common in the historical group (p = 0.0288), considering together the two causes of death. A more accurate patient stratification according to multifactorial and new diagnostic investigations identifying HCC risk might allow an improvement in management and access to curative therapies.

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