Dengue Virus NS1 Protein Research Articles

Harnessing high potential benzothiazole chalcones against dengue virus NS5 protein: A multi-faceted theoretical study through molecular docking, ADME, and DFT

Chalcones bearing tetralone, indanone and benzothiazole cores were synthesized successfully using a general Claisen-Schmidt condensation protocol. The prepared compounds were purified and structurally analyzed by 1H, 13C NMR, and FT-IR techniques. A multi-faceted theoretical approach, combining Density Functional Theory (DFT), molecular docking, and ADME predictions, was employed to evaluate their therapeutic potential. DFT calculations at the B3LYP/def2-TZVP level revealed key electronic properties, with TD3 compound demonstrating the highest chemical reactivity. Molecular Electrostatic Potential (MEP) and Reduced Density Gradient (RDG) analyses provided insights into the compounds' non-covalent interactions and charge distributions. Molecular docking studies against the NS5 protein (PDB: 6KR2) showed superior binding affinities for all three compounds compared to the control ligand SAH, with TD3 exhibiting the lowest binding energy (−8.41 kcal/mol) and theoretical inhibition constant (689.31 nM). ADME predictions indicated favorable drug-like properties with concerns regarding aqueous solubility and potential P-glycoprotein interactions. Toxicity evaluations highlighted challenges, particularly in hepatotoxicity and carcinogenicity. The study identified TD3 as a promising lead compound for Dengue Virus NS5 inhibition, while also emphasizing the need for targeted modifications to address toxicity concerns. This research not only contributes to anti-dengue drug discovery efforts but also provides a robust methodological framework for the theoretical evaluation of similar small compounds in future investigations.

The N and C-terminal deleted variant of the dengue virus NS1 protein is a potential candidate for dengue vaccine development

NS1 is an elusive dengue protein, involved in viral replication, assembly, pathogenesis, and immune evasion. Its levels in blood plasm are positively related to disease severity like thrombocytopenia, hemorrhage, and vascular leakage. Despite its pathogenic roles, NS1 is being used in various vaccine formulations due to its sequence conservancy, ability to produce protective antibodies and low risk for inducing antibody-dependent enhancement. In this study, we have used bioinformatics tools and reported literature to develop an NS1 variant (dNS1). Molecular docking studies were performed to evaluate the receptor-binding ability of the NS1 and dNS1 with TLR4. NS1 and dNS1 (153 to 312 amino acid region) genes were cloned, expressed and protein was purified followed by refolding. Docking studies showed the binding of NS1 and dNS1 with the TLR4 receptor which suggests that N and C-terminal sequences of NS1 are not critical for receptor binding. Antibodies against NS1 and dNS1 were raised in rabbits and binding affinity of anti-dNS1 anti-NS1 sera was evaluated against both NS1 and dNS1. Similar results were observed through western blotting which highlight that N and C-terminal deletion of NS1 does not compromise the immunogenic potential of dNS1 hence, supports its use in future vaccine formulations as a substitute for NS1.

In Silico Evaluation of 1‐Aminoisoquinoline Derivatives against Dengue Virus: Greener Access via a Sonochemical Method

AbstractThe reported antiviral properties of isoquinolines including that of berberine against dengue virus prompted us exploring a series of 1‐aminoisoquinoline derivatives against RdRp and MTase domain of NS5 protein of dengue virus (DENV) in silico. While MTase is known to assists in viral RNA capping, the RdRp plays a key role in the virus replication. The docking of 1‐aminoisoquinolines into the DENV NS5 protein RdRp domain (PDB: 5I3Q) in silico revealed good interactions of one molecule involving the H‐bond interactions through its NO2 group with GLN802, LEU511 and HIS512 residues. Notably, the docking of these compounds into the DENV NS5 protein DENV3 MTase (PDB: 5EHG) in silico also indicated same molecule as the most encouraging potential entity as the molecule participated in three H‐bond interactions through its NO2 group with GLY86, TRP87, SER56 residues. The synthesis of 1‐aminoisoquinolines was undertaken under sonochemical conditions via the reaction of 1‐chloroisoquinoline with appropriate amines in the presence of Cs2CO3 in DMSO. Among them, three encouraging compounds did not cause any significant cytotoxicity towards Vero cells but showed good to moderate inhibition of DENV2.

ANTIVIRAL SCREENING OF AZADIRACHTA INDICA PHYTOCHEMICALS AS DENGUE NS5 INHIBITOR: A MOLECULAR DOCKING APPROACH

Dengue has been an alarming viral infection in tropical and subtropical regions of the world for the past few decades, resulting in millions of deaths. There is no effective drug to treat this arbovirus-based infection. Dengue virus non-structural protein NS5 contains N terminus methyl transferase domain and C terminus RNA-dependent RNA polymerase domain, which is involved in viral RNA replication and serves as a potential target. The current in-silico study aims to find new potential dengue virus NS5 protein inhibitors. The designed library containing eight compounds from Azadirachta Indica was used to perform molecular docking against active residues of dengue virus NS5 protein. Four compounds (Desacetyl Salanin, Azadirchtin-A, Castalagin, Vilasinin) with high negative binding energy values and zero RMSD values were selected, and their drug-likeness and ADMET analysis was performed. Among the best-docked compounds, Vilasinin (-11kcal/mol) exhibited drug-like properties as it has a molecular weight less than 500 D and has zero violation value. Moreover, it has 5 hydrogen bond donors and 10 hydrogen bond acceptors. It is well soluble in water so that it can be used as a potential inhibitor and drug candidate for the treatment of dengue infection.

Electrochemical Immunosensor Based on Al-TCPP Nanomaterial Adsorption Aggregation Signal Amplification for the Detection of Dengue Virus NS1 Protein

Electrochemical Immunosensor Based on Al-TCPP Nanomaterial Adsorption Aggregation Signal Amplification for the Detection of Dengue Virus NS1 Protein

Dengue 1 outbreak in Rosso, northern Senegal, October 2021: entomologic investigations.

Senegal has experienced periodic epidemics of dengue in urban areas with increased incidence in recent years. However, few data are available on the local ecology of the epidemic vectors. In October 2021, a dengue outbreak was reported in northern Senegal to the Institute Pasteur de Dakar. Entomologic investigations then were undertaken to identify the areas at risk of transmission and to identify the vector(s). Adult mosquitoes were collected indoors and outdoors at selected households, while containers with water were inspected for mosquito larvae. All the Aedes aegypti (L.) collected were tested for dengue virus NS1 protein using a rapid diagnostic test (RDT), and positive samples were confirmed by real-time RT-PCR. The qRT-PCR positive samples were subjected to whole genome sequencing using Nanopore technology. The majority of the larvae-positive containers (83.1%) were used for water storage. The Breteau and Container indices exceeded the WHO-recommended thresholds for the risk of dengue virus transmission except at 2 localities. Ae. aegypti, the only reputed dengue vector, was collected resting indoors as well as outdoors and biting during the day and night. The NS1 protein was detected in 22 mosquito pools, including one pool of females emerging from field-collected larvae. All NS1-positive results were confirmed by RT-PCR. Virus serotyping showed that the outbreak was caused by DENV-1. This study demonstrates the need for continuous control of adult and aquatic stages of Ae. aegypti to prevent future dengue epidemics in Senegal. RDTs appear to be a promising tool for dengue diagnostics and surveillance.

The dengue virus NS1 protein; new roles in pathogenesis due to similarities with and affinity for the high-density lipoprotein (HDL)?

The dengue virus NS1 protein; new roles in pathogenesis due to similarities with and affinity for the high-density lipoprotein (HDL)?

A comprehensive protein interaction map and druggability investigation prioritized dengue virus NS1 protein as promising therapeutic candidate.

Dengue Virus (DENV) is a serious threat to human life worldwide and is one of the most dangerous vector-borne diseases, causing thousands of deaths annually. We constructed a comprehensive PPI map of DENV with its host Homo sapiens and performed various bioinformatics analyses. We found 1195 interactions between 858 human and 10 DENV proteins. Pathway enrichment analysis was performed on the two sets of gene products, and the top 5 human proteins with the maximum number of interactions with dengue viral proteins revealed noticeable results. The non-structural protein NS1 in DENV had the maximum number of interactions with the host protein, followed by NS5 and NS3. Among the human proteins, HBA1 and UBE2I were associated with 7 viral proteins, and 3 human proteins (CSNK2A1, RRP12, and HSP90AB1) were found to interact with 6 viral proteins. Pharmacophore-based virtual screening of millions of compounds in the public databases was performed to identify potential DENV-NS1 inhibitors. The lead compounds were selected based on RMSD values, docking scores, and strong binding affinities. The top ten hit compounds were subjected to ADME profiling which identified compounds C2 (MolPort-044-180-163) and C6 (MolPort-001-742-737) as lead inhibitors against DENV-NS1. Molecular dynamics trajectory analysis and intermolecular interactions between NS1 and the ligands displayed the molecular stability of the complexes in the cellular environment. The in-silico approaches used in this study could pave the way for the development of potential specie-specific drugs and help in eliminating deadly viral infections. Therefore, experimental and clinical assays are required to validate the results of this study.

Antiviral Activity of an Indole-Type Compound Derived from Natural Products, Identified by Virtual Screening by Interaction on Dengue Virus NS5 Protein.

Dengue is an acute febrile illness caused by the Dengue virus (DENV), with a high number of cases worldwide. There is no available treatment that directly affects the virus or the viral cycle. The objective of this study was to identify a compound derived from natural products that interacts with the NS5 protein of the dengue virus through virtual screening and evaluate its in vitro antiviral effect on DENV-2. Molecular docking was performed on NS5 using AutoDock Vina software, and compounds with physicochemical and pharmacological properties of interest were selected. The preliminary antiviral effect was evaluated by the expression of the NS1 protein. The effect on viral genome replication and/or translation was determined by NS5 production using DENV-2 Huh-7 replicon through ELISA and viral RNA quantification using RT-qPCR. The in silico strategy proved effective in finding a compound (M78) with an indole-like structure and with an effect on the replication cycle of DENV-2. Treatment at 50 µM reduced the expression of the NS5 protein by 70% and decreased viral RNA by 1.7 times. M78 is involved in the replication and/or translation of the viral genome.

Novel insights into the structure and function of dengue virus NS1 protein.

The dengue flavivirus is responsible for dengue fever. While generally mild, a proportion of cases develop into life-threatening dengue haemorrhagic fever. Flaviviruses produce a non-structural protein, NS1, that is essential to flavivirus genome replication, though it has no known catalytic function. Early in infection, dimeric NS1 localises on the endoplasmic reticulum membrane at the site of viral RNA replication and may be involved in the replication complexs formation. Later on NS1 is secreted as a hexameric lipoprotein that interacts with components of the complement-mediated immune system. In 2014, crystal structures of full-length, glycosylated, and truncated West Nile Virus and Dengue Type 2 Virus (DENV2) NS1 dimers were obtained, which have aided interpretation of low-resolution cryo-electron microscopy reconstructions of the hexameric structure of secreted NS1. This along with biochemical and NMR analyses of the NS1 lipid cargo was used to build and simulate models of the DENV2 NS1 hexamer with and without a lipid cargo. Coarse-grained molecular dynamics simulations showed that the glycosylation of NS1 is essential for hexamer stability, with the glycans compensating for the paucity of protein-protein contacts between dimers. Lipid loaded NS1 hexamers can pick up lipids from their environment and deposit lipids into membranes but are not able to pick up lipids from membranes, whereas NS1 hexamers without a lipid cargo are not effective at picking up environmental lipids. The lipid cargo forms a dumbbell shape, with polar lipids towards the outside of the bulbs and non-polar lipids in the centre of the bulbs and bar of the dumbbell. These results add to our somewhat scarce understanding of the otherwise enigmatic function of a protein whose presence is an important biomarker for dengue fever, but whose role in infection has been controversial and not well understood.

Dengue virus downregulates TNFR1- and TLR3-stimulated NF-κB activation by targeting RIPK1.

Dengue virus (DENV) infection is the most prevalent arthropod-borne virus disease and is endemic in more than 100 countries. Several DENV proteins have been shown to target crucial human host proteins to evade innate immune responses and establish a productive infection. Here we report that the DENV NS3 protein targets RIPK1 (Receptor Interacting Protein Kinase I), a central mediator of inflammation and cell death, and decreases intracellular RIPK1 levels during DENV infection. The interaction of NS3 with RIPK1 results in the inhibition of NF-κB activation in response to TNFR or TLR3 stimulation. Also, we observed that the effects of NS3 on RIPK1 were independent of NS3 protease activity. Our data demonstrate a novel mechanism by which DENV suppresses normal cellular functions to evade host innate immune responses

SUMOylation Is Essential for Dengue Virus Replication and Transmission in the Mosquito Aedes aegypti.

Small ubiquitin-like modifier (SUMO) is a reversible post-translational protein modifier. Protein SUMOylation regulates a wide variety of cellular processes and is important for controlling virus replication. Earlier studies suggest that dengue virus envelope protein interacts with Ubc9, the sole E2-conjugating enzyme required for protein SUMOylation in mammalian cells. However, little is known about the effect of protein SUMOylation on dengue virus replication in the major dengue vector, Aedes aegypti. Thus, in this study, we investigated the impact of protein SUMOylation on dengue virus replication in A. aegypti. The transcription of A. aegypti Ubc9 was significantly increased in the midgut after a normal blood meal. Silencing AaUbc9 resulted in significant inhibition of dengue virus NS1 protein production, viral genome transcription, and reduced viral titer in the mosquito saliva. In addition, we showed that dengue virus E proteins and prM proteins were SUMOylated post-infection. The amino acid residues K51 and K241 of dengue virus E protein were essential for protein SUMOylation. Taken together, our results reveal that protein SUMOylation contributes to dengue virus replication and transmission in the mosquito A. aegypti. This study introduces the possibility that protein SUMOylation is beneficial for virus replication and facilitates virus transmission from the mosquito.

Advancement of dengue virus NS1 protein detection by 3D-nanoassembly complex gold nanoparticles utilizing competitive sandwich aptamer on disposable electrode

Signal amplification have been centralized in developing the highly reliable biosensor for analyte detection with a narrow detection window. We proposed an aptasensor to provide a highly sensitive early-stage diagnostic platform of dengue virus NS1 protein (DENV-NS1) by dual-approach – colorimetric and electrochemical detection. This work utilized two different aptamers specific to DENV-NS1: One conjugated to gold nanoparticles (AuNPs), forming AuNPs-Apt1 and its complementary sequence aptamer, forming AuNPs-Apt2. The unbound Apt1 of AuNPs-Apt1 by DENV-NS1 were to hybridize to AuNPs-Apt2 and induced a 3D-nanoassembled formation, resulting in DENV-NS1 concentration-dependent plasmonic color change. Occurrence of the hybridization of Apt1 and Apt2, the 3D-assembled hybridized aptamers of AuNPs was incubated with methylene blue (MB) solution, which intercalated a high number of MB molecules within the duplex structure of aptamers, and the complex was captured on the Apt2-conjugated disposable gold electrode (DGE). The developed aptamer-based biosensor showed high sensitivity with colorimetric response down to 1.28 pg/mL and electrochemical approach down to 30 fg/mL of DENV-NS1 with good selectivity. This work showcases an advanced utilization of aptamer and its complementary anti-sense aptamer in signal amplification and nanocarrier for biosensing.

Virtual Screening of Drug-Like Compounds as Potential Inhibitors of the Dengue Virus NS5 Protein.

Dengue virus (DENV) is the causative agent of dengue fever. Annually, there are about 400 million new cases of dengue worldwide, and so far there is no specific treatment against this disease. The NS5 protein is the largest and most conserved viral protein among flaviviruses and is considered a therapeutic target of great interest. This study aims to search drug-like compounds for possible inhibitors of the NS5 protein in the four serotypes of DENV. Using a virtual screening from a ∼642,759-compound database, we suggest 18 compounds with NS5 binding and highlight the best compound per region, in the methyltransferase and RNA-dependent RNA polymerase domains. These compounds interact mainly with the amino acids of the catalytic sites and/or are involved in processes of protein activity. The identified compounds presented physicochemical and pharmacological properties of interest for their use as possible drugs; furthermore, we found that some of these compounds do not affect cell viability in Huh-7; therefore, we suggest evaluating these compounds in vitro as candidates in future research.

Triphala in Traditional Ayurvedic Medicine Inhibits Dengue Virus Infection in Huh7 Hepatoma Cells.

Traditional Triphala (three fruits), consisting of Phyllanthus emblica, Terminalia chebula, and Terminalia bellirica, presents a broad range of biological activities. However, its ability to inhibit dengue virus (DENV) infection has not been reported yet. Herein, the authors investigated the efficiency of three different Triphala formulations and its individual extract constituents to inhibit DENV infection. Treatment with T. bellirica extract or Triphala formulated with a high ratio of T. bellirica extract showed remarkable efficiency in significantly lowering DENV infection in Vero cells. Their effects were further studied in Huh7 cells, to address its potential ability in human cells. Treatment with 100 μg/mL of T. bellirica extract or Triphala resulted in an approximate 3000-fold or 1000-fold lowering of virus production, respectively. Furthermore, the treatment diminished IL-6 and CXCL-10 expressions, which are the hallmark of the cytokine storm phenomenon in DENV infection. The HPLC profiling demonstrated gallic acid as a major compound, the treatment by which showed its ability to effectively inhibit DENV infection after virus entry. Molecular docking demonstrated that gallic acid was able to interact with DENV NS5 protein, which could be one of Triphala’s antiviral mechanism. This study offers Triphala formulation and its ingredient, T. bellirica extract, as a natural based pharmaceutical to be used in DENV infection treatment.

Production of Properly Folded NS1 Protein in Bacterial Cells.

Dengue virus (DENV) NS1 protein is a multifunctional protein involved in several pathogenic processes but also has been described as a protective antigen suitable for eliciting humoral response against DENV. NS1 is essential for virus replication and can be found in different cell compartments and at different oligomeric states. It is secreted to the extracellular medium and can also be found circulating in the blood of infected patients, being routinely used as the serum biomarker for early dengue diagnosis. High-yield production of the recombinant NS1 protein in a native-like conformation is essential for studies regarding its function during DENV infection as well as to those interested in the development of new diagnostic approaches based on this protein. In this chapter, we describe an optimized protocol for high-yield expression of native-like NS1 in Escherichia coli bacterial cells.

ApoA1 Neutralizes Proinflammatory Effects of Dengue Virus NS1 Protein and Modulates Viral Immune Evasion.

Dengue is a mosquito-borne infectious disease that is highly endemic in tropical and subtropical countries. Symptomatic patients can rapidly progress to severe conditions of hemorrhage, plasma extravasation, and hypovolemic shock, which leads to death. The blood tests of patients with severe dengue typically reveal low levels of high-density lipoprotein (HDL), which is responsible for reverse cholesterol transport (RCT) and regulation of the lipid composition in peripheral tissues. It is well known that dengue virus (DENV) depends on membrane cholesterol rafts to infect and to replicate in mammalian cells. Here, we describe the interaction of DENV nonstructural protein 1 (NS1) with apolipoprotein A1 (ApoA1), which is the major protein component of HDL. NS1 is secreted by infected cells and can be found circulating in the serum of patients with the onset of symptoms. NS1 concentrations in plasma are related to dengue severity, which is attributed to immune evasion and an acute inflammatory response. Our data show that the DENV NS1 protein induces an increase of lipid rafts in noninfected cell membranes and enhances further DENV infection. We also show that ApoA1-mediated lipid raft depletion inhibits DENV attachment to the cell surface. In addition, ApoA1 is able to neutralize NS1-induced cell activation and to prevent NS1-mediated enhancement of DENV infection. Furthermore, we demonstrate that the ApoA1 mimetic peptide 4F is also capable of mediating lipid raft depletion to control DENV infection. Taken together, our results suggest the potential of RCT-based therapies for dengue treatment. These results should motivate studies to assess the importance of RCT in DENV infection in vivo. IMPORTANCE DENV is one of the most relevant mosquito-transmitted viruses worldwide, infecting more than 390 million people every year and leading to more than 20 thousand deaths. Although a DENV vaccine has already been approved, its potential side effects have hampered its use in large-scale immunizations. Therefore, new treatment options are urgently needed to prevent disease worsening or to improve current clinical management of severe cases. In this study, we describe a new interaction of the NS1 protein, one of the major viral components, with a key component of HDL, ApoA1. This interaction seems to alter membrane susceptibility to virus infection and modulates the mechanisms triggered by DENV to evade the immune response. We also propose the use of a mimetic peptide named 4F, which was originally developed for atherosclerosis, as a potential therapy for relieving DENV symptoms.

Structural Non-Structural Protein-1 Virus Dengue of Risk Factors on Functional Interference Hepar

The causes of hepatic damage to DHF are mixed. Dengue virus can infect the liver and cause damage.Histopathology of the liver in cases of fatal dengue shows that hepatocytes and Kupffer cells can be thetarget of viral replication and there is involvement of apoptotic mechanism. This study aims to determinethe association between dengue virus NS1 protein and degree of clinical manifestation of dengue infectionwith hepatic dysfunction. Blood samples after taking the serum, were examined for dengue virus NS1protein and SGOT and SGPT examinations at the Surabaya Health Laboratory Center. Data analysis usedChi Square, Fisher's Exact, Anava and Dunnet (a = 0.05). The results shows that the correlated variablesignificantly with dengue hemorrhagic manifestation degree was dengue virus NS protein1 (p = 0.047),with correlation strength of 26.8%. Variables significantly correlated with liver dysfunction were degreeof clinical manifestation of dengue fever (p = 0.037) with correlation strength of 33.5% and dengue virusNS protein1 (p = 0.023) with correlation strength of 29.3%. There was a significant relationship betweenthe presence of dengue virus NS1 protein and the incidence of DHF. There was a significant relationshipbetween the presence of dengue virus NS1 protein with hepatic dysfunction (SGOT and SGPT) in denguevirus infection.

Structural Non-Structural Protein-1 Virus Dengue of Risk Factors on Functional Interference Hepar

The causes of hepatic damage to DHF are mixed. Dengue virus can infect the liver and cause damage.Histopathology of the liver in cases of fatal dengue shows that hepatocytes and Kupffer cells can be thetarget of viral replication and there is involvement of apoptotic mechanism. This study aims to determinethe association between dengue virus NS1 protein and degree of clinical manifestation of dengue infectionwith hepatic dysfunction. Blood samples after taking the serum, were examined for dengue virus NS1protein and SGOT and SGPT examinations at the Surabaya Health Laboratory Center. Data analysis usedChi Square, Fisher's Exact, Anava and Dunnet (a = 0.05). The results shows that the correlated variablesignificantly with dengue hemorrhagic manifestation degree was dengue virus NS protein1 (p = 0.047),with correlation strength of 26.8%. Variables significantly correlated with liver dysfunction were degreeof clinical manifestation of dengue fever (p = 0.037) with correlation strength of 33.5% and dengue virusNS protein1 (p = 0.023) with correlation strength of 29.3%. There was a significant relationship betweenthe presence of dengue virus NS1 protein and the incidence of DHF. There was a significant relationshipbetween the presence of dengue virus NS1 protein with hepatic dysfunction (SGOT and SGPT) in denguevirus infection.

A magnetic immunoconjugate nanoplatform for easy colorimetric detection of the NS1 protein of dengue virus in infected serum.

In this work, as a proof of principle, the design and performance evaluation of a simple, cheap and efficient colorimetric test for the detection of the NS1 protein of dengue virus, assisted by an immunoconjugate of magnetite (Fe3O4) nanoparticles coupled to anti-NS1 antibodies is reported. A monoclonal antibody against the NS1 antigen was covalently immobilized on the surface of superparamagnetic iron oxide nanoparticles (SPIONs ∼ 20 nm) and used for the immunodetection of this protein. When the magnetic immuno-nanoplatform is added into infected serum, it conjugates with the NS1 protein and can then be easily separated using an external magnetic field; then, the recovered immunoconjugate is transferred into a well containing a second immobilized NS1-antibody to form an ELISA-type system. When the NS1 protein is present, a color change to blue is induced by reaction with the Perls reagent, which is consistent with the formation of a SPION-antibody-NS1 antigen-antibody conjugate that confirms infection. No false positives were found when NS1 was not present or a different antibody and the NS1 protein were added into the system. The experimental findings could be extrapolated and scaled up to lead to future developments of simple, quick, and inexpensive, in situ biomolecular diagnostic tests for emergent viral infections.