scholarly journals Lassa viral dynamics in non-human primates treated with favipiravir or ribavirin

2021 ◽  
Vol 17 (1) ◽  
pp. e1008535
Author(s):  
Guillaume Lingas ◽  
Kyle Rosenke ◽  
David Safronetz ◽  
Jérémie Guedj
Keyword(s):  
Mechanism Of Action ◽  
Ebola Virus ◽  
Antiviral Treatment ◽  
Antiviral Effect ◽  
Lassa Fever ◽  
Pharmacokinetic Data ◽  
Virus Infectivity ◽  
Lassa Virus ◽  
Viral Dynamics

Lassa fever is an haemorrhagic fever caused by Lassa virus (LASV). There is no vaccine approved against LASV and the only recommended antiviral treatment relies on ribavirin, despite limited evidence of efficacy. Recently, the nucleotide analogue favipiravir showed a high antiviral efficacy, with 100% survival obtained in an otherwise fully lethal non-human primate (NHP) model of Lassa fever. However the mechanism of action of the drug is not known and the absence of pharmacokinetic data limits the translation of these results to the human setting. Here we aimed to better understand the antiviral effect of favipiravir by developping the first mathematical model recapitulating Lassa viral dynamics and treatment. We analyzed the viral dynamics in 24 NHPs left untreated or treated with ribavirin or favipiravir, and we put the results in perspective with those obtained with the same drugs in the context of Ebola infection. Our model estimates favipiravir EC50 in vivo to 2.89 μg.mL-1, which is much lower than what was found against Ebola virus. The main mechanism of action of favipiravir was to decrease virus infectivity, with an efficacy of 91% at the highest dose. Based on our knowledge acquired on the drug pharmacokinetics in humans, our model predicts that favipiravir doses larger than 1200 mg twice a day should have the capability to strongly reduce the production infectious virus and provide a milestone towards a future use in humans.

scholarly journals Differential pathogenesis of closely related 2018 Nigerian outbreak clade III Lassa virus isolates

2021 ◽  
Vol 17 (10) ◽  
pp. e1009966
Author(s):  
Derek R. Stein ◽  
Bryce M. Warner ◽  
Jonathan Audet ◽  
Geoff Soule ◽  
Vinayakumar Siragam ◽  
...  
Keyword(s):  
Animal Models ◽  
Lassa Fever ◽  
Geographic Region ◽  
World Health ◽  
Limiting Factor ◽  
Lassa Virus ◽  
African Countries ◽  
Animal Models Of Disease ◽  
Medical Countermeasures

Nigeria continues to experience ever increasing annual outbreaks of Lassa fever (LF). The World Health Organization has recently declared Lassa virus (LASV) as a priority pathogen for accelerated research leading to a renewed international effort to develop relevant animal models of disease and effective countermeasures to reduce LF morbidity and mortality in endemic West African countries. A limiting factor in evaluating medical countermeasures against LF is a lack of well characterized animal models outside of those based on infection with LASV strain Josiah originating form Sierra Leone, circa 1976. Here we genetically characterize five recent LASV isolates collected from the 2018 outbreak in Nigeria. Three isolates were further evaluated in vivo and despite being closely related and from the same spatial / geographic region of Nigeria, only one of the three isolates proved lethal in strain 13 guinea pigs and non-human primates (NHP). Additionally, this isolate exhibited atypical pathogenesis characteristics in the NHP model, most notably respiratory failure, not commonly described in hemorrhagic cases of LF. These results suggest that there is considerable phenotypic heterogeneity in LASV infections in Nigeria, which leads to a multitude of pathogenesis characteristics that could account for differences between subclinical and lethal LF infections. Most importantly, the development of disease models using currently circulating LASV strains in West Africa are critical for the evaluation of potential vaccines and medical countermeasures.

scholarly journals Elevated l-threonine is a biomarker for Lassa fever and Ebola

2020 ◽  
Vol 17 (1) ◽  
Author(s):  
Trevor V. Gale ◽  
John S. Schieffelin ◽  
Luis M. Branco ◽  
Robert F. Garry ◽  
Donald S. Grant
Keyword(s):  
Virus Infection ◽  
Prognostic Value ◽  
Ebola Virus ◽  
Platelet Activating Factor ◽  
Lassa Fever ◽  
Lassa Virus ◽  
Liquid Chromatography Mass Spectrometry ◽  
Hemorrhagic Fevers ◽  
Viral Hemorrhagic Fevers ◽  
Ebola Virus Infection

Abstract Background Lassa fever and Ebola are characterized by non-specific initial presentations that can progress to severe multisystem illnesses with high fatality rates. Samples from additional subjects are examined to extend and corroborate biomarkers with prognostic value for these diseases. Methods Liquid Chromatography Mass Spectrometry metabolomics was used to identify and confirm metabolites disrupted in the blood of Lassa fever and Ebola patients. Authenticated standards are used to confirm the identify of key metabolites. Results We confirm prior results by other investigators that the amino acid l-threonine is elevated during Ebola virus infection. l-Threonine is also elevated during Lassa virus infection. We also confirmed that platelet-activating factor (PAF) and molecules with PAF moiety are reduced in the blood of patients with fatal Lassa fever. Similar changes in PAF and PAF-like molecules were not observed in the blood of Ebola patients. Conclusions Metabolomics may provide tools to identify pathways that are differentially affected during viral hemorrhagic fevers and guide development of diagnostics to monitor and predict outcome.

scholarly journals 25-Hydroxycholesterol Inhibition of Lassa Virus Infection through Aberrant GP1 Glycosylation

mBio ◽  
2016 ◽  
Vol 7 (6) ◽  
Author(s):  
Punya Shrivastava-Ranjan ◽  
Éric Bergeron ◽  
Ayan K. Chakrabarti ◽  
César G. Albariño ◽  
Mike Flint ◽  
...  
Keyword(s):  
Cholesterol Biosynthesis ◽  
Hemorrhagic Fever ◽  
Lassa Fever ◽  
Health Concern ◽  
Virus Infectivity ◽  
Lassa Virus ◽  
Critical Feature ◽  
Course Of Illness ◽  
Enveloped Virus ◽  
Alpha Dystroglycan

ABSTRACT Lassa virus (LASV) infection is a major public health concern due to high fatality rates and limited effective treatment. The interferon-stimulated gene cholesterol 25-hydroxylase ( CH25H ) encodes an enzyme that catalyzes the production of 25-hydroxycholesterol (25HC). 25HC is involved in regulating cholesterol biosynthesis and has recently been identified as a potent antiviral targeting enveloped virus entry. Here, we show a previously unrecognized role of CH25H in inhibiting LASV glycoprotein glycosylation and the production of infectious virus. Overexpression of CH25H or treatment with 25HC decreased LASV G1 glycoprotein N -glycan maturation and reduced the production of infectious LASV. Depletion of endogenous CH25H using small interfering RNA (siRNA) enhanced the levels of fully glycosylated G1 and increased infectious LASV production. Finally, LASV particles produced from 25HC-treated cells were found to be less infectious, to incorporate aberrantly glycosylated GP1 species, and to be defective in binding alpha-dystroglycan, an attachment and entry receptor. Our findings identify a novel role for CH25H in controlling LASV propagation and indicate that manipulation of the expression of CH25H or the administration of 25HC may be a useful anti-LASV therapy. IMPORTANCE Lassa fever is an acute viral hemorrhagic fever in humans caused by Lassa virus (LASV). No vaccine for LASV is currently available. Treatment is limited to the administration of ribavirin, which is only effective when given early in the course of illness. Cholesterol 25-hydroxylase ( CH25H ) is a recently identified interferon-stimulated gene (ISG); it encodes an enzyme that catalyzes the production of 25-hydroxycholesterol (25HC), which inhibits several viruses. Here, we identify a novel antiviral mechanism of 25HC that is dependent on inhibiting the glycosylation of Lassa virus (LASV) glycoprotein and reducing the infectivity of LASV as a means of suppressing viral replication. Since N-linked glycosylation is a critical feature of other enveloped-virus glycoproteins, 25HC may be a broad inhibitor of virus infectivity.

scholarly journals Inhibition of Different Lassa Virus Strains by Alpha and Gamma Interferons and Comparison with a Less Pathogenic Arenavirus

2004 ◽  
Vol 78 (6) ◽  
pp. 3162-3169 ◽  
Author(s):  
Marcel Asper ◽  
Thomas Sternsdorf ◽  
Meike Hass ◽  
Christian Drosten ◽  
Antje Rhode ◽  
...  
Keyword(s):  
Vero Cells ◽  
Lassa Fever ◽  
Lassa Virus ◽  
Necrosis Factor Alpha ◽  
Tnf Α ◽  
High Pathogenicity ◽  
Ifn Γ ◽  
Virus Strains

ABSTRACT The high pathogenicity of Lassa virus is assumed to involve resistance to the effects of interferon (IFN). We have analyzed the effects of alpha IFN (IFN-α), IFN-γ, and tumor necrosis factor alpha (TNF-α) on replication of Lassa virus compared to the related, but less pathogenic, lymphocytic choriomeningitis virus (LCMV). Three low-passage Lassa virus strains (AV, NL, and CSF), isolated from humans with mild to fulminant Lassa fever, were tested. Lassa virus replication was inhibited by IFN-α and IFN-γ, but not TNF-α, in Huh7 and Vero cells. The degree of IFN sensitivity of a Lassa virus isolate did not correlate with disease severity in human patients. Furthermore, cytokine effects observed for Lassa virus and LCMV (strains CH-5692, Armstrong, and WE) were similar. To address the mechanisms involved in the IFN effect, we used cell lines in which overexpression of IFN-stimulated proteins promyelocytic leukemia protein (PML) and Sp100 could be induced. Both proteins reside in PML bodies, a cellular target of the LCMV and Lassa virus Z proteins. Overexpression of PML or Sp100 did not affect replication of either virus. This, together with the previous finding that PML knockout facilitates LCMV replication in vitro and in vivo (M. Djavani, J. Rodas, I. S. Lukashevich, D. Horejsh, P. P. Pandolfi, K. L. Borden, and M. S. Salvato, J. Virol. 75:6204-6208, 2001; W. V. Bonilla, D. D. Pinschewer, P. Klenerman, V. Rousson, M. Gaboli, P. P. Pandolfi, R. M. Zinkernagel, M. S. Salvato, and H. Hengartner, J. Virol. 76:3810-3818, 2002), describes PML as a mediator within the antiviral pathway rather than as a direct effector protein. In conclusion, the high pathogenicity of Lassa virus compared to LCMV is probably not due to increased resistance to the effects of IFN-α or IFN-γ. Both cytokines inhibit replication which is relevant for the design of antiviral strategies against Lassa fever with the aim of enhancing the IFN response.

scholarly journals Lactoferrin as Antiviral Treatment in COVID-19 Management: Preliminary Evidence

2021 ◽  
Vol 18 (20) ◽  
pp. 10985
Author(s):  
Elena Campione ◽  
Caterina Lanna ◽  
Terenzio Cosio ◽  
Luigi Rosa ◽  
Maria Pia Conte ◽  
...  
Keyword(s):  
Clinical Symptoms ◽  
Antiviral Treatment ◽  
Standard Of Care ◽  
Antiviral Effect ◽  
Preliminary Evidence ◽  
Home Based ◽  
Negative Conversion

Lactoferrin (Lf), a multifunctional cationic glycoprotein synthesized by exocrine glands and neutrophils, possesses an in vitro antiviral activity against SARS-CoV-2. Thus, we conducted an in vivo preliminary study to investigate the antiviral effect of oral and intranasal liposomal bovine Lf (bLf) in asymptomatic and mild-to-moderate COVID-19 patients. From April 2020 to June 2020, a total of 92 mild-to-moderate (67/92) and asymptomatic (25/92) COVID-19 patients were recruited and divided into three groups. Thirty-two patients (14 hospitalized and 18 in home-based isolation) received only oral and intranasal liposomal bLf; 32 hospitalized patients were treated only with standard of care (SOC) treatment; and 28, in home-based isolation, did not take any medication. Furthermore, 32 COVID-19 negative, untreated, healthy subjects were added for ancillary analysis. Liposomal bLf-treated COVID-19 patients obtained an earlier and significant (p < 0.0001) SARS-CoV-2 RNA negative conversion compared to the SOC-treated and untreated COVID-19 patients (14.25 vs. 27.13 vs. 32.61 days, respectively). Liposomal bLf-treated COVID-19 patients showed fast clinical symptoms recovery compared to the SOC-treated COVID-19 patients. In bLf-treated patients, a significant decrease in serum ferritin, IL-6, and D-dimers levels was observed. No adverse events were reported. These observations led us to speculate a potential role of bLf in the management of mild-to-moderate and asymptomatic COVID-19 patients.

scholarly journals Deployable CRISPR-Cas13a diagnostic tools to detect and report Ebola and Lassa virus cases in real-time

2020 ◽  
Author(s):  
Kayla G. Barnes ◽  
Anna E. Lachenauer ◽  
Adam Nitido ◽  
Sameed Siddiqui ◽  
Robin Gross ◽  
...  
Keyword(s):  
Ebola Virus ◽  
Virus Disease ◽  
Lassa Fever ◽  
Diagnostic Tools ◽  
Clinical Samples ◽  
Viral Diversity ◽  
Lassa Virus ◽  
Live Attenuated Vaccine ◽  
Safety Testing ◽  
User Friendly

AbstractViral hemorrhagic fevers (VHFs) remain some of the most devastating human diseases, and recent outbreaks of Ebola virus disease (EVD) 1,2 and Lassa fever (LF) 3,4 highlight the urgent need for sensitive, field-deployable tests to diagnose them 5,6. Here we develop CRISPR-Cas13a-based (SHERLOCK) diagnostics targeting Ebola virus (EBOV) and Lassa virus (LASV), with both fluorescent and lateral flow readouts. We demonstrate on laboratory and clinical samples the sensitivity of these assays and the capacity of the SHERLOCK platform to handle virus-specific diagnostic challenges. Our EBOV diagnostic detects both the L and NP genes, thereby eliminating the potential for false positive results caused by the rVSVΔG-ZEBOV-GP live attenuated vaccine. Our two LASV diagnostics together capture 90% of known viral diversity and demonstrate that CRISPR-RNAs (crRNAs) can be effectively multiplexed to provide greater coverage of known viral diversity. We performed safety testing to demonstrate the efficacy of our HUDSON protocol in heat-inactivating and chemically treating VHF viruses before SHERLOCK testing, eliminating the need for an extraction. We developed a user-friendly field protocol and mobile application (HandLens) to report results, facilitating SHERLOCK’s use in endemic regions. Finally, we successfully deployed our tests in Sierra Leone and Nigeria in response to recent outbreaks.

scholarly journals Combatting SARS-CoV-2: Potential Therapeutic Candidates Against COVID-19

2021 ◽  
pp. 61-70
Author(s):  
Pramod Kumar Gupta ◽  
Savita Kulkarn
Keyword(s):  
Antiviral Treatment ◽  
Symptomatic Treatment ◽  
Antiviral Effect ◽  
Therapeutic Agents ◽  
Severe Illness ◽  
Global Pandemic ◽  
Treatment Summary ◽  
Therapeutic Compounds

Background: COVID-19, a global pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), emerged in December 2019 in China and has spread to 210 countries and territories. Since then, it has infected >187.3 million people worldwide, causing >4.0 million deaths, and numbers are continuing to rise. Fever, dry cough, shortness of breath, and pneumonia are the main symptoms of this disease, which does not have any specific antiviral treatment or vaccines to date, and clinical management is mainly symptomatic treatment. Summary: The global spread of SARS-CoV-2 has necessitated the development of novel therapeutic agents against the virus to stop the pandemic. Drugs targeting viral as well as host factors may have a potential antiviral effect. The development of novel drugs may take years; hence, the best alternative available is to repurpose existing antiviral drugs with a known safety profile in humans. Further, compounds with known in vitro and in vivo efficacy against SARS-CoV and Middle East respiratory syndrome coronavirus have been included in recent clinical trials and exhibited encouraging results against SARS-CoV-2. Here, the authors provide a summary of therapeutic compounds that have shown antiviral effects against SARS-CoV-2 infections in cell lines, animal models, and patients. Key Messages: With every passing day, knowledge about SARS-CoV-2 is increasing due to continued efforts of scientists working in this area globally. Approximately 15% of patients with COVID-19 are affected by severe illness and treatments are desperately needed. In this time of global pandemic, collective and co-ordinated efforts are needed to develop therapeutic agents against this disease.

scholarly journals Tomatidine reduces Chikungunya virus progeny release by controlling viral protein expression

2021 ◽  
Vol 15 (11) ◽  
pp. e0009916
Author(s):  
Berit Troost-Kind ◽  
Martijn J. van Hemert ◽  
Denise van de Pol ◽  
Heidi van der Ende-Metselaar ◽  
Andres Merits ◽  
...  
Keyword(s):  
Protein Expression ◽  
Viral Protein ◽  
Chikungunya Virus ◽  
Antiviral Treatment ◽  
Antiviral Effect ◽  
Virus Infectivity ◽  
Expression Levels ◽  
Viral Protein Expression ◽  
Huh7 Cells

Tomatidine, a natural steroidal alkaloid from unripe green tomatoes has been shown to exhibit many health benefits. We recently provided in vitro evidence that tomatidine reduces the infectivity of Dengue virus (DENV) and Chikungunya virus (CHIKV), two medically important arthropod-borne human infections for which no treatment options are available. We observed a potent antiviral effect with EC50 values of 0.82 μM for DENV-2 and 1.3 μM for CHIKV-LR. In this study, we investigated how tomatidine controls CHIKV infectivity. Using mass spectrometry, we identified that tomatidine induces the expression of p62, CD98, metallothionein and thioredoxin-related transmembrane protein 2 in Huh7 cells. The hits p62 and CD98 were validated, yet subsequent analysis revealed that they are not responsible for the observed antiviral effect. In parallel, we sought to identify at which step of the virus replication cycle tomatidine controls virus infectivity. A strong antiviral effect was seen when in vitro transcribed CHIKV RNA was transfected into Huh7 cells treated with tomatidine, thereby excluding a role for tomatidine during CHIKV cell entry. Subsequent determination of the number of intracellular viral RNA copies and viral protein expression levels during natural infection revealed that tomatidine reduces the RNA copy number and viral protein expression levels in infected cells. Once cells are infected, tomatidine is not able to interfere with active RNA replication yet it can reduce viral protein expression. Collectively, the results delineate that tomatidine controls viral protein expression to exert its antiviral activity. Lastly, sequential passaging of CHIKV in presence of tomatidine did not lead to viral resistance. Collectively, these results further emphasize the potential of tomatidine as an antiviral treatment towards CHIKV infection.

scholarly journals Rethinking antiviral effects for COVID-19 in clinical studies: early initiation is key to successful treatment

2020 ◽  
Author(s):  
Shoya Iwanami ◽  
Keisuke Ejima ◽  
Kwang Su Kim ◽  
Koji Noshita ◽  
Yasuhisa Fujita ◽  
...  
Keyword(s):  
Symptom Onset ◽  
Clinical Studies ◽  
Randomized Clinical Trials ◽  
Antiviral Treatment ◽  
Antiviral Drug ◽  
Antiviral Effect ◽  
Short Period ◽  
Effective Drugs

AbstractDevelopment of an effective antiviral drug for COVID-19 is a global health priority. Although several candidate drugs have been identified through in vitro and in vivo models, consistent and compelling evidence for effective drugs from clinical studies is limited. The lack of evidence could be in part due to heterogeneity of virus dynamics among patients and late initiation of treatment. We first quantified the heterogeneity of viral dynamics which could be a confounder in compassionate use programs. Second, we demonstrated that an antiviral drug is unlikely to be effective if initiated after a short period following symptom onset. For accurate evaluation of the efficacy of an antiviral drug for COVID-19, antiviral treatment should be initiated before or soon after symptom onset in randomized clinical trials.One Sentence SummaryStudy design to evaluate antiviral effect.

scholarly journals 2642. Development of Human Intestinal Organoids as an Antiviral Evaluation Platform for Enteroviruses

2019 ◽  
Vol 6 (Supplement_2) ◽  
pp. S924-S924
Author(s):  
Jasper Fuk-Woo Chan ◽  
Jessica Tsang ◽  
Jie Zhou ◽  
Xiaoyu Zhao ◽  
Kwok-Yung Yuen
Keyword(s):  
Viral Infections ◽  
Antiviral Treatment ◽  
Treatment Options ◽  
Cell Types ◽  
Antiviral Effect ◽  
Virus Yield ◽  
Yield Reduction ◽  
Cell Protection ◽  
Intestinal Organoids

Abstract Background Enteroviruses are non-enveloped, single-stranded positive-sense RNA viruses belonging to the family Picornaviridae. Enterovirus A71 (EV-A71) has caused recurrent outbreaks of hand, foot, and mouth disease especially among children in Asia. Some patients develop severe complications, such as meningitis, encephalitis, myocarditis, and pulmonary edema. A major hurdle for the development of antivirals for EV-A71 infection is the lack of robust antiviral platforms that closely mimic the in vivo setting. Organoids are laboratory-adapted miniaturized organs with preserved three-dimensional micro-anatomical architecture. In recent years, organoid cultures have been increasingly used for studying the pathogenesis of and evaluating antiviral treatment options for viral infections. In this study, we developed human intestinal organoids as a robust platform for evaluating antiviral options for EV-A71. Methods An epidemic strain of EV-A71 isolated from a patient with laboratory-confirmed EV-A71 infection was used. We compared the performance of multiple antiviral evaluation assays (virus yield reduction, plaque reduction, and cell protection assays) between human intestinal organoids and Caco-2 cells, using itraconazole (an antifungal previously shown to exhibit potent anti-enteroviral effects) and DMSO as positive and negative controls, respectively. Results The antiviral effect of itraconazole was comparable between human intestinal organoids and Caco-2 cells in the virus yield reduction and plaque reduction assays. In the cell protection assay, Caco-2 cells failed to demonstrate significant differences between the itraconazole-treated and DMSO-treated groups. In contrast, cell protection effects were easily observed and quantified in human intestinal organoids. Moreover, the human intestinal organoids allowed the characterization of the different cell types affected in EV-A71 infection with or without itraconazole treatment. Conclusion Human intestinal organoids support the replication of EV-A71 and provides a robust platform for antiviral evaluation for EV-A71 infection. Disclosures All authors: No reported disclosures.

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