Against the clock towards new Ebola virus therapies

Martínez-Romero, Carles; García‐Sastre, Adolfo

doi:10.1016/j.virusres.2015.05.025

Cited by 14 publications

(9 citation statements)

References 63 publications

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“…As stated before in perspectives by us 72 and others 2, 16, 20, 73 , the fact that approved drugs may be repurposed for other diseases should not be viewed as a negative aspect of the small molecules, belying undesirable target promiscuity 74 . Instead, we prefer to reference recently published crystallographic analyses 75 demonstrating that small molecules may bind multiple proteins in different types of binding sites and with distinct conformations to ultimately facilitate molecular repurposing.…”

Section: Discussionmentioning

confidence: 86%

Machine learning models identify molecules active against the Ebola virus in vitro

et al. 2016

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The search for small molecule inhibitors of Ebola virus (EBOV) has led to several high throughput screens over the past 3 years. These have identified a range of FDA-approved active pharmaceutical ingredients (APIs) with anti-EBOV activity in vitro and several of which are also active in a mouse infection model. There are millions of additional commercially-available molecules that could be screened for potential activities as anti-EBOV compounds. One way to prioritize compounds for testing is to generate computational models based on the high throughput screening data and then virtually screen compound libraries. In the current study, we have generated Bayesian machine learning models with viral pseudotype entry assay and the EBOV replication assay data. We have validated the models internally and externally. We have also used these models to computationally score the MicroSource library of drugs to select those likely to be potential inhibitors. Three of the highest scoring molecules that were not in the model training sets, quinacrine, pyronaridine and tilorone, were tested in vitro and had EC 50 values of 350, 420 and 230 nM, respectively. Pyronaridine is a component of a combination therapy for malaria that was recently approved by the European Medicines Agency, which may make it more readily accessible for clinical testing. Like other known antimalarial drugs active against EBOV, it shares the 4-aminoquinoline scaffold. Tilorone, is an investigational antiviral agent that has shown a broad array of biological activities including cell growth inhibition in cancer cells, antifibrotic properties, α7 nicotinic receptor agonist activity, radioprotective activity and activation of hypoxia inducible factor-1. Quinacrine is an antimalarial but also has use as an anthelmintic. Our results suggest data sets with less than 1,000 molecules can produce validated machine learning models that can in turn be utilized to identify novel EBOV inhibitors in vitro.

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Section: Discussionmentioning

confidence: 86%

Machine learning models identify molecules active against the Ebola virus in vitro

et al. 2016

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“…The 2013–2016 epidemic of Ebola virus disease (EVD) in West Africa has highlighted the paucity of licensed, direct acting antivirals that can be quickly mobilised for use in outbreak situations [1]. With this in mind, we sought to identify whether a licensed drug, Miglustat ( N -butyl deoxynojirimycin, N B-DNJ), could be of use in the treatment of EVD.…”

Section: Introductionmentioning

confidence: 99%

Minimal In Vivo Efficacy of Iminosugars in a Lethal Ebola Virus Guinea Pig Model

et al. 2016

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The antiviral properties of iminosugars have been reported previously in vitro and in small animal models against Ebola virus (EBOV); however, their effects have not been tested in larger animal models such as guinea pigs. We tested the iminosugars N-butyl-deoxynojirimycin (NB-DNJ) and N-(9-methoxynonyl)-1deoxynojirimycin (MON-DNJ) for safety in uninfected animals, and for antiviral efficacy in animals infected with a lethal dose of guinea pig adapted EBOV. 1850 mg/kg/day NB-DNJ and 120 mg/kg/day MON-DNJ administered intravenously, three times daily, caused no adverse effects and were well tolerated. A pilot study treating infected animals three times within an 8 hour period was promising with 1 of 4 infected NB-DNJ treated animals surviving and the remaining three showing improved clinical signs. MON-DNJ showed no protective effects when EBOV-infected guinea pigs were treated. On histopathological examination, animals treated with NB-DNJ had reduced lesion severity in liver and spleen. However, a second study, in which NB-DNJ was administered at equally-spaced 8 hour intervals, could not confirm drug-associated benefits. Neither was any antiviral effect of iminosugars detected in an EBOV glycoprotein pseudotyped virus assay. Overall, this study provides evidence that NB-DNJ and MON-DNJ do not protect guinea pigs from a lethal EBOV-infection at the dose levels and regimens tested. However, the one surviving animal and signs of improvements in three animals of the NB-DNJ treated cohort could indicate that NB-DNJ at these levels may have a marginal beneficial effect. Future work could be focused on the development of more potent iminosugars.

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“…Ebola virus (EBOV), a filovirus, causes hemorrhagic fever with an average case fatality rate as high as 65% (1). Although there are EBOV vaccine candidates (2,3), there is currently no licensed vaccine or treatment. Dengue virus (DENV) and West Nile virus (WNV) belong to the flavivirus family.…”

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confidence: 99%

Virion-associated phosphatidylethanolamine promotes TIM1-mediated infection by Ebola, dengue, and West Nile viruses

Richard

Zhang

Park

et al. 2015

Proc. Natl. Acad. Sci. U.S.A.

115

105

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Phosphatidylserine (PS) receptors contribute to two crucial biological processes: apoptotic clearance and entry of many enveloped viruses. In both cases, they recognize PS exposed on the plasma membrane. Here we demonstrate that phosphatidylethanolamine (PE) is also a ligand for PS receptors and that this phospholipid mediates phagocytosis and viral entry. We show that a subset of PS receptors, including T-cell immunoglobulin (Ig) mucin domain protein 1 (TIM1), efficiently bind PE. We further show that PE is present in the virions of flaviviruses and filoviruses, and that the PE-specific cyclic peptide lantibiotic agent Duramycin efficiently inhibits the entry of West Nile, dengue, and Ebola viruses. The inhibitory effect of Duramycin is specific: it inhibits TIM1-mediated, but not L-SIGNmediated, virus infection, and it does so by blocking virus attachment to TIM1. We further demonstrate that PE is exposed on the surface of apoptotic cells, and promotes their phagocytic uptake by TIM1-expressing cells. Together, our data show that PE plays a key role in TIM1-mediated virus entry, suggest that disrupting PE association with PS receptors is a promising broad-spectrum antiviral strategy, and deepen our understanding of the process by which apoptotic cells are cleared. M embers of the filovirus and flavivirus families are the causative agents of life-threatening diseases. Ebola virus (EBOV), a filovirus, causes hemorrhagic fever with an average case fatality rate as high as 65% (1). Although there are EBOV vaccine candidates (2, 3), there is currently no licensed vaccine or treatment. Dengue virus (DENV) and West Nile virus (WNV) belong to the flavivirus family. Both are transmitted to humans through mosquito bites and can cause lethal hemorrhagic fever (in the case of DENV) or severe neurological diseases (in the case of WNV) (4, 5). Flaviviruses are emerging as major health concerns in tropical and subtropical areas worldwide. More than one third of the world's population is estimated to be at risk for DENV infection, with approximately 400 million people infected yearly (6). There are currently no approved vaccines or therapeutic agents against DENV or WNV.Virus entry into host cells typically initiates with the interaction between viral entry glycoproteins (GPs) and a receptor or coreceptor expressed at the surface of the target cell. Viruses also use less specific mechanisms to localize to target cell membranes, for example through GP association with various attachment factors (7). During the past few years, it has been increasingly recognized that many viruses also use a strategy known as apoptotic mimicry to promote their association with, and internalization into their target cells (8). Receptors for phospholipids, specifically phosphatidylserine (PS), normally involved in the clearance of apoptotic cells, markedly enhance the infection of a number of enveloped viruses. These PS receptors are presumed to engage PS on the virion membrane rather than the viral entry protein (9, 10). Enveloped viruses acquire...

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Against the clock towards new Ebola virus therapies

Cited by 14 publications

References 63 publications

Machine learning models identify molecules active against the Ebola virus in vitro

Machine learning models identify molecules active against the Ebola virus in vitro

Minimal In Vivo Efficacy of Iminosugars in a Lethal Ebola Virus Guinea Pig Model

Virion-associated phosphatidylethanolamine promotes TIM1-mediated infection by Ebola, dengue, and West Nile viruses

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