scholarly journals Ebolavirus Entry: From Molecular Characterization to Drug Discovery

2019 ◽  
Author(s):  
Cristiano Salata ◽  
Arianna Calistri ◽  
Gualtiero Alvisi ◽  
Michele Celestino ◽  
Cristina Parolin ◽  
...  
Keyword(s):  
Life Cycle ◽  
Viral Entry ◽  
Large Scale ◽  
Ebola Virus ◽  
Virus Disease ◽  
Drug Repurposing ◽  
In Vitro Study ◽  
Rational Drug Design ◽  
Global Public Health

Ebola Virus Disease (EVD) is one of the most lethal transmissible infections characterized by a high fatality rate, and caused by members of the Filoviridae family. The recent large outbreak of EVD in West Africa (2013-2016), highlighted the worldwide danger of this disease and its impact on global public health and economy. The development of highly needed anti-Filoviridae antivirals has been so far hampered by the shortage of tools to study their life cycle in vitro, and therefore screen for potential active compounds outside a biosafety level-4 (BSL-4) containment. Importantly, the development of surrogate models to in vitro study of Filoviridae entry in a BSL-2 setting, such as viral pseudotypes and Ebola virus like particles, tremendously boosted both our knowledge on viral life cycle and the identification of promising anti-Filoviridae compounds interfering with viral entry. In this context, the combination of such surrogate systems with large-scale small molecule compounds and haploid genetic screenings, as well as rational drug design and drug repurposing approaches will prove priceless in our quest for the development of a treatment for EVD.

scholarly journals Ebola Virus Entry: From Molecular Characterization to Drug Discovery

Viruses ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 274 ◽  
Author(s):  
Cristiano Salata ◽  
Arianna Calistri ◽  
Gualtiero Alvisi ◽  
Michele Celestino ◽  
Cristina Parolin ◽  
...  
Keyword(s):  
Life Cycle ◽  
Viral Entry ◽  
Large Scale ◽  
Ebola Virus ◽  
Virus Disease ◽  
Virus Entry ◽  
Drug Repurposing ◽  
Rational Drug Design ◽  
Global Public Health

Ebola Virus Disease (EVD) is one of the most lethal transmissible infections, characterized by a high fatality rate, and caused by a member of the Filoviridae family. The recent large outbreak of EVD in Western Africa (2013–2016) highlighted the worldwide threat represented by the disease and its impact on global public health and the economy. The development of highly needed anti-Ebola virus antivirals has been so far hampered by the shortage of tools to study their life cycle in vitro, allowing to screen for potential active compounds outside a biosafety level-4 (BSL-4) containment. Importantly, the development of surrogate models to study Ebola virus entry in a BSL-2 setting, such as viral pseudotypes and Ebola virus-like particles, tremendously boosted both our knowledge of the viral life cycle and the identification of promising antiviral compounds interfering with viral entry. In this context, the combination of such surrogate systems with large-scale small molecule compounds and haploid genetic screenings, as well as rational drug design and drug repurposing approaches will prove priceless in our quest for the development of a treatment for EVD.

scholarly journals Between inhibitors and repurposed drugs: COVID19 pharmacological approaches based on virus pathological life cycle

2021 ◽  
Author(s):  
Heba Baioumy
Keyword(s):  
Life Cycle ◽  
Viral Entry ◽  
Drug Repositioning ◽  
Healthcare Providers ◽  
Drug Repurposing ◽  
In Vitro Study ◽  
Cell Entry ◽  
Effective Vaccine ◽  
In Silico Studies

Commendable efforts are being invested to combat CoronaVIrus Disease-19 (COVID-19) through drug repurposing and developing an effective vaccine. Since the declaration of the outbreak of COVID19 by the WHO, scientists, researchers, and healthcare providers are collaborating worldwide to find a cure against the causative virus SARS CoV-2 through drug repurposing (also known as drug repositioning). The therapeutic inhibition of a virus infection involves several targets from various steps of the virus life cycle; such as receptor-binding, cell fusion, virus replication, and release of virions. Researchers have established that SARS CoV-1, MERS and SARS CoV-2 fuse with the host cell through their S spike. Two pathways of viral cell entry are proposed: TMPRSS2 dependent pathway and TMPRSS2-independent pathway. Researches also showed through in-silico studies that drugs could work similarly on them. According to a fusion-assay study in 2005 on SARS CoV-1 cell entry, Cathepsin protease L (CatL) induced viral entry in a pH dependant manner; the optimum being acidic pH (Lysosomes). A recent in-vitro study published in 2020, added that CatL continues S1 subunit degradation in the acidic endosome and lysosome compartments. Several studies have published possible candidates blocking the two pathways for virus cell-entry before its replication in the host. Clinical documentations over the past year have shown that the severity of SARS CoV-2 lingers beyond reducing viral load due to the inflammatory response resulting in a cytokine storm. Hence, we hereby take the opportunity to highlight that the use of Ulinastatin could greatly benefit moderate and severe cases of COVID19 and reduce mortality as an addition to a comprehensive protocol.

scholarly journals Equine-Origin Immunoglobulin Fragments Protect Nonhuman Primates from Ebola Virus Disease

2018 ◽  
Vol 93 (5) ◽  
Author(s):  
Hualei Wang ◽  
Gary Wong ◽  
Wenjun Zhu ◽  
Shihua He ◽  
Yongkun Zhao ◽  
...  
Keyword(s):  
Large Scale ◽  
Nonhuman Primates ◽  
Ebola Virus ◽  
Virus Disease ◽  
Hemorrhagic Fever ◽  
West African ◽  
Clinical Testing ◽  
The Past ◽  
Over 40 Years

ABSTRACT Ebola virus (EBOV) infections result in aggressive hemorrhagic fever in humans, with fatality rates reaching 90% and with no licensed specific therapeutics to treat ill patients. Advances over the past 5 years have firmly established monoclonal antibody (MAb)-based products as the most promising therapeutics for treating EBOV infections, but production is costly and quantities are limited; therefore, MAbs are not the best candidates for mass use in the case of an epidemic. To address this need, we generated EBOV-specific polyclonal F(ab′)2 fragments from horses hyperimmunized with an EBOV vaccine. The F(ab′)2 was found to potently neutralize West African and Central African EBOV in vitro. Treatment of nonhuman primates (NHPs) with seven doses of 100 mg/kg F(ab′)2 beginning 3 or 5 days postinfection (dpi) resulted in a 100% survival rate. Notably, NHPs for which treatment was initiated at 5 dpi were already highly viremic, with observable signs of EBOV disease, which demonstrated that F(ab′)2 was still effective as a therapeutic agent even in symptomatic subjects. These results show that F(ab′)2 should be advanced for clinical testing in preparation for future EBOV outbreaks and epidemics. IMPORTANCE EBOV is one of the deadliest viruses to humans. It has been over 40 years since EBOV was first reported, but no cure is available. Research breakthroughs over the past 5 years have shown that MAbs constitute an effective therapy for EBOV infections. However, MAbs are expensive and difficult to produce in large amounts and therefore may only play a limited role during an epidemic. A cheaper alternative is required, especially since EBOV is endemic in several third world countries with limited medical resources. Here, we used a standard protocol to produce large amounts of antiserum F(ab′)2 fragments from horses vaccinated with an EBOV vaccine, and we tested the protectiveness in monkeys. We showed that F(ab′)2 was effective in 100% of monkeys even after the animals were visibly ill with EBOV disease. Thus, F(ab′)2 could be a very good option for large-scale treatments of patients and should be advanced to clinical testing.

scholarly journals Repurposing Pyramax® for the Treatment of Ebola Virus Disease: Additivity of the Lysosomotropic Pyronaridine and Non-Lysosomotropic Artesunate

2020 ◽  
Author(s):  
Thomas R. Lane ◽  
Julie Dyall ◽  
Luke Mercer ◽  
Caleb Goodin ◽  
Daniel H. Foil ◽  
...  
Keyword(s):  
Machine Learning ◽  
Mouse Model ◽  
Viral Entry ◽  
Ebola Virus ◽  
Virus Disease ◽  
Combination Effect ◽  
Combination Product ◽  
Machine Learning Model ◽  
Mouse Model Of Infection

AbstractWe have recently identified three molecules (tilorone, quinacrine and pyronaridine tetraphosphate) which all demonstrated efficacy in the mouse model of infection with mouse-adapted Ebola virus (EBOV) model of disease and had similar in vitro inhibition of an Ebola pseudovirus (VSV-EBOV-GP), suggesting they interfere with viral entry. Using a machine learning model to predict lysosomotropism these compounds were evaluated for their ability to inhibit via a lysosomotropic mechanism in vitro. We now demonstrate in vitro that pyronaridine tetraphosphate is an inhibitor of Lysotracker accumulation in lysosomes (IC50 = 0.56 μM). Further, we evaluated synergy between pyronaridine and artesunate (Pyramax®), which are used in combination to treat malaria. Artesunate was not found to have lysosomotropic activity in vitro and the combination effect on EBOV inhibition was shown to be additive. Pyramax® may represent a unique example of the repurposing of a combination product for another disease.

scholarly journals Enzyme-catalyzed biodegradation of penicillin fermentation residues by β-lactamase OtLac from Ochrobactrum tritici

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Peng Wang ◽  
Chen Shen ◽  
Qinqin Cong ◽  
Kaili Xu ◽  
Jialin Lu
Keyword(s):  
Large Scale ◽  
In Vitro Study ◽  
Scale Removal ◽  
E Coli ◽  
Penicillin V ◽  
Highly Active ◽  
Steady State Kinetics ◽  
Biodegradation Process ◽  
Km Value

Abstract Background Biodegradation of antibiotics is a promising method for the large-scale removal of antibiotic residues in the environment. However, the enzyme that is involved in the biodegradation process is the key information to be revealed. Results In this study, the beta-lactamase from Ochrobactrumtritici that mediates the biodegradation of penicillin V was identified and characterized. When searching the proteins of Ochrobactrumtritici, the β-lactamase (OtLac) was identified. OtLac consists of 347 amino acids, and predicted isoelectric point is 7.0. It is a class C β-lactamase according to BLAST analysis. The coding gene of OtLac was amplified from the genomic DNA of Ochrobactrumtritici. The OtLac was overexpressed in E. coli BL21 (DE3) and purified with Ni2+ column affinity chromatography. The biodegradation ability of penicillin V by OtLac was identified in an in vitro study and analyzed by HPLC. The optimal temperature for OtLac is 32 ℃ and the optimal pH is 7.0. Steady-state kinetics showed that OtLac was highly active against penicillin V with a Km value of 17.86 μM and a kcat value of 25.28 s−1 respectively. Conclusions OtLac demonstrated biodegradation activity towards penicillin V potassium, indicating that OtLac is expected to degrade penicillin V in the future.

scholarly journals The Large Scale Machine Learning in an Artificial Society: Prediction of the Ebola Outbreak in Beijing

2015 ◽  
Vol 2015 ◽  
pp. 1-12 ◽  
Author(s):  
Peng Zhang ◽  
Bin Chen ◽  
Liang Ma ◽  
Zhen Li ◽  
Zhichao Song ◽  
...  
Keyword(s):  
Machine Learning ◽  
Large Scale ◽  
Ebola Virus ◽  
Virus Disease ◽  
Propagation Model ◽  
Propagation Mechanism ◽  
Chinese Government ◽  
Emergency Plans ◽  
Artificial Society ◽  
The City

Ebola virus disease (EVD) distinguishes its feature as high infectivity and mortality. Thus, it is urgent for governments to draw up emergency plans against Ebola. However, it is hard to predict the possible epidemic situations in practice. Luckily, in recent years, computational experiments based on artificial society appeared, providing a new approach to study the propagation of EVD and analyze the corresponding interventions. Therefore, the rationality of artificial society is the key to the accuracy and reliability of experiment results. Individuals’ behaviors along with travel mode directly affect the propagation among individuals. Firstly, artificial Beijing is reconstructed based on geodemographics and machine learning is involved to optimize individuals’ behaviors. Meanwhile, Ebola course model and propagation model are built, according to the parameters in West Africa. Subsequently, propagation mechanism of EVD is analyzed, epidemic scenario is predicted, and corresponding interventions are presented. Finally, by simulating the emergency responses of Chinese government, the conclusion is finally drawn that Ebola is impossible to outbreak in large scale in the city of Beijing.

scholarly journals Differences in Viral RNA Synthesis but Not Budding or Entry Contribute to the In Vitro Attenuation of Reston Virus Compared to Ebola Virus

2020 ◽  
Vol 8 (8) ◽  
pp. 1215
Author(s):  
Bianca S. Bodmer ◽  
Josephin Greßler ◽  
Marie L. Schmidt ◽  
Julia Holzerland ◽  
Janine Brandt ◽  
...  
Keyword(s):  
Life Cycle ◽  
Rna Synthesis ◽  
Ebola Virus ◽  
Severe Disease ◽  
Case Fatality ◽  
Viral Rna ◽  
Pathogenic Potential ◽  
Rnp Complex ◽  
Reston Virus

Most filoviruses cause severe disease in humans. For example, Ebola virus (EBOV) is responsible for the two most extensive outbreaks of filovirus disease to date, with case fatality rates of 66% and 40%, respectively. In contrast, Reston virus (RESTV) is apparently apathogenic in humans, and while transmission of RESTV from domestic pigs to people results in seroconversion, no signs of disease have been reported in such cases. The determinants leading to these differences in pathogenicity are not well understood, but such information is needed in order to better evaluate the risks posed by the repeated spillover of RESTV into the human population and to perform risk assessments for newly emerging filoviruses with unknown pathogenic potential. Interestingly, RESTV and EBOV already show marked differences in their growth in vitro, with RESTV growing slower and reaching lower end titers. In order to understand the basis for this in vitro attenuation of RESTV, we used various life cycle modeling systems mimicking different aspects of the virus life cycle. Our results showed that viral RNA synthesis was markedly slower when using the ribonucleoprotein (RNP) components from RESTV, rather than those for EBOV. In contrast, the kinetics of budding and entry were indistinguishable between these two viruses. These data contribute to our understanding of the molecular basis for filovirus pathogenicity by showing that it is primarily differences in the robustness of RNA synthesis by the viral RNP complex that are responsible for the impaired growth of RESTV in tissue culture.

A screen of approved drugs and molecular probes identifies therapeutics with anti–Ebola virus activity

2015 ◽  
Vol 7 (290) ◽  
pp. 290ra89-290ra89 ◽  
Author(s):  
Lisa M. Johansen ◽  
Lisa Evans DeWald ◽  
Charles J. Shoemaker ◽  
Benjamin G. Hoffstrom ◽  
Calli M. Lear-Rooney ◽  
...  
Keyword(s):  
Viral Entry ◽  
Ebola Virus ◽  
Molecular Probes ◽  
Infection Model ◽  
Channel Blockers ◽  
Emerging Infections ◽  
Virus Infections ◽  
Approved Drugs

Currently, no approved therapeutics exist to treat or prevent infections induced by Ebola viruses, and recent events have demonstrated an urgent need for rapid discovery of new treatments. Repurposing approved drugs for emerging infections remains a critical resource for potential antiviral therapies. We tested ~2600 approved drugs and molecular probes in an in vitro infection assay using the type species, Zaire ebolavirus. Selective antiviral activity was found for 80 U.S. Food and Drug Administration–approved drugs spanning multiple mechanistic classes, including selective estrogen receptor modulators, antihistamines, calcium channel blockers, and antidepressants. Results using an in vivo murine Ebola virus infection model confirmed the protective ability of several drugs, such as bepridil and sertraline. Viral entry assays indicated that most of these antiviral drugs block a late stage of viral entry. By nature of their approved status, these drugs have the potential to be rapidly advanced to clinical settings and used as therapeutic countermeasures for Ebola virus infections.

scholarly journals The Vaccinia Virus E8R Gene Product: a Viral Membrane Protein That Is Made Early in Infection and Packaged into the Virions' Core

2002 ◽  
Vol 76 (19) ◽  
pp. 9773-9786 ◽  
Author(s):  
Laura Doglio ◽  
Ario De Marco ◽  
Sibylle Schleich ◽  
Norbert Roos ◽  
Jacomine Krijnse Locker
Keyword(s):  
Life Cycle ◽  
Membrane Protein ◽  
Vaccinia Virus ◽  
Gene Product ◽  
Viral Entry ◽  
Hela Cells ◽  
Two Dimensional Gel Electrophoresis ◽  
Dna Viruses ◽  
Replication Sites

ABSTRACT Vaccinia virus (VV), a member of the poxvirus family, is unique among most other DNA viruses in that both transcription and DNA replication occur in the cytoplasm of the host cell. It was recently shown by electron microscopy (EM) that soon after viral DNA synthesis is initiated in HeLa cells, the replication sites become enwrapped by the membrane of the endoplasmic reticulum (ER). In the same study, a novel VV membrane protein, the E8R gene product, that may play a role in the ER wrapping process was identified (N. Tolonen, L. Doglio, S. Schleich, and J. Krijnse Locker, Mol. Biol. Cell 12:2031-2046, 2001). In the present study, the gene product of E8R was characterized both biochemically and morphologically. We show that E8R is made predominantly early in infection but is packaged into the virion. On two-dimensional gel electrophoresis, the protein appeared as a single spot throughout the VV life cycle; however, in the assembled virion, the protein underwent several modifications which resulted in a change in its molecular weight and its isoelectric point. EM of labeled cryosections of infected HeLa cells showed that the protein localized to the ER and to membranes located on one side of the Golgi complex as early as 1 h postinfection. Late in infection, E8R was additionally associated with membranes of immature virions and with intracellular mature viruses. Although E8R is predominantly associated with membranes, we show that the protein is associated with viral cores; the protein is present in cores made with NP-40-dithiothreitol as well as in incoming cores, the result of the viral entry process, early in infection. Finally, we show that E8R can be phosphorylated in vitro by the viral kinase F10L. It is able to bind DNA in vitro, and this binding may be modulated by phosphorylation by F10L. A putative role of the E8R gene product throughout the VV life cycle is discussed.

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