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Journal of Biomolecular Structure &... Jun 2024The rise in dengue cases in tropical and sub-tropical areas has become a significant health concern. At present, there is no definitive cure for dengue fever, which...
The rise in dengue cases in tropical and sub-tropical areas has become a significant health concern. At present, there is no definitive cure for dengue fever, which underscores the importance of identifying potent inhibitors. Dengue NS2B-NS3 protease is the prime drug target due to its vital function for replication. Quercetin, a flavone, has anti-dengue virus properties but is limited by low bioavailability. Previous studies have shown that methoxy substitution in flavones improves bioavailability and metabolic stability. Azaleatin is a derivative of quercetin with a methoxy substitution at the C5 position, however its ability to inhibit dengue is unknown. In this study, azaleatin was investigated for its inhibition against dengue NS2B-NS3 protease using and techniques. The fluorescence assay was used to determine the IC value and inhibition kinetics. The molecular interaction between azaleatin and NS2B-NS3 was studied using CB-Dock2 and AutoDock Vina. The complex's stability was then analysed using GROMACS. Besides, the ADMETlab 2.0 was utilized to predict pharmacokinetic of the azaleatin. Results showed that azaleatin inhibits dengue NS2B-NS3 protease non-competitively with a K of 26.82 µg/ml and an IC of 38 µg/ml. Molecular docking indicated binding of the azaleatin to the allosteric pocket of NS2B-NS3 with a docking score of -8.2 kcal/mol. Azaleatin was found stable in the pocket along 100 ns, supporting its inhibitory mode. The compound has favourable pharmacokinetic profiles and conformed to Lipinski's Rule of Five. Taken together, azaleatin inhibits NS2B-NS3 protease in a non-competitive mode, suggesting its potential as safer anti-dengue compound.Communicated by Ramaswamy H. Sarma.
PubMed: 38881303
DOI: 10.1080/07391102.2024.2335296 -
Microbes and Infection Jun 2024Antibody-dependent enhancement (ADE) of dengue virus (DENV) infection is one of the mechanisms contributing to increased severity during heterotypic, secondary...
Antibody-dependent enhancement (ADE) of dengue virus (DENV) infection is one of the mechanisms contributing to increased severity during heterotypic, secondary infection. The complement protein C1q has been shown to reduce the magnitude of ADE in vitro. Therefore, we investigated the mechanisms of C1q modulation of ADE, focusing on processes of viral entry. Using a model of ADE of DENV-1 infection in human myeloid cell lines in the presence of monoclonal antibodies, 4G2 and 2H2, we found that C1q produced nearly a 40-fold reduction of ADE of DENV-1 in K562 cells, but had no effect in U937 cells. In K562 cells, C1q reduced adsorption of DENV-1/4G2 and exerted a dual inhibitory effect on adsorption and internalization of DENV-1/2H2. Distinct endocytic pathways in the presence of antibody corresponded to conditions where C1q produced a differential action. Also, C1q did not affect the intrinsic cell response mediated by FcγR in human myeloid cells. The modulation of ADE of DENV-1 by C1q is dependent on the FcγR expressed on immune cells and the specificity of the antibody comprising the immune complex. Understanding protective and pathogenic mechanisms in the humoral response to DENV infections is crucial for the successful design of antivirals and vaccines.
PubMed: 38880233
DOI: 10.1016/j.micinf.2024.105378 -
Transfusion Jun 2024The large dengue (DENV) and chikungunya (CHIKV) outbreaks observed during the last decade across the world, as well as local transmissions in non-endemic areas are a...
BACKGROUND
The large dengue (DENV) and chikungunya (CHIKV) outbreaks observed during the last decade across the world, as well as local transmissions in non-endemic areas are a growing concern for blood safety. The aim of this study was to evaluate and compare the sensitivity of nucleic acid tests (NAT) detecting DENV and CHIKV RNA.
MATERIALS AND METHODS
Using DENV 1 to 4 International Standards, the limits of detection (LODs) calculated by probit analysis of two NAT assays; the cobas CHIKV/DENV assay (Roche Diagnostics) and the Procleix Dengue Virus Assay (Grifols) were compared. In addition, CHIKV-RNA LOD of the cobas CHIKV/DENV assay was evaluated.
RESULTS
For dengue, the 95% LOD of the cobas assay ranged between 4.10 [CI95%: 2.70-8.19] IU/mL (DENV-2) and 7.07 [CI95%: 4.34-14.89] IU/mL (DENV-4), and between 2.19 [CI95%: 1.53-3.83] IU/mL (DENV-3) and 5.84 [CI95%: 3.84-10.77] IU/mL (DENV-1) for Procleix assay. The Procleix assay had a significant lower LOD for DENV-3 (2.19 vs. 5.89 IU/mL) when compared to the cobas assay (p = 0.005). The 95% LOD for CHIKV-RNA detection of the cobas assay was 4.76 [CI95%: 3.08-8.94] IU/mL.
DISCUSSION
The two NAT assays developed for blood donor screening evaluated in this study demonstrated high and similar analytical performance. Subject to an appropriate risk-benefit assessment, they can be used to support blood safety during outbreaks in endemic areas or in non-endemic areas as an alternative to deferring blood donors during local transmission likely to affect the blood supply. The development of multiplex assays is expected to optimize laboratory organization.
PubMed: 38877832
DOI: 10.1111/trf.17921 -
Scientific Reports Jun 2024Dengue virus (DENV), mainly transmitted by Aedes aegypti mosquitoes, is the most prevalent arbovirus worldwide, representing a public health problem in tropical and...
Dengue virus (DENV), mainly transmitted by Aedes aegypti mosquitoes, is the most prevalent arbovirus worldwide, representing a public health problem in tropical and subtropical countries. In these areas, antibiotic consumption rises which may impact both mosquito microbiota and dengue transmission. Here, we assessed how the ingestion by Ae. aegypti of therapeutic concentrations of amoxicillin-clavulanic Acid association (Amox/Clav), a broad-spectrum antibiotic used to treat febrile symptoms worldwide, impacted its microbiota. We also evaluated whether simultaneous ingestion of antibiotic and DENV impacted Ae. aegypti ability to transmit this virus. We found that Amox/Clav ingestion impacted microbiota composition in Ae. aegypti and we confirmed such impact in field-collected mosquitoes. Furthermore, we observed that Amox/Clav ingestion enhanced DENV dissemination and transmission by this mosquito at 21 days post-DENV exposure. These findings increase our understanding of factors linked to human hosts that may influence dengue transmission dynamics in regions with mass-drug administration programs.
Topics: Aedes; Animals; Dengue Virus; Dengue; Microbiota; Mosquito Vectors; Amoxicillin-Potassium Clavulanate Combination; Anti-Bacterial Agents; Humans; Female
PubMed: 38871831
DOI: 10.1038/s41598-024-64221-2 -
Biochimie Jun 2024Proteases are key enzymes in viral replication, and interfering with these targets is the basis for therapeutic interventions. We previously introduced a hypothesis...
Proteases are key enzymes in viral replication, and interfering with these targets is the basis for therapeutic interventions. We previously introduced a hypothesis about conformational selection in the protease of dengue virus and related flaviviruses, based on conformational plasticity noted in X-ray structures. The present work presents the first functional evidence for alternate recognition by the dengue protease, in a mechanism based primarily on conformational selection rather than induced-fit. Recognition of distinct substrates and inhibitors in proteolytic and binding assays varies to a different extent, depending on factors reported to influence the protease structure. The pH, salinity, buffer type, and temperature cause a change in binding, proteolysis, or inhibition behavior. Using representative inhibitors with distinct structural scaffolds, we identify two contrasting binding profiles to dengue protease. Noticeable effects are observed in the binding assay upon inclusion of a non-ionic detergent in comparison to the proteolytic assay. The findings highlight the impact of the selection of testing conditions on the observed ligand affinity or inhibitory potency. From a broader scope, the dengue protease presents an example, where the induced-fit paradigm appears insufficient to explain binding events with the biological target. Furthermore, this protein reveals the complexity of comparing or combining biochemical assay data obtained under different conditions. This can be particularly critical for artificial intelligence (AI) approaches in drug discovery that rely on large datasets of compounds activity, compiled from different sources using non-identical testing procedures. In such cases, mismatched results will compromise the model quality and its predictive power.
PubMed: 38871044
DOI: 10.1016/j.biochi.2024.06.002 -
PLoS Neglected Tropical Diseases Jun 2024Dengue virus (DENV) causes approximately 390 million dengue infections worldwide every year. There were 22,777 reported DENV infections in Tainan, Taiwan in 2015. In...
Dengue virus (DENV) causes approximately 390 million dengue infections worldwide every year. There were 22,777 reported DENV infections in Tainan, Taiwan in 2015. In this study, we sequenced the C-prM-E genes from 45 DENV 2015 strains, and phylogenetic analysis based on C-prM-E genes revealed that all strains were classified as DENV serotype 2 Cosmopolitan genotype. Sequence analysis comparing different DENV-2 genotypes and Cosmopolitan DENV-2 sequences prior to 2015 showed a clade replacement event in the DENV-2 Cosmopolitan genotype. Additionally, a major substitution C-A314G (K73R) was found in the capsid region which may have contributed to the clade replacement event. Reverse genetics virus rgC-A314G (K73R) showed slower replication in BHK-21 and C6/36 cells compared to wildtype virus, as well as a decrease in NS1 production in BHK-21-infected cells. After a series of passaging, the C-A314G (K73R) mutation reverted to wildtype and was thus considered to be unstable. Next generation sequencing (NGS) of three sera collected from a single DENV2-infected patient at 1-, 2-, and 5-days post-admission was employed to examine the genetic diversity over-time and mutations that may work in conjunction with C-A314G (K73R). Results showed that the number of haplotypes decreased with time in the DENV-infected patient. On the fifth day after admission, two new haplotypes emerged, and a single non-synonymous NS4A-L115I mutation was identified. Therefore, we have identified a persistent mutation C-A314G (K73R) in all of the DENV-2 isolates, and during the course of an infection, a single new non-synonymous mutation in the NS4A region appears in the virus population within a single host. The C-A314G (K73R) thus may have played a role in the DENV-2 2015 outbreak while the NS4A-L115I may be advantageous during DENV infection within the host.
Topics: Dengue Virus; Dengue; Taiwan; Humans; Phylogeny; Disease Outbreaks; Molecular Epidemiology; Genotype; Mutation; DNA Mutational Analysis; Animals; Cell Line; Genetic Variation
PubMed: 38870242
DOI: 10.1371/journal.pntd.0012268 -
PLoS Neglected Tropical Diseases Jun 2024Chikungunya virus (CHIKV) and O'nyong nyong virus (ONNV) are phylogenetically related alphaviruses in the Semliki Forest Virus (SFV) antigenic complex of the Togaviridae...
BACKGROUND
Chikungunya virus (CHIKV) and O'nyong nyong virus (ONNV) are phylogenetically related alphaviruses in the Semliki Forest Virus (SFV) antigenic complex of the Togaviridae family. There are limited data on the circulation of these two viruses in Burkina Faso. The aim of our study was to assess their circulation in the country by determining seroprevalence to each of the viruses in blood donor samples and by retrospective molecular and serological testing of samples collected as part of national measles and rubella surveillance.
METHODOLOGY/PRINCIPAL FINDINGS
All blood donor samples were analyzed on the Luminex platform using CHIKV and ONNV E2 antigens. Patient samples collected during national measles-rubella surveillance were screened by an initial ELISA for CHIKV IgM (CHIKjj Detect IgM ELISA) at the national laboratory. The positive samples were then analyzed by a second ELISA test for CHIKV IgM (CDC MAC-ELISA) at the reference laboratory. Finally, samples that had IgM positive results for both ELISA tests and had sufficient residual volume were tested by plaque reduction neutralization testing (PRNT) for CHIKV and ONNV. These same patient samples were also analyzed by rRT-PCR for CHIKV. Among the blood donor specimens, 55.49% of the samples were positive for alphaviruses including both CHIKV and ONNV positive samples. Among patient samples collected as part of national measles and rubella surveillance, 3.09% were IgM positive for CHIKV, including 2.5% confirmed by PRNT. PRNT failed to demonstrate any ONNV infections in these samples. No samples tested by RT-qPCR. had detectable CHIKV RNA.
CONCLUSIONS/SIGNIFICANCE
Our results suggest that CHIKV and ONNV have been circulating in the population of Burkina Faso and may have been confused with malaria, dengue fever or other febrile diseases such as measles or rubella. Our study underscores the necessity to enhance arbovirus surveillance systems in Burkina Faso.
Topics: Humans; Burkina Faso; Chikungunya virus; Antibodies, Viral; Seroepidemiologic Studies; Immunoglobulin M; Male; Female; Adult; O'nyong-nyong Virus; Alphavirus Infections; Enzyme-Linked Immunosorbent Assay; Young Adult; Adolescent; Retrospective Studies; Chikungunya Fever; Middle Aged; Blood Donors; Child; Child, Preschool; Coinfection
PubMed: 38870214
DOI: 10.1371/journal.pntd.0011712 -
GigaScience Jan 2024Viral helicases are promising targets for the development of antiviral therapies. Given their vital function of unwinding double-stranded nucleic acids, inhibiting them...
Viral helicases are promising targets for the development of antiviral therapies. Given their vital function of unwinding double-stranded nucleic acids, inhibiting them blocks the viral replication cycle. Previous studies have elucidated key structural details of these helicases, including the location of substrate binding sites, flexible domains, and the discovery of potential inhibitors. Here we present a series of new Galaxy tools and workflows for performing and analyzing molecular dynamics simulations of viral helicases. We first validate them by demonstrating recapitulation of data from previous simulations of Zika (NS3) and SARS-CoV-2 (NSP13) helicases in apo and complex with inhibitors. We further demonstrate the utility and generalizability of these Galaxy workflows by applying them to new cases, proving their usefulness as a widely accessible method for exploring antiviral activity.
Topics: Molecular Dynamics Simulation; SARS-CoV-2; Zika Virus; Workflow; RNA Helicases; Humans; DNA Helicases; Antiviral Agents; Coronavirus Papain-Like Proteases; Binding Sites; Viral Nonstructural Proteins
PubMed: 38869150
DOI: 10.1093/gigascience/giae026 -
Infectious Diseases of Poverty Jun 2024In 2023, Burkina Faso experienced the largest dengue epidemic ever in Africa. This study aimed to estimate the prevalence of symptomatic, subclinical, and asymptomatic...
BACKGROUND
In 2023, Burkina Faso experienced the largest dengue epidemic ever in Africa. This study aimed to estimate the prevalence of symptomatic, subclinical, and asymptomatic dengue and determine the associated factors among adult contacts of dengue in the Central Region, Burkina Faso.
METHODS
This cross-sectional study included contacts of dengue probable cases through cluster sampling in 2022-2023. These suspected cases that tested positive were identified from the five health facilities (Pissy CMA, Saaba CM, Kossodo CMA, Samandin CM, and Marcoussis CSPS) that reported the highest number of cases in 2021 per district. All participants underwent dengue and malaria rapid diagnostic tests (RDT). Samples positive for non-structural 1 protein antigen (AgNS1) and/or immunoglobulin M (IgM) were tested for serotype detection by reverse transcription polymerase chain reaction (RT-PCR). Binary logistic regression was done to identify the determinants of asymptomatic, subclinical, and symptomatic dengue among contacts of probable dengue cases.
RESULTS
A total of 484 contacts were included, mostly in 2023 (75.2%). Most participants were females (58.6%), residing (24.3%) and passing their daytime (23.1%) in Saaba. The overall prevalence of dengue was estimated at 15.1% [95% confidence interval (CI): 12.0-18.6%], representing cases not seeking care in hospitals. Asymptomatic cases represented 2.9% (95% CI: 1.6-4.8%). Subclinical and symptomatic cases accounted for 6.0% (95% CI: 4.1-8.5%) and 6.2% (95% CI: 4.2-8.7%), respectively. Of the 58 samples tested by RT-PCR, 10 were confirmed for serotype 3 in 2023. Malaria cases were estimated at 5.6% (95% CI: 3.7-8.0%). After adjustment, participants claiming that a virus transmits dengue were likelier to have asymptomatic dengue [adjusted odds ratio (aOR) = 7.1, 95% CI: 2.4-21.0]. From the multivariable analysis, subclinical dengue was statistically associated with being included in the study in 2023 (aOR = 30.2, 95% CI: 2.0-455.5) and spending the daytime at Arrondissement 4 (aOR = 11.5, 95% CI: 1.0-131.0). After adjustment, symptomatic dengue was associated with living less than 50 m away from cultivated land (aOR = 2.8, 95% CI: 1.1-6.9) and living less than 50 m from a stretch of water (aOR = 0.1, 95% CI: 0.0-0.6).
CONCLUSIONS
The overall burden of dengue among populations not seeking care in hospitals was quite high, with few asymptomatic cases. Efforts to manage dengue cases should also target non-hospital cases and raise population awareness. The 2023 epidemic could be due to dengue virus (DENV)-3.
Topics: Humans; Dengue; Female; Male; Burkina Faso; Adult; Cross-Sectional Studies; Young Adult; Adolescent; Middle Aged; Prevalence; Dengue Virus; Family; Cluster Analysis; Child; Child, Preschool
PubMed: 38867325
DOI: 10.1186/s40249-024-01212-5 -
Journal of Medical Virology Jun 2024Dengue, a mosquito-borne viral disease, poses a significant public health challenge in Pakistan, with a significant outbreak in 2023, prompting our investigation into...
Dengue, a mosquito-borne viral disease, poses a significant public health challenge in Pakistan, with a significant outbreak in 2023, prompting our investigation into the serotype and genomic diversity of the dengue virus (DENV). NS-1 positive blood samples from 153 patients were referred to the National Institute of Health, Pakistan, between July and October 2023. Among these, 98 (64.1%) tested positive using multiplex real-time PCR, with higher prevalence among males (65.8%) and individuals aged 31-40. Serotyping revealed DENV-1 as the predominant serotype (84.7%), followed by DENV-2 (15.3%). Whole-genome sequencing of 18 samples (DENV-1 = 17, DENV-2 = 01) showed that DENV-1 (genotype III) samples were closely related (>99%) to Pakistan outbreak samples (2022), and approx. > 98% with USA (2022), Singapore and China (2016), Bangladesh (2017), and Pakistan (2019). The DENV-2 sequence (cosmopolitan genotype; clade IVA) shared genetic similarity with Pakistan outbreak sequences (2022), approx. > 99% with China and Singapore (2018-2019) and showed divergence from Pakistan sequences (2008-2013). No coinfection with dengue serotypes or other viruses were observed. Comparisons with previous DENV-1 sequences highlighted genetic variations affecting viral replication efficiency (NS2B:K55R) and infectivity (E:M272T). These findings contribute to dengue epidemiology understanding and underscore the importance of ongoing genomic surveillance for future outbreak responses in Pakistan.
Topics: Humans; Pakistan; Dengue Virus; Dengue; Disease Outbreaks; Male; Genotype; Serogroup; Adult; Female; Genetic Variation; Young Adult; Middle Aged; Adolescent; Phylogeny; Child; Genome, Viral; Whole Genome Sequencing; Child, Preschool; Aged; Infant; Serotyping; RNA, Viral
PubMed: 38864343
DOI: 10.1002/jmv.29727