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Journal of Virology May 2017The mosquito-transmitted dengue virus (DENV) infects millions of people in tropical and subtropical regions. Maturation of DENV particles requires proper cleavage of the...
The mosquito-transmitted dengue virus (DENV) infects millions of people in tropical and subtropical regions. Maturation of DENV particles requires proper cleavage of the viral polyprotein, including processing of 8 of the 13 substrate cleavage sites by dengue virus NS2B/NS3 protease. With no available direct-acting antiviral targeting DENV, NS2/NS3 protease is a promising target for inhibitor design. Current design efforts focus on the nonprime side of the DENV protease active site, resulting in highly hydrophilic and nonspecific scaffolds. However, the prime side also significantly modulates DENV protease binding affinity, as revealed by engineering the binding loop of aprotinin, a small protein with high affinity for DENV protease. In this study, we designed a series of cyclic peptides interacting with both sides of the active site as inhibitors of dengue virus protease. The design was based on two aprotinin loops and aimed to leverage both key specific interactions of substrate sequences and the entropic advantage driving aprotinin's high affinity. By optimizing the cyclization linker, length, and amino acid sequence, the tightest cyclic peptide achieved a value of 2.9 μM against DENV3 wild-type (WT) protease. These inhibitors provide proof of concept that both sides of DENV protease active site can be exploited to potentially achieve specificity and lower hydrophilicity in the design of inhibitors targeting DENV. Viruses of the flaviviral family, including DENV and Zika virus transmitted by , continue to be a threat to global health by causing major outbreaks in tropical and subtropical regions, with no available direct-acting antivirals for treatment. A better understanding of the molecular requirements for the design of potent and specific inhibitors against flaviviral proteins will contribute to the development of targeted therapies for infections by these viruses. The cyclic peptides reported here as DENV protease inhibitors provide novel scaffolds that enable exploiting the prime side of the protease active site, with the aim of achieving better specificity and lower hydrophilicity than those of current scaffolds in the design of antiflaviviral inhibitors.
Topics: Amino Acid Sequence; Antiviral Agents; Aprotinin; Catalytic Domain; Computer Simulation; Dengue Virus; Drug Discovery; Humans; Hydrophobic and Hydrophilic Interactions; Kinetics; Peptides, Cyclic; Protease Inhibitors; Protein Binding; Serine Endopeptidases; Viral Nonstructural Proteins
PubMed: 28298600
DOI: 10.1128/JVI.00045-17 -
Scientific Reports Dec 2018Reliable detection and diagnosis of dengue virus (DENV) is important for both patient care and epidemiological control. Starting with a llama immunized with a mixture of...
Reliable detection and diagnosis of dengue virus (DENV) is important for both patient care and epidemiological control. Starting with a llama immunized with a mixture of recombinant nonstructural protein 1 (NS1) antigen from the four DENV serotypes, a phage display immune library of single domain antibodies was constructed and binders selected which exhibited specificity and affinity for DENV NS1. Each of these single domain antibodies was evaluated for its binding affinity to NS1 from the four serotypes, and incorporated into a sandwich format for NS1 detection. An optimal pair was chosen that provided the best combination of sensitivity for all four DENV NS1 antigens spiked into 50% human serum while showing no cross reactivity to NS1 from Zika virus, yellow fever virus, tick-borne encephalitis virus, and minimal binding to NS1 from Japanese encephalitis virus and West Nile virus. These rugged and robust recombinant binding molecules offer attractive alternatives to conventional antibodies for implementation into immunoassays destined for resource limited locals.
Topics: Amino Acid Sequence; Antibodies, Viral; Dengue Virus; Humans; Single-Domain Antibodies; Spectrum Analysis; Surface Plasmon Resonance; Viral Nonstructural Proteins
PubMed: 30591706
DOI: 10.1038/s41598-018-35923-1 -
Nature Communications Feb 2017Dengue virus serotype 2 (DENV2) alone undergoes structural expansion at 37 °C (associated with host entry), despite high sequence and structural homology among the...
Dengue virus serotype 2 (DENV2) alone undergoes structural expansion at 37 °C (associated with host entry), despite high sequence and structural homology among the four known serotypes. The basis for this differential expansion across strains and serotypes is unknown and necessitates mapping of the dynamics of dengue whole viral particles to describe their coordinated motions and conformational changes when exposed to host-like environments. Here we capture the dynamics of intact viral particles of two serotypes, DENV1 and DENV2, by amide hydrogen/deuterium exchange mass spectrometry (HDXMS) and time resolved Förster Resonance Energy Transfer. Our results show temperature-dependent dynamics hotspots on DENV2 and DENV1 particles with DENV1 showing expansion at 40 °C but not at 37 °C. HDXMS measurement of virion dynamics in solution offers a powerful approach to identify potential epitopes, map virus-antibody complex structure and dynamics, and test effects of multiple host-specific perturbations on viruses and virus-antibody complexes.
Topics: Amino Acid Sequence; Antibodies, Viral; Dengue; Dengue Virus; Deuterium Exchange Measurement; Host-Pathogen Interactions; Humans; Models, Molecular; Molecular Conformation; Protein Conformation; Serogroup; Temperature; Viral Envelope Proteins; Virion
PubMed: 28186093
DOI: 10.1038/ncomms14339 -
Emerging Infectious Diseases Oct 2023We performed phylogenetic analysis on dengue virus serotype 2 Cosmopolitan genotype in Ho Chi Minh City, Vietnam. We document virus emergence, probable routes of...
We performed phylogenetic analysis on dengue virus serotype 2 Cosmopolitan genotype in Ho Chi Minh City, Vietnam. We document virus emergence, probable routes of introduction, and timeline of events. Our findings highlight the need for continuous, systematic genomic surveillance to manage outbreaks and forecast future epidemics.
Topics: Dengue Virus; Phylogeny; Serogroup; Vietnam; Genotype
PubMed: 37735803
DOI: 10.3201/eid2910.230529 -
Virologica Sinica Feb 2017Dengue virus (DENV) belongs to the genus Flavivirus of the family Flaviviridae and it is primarily transmitted via Aedes aegypti and Aedes albopictus mosquitoes. The... (Review)
Review
Dengue virus (DENV) belongs to the genus Flavivirus of the family Flaviviridae and it is primarily transmitted via Aedes aegypti and Aedes albopictus mosquitoes. The life cycle of DENV includes attachment, endocytosis, protein translation, RNA synthesis, assembly, egress, and maturation. Recent researches have indicated that a variety of host factors, including cellular proteins and microRNAs, positively or negatively regulate the DENV replication process. This review summarizes the latest findings (from 2014 to 2016) in the identification of the host factors involved in the DENV life cycle and Dengue infection.
Topics: Animals; Dengue Virus; Host-Pathogen Interactions; Humans; MicroRNAs; Proteins; Virus Replication
PubMed: 28124222
DOI: 10.1007/s12250-016-3902-6 -
Biochimica Et Biophysica Acta.... Nov 2020Zika virus capsid protein is involved in multiple essential steps of the viral life cycle. Many vital functionalities are attributed to the dynamic N- terminal domain of...
Zika virus capsid protein is involved in multiple essential steps of the viral life cycle. Many vital functionalities are attributed to the dynamic N- terminal domain of this protein, which is intrinsically disordered in ZIKV and among several flaviviruses too. Other than genome encapsulation, studies have shown interaction with host lipid droplets to be crucial for replication and maturation. In Dengue virus, the molecular basis of such interplay has been studied in detail, and residues within the capsid N-terminal disordered domain has been mapped. It revealed a new function of a conserved region in mediating capsid-lipid droplet association through a conformational transition. Therefore, in this study, we attempt to analyze the structural dynamics of Zika virus capsid's N- terminal domain and analyzed it through a reductionist approach by dividing the N-terminal domain into three truncated segments and studied them individually. Techniques such as Circular dichroism spectroscopy, Dynamic light scattering, Zeta potential and Molecular dynamic simulations were employed to identify the motif responsible for structural flexibility and ability to interact with membrane models. Our results confirm that the truncated segments 5-26 and 1-30 readily adopt an α-helical conformation in the presence of 2,2,2-trifluoro-ethanol, detergent and negatively charged phospholipids. However, in contrast to Dengue virus, we report the conserved residues 14-23 region to be unstructured and do not undergo a conformational switch in Zika virus. Thus, our study illustrates the possibility of conserved 14-23 region's non-involvement in ZIKV capsid-lipid droplet association, unlike DENV.
Topics: Capsid Proteins; Dengue Virus; Intrinsically Disordered Proteins; Membrane Lipids; Molecular Dynamics Simulation; Protein Domains; Protein Structure, Secondary; Zika Virus
PubMed: 32783888
DOI: 10.1016/j.bbamem.2020.183440 -
The American Journal of Tropical... Oct 2019The incidence of dengue is increasing in Guangdong, China, with the largest outbreak to date in 2014. Widespread awareness of epidemiological and molecular...
The incidence of dengue is increasing in Guangdong, China, with the largest outbreak to date in 2014. Widespread awareness of epidemiological and molecular characteristics of the dengue virus (DENV) is required. In 2014, we isolated the virus from patients and sequenced its genome. The sequences of DENV isolated from Guangdong and other countries screened since 2005 were studied to establish molecular evolutionary databases along with epidemiological data to explore its epidemiological, phylogenetic, and molecular characteristics. Causes underlying the occurrence of the dengue epidemic included importation and localization of the virus. The number of indigenous cases significantly exceeded that of imported cases. Dengue virus 1 is the most important serotype and caused the long-term epidemic locally. Based on the data available since 2005, DENV1 was divided into three genotypes (I, IV, and V). Only genotypes I and V were detected in 2014. In 2014, an epidemic involving old lineages of DENV1 genotype V occurred after 2 years of silence. The genotype was previously detected from 2009 to 2011. Genotype I, which caused recent epidemics, demonstrated a continuation of new lineages, and a predictive pattern of molecular evolution since 2005 among the four lineages was present. The DENV isolated from Guangdong was closely related to those causing large-scale epidemics in neighboring countries, suggesting the possibility of its import from these countries. The lack of sufficient epidemiological data and evidence on the local mosquito-borne DENV emphasizes the importance of studying the molecular evolutionary features and establishing a well-established phylogenetic tree for dengue prevention and control in Guangdong.
Topics: Dengue Virus; Endoplasmic Reticulum Chaperone BiP; Evolution, Molecular; Genotype; Heat-Shock Proteins; Molecular Docking Simulation; Phylogeny; Protein Conformation; Viral Proteins
PubMed: 31392945
DOI: 10.4269/ajtmh.18-0951 -
The Journal of General Virology Apr 2021Reactive oxygen species (ROS) are chemically active species which are involved in maintaining cellular and signalling processes at physiological concentrations....
Reactive oxygen species (ROS) are chemically active species which are involved in maintaining cellular and signalling processes at physiological concentrations. Therefore, cellular components that regulate redox balance are likely to play a crucial role in viral life-cycle either as promoters of viral replication or with antiviral functions. Zinc is an essential micronutrient associated with anti-oxidative systems and helps in maintaining a balanced cellular redox state. Here, we show that zinc chelation leads to induction of reactive oxygen species (ROS) in epithelial cells and addition of zinc restores ROS levels to basal state. Addition of ROS (HO) inhibited dengue virus (DENV) infection in a dose-dependent manner indicating that oxidative stress has adverse effects on DENV infection. ROS affects early stages of DENV replication as observed by quantitation of positive and negative strand viral RNA. We observed that addition of ROS specifically affected viral titres of positive strand RNA viruses. We further demonstrate that ROS specifically altered SEC31A expression at the ER suggesting a role for SEC31A-mediated pathways in the life-cycle of positive strand RNA viruses and provides an opportunity to identify drug targets regulating oxidative stress responses for antiviral development.
Topics: Adolescent; Aedes; Animals; Caco-2 Cells; Child; Child, Preschool; Chlorocebus aethiops; Cricetinae; Dengue; Dengue Virus; Humans; Hydrogen Peroxide; Oxidative Stress; RNA, Viral; Reactive Oxygen Species; Virus Replication; Zinc
PubMed: 33904816
DOI: 10.1099/jgv.0.001596 -
PLoS Neglected Tropical Diseases 2014A literature survey and analysis was conducted to describe the epidemiology of dengue disease in Thailand reported between 2000 and 2011. The literature search... (Review)
Review
UNLABELLED
A literature survey and analysis was conducted to describe the epidemiology of dengue disease in Thailand reported between 2000 and 2011. The literature search identified 610 relevant sources, 40 of which fulfilled the inclusion criteria defined in the review protocol. Peaks in the number of cases occurred during the review period in 2001, 2002, 2008 and 2010. A shift in age group predominance towards older ages continued through the review period. Disease incidence and deaths remained highest in children aged ≤ 15 years and case fatality rates were highest in young children. Heterogeneous geographical patterns were observed with higher incidence rates reported in the Southern region and serotype distribution varied in time and place. Gaps identified in epidemiological knowledge regarding dengue disease in Thailand provide several avenues for future research, in particular studies of seroprevalence.
PROTOCOL REGISTRATION
PROSPERO CRD42012002170.
Topics: Dengue; Dengue Virus; Genotype; Humans; Incidence; Seasons; Seroepidemiologic Studies; Serogroup; Thailand
PubMed: 25375766
DOI: 10.1371/journal.pntd.0003241 -
Parasites & Vectors Feb 2021Dengue fever is a mosquito-borne infectious disease that has caused major health problems. Variations in dengue virus (DENV) genes are important features of epidemic...
BACKGROUND
Dengue fever is a mosquito-borne infectious disease that has caused major health problems. Variations in dengue virus (DENV) genes are important features of epidemic outbreaks. However, the associations of DENV genes with epidemic potential have not been extensively examined. Here, we assessed new genotype invasion of DENV-1 isolated from Guangzhou in China to evaluate associations with epidemic outbreaks.
METHODOLOGY/PRINCIPAL FINDINGS
We used DENV-1 strains isolated from sera of dengue cases from 2002 to 2016 in Guangzhou for complete genome sequencing. A neighbor-joining phylogenetic tree was constructed to elucidate the genotype characteristics and determine if new genotype invasion was correlated with major outbreaks. In our study, a new genotype invasion event was observed during each significant outbreak period in 2002-2003, 2006-2007, and 2013-2014. Genotype II was the main epidemic genotype in 2003 and before. Invasion of genotype I in 2006 caused an unusual outbreak with 765 cases (relative risk [RR] = 16.24, 95% confidence interval [CI] 12.41-21.25). At the middle and late stages of the 2013 outbreak, genotype III was introduced to Guangzhou as a new genotype invasion responsible for 37,340 cases with RR 541.73 (95% CI 417.78-702.45), after which genotypes I and III began co-circulating. Base mutations occurred after new genotype invasion, and the gene sequence of NS3 protein had the lowest average similarity ratio (99.82%), followed by the gene sequence of E protein (99.86%), as compared to the 2013 strain.
CONCLUSIONS/SIGNIFICANCE
Genotype replacement and co-circulation of multiple DENV-1 genotypes were observed. New genotype invasion was highly correlated with local unusual outbreaks. In addition to DENV-1 genotype I in the unprecedented outbreak in 2014, new genotype invasion by DENV-1 genotype III occurred in Guangzhou.
Topics: China; Dengue; Dengue Virus; Disease Outbreaks; Genome, Viral; Genotype; Humans; Phylogeny; RNA, Viral; Sequence Analysis, DNA; Serogroup; Whole Genome Sequencing
PubMed: 33639996
DOI: 10.1186/s13071-021-04631-7