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BioRxiv : the Preprint Server For... Jun 2024Dengue virus (DENV) is a mosquito-borne flavivirus that poses a threat to nearly 50% of the global population. DENV has been endemic in Nepal since 2006; however, little...
Dengue virus (DENV) is a mosquito-borne flavivirus that poses a threat to nearly 50% of the global population. DENV has been endemic in Nepal since 2006; however, little is known about how DENV is evolving or the prevalence of anti-DENV immunity within the Nepalese population. To begin to address these gaps, we performed a serologic and genetic study of 49 patients from across Nepal who presented at central hospitals during the 2017 dengue season with suspected DENV infection. Of the 49 subjects assessed, 21 (43%) were positive for DENV NS1 antigen; of these; 5 were also anti-DENV IgM IgG ; 7 were DENV IgM IgG , 2 were IgM IgG , and 7 were IgM IgG by specific ELISAs. Seven of the 21 NS1+ sera were RNA+ by RT-PCR (six DENV2, one DENV3), suggesting that DENV2 was the dominant serotype in our cohort. Whole-genome sequencing of two DENV2 isolates showed similarity with strains circulating in Singapore in 2016, and the envelope genes were also similar to strains circulating in India in 2017. DENV-neutralizing antibodies (nAbs) were present in 31 of 47 sera tested (66%); among these, 20, 24, 26, and 12 sera contained nAbs against DENV1, 2, 3, and 4 serotypes, respectively. Serology analysis suggested that 12 (26%) and 19 (40%) of the 49 subjects were experiencing primary and secondary DENV infections, respectively. Collectively, our results provide evidence for current and/or past exposure to multiple DENV serotypes in our cohort, and the RNA analyses further indicate that DENV2 was the likely dominant serotype circulating in Nepal in 2017. These data suggest that expanded local surveillance of circulating DENV genotypes and population immunity will be important to effectively manage and mitigate future dengue outbreaks in Nepal.
PubMed: 38895290
DOI: 10.1101/2024.06.03.597174 -
Molecules (Basel, Switzerland) May 2024Within the fields of infectious disease diagnostics, microfluidic-based integrated technology systems have become a vital technology in enhancing the rapidity, accuracy,... (Review)
Review
Within the fields of infectious disease diagnostics, microfluidic-based integrated technology systems have become a vital technology in enhancing the rapidity, accuracy, and portability of pathogen detection. These systems synergize microfluidic techniques with advanced molecular biology methods, including reverse transcription polymerase chain reaction (RT-PCR), loop-mediated isothermal amplification (LAMP), and clustered regularly interspaced short palindromic repeats (CRISPR), have been successfully used to identify a diverse array of pathogens, including COVID-19, Ebola, Zika, and dengue fever. This review outlines the advances in pathogen detection, attributing them to the integration of microfluidic technology with traditional molecular biology methods and smartphone- and paper-based diagnostic assays. The cutting-edge diagnostic technologies are of critical importance for disease prevention and epidemic surveillance. Looking ahead, research is expected to focus on increasing detection sensitivity, streamlining testing processes, reducing costs, and enhancing the capability for remote data sharing. These improvements aim to achieve broader coverage and quicker response mechanisms, thereby constructing a more robust defense for global public health security.
Topics: Humans; Nucleic Acid Amplification Techniques; Molecular Diagnostic Techniques; Microfluidics; Communicable Diseases; COVID-19; SARS-CoV-2; Microfluidic Analytical Techniques; Dengue; Zika Virus Infection; Zika Virus
PubMed: 38893293
DOI: 10.3390/molecules29112417 -
PLoS Pathogens Jun 2024The obligate endosymbiont Wolbachia induces pathogen interference in the primary disease vector Aedes aegypti, facilitating the utilization of Wolbachia-based mosquito...
The obligate endosymbiont Wolbachia induces pathogen interference in the primary disease vector Aedes aegypti, facilitating the utilization of Wolbachia-based mosquito control for arbovirus prevention, particularly against dengue virus (DENV). However, the mechanisms underlying Wolbachia-mediated virus blockade have not been fully elucidated. Here, we report that Wolbachia activates the host cytoplasmic miRNA biogenesis pathway to suppress DENV infection. Through the suppression of the long noncoding RNA aae-lnc-2268 by Wolbachia wAlbB, aae-miR-34-3p, a miRNA upregulated by the Wolbachia strains wAlbB and wMelPop, promoted the expression of the antiviral effector defensin and cecropin genes through the Toll pathway regulator MyD88. Notably, anti-DENV resistance induced by Wolbachia can be further enhanced, with the potential to achieve complete virus blockade by increasing the expression of aae-miR-34-3p in Ae. aegypti. Furthermore, the downregulation of aae-miR-34-3p compromised Wolbachia-mediated virus blockade. These findings reveal a novel mechanism by which Wolbachia establishes crosstalk between the cytoplasmic miRNA pathway and the Toll pathway via aae-miR-34-3p to strengthen antiviral immune responses against DENV. Our results will aid in the advancement of Wolbachia for arbovirus control by enhancing its virus-blocking efficiency.
Topics: Wolbachia; Aedes; Animals; MicroRNAs; Dengue Virus; Dengue; Toll-Like Receptors; Mosquito Vectors; Signal Transduction; RNA, Long Noncoding; Immunity, Innate; Symbiosis
PubMed: 38885278
DOI: 10.1371/journal.ppat.1012296 -
MedRxiv : the Preprint Server For... Jun 2024Primary infection with one of four dengue virus serotypes (DENV1-4) may generate antibodies that protect or enhance subsequent secondary heterotypic infections. However,...
Primary infection with one of four dengue virus serotypes (DENV1-4) may generate antibodies that protect or enhance subsequent secondary heterotypic infections. However, the characteristics of heterotypic cross-reactive antibodies associated with protection from symptomatic infection and severe disease are not well-defined. We selected plasma samples collected before a secondary DENV heterotypic infection that was classified either as dengue fever (DF, n = 31) or dengue hemorrhagic fever/dengue shock syndrome (DHF/DSS, n = 33) from our longstanding pediatric cohort in Nicaragua. We screened various antibody properties to determine the features correlated with protection from DHF/DSS. Protection was associated with high levels of binding of various antibody isotypes, IgG subclasses and effector functions, including antibody-dependent complement deposition, ADCD. Although the samples were derived from DENV-exposed, Zika virus (ZIKV)-naïve individuals, the protective ADCD association was stronger when assays were conducted with recombinant ZIKV antigens. Further, we showed that a complement-mediated virion lysis (virolysis) assay conducted with ZIKV virions was strongly associated with protection, a finding reproduced in an independent sample set collected prior to secondary heterotypic inapparent versus symptomatic DENV infection. Virolysis was the main antibody feature correlated with protection from DHF/DSS and severe symptoms, such as thrombocytopenia, hemorrhagic manifestations, and plasma leakage. Hence, anti-DENV antibodies that cross-react with ZIKV, target virion-associated epitopes, and mediate complement-dependent virolysis are correlated with protection from secondary symptomatic DENV infection and DHF/DSS. These findings may support the rational design and evaluation of dengue vaccines and development of therapeutics.
PubMed: 38883768
DOI: 10.1101/2024.06.03.24308395 -
MedRxiv : the Preprint Server For... Jun 2024Dengue is a vector-borne viral disease impacting millions across the globe. Nevertheless, akin to many other diseases, reports indicated a decline in dengue incidence...
Serosurveillance of dengue infection and correlation with mosquito pools for dengue virus positivity during the COVID-19 pandemic in Tamil Nadu, India - A state-wide cross-sectional cluster randomized community-based study.
BACKGROUND
Dengue is a vector-borne viral disease impacting millions across the globe. Nevertheless, akin to many other diseases, reports indicated a decline in dengue incidence and seroprevalence during the COVID-19 pandemic (2020-22). This presumably could be attributed to reduced treatment-seeking rates, under-reporting, misdiagnosis, disrupted health services and reduced exposure to vectors due to lockdowns. Scientific evidence on dengue virus (DENV) disease during the COVID-19 pandemic is limited globally.
METHODS
A cross-sectional, randomized cluster sampling community-based survey was carried out to assess anti-dengue IgM and IgG and SARS-CoV-2 IgG seroprevalence across all 38 districts of Tamil Nadu, India. The prevalence of DENV in the Aedes mosquito pools during 2021 was analyzed and compared with previous and following years of vector surveillance for DENV by real-time PCR.
FINDINGS
Results implicate that both DENV-IgM and IgG seroprevalence and mosquito viral positivity were reduced across all the districts. A total of 13464 mosquito pools and 5577 human serum samples from 186 clusters were collected. Of these, 3·76% of mosquito pools were positive for DENV. In the human sera, 4·12% were positive for DENV IgM and 6·4% were positive for DENV IgG. The anti-SARS-CoV-2 antibody titres correlated with dengue seropositivity with a significant association whereas vaccination status significantly correlated with dengue IgM levels.
INTERPRETATION
Continuous monitoring of DENV seroprevalence, especially with the evolving variants of the SARS-CoV-2 virus and surge in COVID-19 cases will shed light on the transmission and therapeutic attributes of dengue infection.
PubMed: 38883728
DOI: 10.1101/2024.06.07.24308595 -
Heliyon Jun 2024Evolution remains an incessant process in viruses, allowing them to elude the host immune response and induce severe diseases, impacting the diagnostic and vaccine...
Evolution remains an incessant process in viruses, allowing them to elude the host immune response and induce severe diseases, impacting the diagnostic and vaccine effectiveness. Emerging and re-emerging diseases are among the significant public health concerns globally. The revival of dengue is mainly due to the potential for naturally arising mutations to induce genotypic alterations in serotypes. These transformations could lead to future outbreaks, underscoring the significance of studying DENV evolution in endemic regions. Predicting the emerging Dengue Virus (DENV) genome is crucial as the virus disrupts host cells, leading to fatal outcomes. Deep learning has been applied to predict dengue fever cases; there has been relatively less emphasis on its significance in forecasting emerging DENV serotypes. While Recurrent Neural Networks (RNN) were initially designed for modeling temporal sequences, our proposed DL-DVE generative and classification model, trained on complete genome data of DENV, transcends traditional approaches by learning semantic relationships between nucleotides in a continuous vector space instead of representing the contextual meaning of nucleotide characters. Leveraging 2000 publicly available DENV complete genome sequences, our Long Short-Term Memory (LSTM) based generative and Feedforward Neural Network (FNN) based classification DL-DVE model showcases proficiency in learning intricate patterns and generating sequences for emerging serotype of DENV. The generated sequences were analyzed along with available DENV serotype sequences to find conserved motifs in the genome through MEME Suite (version 5.5.5). The generative model showed an accuracy of 93 %, and the classification model provided insight into the specific serotype label, corroborated by BLAST search verification. Evaluation metrics such as ROC-AUC value 0.818, accuracy, precision, recall and F1 score, all to be around 99.00 %, demonstrating the classification model's reliability. Our model classified the generated sequences as DENV-4, exhibiting 65.99 % similarity to DENV-4 and around 63-65 % similarity with other serotypes, indicating notable distinction from other serotypes. Moreover, the intra-serotype divergence of sequences with a minimum of 90 % similarity underscored their uniqueness.
PubMed: 38882365
DOI: 10.1016/j.heliyon.2024.e32061 -
Biotechnology Reports (Amsterdam,... Jun 2024Dengue virus (DENV), transmitted by mosquitoes, is classified into four serotypes (DENV1-4) and typically causes mild, self-limiting symptoms upon initial infection....
Dengue virus (DENV), transmitted by mosquitoes, is classified into four serotypes (DENV1-4) and typically causes mild, self-limiting symptoms upon initial infection. However, secondary infection can lead to severe symptoms due to antibody-dependent enhancement (ADE). To address this, anti-DENV antibodies are being developed with the goal of neutralizing infection without ADE activity. Previous attempts using a 54_hG1 antibody from CHO-K1 mammalian cells resulted in ADE induction, increasing viral infection. This study aimed to express the D54 monoclonal antibody in . The plant-produced antibody had a similar neutralizing profile to the previous 54_hG1 antibody. Notably, the ADE activities of the plant-derived antibody were successfully eliminated, with no sign of viral induction. These findings suggest that could be a source of therapeutic DENV antibodies. The method offers several advantages, including lower ADE, cost-effectiveness, simple facility requirements, scalability, and potential industrial-scale production in GMP facilities.
PubMed: 38881650
DOI: 10.1016/j.btre.2024.e00844 -
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