scholarly journals AT-752, a double prodrug of a guanosine nucleotide analog, inhibits yellow fever virus in a hamster model

2021 ◽  
Author(s):  
Kai Lin ◽  
Steven S Good ◽  
Justin G. Julander ◽  
Abbie Weight ◽  
Adel Moussa
Keyword(s):  
Yellow Fever ◽  
Yellow Fever Virus ◽  
Limit Of Detection ◽  
Virus Titer ◽  
Fever Virus ◽  
Effective Vaccine ◽  
Hamster Model ◽  
Nucleotide Analog

Yellow fever virus (YFV) is a zoonotic pathogen re-emerging in parts of the world, causing a viral hemorrhagic fever associated with high mortality rates. While an effective vaccine is available, having an effective antiviral against YFV is critical against unexpected outbreaks, or when vaccination is not recommended. We have previously identified AT-281, the free base of AT-752, an orally available double prodrug of a guanosine nucleotide analog, as a potent inhibitor of YFV in vitro , with a 50% effective concentration (EC 50 ) of 0.31 µM. In hamsters infected with YFV (Jimenez strain), viremia rose about 4 log 10 -fold and serum alanine aminotransferase (ALT) 2-fold compared to sham-infected animals. Treatment with 1000 mg/kg AT-752 for 7 days, initiated 4 h prior to viral challenge, reduced viremia to below the limit of detection by day 4 post infection (pi) and returned ALT to normal levels by day 6 pi. When treatment with AT-752 was initiated 2 days pi, the virus titer and ALT dropped >2 log 10 and 53% by day 4 and 6 pi, respectively. In addition, at 21 days pi, 70 – 100% of the infected animals in the treatment groups survived compared to 0% of the untreated group (p<0.001). Moreover, in vivo formation of the active triphosphate metabolite AT-9010 was measured in the animal tissues, with the highest concentrations in liver and kidney, organs that are vulnerable to the virus. The demonstrated in vivo activity of AT-752 suggests that it is a promising compound for clinical development in the treatment of YFV infection.

scholarly journals Yellow Fever Virus Down-Regulates mRNA Expression of SOCS1 in the Initial Phase of Infection in Human Cell Lines

Viruses ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 802
Author(s):  
Michael B. Yakass ◽  
David Franco ◽  
Osbourne Quaye
Keyword(s):  
Mrna Expression ◽  
Yellow Fever ◽  
Yellow Fever Virus ◽  
Expression Patterns ◽  
Fever Virus ◽  
Effective Vaccine ◽  
Interferon Β ◽  
Infected Cells ◽  
Insight Into

Flaviviruses are constantly evolving diverse immune evasion strategies, and the exploitation of the functions of suppressors of cytokine signalling (SOCS) and protein inhibitors of activated STATs (PIAS) to favour virus replication has been described for Dengue and Japanese encephalitis viruses but not for yellow fever virus (YFV), which is still of global importance despite the existence of an effective vaccine. Some mechanisms that YFV employs to evade host immune defence has been reported, but the expression patterns of SOCS and PIAS in infected cells is yet to be determined. Here, we show that SOCS1 is down-regulated early in YFV-infected HeLa and HEK 293T cells, while SOCS3 and SOCS5 are not significantly altered, and PIAS mRNA expression appears to follow a rise-dip pattern akin to circadian-controlled genes. We also demonstrate that YFV evades interferon-β application to produce comparable viral titres. This report provides initial insight into the in vitro expression dynamics of SOCS and PIAS upon YFV infection and a basis for further investigation into SOCS/PIAS expression and how these modulate the immune response in animal models.

scholarly journals Yellow fever virus is susceptible to sofosbuvir both in vitro and in vivo

2019 ◽  
Vol 13 (1) ◽  
pp. e0007072 ◽  
Author(s):  
Caroline S. de Freitas ◽  
Luiza M. Higa ◽  
Carolina Q. Sacramento ◽  
André C. Ferreira ◽  
Patrícia A. Reis ◽  
...  
Keyword(s):  
Yellow Fever ◽  
Yellow Fever Virus ◽  
Fever Virus

RNA interference inhibits yellow fever virus replication in vitro and in vivo

Virus Genes ◽  
2009 ◽  
Vol 38 (2) ◽  
pp. 224-231 ◽  
Author(s):  
Carolina C. Pacca ◽  
Adriana A. Severino ◽  
Adriano Mondini ◽  
Paula Rahal ◽  
Solange G. P. D’avila ◽  
...  
Keyword(s):  
Rna Interference ◽  
Yellow Fever ◽  
Virus Replication ◽  
Yellow Fever Virus ◽  
Fever Virus

In vitro and in vivo antiviral properties of sulfated galactomannans against yellow fever virus (BeH111 strain) and dengue 1 virus (Hawaii strain)

2003 ◽  
Vol 60 (3) ◽  
pp. 201-208 ◽  
Author(s):  
Lucy Ono ◽  
Wagner Wollinger ◽  
Iray M Rocco ◽  
Terezinha L.M Coimbra ◽  
Philip A.J Gorin ◽  
...  
Keyword(s):  
Yellow Fever ◽  
Yellow Fever Virus ◽  
Fever Virus

scholarly journals In Silico Approach To Design a B-cell Epitope Based Vaccine Target Against Yellow Fever Virus

2019 ◽  
Vol 35 (1) ◽  
pp. 27-35
Author(s):  
Shamira Tabrejee ◽  
M Mahboob Hossain
Keyword(s):  
Yellow Fever ◽  
Yellow Fever Virus ◽  
Peptide Vaccine ◽  
Cell Epitope ◽  
Epitope Prediction ◽  
Fever Virus ◽  
Young Infants ◽  
E Protein

Yellow fever virus is a prototype member of the Flaviviridae family causing high fever and jaundice. Though YF 17D vaccine is administered to yellow fever patients, however it can produce adverse effects in immunocompromised, older people and young infants. The aim of this study is to design an epitope-based peptide vaccine by targeting envelope (E) protein of Yellow Fever Virus. Thirty sequences of E protein of Yellow Fever Virus strains were retrieved from NCBI database. E protein was found to be mostly conserved among all the sequences with little variability and also was identified as a probable antigen. Different epitope prediction tools predicted 4 common epitopes, 3 of which were found to be antigenic. A peptide VKNPTDTGin E protein was predicted to have surface accessibility which overlaps with the VKNPTDTGHGT epitope.So, the whole VKNPTDTGHGT epitope was taken for further analysis. The VKNPTDTGHGT epitope showed 96.67% conservancy and also possesses flexibility, hydrophilicity and non-toxicity. Therefore, VKNPTDTGHGT can be regarded as a potential vaccine candidate against Yellow fever virus with further in vitro and in vivo validation. Bangladesh J Microbiol, Volume 35 Number 1 June 2018, pp 27-35

scholarly journals Yellow fever virus is susceptible to sofosbuvir both in vitro and in vivo

2018 ◽  
Author(s):  
Caroline S. de Freitas ◽  
Luiza M. Higa ◽  
Carolina Sacramento ◽  
André C. Ferreira ◽  
Patrícia A. Reis ◽  
...  
Keyword(s):  
Yellow Fever ◽  
Yellow Fever Virus ◽  
Clinical Results ◽  
Fever Virus ◽  
Health Concern ◽  
Public Health Concern ◽  
Human Hepatoma Cells ◽  
Attractive Option

AbstractYellow fever virus (YFV) is a member of the Flaviviridae family, that causes major mortality. In Brazil, YFV activity increased in the last years. It has been registered that sylvatic, instead of urban, yellow fever (YF) leads our contemporary public health concern. Low vaccinal coverage leaves the human population near the jangle vulnerable to the outbreak, making it necessary to identify therapeutic options. Repurposing of clinically approved antiviral drugs represents an alternative for such identification. Other Flaviviruses, such Zika (ZIKV) and dengue (DENV) viruses, are susceptible to Sofosbuvir, a clinically approved drug against hepatitis C virus (HCV). Moreover, sofosbuvir has a safety record on critically ill hepatic patients, making it an attractive option. Our data show that YFV RNA polymerase uses conserved amino acid resides for nucleotide binding to dock sofosbuvir. This drug inhibited YFV replication in different lineages of human hepatoma cells, Huh-7 and HepG2, with EC50 value of 4.8 µM. Sofosbuvir protected YFV-infected neonatal Swiss mice from mortality and weight loss. Our pre-clinical results indicate that sofosbuvir could represent an option against YFV.

scholarly journals Exploratory re-encoding of Yellow Fever Virus genome: new insights for the design of live-attenuated viruses

2018 ◽  
Author(s):  
R. Klitting ◽  
T. Riziki ◽  
G. Moureau ◽  
G. Piorkowski ◽  
E. A. Gould ◽  
...  
Keyword(s):  
Yellow Fever ◽  
Yellow Fever Virus ◽  
Fever Virus ◽  
Coding Region ◽  
Live Attenuated Vaccine ◽  
Replicative Fitness ◽  
Synonymous Mutations ◽  
Attenuated Viruses

AbstractVirus attenuation by genome re-encoding is a pioneering approach for generating effective live-attenuated vaccine candidates. Its core principle is to introduce a large number of synonymous substitutions into the viral genome to produce stable attenuation of the targeted virus. Introduction of large numbers of mutations has also been shown to maintain stability of the attenuated phenotype by lowering the risk of reversion and recombination of re-encoded genomes. Identifying mutations with low fitness cost is pivotal as this increases the number that can be introduced and generates more stable and attenuated viruses. Here, we sought to identify mutations with low deleterious impact on thein vivoreplication and virulence of yellow fever virus (YFV). Following comparative bioinformatic analyses of flaviviral genomes, we categorized synonymous transition mutations according to their impact on CpG/UpA composition and secondary RNA structures. We then designed 17 re-encoded viruses with 100-400 synonymous mutations in the NS2A-to-NS4B coding region of YFVAsibiandAp7M(hamster-adapted) genomes. Each virus contained a panel of synonymous mutations designed according to the above categorisation criteria. The replication and fitness characteristics of parent and re-encoded viruses were comparedin vitrousing cell culture competition experiments.In vivolaboratory hamster models were also used to compare relative virulence and immunogenicity characteristics. Most of the re-encoded strains showed no decrease in replicative fitnessin vitro. However, they showed reduced virulence and, in some instances, decreased replicative fitnessin vivo. Importantly, the most attenuated of the re-encoded strains induced robust, protective immunity in hamsters following challenge withAp7M, a virulent virus. Overall, the introduction of transitions with no or a marginal increase in the number of CpG/UpA dinucleotides had the mildest impact on YFV replication and virulencein vivo. Thus, this strategy can be incorporated in procedures for the finely tuned creation of substantially re-encoded viral genomes.

scholarly journals Activity of T-1106 in a Hamster Model of Yellow Fever Virus Infection

2007 ◽  
Vol 51 (6) ◽  
pp. 1962-1966 ◽  
Author(s):  
Justin G. Julander ◽  
Yousuke Furuta ◽  
Kristiina Shafer ◽  
Robert W. Sidwell
Keyword(s):  
Yellow Fever ◽  
Yellow Fever Virus ◽  
Virus Titer ◽  
Fever Virus ◽  
Virus Inoculation ◽  
Hamster Model ◽  
Minimal Effective Dose ◽  
Virus Challenge ◽  
Cell Culture Assay ◽  
Favorable Safety

ABSTRACT Yellow fever virus (YFV) causes 30,000 deaths worldwide, despite the availability of a vaccine. There are no approved antiviral therapies for the treatment of YFV disease in humans, and, therefore, these studies were designed to investigate the anti-YFV properties of T-1106, a substituted pyrazine, in a hamster model of YFV disease. Intraperitoneal (i.p.) treatment with 100 mg/kg of body weight/day of T-1106 starting 4 h prior to virus inoculation and continuing twice daily through 7 days post-virus inoculation (dpi) resulted in significantly improved survival, alanine aminotransferase levels in the serum, weight gain, and mean day to death. Virus titer in the liver at 4 dpi was significantly reduced in treated animals, as determined by both quantitative real-time PCR and infectious cell culture assay. No toxicity (weight loss or mortality) was observed at a dose of 100 mg/kg/day in sham-infected control animals. The observed minimal effective dose of T-1106 was 32 mg/kg/day administered either by oral or i.p. treatment. Therapeutic treatment was effective in significantly improving survival when T-1106 was administered beginning as late as 4 days after virus challenge with twice-daily treatment for 8 days at a dose of 100 mg/kg/day. With favorable safety, bioavailability, and postviral challenge treatment efficacy, T-1106 was effective in the treatment of disease in hamsters infected with YFV and should be further studied for potential use as a therapy for human YFV disease.

scholarly journals Yellow Fever Outbreak in Eastern Senegal, 2020–2021

Viruses ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1475
Author(s):  
Moussa Moïse Diagne ◽  
Marie Henriette Dior Ndione ◽  
Alioune Gaye ◽  
Mamadou Aliou Barry ◽  
Diawo Diallo ◽  
...  
Keyword(s):  
Yellow Fever ◽  
Yellow Fever Virus ◽  
Mosquito Species ◽  
Virus Transmission ◽  
Genomic Analysis ◽  
Hemorrhagic Fever ◽  
Fever Virus ◽  
World Health ◽  
Effective Vaccine ◽  
Ministry Of Health

Yellow fever virus remains a major threat in low resource countries in South America and Africa despite the existence of an effective vaccine. In Senegal and particularly in the eastern part of the country, periodic sylvatic circulation has been demonstrated with varying degrees of impact on populations in perpetual renewal. We report an outbreak that occurred from October 2020 to February 2021 in eastern Senegal, notified and managed through the synergistic effort yellow fever national surveillance implemented by the Senegalese Ministry of Health in collaboration with the World Health Organization, the countrywide 4S network set up by the Ministry of Health, the Institut Pasteur de Dakar, and the surveillance of arboviruses and hemorrhagic fever viruses in human and vector populations implemented since mid 2020 in eastern Senegal. Virological analyses highlighted the implication of sylvatic mosquito species in virus transmission. Genomic analysis showed a close relationship between the circulating strain in eastern Senegal, 2020, and another one from the West African lineage previously detected and sequenced two years ago from an unvaccinated Dutch traveler who visited the Gambia and Senegal before developing signs after returning to Europe. Moreover, genome analysis identified a 6-nucleotide deletion in the variable domain of the 3′UTR with potential impact on the biology of the viral strain that merits further investigations. Integrated surveillance of yellow fever virus but also of other arboviruses of public health interest is crucial in an ecosystem such as eastern Senegal.

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