scholarly journals Enhancing the Antiviral Potency of Nucleobases for Potential Broad-Spectrum Antiviral Therapies

Viruses ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 2508
Author(s):  
Ruben Soto-Acosta ◽  
Tiffany C. Edwards ◽  
Christine D. Dreis ◽  
Venkatramana D. Krishna ◽  
Maxim C-J. Cheeran ◽  
...  
Keyword(s):  
Small Molecules ◽  
Broad Spectrum ◽  
Influenza A ◽  
Ebola Virus ◽  
Rna Virus ◽  
Virus Infections ◽  
Emerging Viruses ◽  
First Line ◽  
Antiviral Therapies ◽  
Rapid Clearance

Broad-spectrum antiviral therapies hold promise as a first-line defense against emerging viruses by blunting illness severity and spread until vaccines and virus-specific antivirals are developed. The nucleobase favipiravir, often discussed as a broad-spectrum inhibitor, was not effective in recent clinical trials involving patients infected with Ebola virus or SARS-CoV-2. A drawback of favipiravir use is its rapid clearance before conversion to its active nucleoside-5′-triphosphate form. In this work, we report a synergistic reduction of flavivirus (dengue, Zika), orthomyxovirus (influenza A), and coronavirus (HCoV-OC43 and SARS-CoV-2) replication when the nucleobases favipiravir or T-1105 were combined with the antimetabolite 6-methylmercaptopurine riboside (6MMPr). The 6MMPr/T-1105 combination increased the C-U and G-A mutation frequency compared to treatment with T-1105 or 6MMPr alone. A further analysis revealed that the 6MMPr/T-1105 co-treatment reduced cellular purine nucleotide triphosphate synthesis and increased conversion of the antiviral nucleobase to its nucleoside-5′-monophosphate, -diphosphate, and -triphosphate forms. The 6MMPr co-treatment specifically increased production of the active antiviral form of the nucleobases (but not corresponding nucleosides) while also reducing levels of competing cellular NTPs to produce the synergistic effect. This in-depth work establishes a foundation for development of small molecules as possible co-treatments with nucleobases like favipiravir in response to emerging RNA virus infections.

Therapeutic Exploitation of Viral Interference

2020 ◽  
Vol 20 (4) ◽  
pp. 423-432 ◽  
Author(s):  
Imre Kovesdi ◽  
Tibor Bakacs
Keyword(s):  
Broad Spectrum ◽  
Viral Infections ◽  
Viral Vector ◽  
Antiviral Treatment ◽  
Type I ◽  
Virus Infections ◽  
Emerging Viruses ◽  
Viral Interference ◽  
Pathogenic Virus ◽  
Hepatitis C Rna

: Viral interference, originally, referred to a state of temporary immunity, is a state whereby infection with a virus limits replication or production of a second infecting virus. However, replication of a second virus could also be dominant over the first virus. In fact, dominance can alternate between the two viruses. Expression of type I interferon genes is many times upregulated in infected epithelial cells. Since the interferon system can control most, if not all, virus infections in the absence of adaptive immunity, it was proposed that viral induction of a nonspecific localized temporary state of immunity may provide a strategy to control viral infections. Clinical observations also support such a theory, which gave credence to the development of superinfection therapy (SIT). SIT is an innovative therapeutic approach where a non-pathogenic virus is used to infect patients harboring a pathogenic virus. : For the functional cure of persistent viral infections and for the development of broad- spectrum antivirals against emerging viruses a paradigm shift was recently proposed. Instead of the virus, the therapy should be directed at the host. Such a host-directed-therapy (HDT) strategy could be the activation of endogenous innate immune response via toll-like receptors (TLRs). Superinfection therapy is such a host-directed-therapy, which has been validated in patients infected with two completely different viruses, the hepatitis B (DNA), and hepatitis C (RNA) viruses. SIT exerts post-infection interference via the constant presence of an attenuated non-pathogenic avian double- stranded (ds) RNA viral vector which boosts the endogenous innate (IFN) response. SIT could, therefore, be developed into a biological platform for a new “one drug, multiple bugs” broad-spectrum antiviral treatment approach.

scholarly journals Fludarabine Inhibits Infection of Zika Virus, SFTS Phlebovirus, and Enterovirus A71

Viruses ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 774
Author(s):  
Chengfeng Gao ◽  
Chunxia Wen ◽  
Zhifeng Li ◽  
Shuhan Lin ◽  
Shu Gao ◽  
...  
Keyword(s):  
Broad Spectrum ◽  
Zika Virus ◽  
Therapeutic Agent ◽  
Viral Infections ◽  
Rna Virus ◽  
Emerging Viruses ◽  
Enterovirus A71 ◽  
Ic50 Values ◽  
High Doses ◽  
Severe Fever

Viral infections are one of the leading causes in human mortality and disease. Broad-spectrum antiviral drugs are a powerful weapon against new and re-emerging viruses. However, viral resistance to existing broad-spectrum antivirals remains a challenge, which demands development of new broad-spectrum therapeutics. In this report, we showed that fludarabine, a fluorinated purine analogue, effectively inhibited infection of RNA viruses, including Zika virus, Severe fever with thrombocytopenia syndrome virus, and Enterovirus A71, with all IC50 values below 1 μM in Vero, BHK21, U251 MG, and HMC3 cells. We observed that fludarabine has shown cytotoxicity to these cells only at high doses indicating it could be safe for future clinical use if approved. In conclusion, this study suggests that fludarabine could be developed as a potential broad-spectrum anti-RNA virus therapeutic agent.

scholarly journals Screening for Anti-Influenza Actives of Prefractionated Traditional Chinese Medicines

2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Qianli Kang ◽  
Yanyan Wang ◽  
Qinghua Cui ◽  
Lili Gong ◽  
Yong Yang ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Ebola Virus ◽  
Antiviral Treatment ◽  
Traditional Chinese Medicines ◽  
Virus Infections ◽  
Clinical Practices ◽  
Emerging Viruses ◽  
Gaussia Luciferase ◽  
Chinese Medicines ◽  
Antiviral Activities

Traditional Chinese medicines (TCMs) have proven to possess advantages in counteracting virus infections according to clinical practices. It’s therefore of great value to discover novel antivirals from TCMs. In this paper, One hundred medicinal plants which have been included in TCM prescriptions for antiviral treatment were selected and prefractionated into 5 fractions each by sequentially using cyclohexane, dichloromethane, ethyl acetate, n-butanol, and water. 500 TCM-simplified extracts were then subjected to a phenotypic screening using a recombinant IAV expressing Gaussia luciferase. Ten TCM fractions were identified to possess antiviral activities against influenza virus. The IC50’s of the hit fractions range from 1.08 to 6.45 μg/mL, while the SIs, from 7.52 to 98.40. Furthermore, all the ten hit fractions inhibited the propagation of progeny influenza virus significantly at 20 μg/mL. The hit TCM fractions deserve further isolation for responsible constituents leading towards anti-influenza drugs. Moreover, a library consisting of 500 simplified TCM extracts was established, facilitating antiviral screening in quick response to emerging and re-emerging viruses such as Ebola virus and current SARS-CoV-2 pandemic.

scholarly journals Pulmonary Surfactant Protein D in First-Line Innate Defence against Influenza A Virus Infections

2013 ◽  
Vol 5 (3) ◽  
pp. 197-208 ◽  
Author(s):  
Marine L.B. Hillaire ◽  
Henk P. Haagsman ◽  
Albert D.M.E. Osterhaus ◽  
Guus F. Rimmelzwaan ◽  
Martin van Eijk
Keyword(s):  
Influenza A Virus ◽  
Pulmonary Surfactant ◽  
Influenza A ◽  
Surfactant Protein ◽  
Surfactant Protein D ◽  
Virus Infections ◽  
First Line ◽  
Innate Defence ◽  
Pulmonary Surfactant Protein

scholarly journals Sirtuins Are Evolutionarily Conserved Viral Restriction Factors

mBio ◽  
2014 ◽  
Vol 5 (6) ◽  
Author(s):  
Emre Koyuncu ◽  
Hanna G. Budayeva ◽  
Yana V. Miteva ◽  
Dante P. Ricci ◽  
Thomas J. Silhavy ◽  
...  
Keyword(s):  
Broad Spectrum ◽  
Influenza A ◽  
Rna Virus ◽  
Immune Defense ◽  
Human Pathogens ◽  
Activity Increase ◽  
Virus Growth ◽  
Cell Defense ◽  
Influenza A H1n1 ◽  
Evolutionarily Conserved

ABSTRACTThe seven human sirtuins are a family of ubiquitously expressed and evolutionarily conserved NAD+-dependent deacylases/mono-ADP ribosyltransferases that regulate numerous cellular and organismal functions, including metabolism, cell cycle, and longevity. Here, we report the discovery that all seven sirtuins have broad-range antiviral properties. We demonstrate that small interfering RNA (siRNA)-mediated knockdown of individual sirtuins and drug-mediated inhibition of sirtuin enzymatic activity increase the production of virus progeny in infected human cells. This impact on virus growth is observed for both DNA and RNA viruses. Importantly, sirtuin-activating drugs inhibit the replication of diverse viruses, as we demonstrate for human cytomegalovirus, a slowly replicating DNA virus, and influenza A (H1N1) virus, an RNA virus that multiplies rapidly. Furthermore, sirtuin defense functions are evolutionarily conserved, since CobB, the sirtuin homologue inEscherichia coli, protects against bacteriophages. Altogether, our findings establish sirtuins as broad-spectrum and evolutionarily conserved components of the immune defense system, providing a framework for elucidating a new set of host cell defense mechanisms and developing sirtuin modulators with antiviral activity.IMPORTANCEWe live in a sea of viruses, some of which are human pathogens. These pathogenic viruses exhibit numerous differences: DNA or RNA genomes, enveloped or naked virions, nuclear or cytoplasmic replication, diverse disease symptoms, etc. Most antiviral drugs target specific viral proteins. Consequently, they often work for only one virus, and their efficacy can be compromised by the rapid evolution of resistant variants. There is a need for the identification of host proteins with broad-spectrum antiviral functions, which provide effective targets for therapeutic treatments that limit the evolution of viral resistance. Here, we report that sirtuins present such an opportunity for the development of broad-spectrum antiviral treatments, since our findings highlight these enzymes as ancient defense factors that protect against a variety of viral pathogens.

scholarly journals Ebola Virus ? A Global Threat

2015 ◽  
Vol 5 (1) ◽  
pp. 44-51
Author(s):  
Mejbah Uddin Ahmed ◽  
Sushmita Roy
Keyword(s):  
Nonhuman Primates ◽  
Ebola Virus ◽  
Rna Virus ◽  
Close Contact ◽  
Multiorgan Failure ◽  
Hemorrhagic Fever ◽  
Human Infection ◽  
Current Data ◽  
Sub Saharan Africa ◽  
Virus Infections

Ebola virus is a filamentous, enveloped, non-segmented, single-stranded, negative-sense RNA virus. It belongs to the Filoviridae and was first recognized near the Ebola River valley in Zaire in 1976. Since then most of the outbreaks have occurred to both human and nonhuman primates in sub-Saharan Africa. Ebola virus causes highly fatal hemorrhagic fever in human and nonhuman primates. In addition to hemorrhagic fever, it could be used as a bioterrorism agent. Although its natural reservoir is yet to be proven, current data suggest that fruit bats are the possibility. Infection has also been documented through the handling of infected chimpanzees, gorillas, monkeys, forest antelope and porcupines. Human infection is caused through close contact with the blood, secretion, organ or other body fluids of infected animal. Human-to-human transmission is also possible. Ebola virus infections are characterized by immune suppression and a systemic inflammatory response that causes impairment of the vascular, coagulation, and immune systems, leading to multiorgan failure and shock. The virus constitutes an important public health threat in Africa and also worldwide as no effective treatment or vaccine is available till now DOI: http://dx.doi.org/10.3329/jemc.v5i1.21497 J Enam Med Col 2015; 5(1): 44-51

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 Role of Remdesivir in COVID-19

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Sumera Shaeen ◽  
◽  
Naila Abdul Sattar ◽  
Mohammad Ibrahim ◽  
Muhammad Irfan ◽  
...  
Keyword(s):  
Hepatitis C ◽  
Infectious Diseases ◽  
Rna Polymerase ◽  
Broad Spectrum ◽  
Common Cold ◽  
Rna Virus ◽  
Antiviral Drug ◽  
Virus Infections ◽  
Polymerase Inhibitor

Remdesivir is an antiviral drug showed broad spectrum against viruses, also RNA polymerase inhibitor that’s why use to treat a variety of RNA virus infections. It is considered to be more effective against family of respiratory infection causing viruses including corona virus as compared to those whom it was originally synthesized like Hepatitis C and common cold viruses. On October 8, 2020, The National Institute of Allergy and Infectious Diseases has completed trials on COVID-19 patients and found Remdesivir satisfactory and beneficiary choice towards the recovery stairs of COVID-19. The pandemic of Covid-19 might wean down by season, but the possibility of reoccurrence exists. Thus, future clearance of Remdesivir might be critical for ensuring effective treatment, diminish mortality and permit early release.

scholarly journals Antiviral activity of Glucosylceramide synthase inhibitors against SARS-CoV-2 and other RNA virus infections

2020 ◽  
Author(s):  
Einat. B. Vitner ◽  
Roy Avraham ◽  
Hagit Achdout ◽  
Hadas Tamir ◽  
Avi Agami ◽  
...  
Keyword(s):  
Broad Spectrum ◽  
Influenza A ◽  
Cell Membranes ◽  
Rna Viruses ◽  
Rna Virus ◽  
Antiviral Drugs ◽  
Membrane Dynamics ◽  
Biologically Active ◽  
Phase Iii ◽  
Glucosylceramide Synthase

AbstractThe need for antiviral drugs is real and relevant. Broad spectrum antiviral drugs have a particular advantage when dealing with rapid disease outbreaks, such as the current COVID-19 pandemic. Since viruses are completely dependent on internal cell mechanisms, they must cross cell membranes during their lifecycle, creating a dependence on processes involving membrane dynamics. Thus, in this study we examined whether the synthesis of glycosphingolipids, biologically active components of cell membranes, can serve as an antiviral therapeutic target. We examined the antiviral effect of two specific inhibitors of GlucosylCeramide synthase (GCS); (i) Genz-123346, an analogue of the FDA-approved drug Cerdelga®, (ii) GENZ-667161, an analogue of venglustat which is currently under phase III clinical trials. We found that both GCS inhibitors inhibit the replication of four different enveloped RNA viruses of different genus, organ-target and transmission route: (i) Neuroinvasive Sindbis virus (SVNI), (ii) West Nile virus (WNV), (iii) Influenza A virus, and (iv) SARS-CoV-2. Moreover, GCS inhibitors significantly increase the survival rate of SVNI-infected mice. Our data suggest that GCS inhibitors can potentially serve as a broad-spectrum antiviral therapy and should be further examined in preclinical and clinical trial. Analogues of the specific compounds tested have already been studied clinically, implying they can be fast-tracked for public use. With the current COVID-19 pandemic, this may be particularly relevant to SARS-CoV-2 infection.One Sentence SummaryAn analogue of Cerdelga®, an FDA-approved drug, is effective against a broad range of RNA-viruses including the newly emerging SARS-CoV-2.

scholarly journals Tilorone, a Broad-Spectrum Antiviral for Emerging Viruses

2020 ◽  
Vol 64 (5) ◽  
Author(s):  
Sean Ekins ◽  
Peter B. Madrid
Keyword(s):  
Broad Spectrum ◽  
Chikungunya Virus ◽  
Ebola Virus ◽  
Middle Eastern ◽  
Emerging Viruses ◽  
Small Molecule Compound ◽  
The Russian Federation ◽  
Synthetic Small Molecule

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).

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