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Chemical & Pharmaceutical Bulletin Mar 2022We previously showed that 5-ethynyl-(1-β-D-ribofuranosyl)imidazole-4-carboxamide (1; EICAR) is a potent anti-dengue virus (DENV) compound but is cytotoxic to some cell...
We previously showed that 5-ethynyl-(1-β-D-ribofuranosyl)imidazole-4-carboxamide (1; EICAR) is a potent anti-dengue virus (DENV) compound but is cytotoxic to some cell lines, while its 4-thio derivative, 5-ethynyl-(4-thio-1-β-D-ribofuranosyl)imidazole-4-carboxamide (2; 4'-thioEICAR), has less cytotoxicity but also less anti-DENV activity. Based on the hypothesis that the lower anti-DENV activity of 2 is due to reduced susceptibility to phosphorylation by cellular kinase(s), we investigated whether a monophosphate prodrug of 2 can improve its activity. Here, we first prepared two types of prodrug of 1, which revealed that the S-acyl-2-thioethyl (SATE) prodrug had stronger anti-DENV activity than the aryloxyphosphoramidate (so-called ProTide) prodrug. Based on these findings, we next prepared the SATE prodrug of 4'-thioEICAR 18. As expected, the resulting 18 showed potent anti-DENV activity, which was comparable to that of 1; however, its cytotoxicity was also increased relative to 2. Our findings suggest that prodrugs of 4'-thioribonucleoside derivatives such as EICAR (1) represent an effective approach to developing potent biologically active compounds; however, the balance between antiviral activity and cytotoxicity remains to be addressed.
Topics: Antiviral Agents; Cell Line; Dengue Virus; Imidazoles; Nucleotides; Prodrugs; Virus Replication
PubMed: 34955490
DOI: 10.1248/cpb.c21-01038 -
Cell Jul 2015Dengue virus (DENV) is a mosquito-transmitted RNA virus that infects an estimated 390 million humans each year. Here, we review recent advances in our understanding of... (Review)
Review
Dengue virus (DENV) is a mosquito-transmitted RNA virus that infects an estimated 390 million humans each year. Here, we review recent advances in our understanding of the biology of DENV and describe knowledge gaps that have impacted the development of effective vaccines and therapeutics.
Topics: Animals; Dengue; Dengue Vaccines; Dengue Virus; Humans; Immune Evasion
PubMed: 26232221
DOI: 10.1016/j.cell.2015.07.005 -
Viruses Apr 2022Dengue is an arthropod-borne acute febrile illness caused by Dengue Virus (DENV), a member of . Severity of the infection ranges from mild self-limiting illness to...
Dengue is an arthropod-borne acute febrile illness caused by Dengue Virus (DENV), a member of . Severity of the infection ranges from mild self-limiting illness to severe life-threatening hemorrhagic fever (DHF) and dengue shock syndrome (DSS). To date, there is no specific antiviral therapy established to treat the infection. The current study reports the epidemiology of DENV infections and potential inhibitors of DENV 'E' protein. Among the various serotypes, DENV-2 serotype was observed more frequently, followed by DENV-4, DENV-1, and DENV-3. New variants of existing genotypes were observed in DENV-1, 2, and 4 serotypes. Predominantly, the severe form of dengue was attributable to DENV-2 infections, and the incidence was more common in males and pediatric populations. Both the incidence and the disease severity were more common among the residents of non-urban environments. Due to the predominantly self-limiting nature of primary dengue infection and folk medicine practices of non-urban populations, we observed a greater number of secondary dengue cases than primary dengue cases. Hemorrhagic manifestations were more in secondary dengue in particularly in the pediatric group. Through different computational methods, ligands RGBLD1, RGBLD2, RGBLD3, and RGBLD4 are proposed as potential inhibitors in silico against DENV-1, -2, -3, and -4 serotypes.
Topics: Antiviral Agents; Dengue; Dengue Virus; Humans; Incidence; Serogroup; Severe Dengue; Viral Envelope Proteins
PubMed: 35632682
DOI: 10.3390/v14050940 -
Viruses May 2016Dengue, the most prevalent arthropod-borne viral disease, is caused by the dengue virus (DENV), a member of the Flaviviridae family, and is a considerable public health... (Review)
Review
Dengue, the most prevalent arthropod-borne viral disease, is caused by the dengue virus (DENV), a member of the Flaviviridae family, and is a considerable public health threat in over 100 countries, with 2.5 billion people living in high-risk areas. However, no specific antiviral drug or licensed vaccine currently targets DENV infection. The replicon system has all the factors needed for viral replication in cells. Since the development of replicon systems, transient and stable reporter replicons, as well as reporter viruses, have been used in the study of various virological aspects of DENV and in the identification of DENV inhibitors. In this review, we summarize the DENV reporter replicon system and its applications in high-throughput screening (HTS) for identification of anti-DENV inhibitors. We also describe the use of this system in elucidation of the mechanisms of virus replication and viral dynamics in vivo and in vitro.
Topics: Antiviral Agents; Dengue Virus; Drug Discovery; Genes, Reporter; Humans; Staining and Labeling; Virology; Virus Replication
PubMed: 27164125
DOI: 10.3390/v8050122 -
Emerging Microbes & Infections Dec 2022Dengue is caused by four genetically distinct viral serotypes, dengue virus (DENV) 1-4. Following transmission by mosquitoes, DENV can cause a broad spectrum of...
Dengue is caused by four genetically distinct viral serotypes, dengue virus (DENV) 1-4. Following transmission by mosquitoes, DENV can cause a broad spectrum of clinically apparent disease ranging from febrile illness to dengue hemorrhagic fever and dengue shock syndrome. Progress in the understanding of different dengue serotypes and their impacts on specific host-virus interactions has been hampered by the scarcity of tools that adequately reflect their antigenic and genetic diversity. To bridge this gap, we created and characterized infectious clones of DENV1-4 originating from South America, Africa, and Southeast Asia. Analysis of whole viral genome sequences of five DENV isolates from each of the four serotypes confirmed their broad genetic and antigenic diversity. Using a modified circular polymerase extension reaction (CPER), we generated viruses from these isolates. The resultant clones replicated robustly in human and insect cells at levels similar to those of the parental strains. To investigate properties of these genetically diverse isolates, representative viruses from each DENV serotype were administered to NOD Rag1, IL2rg Flk2 (NRGF) mice, engrafted with components of a human immune system. All DENV strains tested resulted in viremia in humanized mice and induced cellular and IgM immune responses. Collectively, we describe here a workflow for rapidly generating infectious clones of DENV - and conceivably other RNA viruses. The infectious clones described here are a valuable resource for reverse genetic studies and for characterizing host responses to DENV and .
Topics: Aedes; Animals; Antibodies, Viral; Antigenic Variation; Dengue; Dengue Virus; Genetic Variation; Humans; Immunoglobulin M; Mice; Mice, Knockout; Reverse Genetics; Serogroup
PubMed: 34931940
DOI: 10.1080/22221751.2021.2021808 -
Viruses Feb 2021Intrahost genetic diversity is thought to facilitate arbovirus adaptation to changing environments and hosts, and it might also be linked to viral pathogenesis. Dengue...
Intrahost genetic diversity is thought to facilitate arbovirus adaptation to changing environments and hosts, and it might also be linked to viral pathogenesis. Dengue virus serotype 2 (DENV-2) has circulated in Brazil since 1990 and is associated with severe disease and explosive outbreaks. Intending to shed light on the viral determinants for severe dengue pathogenesis, we sought to analyze the DENV-2 intrahost genetic diversity in 68 patient cases clinically classified as dengue fever ( = 31), dengue with warning signs ( = 19), and severe dengue ( = 18). Unlike previous DENV intrahost diversity studies whose approaches employed PCR, here we performed viral whole-genome deep sequencing from clinical samples with an amplicon-free approach, representing the real intrahost diversity scenario. Striking differences were detected in the viral population structure between the three clinical categories, which appear to be driven mainly by different infection times and selection pressures, rather than being linked with the clinical outcome itself. Diversity in the NS2B gene, however, showed to be constrained, irrespective of clinical outcome and infection time. Finally, 385 non-synonymous intrahost single-nucleotide variants located along the viral polyprotein, plus variants located in the untranslated regions, were consistently identified among the samples. Of them, 124 were exclusively or highly detected among cases with warning signs and among severe cases. However, there was no variant that by itself appeared to characterize the cases of greater severity, either due to its low intrahost frequency or the conservative effect on amino acid substitution. Although further studies are necessary to determine their real effect on viral proteins, this heightens the possibility of epistatic interactions. The present analysis represents an initial effort to correlate DENV-2 genetic diversity to its pathogenic potential and thus contribute to understanding the virus's dynamics within its human host.
Topics: Adolescent; Adult; Aged; Aged, 80 and over; Brazil; Child; Child, Preschool; Dengue; Dengue Virus; Female; Genetic Variation; Genome, Viral; Humans; Infant; Male; Middle Aged; Phylogeny; Serogroup; Viral Nonstructural Proteins; Young Adult
PubMed: 33672226
DOI: 10.3390/v13020349 -
Viruses Feb 2020Dengue virus (DENV)-mediated hair loss is one of the post-dengue fatigue syndromes and its pathophysiology remains unknown. Whether long-term or persistent infection...
Dengue virus (DENV)-mediated hair loss is one of the post-dengue fatigue syndromes and its pathophysiology remains unknown. Whether long-term or persistent infection with DENV in the scalp results in hair loss is unclear. In this study, we cultured human dermal fibroblasts (WS1 cells) and primary human hair-follicle dermal papilla cells (HFDPCs) in the long term with DENV-2 infection. The production of virion, the expression of inflammatory and anti-virus genes, and their signaling transduction activity in the infected cells were analyzed. DENV-2 NS3 protein and DENV-2 5' UTR RNA were detected in fibroblasts and HFDPCs that were subjected to long-term infection with DENV-2 for 33 days. A significant amount of DENV-2 virion was produced by both WS1 cells and HFDPCs in the first two days of acute infection. The virion was also detected in WS1 cells that were infected in the long term, but HFDPCs failed to produce DENV-2 after long-term culture. Type I and type III interferons, and inflammatory cytokines were highly expressed in the acute phase of DENV infection in HFPDC and WS1 cells. However, in the long-term cultured cells, modest levels of anti-viral protein genes were expressed and we observed reduced signaling activity, which was correlated with the level of virus production changes. Long-term infection of DENV-2 downregulated the expression of hair growth regulatory factors, such as Rip1, Wnt1, and Wnt4. This in vitro study shows that the long-term infection with DENV-2 in dermal fibroblasts and dermal papilla cells may be involved with the prolonged-DENV-infection-mediated hair loss of post-dengue fatigue syndrome. However, direct evidence for viral replication in the human hair of a dengue victim or animal infection model is required.
Topics: Cell Line; Cells, Cultured; Dengue; Dengue Virus; Dermis; Fibroblasts; Hair Follicle; Host-Pathogen Interactions; Humans; Viral Plaque Assay; Virus Replication
PubMed: 32121148
DOI: 10.3390/v12030267 -
The Journal of Infectious Diseases Sep 2016
Topics: Dengue; Dengue Vaccines; Dengue Virus; Humans; Vaccines, Attenuated
PubMed: 26908750
DOI: 10.1093/infdis/jiw068 -
Viruses Jul 2021Dengue virus (DENV) is one of the most prevalent neglected tropical diseases, with half of the world's population at risk of infection. In Nepal, DENV was first reported...
Dengue virus (DENV) is one of the most prevalent neglected tropical diseases, with half of the world's population at risk of infection. In Nepal, DENV was first reported in 2004, and its prevalence is increasing every year. The present study aimed to obtain and characterize the full-length genome sequence of DENV from the 2017 outbreak. Hospital-based surveillance was conducted in two provinces of Nepal during the outbreak. Acute-phase serum samples were collected from 141 clinically suspected dengue patients after the rainy season. By serological and molecular techniques, 37 (26.9%) and 49 (34.8%), respectively, were confirmed as dengue patients. The cosmopolitan genotype of DENV-2 was isolated from 27 laboratory-confirmed dengue patients. Genomic analysis showed many amino acid substitutions distributed mainly among the E, NS3, and NS5 genes. Phylogenetic analyses of the whole genome sequence revealed two clades (Asian and Indian) among DENV-2 isolates from Nepal. The DENV isolates from hilly and Terai areas were similar to Asian and Indian strains, respectively. Further genomic study on different DENV serotypes is warranted to understand DENV epidemics in Nepal, where there are limited scientific resources and infrastructure.
Topics: Adolescent; Adult; Aged; Child; Child, Preschool; Cross-Sectional Studies; Dengue; Dengue Virus; Disease Outbreaks; Female; Genotype; Humans; Infant; Male; Middle Aged; Nepal; Phylogeny; Serogroup; Whole Genome Sequencing; Young Adult
PubMed: 34452310
DOI: 10.3390/v13081444 -
PLoS Neglected Tropical Diseases Oct 2021The number of sporadic and epidemic dengue fever cases have reportedly been increasing in recent years in some West African countries, such as Senegal and Mali. The...
The number of sporadic and epidemic dengue fever cases have reportedly been increasing in recent years in some West African countries, such as Senegal and Mali. The first epidemic of laboratory-confirmed dengue occurred in Nouakchott, the capital city of Mauritania situated in the Saharan desert, in 2014. On-site diagnosis of dengue fever was established using a rapid diagnostic test for dengue. In parallel, the presence of Aedes aegypti mosquitoes in the city was confirmed. The initial diagnosis was confirmed by RT-PCR, which showed that all samples from the 2014 dengue epidemic in Nouakchott were dengue virus serotype 2 (DENV-2). The whole genome or envelope protein gene of these strains, together with other DENV-2 strains obtained from travelers returning from West African countries to France between 2016 and 2019 (including two Mauritanian strains in 2017 and 2018), were sequenced. Phylogenetic analysis suggested a recent emergence of an epidemic strain from the cosmopolitan genotype belonging to West African cosmopolitan lineage II, which is genetically distinct from African sylvatic genotype. The origin of this DENV-2 lineage is still unknown, but our data seem to suggest a recent and rapid dispersion of the epidemic strain throughout the region. More complete genome sequences of West African DENV-2 are required for a better understanding of the dynamics of its circulation. Arboviral surveillance and outbreak forecasting are urgently needed in West Africa.
Topics: Africa, Western; Dengue; Dengue Virus; France; Genome, Viral; Genotype; Humans; Mauritania; Phylogeny; Serogroup; Travel
PubMed: 34695119
DOI: 10.1371/journal.pntd.0009829