Displaying publications 41 - 60 of 86 in total

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  1. Hasebe F, Parquet MC, Pandey BD, Mathenge EG, Morita K, Balasubramaniam V, et al.
    J Med Virol, 2002 Jul;67(3):370-4.
    PMID: 12116030
    A reverse transcription-polymerase chain reaction (RT-PCR) was developed for the detection of Chikungunya virus infection. Based on the nonstructural protein 1 (nsP1) and glycoprotein E1 (E1) genes of Chikungunya, two primer sets were designed. Total RNA were extracted from the cell culture fluid of Aedes albopictus C6/36 cells inoculated with the S27 prototype virus, isolated in Tanzania in 1953, and the Malaysian strains (MALh0198, MALh0298, and MALh0398), isolated in Malaysia in 1998. For both sets of RNA samples, the expected 354- and 294-base pair (bp) cDNA fragments were amplified effectively from the nsP1 and E1 genes, respectively. Phylogenetic analysis was conducted for the Malaysian strain and other virus strains isolated from different regions in the world endemic for Chikungunya, using partial E1 gene sequence data. The Malaysian strains isolated during the epidemics of 1998 fell into a cluster with other members of the Asian genotype.
    Matched MeSH terms: Viral Nonstructural Proteins/genetics; Viral Nonstructural Proteins/metabolism; Viral Nonstructural Proteins/chemistry
  2. Sakhor W, Teoh TC, Yusof R, Lim SK, Razif MFM
    Trop Biomed, 2020 Sep 01;37(3):609-625.
    PMID: 33612776 DOI: 10.47665/tb.37.3.609
    The hepatitis C virus (HCV) consists of eight genotypes and 90 subtypes, with genotype (GT) 3 being the second most common globally and is linked to higher incidences of steatosis and rapid development of fibrosis and cirrhosis. The NS3/4A serine protease, a heterodimer complex of two HCV non-structural proteins, is an effective target for pharmaceutical intervention due to its essential roles in processing HCV polyproteins and inhibiting innate immunity. This study combines structure-based virtual screening (SBVS) of predefined compound libraries, pharmacokinetic prediction (ADME/T) and in vitro evaluation to identify potential low molecular weight (<500 Dalton) inhibitors of the NS3/4A serine protease (GT3). In silico screening of ZINC and PubChem libraries yielded five selected compounds as potential candidates. Dose-dependent inhibition of the NS3/4A serine protease and HCV replication in HuH-7.5 cells revealed that compound A (PubChem ID No. 16672637) exhibited inhibition towards HCV GT3 with an IC50 of 106.7µM and EC50 of 25.8µM, respectively. Thus, compound A may be developed as a potent, low molecular weight drug against the HCV NS3/4A serine protease of GT3.
    Matched MeSH terms: Viral Nonstructural Proteins
  3. Sivasothy Y, Liew SY, Othman MA, Abdul Wahab SM, Hariono M, Mohd Nawi MS, et al.
    Trop Biomed, 2021 Jun 01;38(2):79-84.
    PMID: 33973577 DOI: 10.47665/tb.38.2.044
    The NS2B/NS3 protease is crucial for the pathogenesis of the DENV. Therefore, the inhibition of this protease is considered to be the key strategy for the development of new antiviral drugs. In the present study, malabaricones C (3) and E (4), acylphenols from the fruits of Myristica cinnamomea King, have been respectively identified as moderate (27.33 ± 5.45 μM) and potent (7.55 ± 1.64 μM) DENV-2 NS2B/NS3 protease inhibitors, thus making this the first report on the DENV-2 NS2B/NS3 protease inhibitory activity of acylphenols. Based on the molecular docking studies, compounds 3 and 4 both have π-π interactions with Tyr161. While compound 3 has hydrogen bonding interactions with Gly151, Gly153 and Tyr161, compound 4 however, forms hydrogen bonds with Ser135, Asp129, Phe130 and Ile86 instead. The results from the present study suggests that malabaricones C (3) and E (4) could be employed as lead compounds for the development of new dengue antivirals from natural origin.
    Matched MeSH terms: Viral Nonstructural Proteins
  4. Chan, S.C., Teoh, L.C.
    MyJurnal
    The non-structural protein 1 (NS1) of the dengue viral genome has been found useful for diagnosis of acute dengue infections, being detected from one day and up to 18 days post onset of symptoms (1). Rapid Dengue NS1 antigen test was made available in commercial test kits for private clinics in Perak in 2014. This study aimed to determine the use usefulness of dengue NS1 test kits in suspected dengue cases in a general practice clinic in Perak and the period in which positive test results were obtained after the onset of symptoms. Clinic records of all suspected dengue cases seen in the ten months from October 2014 to July 2015 were traced. Patients’ demographic characteristics, presenting symptoms and the use of One Step Dengue NS1 Antigen test (Avo Diagnostics) were analyzed using SPSS version 17. Seventy one suspected dengue fever cases were seen in the study period, the highest number in July 2015 (25%). Majority were Chinese (80%), female (63%), and aged 40 years and above (51%). Most patients presented with fever (99%), body-ache (51%), gastrointestinal symptoms (51%) and headache (44%). Dengue NS1 antigen test was done in 94% of the suspected cases with 61% testing positive. The majority of the cases presenting one day to five days after onset of symptoms tested positive i.e. 59% (1 day), 90% (2 days), 54% (3-4 days) and 89% (5 days). Using dengue NS1 antigen test, positive results can be obtained as early as one day after the onset of symptoms. This test is a useful tool to aid primary care physicians detect dengue fever early.
    Matched MeSH terms: Viral Nonstructural Proteins
  5. Darwish NT, Sekaran SD, Alias Y, Khor SM
    J Pharm Biomed Anal, 2018 Feb 05;149:591-602.
    PMID: 29197806 DOI: 10.1016/j.jpba.2017.11.064
    The sharp increase in incidence of dengue infection has necessitated the development of methods for the rapid diagnosis of this deadly disease. Here we report the design and development of a reliable, sensitive, and specific optical immunosensor for the detection of the dengue nonstructural protein 1 (NS1) biomarker in clinical samples obtained during early stages of infection. The present optical NS1 immunosensor comprises a biosensing surface consisting of specific monoclonal NS1 antibody for immunofluorescence-based NS1 antigen determination using fluorescein isothiocyanate (FITC) conjugated to IgG antibody. The linear range of the optical immunosensor was from 15-500ngmL-1, with coefficient of determination (R2) of 0.92, high reproducibility (the relative standard deviation obtained was 2%), good stability for 21days at 4°C, and low detection limit (LOD) at 15ngmL-1. Furthermore, the optical immunosensor was capable of detecting NS1 analytes in plasma specimens from patients infected with the dengue virus, with low cross-reaction with plasma specimens containing the Japanese encephalitis virus (JEV) and Zika virus. No studies have been performed on the reproducibility and cross-reactivity regarding NS1 specificity, which is thus a limitation for optical NS1 immunosensors. In contrast, the present study addressed these limitations carefully where these two important experiments were conducted to showcase the robustness of our newly developed optical-based fluorescence immunosensor, which can be practically used for direct NS1 determination in any untreated clinical sample.
    Matched MeSH terms: Viral Nonstructural Proteins/blood; Viral Nonstructural Proteins/immunology; Viral Nonstructural Proteins/isolation & purification*
  6. Teoh BT, Sam SS, Tan KK, Johari J, Abd-Jamil J, Hooi PS, et al.
    Sci Rep, 2016 06 09;6:27663.
    PMID: 27278716 DOI: 10.1038/srep27663
    Timely and accurate dengue diagnosis is important for differential diagnosis and immediate implementation of appropriate disease control measures. In this study, we compared the usefulness and applicability of NS1 RDT (NS1 Ag Strip) and qRT-PCR tests in complementing the IgM ELISA for dengue diagnosis on single serum specimen (n = 375). The NS1 Ag Strip and qRT-PCR showed a fair concordance (κ = 0.207, p = 0.001). While the NS1 Ag Strip showed higher positivity than qRT-PCR for acute (97.8% vs. 84.8%) and post-acute samples (94.8% vs. 71.8%) of primary infection, qRT-PCR showed higher positivity for acute (58.1% vs. 48.4%) and post-acute (50.0% vs.41.4%) samples in secondary infection. IgM ELISA showed higher positivity in samples from secondary dengue (74.2-94.8%) than in those from primary dengue (21.7-64.1%). More primary dengue samples showed positive with combined NS1 Ag Strip/IgM ELISA (99.0% vs. 92.8%) whereas more secondary samples showed positive with combined qRT-PCR/IgM ELISA (99.4% vs. 96.2%). Combined NS1 Ag Strip/IgM ELISA is a suitable combination tests for timely and accurate dengue diagnosis on single serum specimen. If complemented with qRT-PCR, combined NS1 Ag Strip/IgM ELISA would improve detection of secondary dengue samples.
    Matched MeSH terms: Viral Nonstructural Proteins/genetics*
  7. Tan PC, Soe MZ, Si Lay K, Wang SM, Sekaran SD, Omar SZ
    PLoS Negl Trop Dis, 2012;6(5):e1637.
    PMID: 22590658 DOI: 10.1371/journal.pntd.0001637
    Dengue is the most prevalent mosquito borne infection worldwide. Vertical transmissions after maternal dengue infection to the fetus and pregnancy losses in relation to dengue illness have been reported. The relationship of dengue to miscarriage is not known.
    Matched MeSH terms: Viral Nonstructural Proteins/blood
  8. Frimayanti N, Zain SM, Lee VS, Wahab HA, Yusof R, Abd Rahman N
    In Silico Biol. (Gedrukt), 2011;11(1-2):29-37.
    PMID: 22475750 DOI: 10.3233/ISB-2012-0442
    Publication year=2011-2012
    Matched MeSH terms: Viral Nonstructural Proteins/antagonists & inhibitors*
  9. Othman R, Wahab HA, Yusof R, Rahman NA
    In Silico Biol. (Gedrukt), 2007;7(2):215-24.
    PMID: 17688447
    Multiple sequence alignment was performed against eight proteases from the Flaviviridae family using ClustalW to illustrate conserved domains. Two sets of prediction approaches were applied and the results compared. Firstly, secondary structure prediction was performed using available structure prediction servers. The second approach made use of the information on the secondary structures extracted from structure prediction servers, threading techniques and DSSP database of some of the templates used in the threading techniques. Consensus on the one-dimensional secondary structure of Den2 protease was obtained from each approach and evaluated against data from the recently crystallised Den2 NS2B/NS3 obtained from the Protein Data Bank (PDB). Results indicated the second approach to show higher accuracy compared to the use of prediction servers only. Thus, it is plausible that this approach is applicable to the initial stage of structural studies of proteins with low amino acid sequence homology against other available proteins in the PDB.
    Matched MeSH terms: Viral Nonstructural Proteins/chemistry*
  10. Scaramozzino N, Crance JM, Drouet C, Roebuck JP, Drouet E, Jouan A, et al.
    Biochem Biophys Res Commun, 2002 May 31;294(1):16-22.
    PMID: 12054734
    Langat (LGT) virus, initially isolated in 1956 from ticks in Malaysia, is a naturally occurring nonpathogenic virus with a very close antigenicity to the highly pathogenic tick-borne encephalitis (TBE) Western subtype virus and TBE Far Eastern subtype virus. NS3, the second largest viral protein of LGT virus, is highly conserved among flaviviruses and contains a characteristic protease moiety (NS3 pro). NS3 pro represents an attractive target for anti-protease molecules against TBE virus. We report herein a purification method specially designed for NS3 pro of LGT using a strategy for proper refolding coupled with the enzymatic characterisation of the protein. Different p-nitroanilide substrates, defined on canonic sequences for their susceptibility to Ser-protease, were applied to the proteolytic assays of the protein. The highest values were obtained from substrates containing an Arg or Lys (amino acid) residue at the P1 position. This purification method will facilitate the future development of reliable testing procedures for anti-proteases directed to NS3 proteins.
    Matched MeSH terms: Viral Nonstructural Proteins/metabolism*
  11. Fong MY, Koh CL, Lam SK
    Res. Virol., 1998 Nov-Dec;149(6):457-64.
    PMID: 9923022
    The limited sequencing approach was used to study the molecular epidemiology of 24 Malaysian dengue 2 viruses which were isolated between 1968 and 1993. The sequences of a 240-nucleotide-long region across the envelope/non-structural 1 protein (E/NS1) gene junction of the isolates were determined and analysed. Alignment and comparison of the nucleotide and deduced amino acid sequences of the isolates revealed that nucleotide changes occurred mostly at the third position of a particular codon and were of the transition (AG, CU) type. Five nucleotide changes resulted in amino acid substitutions. Pairwise comparisons of the nucleotide sequences gave divergence values ranging from 0 to 9.2%. At the amino acid level, the divergence ranged between 0 and 3.8%. Based on the 6% divergence as the cut-off point for genotypic classification, the isolates were grouped into two genotypes, I and II. Comparison of the nucleotide sequences of the Malaysian dengue isolates with those of the dengue viruses of other regions of the world revealed that members of genotypes I and II were closely related to viruses from the Indian Ocean and Western Pacific regions, respectively.
    Matched MeSH terms: Viral Nonstructural Proteins/genetics*
  12. Thayan R, Morita K, Vijayamalar B, Zainah S, Chew TK, Oda K, et al.
    PMID: 9444025
    The aim of this study was to determine whether mutations could occur in the dengue virus genome following three subpassages of the virus in a mosquito cell line. This was done because sources of virus isolates used for sequencing studies are usually maintained in cell lines rather than in patients' sera. Therefore it must be assured that no mutation occurred during the passaging. For this purpose, sequencing was carried out using the polymerase chain reaction (PCR) products of the envelope/non-structural protein 1 junction region (280 nucleotides) of dengue type 3 virus. Sequence data were compared between the virus from a patient's serum against the virus subpassaged three times in the C6/36 cell line. We found that the sequence data of the virus from serum was identical to the virus that was subpassaged three times in C6/36 cell line.
    Matched MeSH terms: Viral Nonstructural Proteins/genetics*
  13. Willeam Peter SS, Hassan SS, Khei Tan VP, Ngim CF, Azreen Adnan NA, Pong LY, et al.
    Vector Borne Zoonotic Dis, 2019 07;19(7):549-552.
    PMID: 30668248 DOI: 10.1089/vbz.2018.2379
    Background:
    There is an escalation of frequency and magnitude of dengue epidemics in Malaysia, with a concomitant increase in patient hospitalization. Prolonged hospitalization (PH) due to dengue virus (DENV) infections causes considerable socioeconomic burden. Early identification of patients needing PH could optimize resource consumption and reduce health care costs. This study aims to identify clinicopathological factors present on admission that are associated with PH among patients with DENV infections.
    Methods:
    This study was conducted in a tertiary referral hospital in Southern Malaysia. Relevant clinical and laboratory data upon admission were retrieved from medical records of 253 consecutive DENV nonstructural protein 1 (NS1) antigen and PCR-positive hospitalized patients. The DENV serotype present in each patient was determined. Patients were stratified based on duration of hospital stay (<4 vs. ≥4 days). Data were analyzed using IBM® SPSS® 25.0. Multivariate logistic regression was performed to examine the association between PH and admission parameters.
    Results:
    Of 253 DENV hospitalized patients, 95 (37.5%) had PH (≥4 days). The mean duration of hospital stay was 3.43 ± 2.085 days (median = 3 days, interquartile range = 7 days). Diabetes mellitus (adjusted odds ratio [AOR] = 6.261, 95% confidence interval [CI] = 2.130-18.406, p = 0.001), DENV-2 serotype (AOR = 2.581, 95% CI = 1.179-5.650, p = 0.018), duration of fever ≤4 days (AOR = 2.423, 95% CI = 0.872-6.734, p = 0.09), and a shorter preadmission fever duration (AOR = 0.679, 95% CI = 0.481-0.957, p = 0.027) were independently associated with PH. However, PH was not found to be associated with symptoms on admission, secondary DENV infections or platelet count, hematocrit, or liver enzyme levels on admission.
    Conclusions:
    Early identification of these factors at presentation may alert clinicians to anticipate and recognize challenges in treating such patients, leading to more focused management plans that may shorten the duration of hospitalization.
    Matched MeSH terms: Viral Nonstructural Proteins/genetics
  14. Panya A, Songprakhon P, Panwong S, Jantakee K, Kaewkod T, Tragoolpua Y, et al.
    Molecules, 2021 May 23;26(11).
    PMID: 34071102 DOI: 10.3390/molecules26113118
    Dengue virus (DENV) infection causes mild to severe illness in humans that can lead to fatality in severe cases. Currently, no specific drug is available for the treatment of DENV infection. Thus, the development of an anti-DENV drug is urgently required. Cordycepin (3'-deoxyadenosine), which is a major bioactive compound in Cordyceps (ascomycete) fungus that has been used for centuries in Chinese traditional medicine, was reported to exhibit antiviral activity. However, the anti-DENV activity of cordycepin is unknown. We hypothesized that cordycepin exerts anti-DENV activity and that, as an adenosine derivative, it inhibits DENV replication. To test this hypothesis, we investigated the anti-DENV activity of cordycepin in DENV-infected Vero cells. Cordycepin treatment significantly decreased DENV protein at a half-maximal effective concentration (EC50) of 26.94 μM. Moreover, DENV RNA was dramatically decreased in cordycepin-treated Vero cells, indicating its effectiveness in inhibiting viral RNA replication. Via in silico molecular docking, the binding of cordycepin to DENV non-structural protein 5 (NS5), which is an important enzyme for RNA synthesis, at both the methyltransferase (MTase) and RNA-dependent RNA polymerase (RdRp) domains, was predicted. The results of this study demonstrate that cordycepin is able to inhibit DENV replication, which portends its potential as an anti-dengue therapy.
    Matched MeSH terms: Viral Nonstructural Proteins/metabolism
  15. Yahiro T, Takaki M, Chandrasena TGAN, Rajindrajith S, Iha H, Ahmed K
    Infect Genet Evol, 2018 11;65:170-186.
    PMID: 30055329 DOI: 10.1016/j.meegid.2018.07.014
    A human-porcine reassortant rotavirus, strain R1207, was identified from 74 group A rotaviruses detected in 197 (37.6%) stool samples collected from patients who attended a tertiary care hospital in Ragama, Sri Lanka. This is the first report of a human-porcine reassortant rotavirus in Sri Lanka. The patient was a 12-month-old boy who had been hospitalized with fever and acute diarrhea with a duration of 6 days. The family had pigs at home before the birth of this boy. However, the neighbors still practice pig farming. The genotype constellation of R1207 was G4-P[6]-I1-R1-C1-M1-A1-N1-T1-E1-H1. This is based on the assignment of all the eleven gene segments a full genome-based genotyping system. R1207 showed a 4-2-3-2 genomic electrophoretic migration pattern, which is characteristic of group A rotaviruses. Our analyses revealed that five (NSP2, NSP4, VP1, VP2, and VP7) of the 11 genes were closely related to the respective genes of porcine strains. Although the remaining six genes (NSP1, NSP3, NSP5, VP3, VP4, and VP6) were related to human strains, with the exception of the gene sequence of NSP1, all of these human strains were human-porcine reassortants. With a genogroup 1 genetic backbone, this strain was possibly formed via multiple genetic reassortments. We do not know whether this strain is circulating in pigs, as no data are available on porcine rotaviruses in Sri Lanka. Surveillance should be strengthened to determine the epidemiology of this genotype of rotavirus in Sri Lanka and to assess whether the infection was limited or sustained by ongoing human-to-human transmission.
    Matched MeSH terms: Viral Nonstructural Proteins/genetics*
  16. Mohd Abd Razak MR, Mohmad Misnan N, Md Jelas NH, Norahmad NA, Muhammad A, Ho TCD, et al.
    BMC Complement Altern Med, 2018 Dec 05;18(1):320.
    PMID: 30518360 DOI: 10.1186/s12906-018-2390-7
    BACKGROUND: Carica papaya leaf juice (CPLJ) was well known for its thrombocytosis activity in rodents and dengue patients. However, the effect of CPLJ treatment on other parameters that could contribute to dengue pathogenesis such as nonstructural protein 1 (NS1) production and viremia level have never been highlighted in any clinical and in vivo studies. The aim of this study is to investigate the effect of freeze-dried CPLJ treatment on NS1 and viremia levels of dengue fever mouse model.

    METHODS: The dengue infection in mouse model was established by inoculation of non-mouse adapted New Guinea C strain dengue virus (DEN-2) in AG129 mice. The freeze-dried CPLJ compounds were identified by Ultra-High Performance Liquid Chromatography High Resolution Accurate Mass Spectrometry analysis. The infected AG129 mice were orally treated with 500 mg/kg/day and 1000 mg/kg/day of freeze-dried CPLJ, starting on day 1 post infection for 3 consecutive days. The blood samples were collected from submandibular vein for plasma NS1 assay and quantitation of viral RNA level by quantitative reverse transcription PCR.

    RESULTS: The AG129 mice infected with dengue virus showed marked increase in the production of plasma NS1, which was detectable on day 1 post infection, peaked on day 3 post-infection and started to decline from day 5 post infection. The infection also caused splenomegaly. Twenty-four compounds were identified in the freeze-dried CPLJ. Oral treatment with 500 mg/kg/day and 1000 mg/kg/day of freeze-dried CPLJ did not affect the plasma NS1 and dengue viral RNA levels. However, the morbidity level of infected AG129 mice were slightly decreased when treated with freeze-dried CPLJ.

    CONCLUSION: Oral treatment of 500 mg/kg/day and 1000 mg/kg/day of freeze-dried CPLJ at the onset of viremia did not affect the plasma NS1 and viral RNA levels in AG129 mice infected with non-mouse adapted New Guinea C strain dengue virus.

    Matched MeSH terms: Viral Nonstructural Proteins/blood*
  17. Zhang W, Jiang B, Zeng M, Duan Y, Wu Z, Wu Y, et al.
    J Virol, 2020 04 16;94(9).
    PMID: 32075929 DOI: 10.1128/JVI.01850-19
    Duck Tembusu virus (DTMUV), which is similar to other mosquito-borne flaviviruses that replicate well in most mammalian cells, is an emerging pathogenic flavivirus that has caused epidemics in egg-laying and breeding waterfowl. Immune organ defects and neurological dysfunction are the main clinical symptoms of DTMUV infection. Preinfection with DTMUV makes the virus impervious to later interferon (IFN) treatment, revealing that DTMUV has evolved some strategies to defend against host IFN-dependent antiviral responses. Immune inhibition was further confirmed by screening for DTMUV-encoded proteins, which suggested that NS2A significantly inhibited IFN-β and IFN-stimulated response element (ISRE) promoter activity in a dose-dependent manner and facilitated reinfection with duck plague virus (DPV). DTMUV NS2A was able to inhibit duck retinoic acid-inducible gene-I (RIG-I)-, and melanoma differentiation-associated gene 5 (MDA5)-, mitochondrial-localized adaptor molecules (MAVS)-, stimulator of interferon genes (STING)-, and TANK-binding kinase 1 (TBK1)-induced IFN-β transcription, but not duck TBK1- and interferon regulatory factor 7 (IRF7)-mediated effective phases of IFN response. Furthermore, we found that NS2A competed with duTBK1 in binding to duck STING (duSTING), impaired duSTING-duSTING binding, and reduced duTBK1 phosphorylation, leading to the subsequent inhibition of IFN production. Importantly, we first identified that the W164A, Y167A, and S361A mutations in duSTING significantly impaired the NS2A-duSTING interaction, which is important for NS2A-induced IFN-β inhibition. Hence, our data demonstrated that DTMUV NS2A disrupts duSTING-dependent antiviral cellular defenses by binding with duSTING, which provides a novel mechanism by which DTMUV subverts host innate immune responses. The potential interaction sites between NS2A and duSTING may be the targets of future novel antiviral therapies and vaccine development.IMPORTANCE Flavivirus infections are transmitted through mosquitos or ticks and lead to significant morbidity and mortality worldwide with a spectrum of manifestations. Infection with an emerging flavivirus, DTMUV, manifests with clinical symptoms that include lesions of the immune organs and neurological dysfunction, leading to heavy egg drop and causing serious harm to the duck industry in China, Thailand, Malaysia, and other Southeast Asian countries. Mosquito cells, bird cells, and mammalian cell lines are all susceptible to DTMUV infection. An in vivo study revealed that BALB/c mice and Kunming mice were susceptible to DTMUV after intracerebral inoculation. Moreover, there are no reports about DTMUV-related human disease, but antibodies against DTMUV and viral RNA were detected in serum samples of duck industry workers. This information implies that DTMUV has expanded its host range and may pose a threat to mammalian health. However, the pathogenesis of DTMUV is largely unclear. Our results show that NS2A strongly blocks the STING-induced signal transduction cascade by binding with STING, which subsequently blocks STING-STING binding and TBK1 phosphorylation. More importantly, the W164, Y167, or S361 residues in duSTING were identified as important interaction sites between STING and NS2A that are vital for NS2A-induced IFN production and effective phases of IFN response. Uncovering the mechanism by which DTMUV NS2A inhibits IFN in the cells of its natural hosts, ducks, will help us understand the role of NS2A in DTMUV pathogenicity.
    Matched MeSH terms: Viral Nonstructural Proteins/metabolism
  18. Kumarasamy V, Wahab AH, Chua SK, Hassan Z, Chem YK, Mohamad M, et al.
    J Virol Methods, 2007 Mar;140(1-2):75-9.
    PMID: 17140671
    A commercial dengue NS1 antigen-capture ELISA was evaluated to demonstrate its potential application for early laboratory diagnosis of acute dengue virus infection. Dengue virus NS1 antigen was detected in 199 of 213 acute serum samples from patients with laboratory confirmation of acute dengue virus infection but none of the 354 healthy blood donors' serum specimens. The dengue NS1 antigen-capture ELISA gave an overall sensitivity of 93.4% (199/213) and a specificity of 100% (354/354). The sensitivity was significantly higher in acute primary dengue (97.3%) than in acute secondary dengue (70.0%). The positive predictive value of the dengue NS1 antigen-capture ELISA was 100% and negative predictive value was 97.3%. Comparatively, virus isolation gave an overall positive isolation rate of 68.1% with a positive isolation rate of 73.9 and 31.0% for acute primary dengue and acute secondary dengue, respectively. Molecular detection of dengue RNA by RT-PCR gave an overall positive detection rate of 66.7% with a detection rate of 65.2 and 75.9% for acute primary dengue and acute secondary dengue, respectively. The results indicate that the commercial dengue NS1 antigen-capture ELISA may be superior to virus isolation and RT-PCR for the laboratory diagnosis of acute dengue infection based on a single serum sample.
    Matched MeSH terms: Viral Nonstructural Proteins/blood*
  19. Kong YY, Thay CH, Tin TC, Devi S
    J Virol Methods, 2006 Dec;138(1-2):123-30.
    PMID: 17000012 DOI: 10.1016/j.jviromet.2006.08.003
    The use of the polymerase chain reaction (PCR) in molecular diagnosis is now accepted worldwide and has become an essential tool in the research laboratory. In the laboratory, a rapid detection, serotyping and quantitation, one-step real-time RT-PCR assay was developed for dengue virus using TaqMan probes. In this assay, a set of forward and reverse primers were designed targeting the serotype conserved region at the NS5 gene, at the same time flanking a variable region for all four serotypes which were used to design the serotype-specific TaqMan probes. This multiplex one-step RT-PCR assay was evaluated using 376 samples collected during the year 2003. These groups included RNA from prototype dengue virus (1-4), RNA from acute serum from which dengue virus was isolated, RNA from tissue culture supernatants of dengue virus isolated, RNA from seronegative acute samples (which were culture and IgM negative) and RNA from samples of dengue IgM positive sera. The specificity of this assay was also evaluated using a panel of sera which were positive for other common tropical disease agents including herpes simplex virus, cytomegalovirus, measles virus, varicella-zoster virus, rubella virus, mumps virus, WWF, West Nile virus, Japanese encephalitis virus, S. typhi, Legionella, Leptospira, Chlamydia, and Mycoplasma. The sensitivity, specificity and real-time PCR efficiency of this assay were 89.54%, 100% and 91.5%, respectively.
    Matched MeSH terms: Viral Nonstructural Proteins/genetics
  20. Rothan HA, Abdulrahman AY, Sasikumer PG, Othman S, Rahman NA, Yusof R
    J Biomed Biotechnol, 2012;2012:251482.
    PMID: 23093838 DOI: 10.1155/2012/251482
    Dengue diseases have an economic as well as social burden worldwide. In this study, the antiviral activity of protegrin-1 (PG-1, RGGRLCYCRRRFCVCVGR) peptide towards dengue NS2B-NS3pro and viral replication in Rhesus monkey kidney (MK2) cells was investigated. The peptide PG-1 was synthesized by solid-phase peptide synthesis, and disulphide bonds formation followed by peptide purification was confirmed by LC-MS and RPHPLC. Dengue NS2B-NS3pro was produced as a single-chain recombinant protein in E. coli. The NS2B-NS3pro assay was carried out by measuring the florescence emission of catalyzed substrate. Real-time PCR was used to evaluate the inhibition potential of PG-1 towards dengue serotype-2 (DENV-2) replication in MK2 cells. The results showed that PG-1 inhibited dengue NS2B-NS3pro at IC(50) of 11.7 μM. The graded concentrations of PG-1 at nontoxic range were able to reduce viral replication significantly (P < 0.001) at 24, 48, and 72 hrs after viral infection. However, the percentage of inhibition was significantly (P < 0.01) higher at 24 hrs compared to 48 and 72 hrs. These data show promising therapeutic potential of PG-1 against dengue infection, hence it warrants further analysis and improvement of the peptide features as a prospective starting point for consideration in designing attractive dengue virus inhibitors.
    Matched MeSH terms: Viral Nonstructural Proteins/metabolism*
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