scholarly journals Comparable Accuracies of Nonstructural Protein 1- and Envelope Protein-Based Enzyme-Linked Immunosorbent Assays in Detecting Anti-Dengue Immunoglobulin G Antibodies

Diagnostics ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 741
Author(s):  
Jedhan Ucat Galula ◽  
Gielenny M. Salem ◽  
Raul V. Destura ◽  
Roland Remenyi ◽  
Day-Yu Chao
Keyword(s):  
Immunoglobulin G ◽  
Nonstructural Protein ◽  
Serological Test ◽  
Denv Infection ◽  
Health Concern ◽  
Natural Immunity ◽  
Global Public Health ◽  
Nonstructural Protein 1 ◽  
Immunosorbent Assays ◽  
Focus Reduction

Background: Dengue virus (DENV) infection remains a global public health concern. Enzyme-linked immunosorbent assays (ELISAs), which detect antibodies targeting the envelope (E) protein of DENV, serve as the front-line serological test for presumptive dengue diagnosis. Very few studies have determined the serostatus by detecting antibodies targeting the nonstructural protein 1 (NS1), which can function as diagnostic biomarkers to distinguish natural immunity from vaccine-induced immunity. Methods: We used community-acquired human serum specimens, with the serostatus confirmed by focus reduction microneutralization test (FRμNT), to evaluate the diagnostic performances of two NS1-based ELISA methods, namely, immunoglobulin G antibody-capture ELISA (NS1 GAC–ELISA) and indirect NS1 IgG ELISA, and compared the results with an E-based virus-like particle (VLP) GAC–ELISA. Results: NS1-based methods had comparable accuracies as VLP GAC–ELISA. Although the sensitivity in detecting anti-NS1 IgM was poor, indirect NS1 IgG ELISA showed similar limits of detection (~1–2 ng/mL) as NS1 GAC–ELISA in detecting anti-NS1 IgG. Combining the results from two or more tests as a composite reference standard can determine the DENV serostatus with a specificity reaching 100%. Conclusion: NS1-based ELISAs have comparable accuracies as VLP GAC–ELISA in determining dengue serostatus, which could effectively assist clinicians during assessments of vaccine eligibility.

scholarly journals Comparison of Two Commercially Available Dengue Virus (DENV) NS1 Capture Enzyme-Linked Immunosorbent Assays Using a Single Clinical Sample for Diagnosis of Acute DENV Infection

2008 ◽  
Vol 15 (10) ◽  
pp. 1513-1518 ◽  
Author(s):  
Kovi Bessoff ◽  
Mark Delorey ◽  
Wellington Sun ◽  
Elizabeth Hunsperger
Keyword(s):  
Dengue Virus ◽  
Real Time ◽  
Virus Isolation ◽  
Nonstructural Protein ◽  
Clinical Sample ◽  
Denv Infection ◽  
Acute Stage ◽  
Rt Pcr ◽  
Nonstructural Protein 1 ◽  
Immunosorbent Assays

ABSTRACT Dengue virus (DENV) nonstructural protein 1 (NS1) has shown promise as a novel diagnostic marker of acute DENV infection. Current techniques used to diagnose acute DENV infection, including virus isolation and reverse transcription-PCR (RT-PCR), are costly and difficult to perform, while traditional serological assays have low sensitivities during the acute stage of infection. Two commercially available NS1 antigen capture enzyme-linked immunosorbent assays (ELISAs), the Platelia dengue NS1Ag test (Bio-Rad Laboratories, Marnes La Coquette, France) and the Pan-E dengue early ELISA test (Panbio Diagnostics, Brisbane, Australia), were evaluated against a well-characterized panel of 208 real-time RT-PCR- and virus isolation-positive sera, as well as 45 real-time RT-PCR- and serologically negative sera from patients with other acute febrile illnesses. The overall sensitivities were 64.9% (95% confidence interval [CI95], 58.2 to 71.1%) for the Panbio test and 83.2% (CI95, 77.5 to 87.7%) for the Bio-Rad test, with interserotype variation, especially for DENV serotype 4. Predictive models were constructed to identify factors that had a significant influence on a test's outcome with respect to this panel of samples in order to identify the conditions in which the test will be most effective as a diagnostic tool. The immunoglobulin G titer was found to be the only covariate that significantly influenced results in the Bio-Rad test, while serotype and the day postonset were found to significantly influence results in the Panbio test. We concluded that the NS1 capture ELISA is a useful tool that can improve testing algorithms to diagnose DENV infection in single samples from acute and early convalescent cases.

scholarly journals Combination of Nonstructural Protein 1-Based Enzyme-Linked Immunosorbent Assays Can Detect and Distinguish Various Dengue Virus and Zika Virus Infections

2018 ◽  
Vol 57 (2) ◽  
Author(s):  
Jasmine Tyson ◽  
Wen-Yang Tsai ◽  
Jih-Jin Tsai ◽  
Carlos Brites ◽  
Ludvig Mässgård ◽  
...  
Keyword(s):  
Dengue Virus ◽  
Zika Virus ◽  
Nonstructural Protein ◽  
Density Ratio ◽  
Denv Infection ◽  
Virus Infections ◽  
Denv Serotypes ◽  
Nonstructural Protein 1 ◽  
Optical Density Ratio ◽  
Immunosorbent Assays

ABSTRACTThe recent outbreaks of Zika virus (ZIKV) and associated birth defects in regions of dengue virus (DENV) endemicity emphasize the need for sensitive and specific serodiagnostic tests. We reported previously that enzyme-linked immunosorbent assays (ELISAs) based on the nonstructural protein 1 (NS1) of DENV serotype 1 (DENV1) and ZIKV can distinguish primary DENV1, secondary DENV, and ZIKV infections. Whether ELISAs based on NS1 proteins of other DENV serotypes can discriminate various DENV and ZIKV infections remains unknown. We herein developed DENV2, DENV3, and DENV4 NS1 IgG ELISAs to test convalescent- and postconvalescent-phase samples from reverse transcription-PCR-confirmed cases, including 25 primary DENV1, 24 primary DENV2, 10 primary DENV3, 67 secondary DENV, 36 primary West Nile virus, 38 primary ZIKV, and 35 ZIKV with previous DENV infections as well as 55 flavivirus-naive samples. Each ELISA detected primary DENV infection with a sensitivity of 100% for the same serotype and 23.8% to 100% for different serotypes. IgG ELISA using a mixture of DENV1-4 NS1 proteins detected different primary and secondary DENV infections with a sensitivity of 95.6% and specificity of 89.5%. The ZIKV NS1 IgG ELISA detected ZIKV infection with a sensitivity of 100% and specificity of 82.9%. On the basis of the relative optical density ratio, the combination of DENV1-4 and ZIKV NS1 IgG ELISAs distinguished ZIKV with previous DENV and secondary DENV infections with a sensitivity of 91.7% to 94.1% and specificity of 87.0% to 95.0%. These findings have important applications to serodiagnosis, serosurveillance, and monitoring of both DENV and ZIKV infections in regions of endemicity.

scholarly journals Potential Phosphorylation of Viral Nonstructural Protein 1 in Dengue Virus Infection

Viruses ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1393
Author(s):  
Thanyaporn Dechtawewat ◽  
Sittiruk Roytrakul ◽  
Yodying Yingchutrakul ◽  
Sawanya Charoenlappanit ◽  
Bunpote Siridechadilok ◽  
...  
Keyword(s):  
Dengue Virus ◽  
Nonstructural Protein ◽  
Antiviral Drug ◽  
Denv Infection ◽  
Site Directed Mutagenesis ◽  
Phosphorylation Sites ◽  
Post Translational Modification ◽  
Multifunctional Protein ◽  
Nonstructural Protein 1 ◽  
Underlying Mechanisms

Dengue virus (DENV) infection causes a spectrum of dengue diseases that have unclear underlying mechanisms. Nonstructural protein 1 (NS1) is a multifunctional protein of DENV that is involved in DENV infection and dengue pathogenesis. This study investigated the potential post-translational modification of DENV NS1 by phosphorylation following DENV infection. Using liquid chromatography-tandem mass spectrometry (LC-MS/MS), 24 potential phosphorylation sites were identified in both cell-associated and extracellular NS1 proteins from three different cell lines infected with DENV. Cell-free kinase assays also demonstrated kinase activity in purified preparations of DENV NS1 proteins. Further studies were conducted to determine the roles of specific phosphorylation sites on NS1 proteins by site-directed mutagenesis with alanine substitution. The T27A and Y32A mutations had a deleterious effect on DENV infectivity. The T29A, T230A, and S233A mutations significantly decreased the production of infectious DENV but did not affect relative levels of intracellular DENV NS1 expression or NS1 secretion. Only the T230A mutation led to a significant reduction of detectable DENV NS1 dimers in virus-infected cells; however, none of the mutations interfered with DENV NS1 oligomeric formation. These findings highlight the importance of DENV NS1 phosphorylation that may pave the way for future target-specific antiviral drug design.

Serological Differences after Acute Zika Virus Infections between Children and Adults: Implication for Use of a Serological Test

2021 ◽  
Author(s):  
Jurai Wongsawat ◽  
Patama Suttha ◽  
Sumalee Chanama ◽  
Somkid Srisopa ◽  
Nichapa Yonchoho ◽  
...  
Keyword(s):  
Zika Virus ◽  
Nonstructural Protein ◽  
Serological Test ◽  
Cross Reactivity ◽  
Virus Infections ◽  
Positive Real ◽  
Nonstructural Protein 1 ◽  
Age Related ◽  
Polymerase Chain ◽  
Post Onset

Information is limited regarding differential serological responses after acute Zika virus (ZIKV) infections and prevalence of cross-reactivity with anti-dengue virus (DENV) assays comparing children and adults. Early convalescent sera from a cohort of suspected mild DENV cases between December 2016 and September 2018 at Bamrasnaradura Infectious Diseases Institute in Thailand were tested for nonstructural protein 1 (NS1)–based anti-ZIKV IgM and IgG ELISAs (Euroimmun), and in-house anti-DENV IgM- and IgG-capture ELISAs. ZIKV cases were identified by positive real-time reverse transcriptase-polymerase chain reaction on urine. Sera from 26 (10 children and 16 adults) ZIKV and 237 (153 children and 74 adults) non-ZIKA cases collected at the median duration of 18 days (interquartile range [IQR] 18,19) post-onset of symptoms were tested. Comparing pediatric ZIKV to adult ZIKV cases, the mean anti-ZIKV IgM ratio was higher (2.12 versus 1.27 units, respectively; P = 0.07), whereas mean anti-ZIKV IgG ratio was lower (3.13 versus 4.24 units, respectively; P = 0.03). Sensitivity of anti-ZIKV IgM and specificity of anti-ZIKV IgG in pediatric ZIKV were higher than in adult ZIKV cases (80.0% versus 43.7% and 79.1% versus 43.2%, respectively). No cross-reactivity with anti-DENV IgM- and IgG-capture ELISA were reported in pediatric ZIKV cases in our study, whereas 25% and 12.5% were found in adult ZIKV cases, respectively. Age-related ZIKV serological differences have been observed. Positive NS1-based anti-ZIKV IgM and IgG ELISA at the early convalescent phase could be useful for ZIKV diagnosis in children, even in a dengue endemic setting.

scholarly journals Performance of a New Microfluidic Dengue NS1 Immuno-magnetic Agglutination Assay for the Rapid Diagnosis of Dengue Infection in Adults

2021 ◽  
Author(s):  
Ekkarat Wongsawat ◽  
Yupin Suputtamongkol ◽  
Susan Assanasaen ◽  
Saowaluk Silpasakorn ◽  
Panisadee Avirutnan ◽  
...  
Keyword(s):  
Detection Rate ◽  
Nonstructural Protein ◽  
Dengue Infection ◽  
Main Tool ◽  
Rapid Diagnosis ◽  
Detection Methods ◽  
Health Concern ◽  
Diagnostic Purpose ◽  
Agglutination Assay ◽  
Nonstructural Protein 1

Dengue (DENV) infections are a public health concern worldwide and thus early diagnosis is important to ensure appropriate clinical management. The rapid diagnostic test (RDT) targets nonstructural protein 1 (NS1) detection and is the main tool used for diagnostic purpose. In this study, we evaluated the performance of a new rapid and semi-quantitative microfluidic DENV NS1 immuno-magnetic agglutination assay or IMA (ViroTrack Dengue Acute, BluSense Diagnostics, Copenhagen, Denmark). We studied 233 subjects confirmed to have DENV infection (by a real-time reverse transcriptase polymerase chain reaction) and 200 control samples were taken from patients with confirmed diagnoses of other febrile illnesses, in Thailand. Samples were tested using the NS1 antigen (Ag) detection methods: in-house NS1 Ag ELISA (ELISA), SD BIOLINE Dengue NS1 Ag RDT (ICT), and ViroTrack Dengue Acute (IMA). Sensitivities of these tests were 86.3%, 78.9%, and 85.5%, respectively. All tests showed high specificity (100%, 99%, and 97% for ELISA, ICT, and IMA, respectively). The sensitivities of both RDTs were affected by the low sensitivity to DENV-2 and DENV-4. NS1 Ag was detected in every patient on day 1 and day 2 after onset of illness by ELISA and IMA with a decline in detection rates over time after day 6 of illness. NS1 detection rate using ICT decreased from 100% on day 1 of illness to 98.6% on day 2 after onset of illness. By day 6, the detection rate was 45.9%. Thus, IMA performed better than ICT for early and rapid diagnosis of DENV infections in endemic countries.

scholarly journals Relative contribution of nonstructural protein 1 in dengue pathogenesis

2020 ◽  
Vol 217 (9) ◽  
Author(s):  
Pei Xuan Lee ◽  
Donald Heng Rong Ting ◽  
Clement Peng Hee Boey ◽  
Eunice Tze Xin Tan ◽  
Janice Zuo Hui Chia ◽  
...  
Keyword(s):  
Nonstructural Protein ◽  
Critical Role ◽  
Health Concern ◽  
Relative Contribution ◽  
Nonstructural Protein 1 ◽  
Structural Region ◽  
Strain Dependent ◽  
Highly Virulent

Dengue is a major public health concern in the tropical and subtropical world, with no effective treatment. The controversial live attenuated virus vaccine Dengvaxia has boosted the pursuit of subunit vaccine approaches, and nonstructural protein 1 (NS1) has recently emerged as a promising candidate. However, we found that NS1 immunization or passive transfer of NS1 antibodies failed to confer protection in symptomatic dengue mouse models using two non–mouse-adapted DENV2 strains that are highly virulent. Exogenous administration of purified NS1 also failed to worsen in vivo vascular leakage in sublethally infected mice. Neither method of NS1 immune neutralization changed the disease outcome of a chimeric strain expressing a vascular leak-potent NS1. Instead, virus chimerization involving the prME structural region indicated that these proteins play a critical role in driving in vivo fitness and virulence of the virus, through induction of key proinflammatory cytokines. This work highlights that the pathogenic role of NS1 is DENV strain dependent, which warrants reevaluation of NS1 as a universal dengue vaccine candidate.

scholarly journals Dengue Nonstructural Protein 1 Maintains Autophagy through Retarding Caspase-Mediated Cleavage of Beclin-1

2020 ◽  
Vol 21 (24) ◽  
pp. 9702
Author(s):  
Zi-Yi Lu ◽  
Miao-Huei Cheng ◽  
Chia-Yi Yu ◽  
Yee-Shin Lin ◽  
Trai-Ming Yeh ◽  
...  
Keyword(s):  
Cell Apoptosis ◽  
Nonstructural Protein ◽  
Antiviral Drug ◽  
Cellular Responses ◽  
Denv Infection ◽  
Beclin 1 ◽  
Protein Inhibition ◽  
Nonstructural Protein 1 ◽  
Significant Public Health ◽  
Related Proteins

Dengue virus (DENV) infection is a significant public health threat in tropical and subtropical regions; however, there is no specific antiviral drug. Accumulated studies have revealed that DENV infection induces several cellular responses, including autophagy and apoptosis. The crosstalk between autophagy and apoptosis is associated with the interactions among components of these two pathways, such as apoptotic caspase-mediated cleavage of autophagy-related proteins. Here, we show that DENV-induced autophagy inhibits early cell apoptosis and hence enhances DENV replication. Later, the apoptotic activities are elevated to suppress autophagy through cleavage of Beclin-1, an essential autophagy-related protein. Inhibition of cleavage of Beclin-1 by a pan-caspase inhibitor, Z-VAD, increases both autophagy and viral replication. Regarding the mechanism, we further found that DENV nonstructural protein 1 (NS1) is able to interact with Beclin-1 during DENV infection. The interaction between Beclin-1 and NS1 attenuates Beclin-1 cleavage and facilitates autophagy to prevent cell apoptosis. Our study suggests a novel mechanism whereby NS1 preserves Beclin-1 for maintaining autophagy to antagonize early cell apoptosis; however, elevated caspases trigger apoptosis by degrading Beclin-1 in the late stage of infection. These findings suggest implications for anti-DENV drug design.

Anti-dengue virus nonstructural protein 1 antibodies contribute to platelet phagocytosis by macrophages

2016 ◽  
Vol 115 (03) ◽  
pp. 646-656 ◽  
Author(s):  
Ya-Ting Chu ◽  
Chiou-Feng Lin ◽  
Chih-Peng Chang ◽  
Trai-Ming Yeh ◽  
Robert Anderson ◽  
...  
Keyword(s):  
Dengue Virus ◽  
Platelet Adhesion ◽  
Molecular Mimicry ◽  
Nonstructural Protein ◽  
Denv Infection ◽  
Dengue Disease ◽  
Nonstructural Protein 1 ◽  
Tnf Α ◽  
Β3 Integrin ◽  
Lines Of Evidence

SummaryThrombocytopenia is an important clinical manifestation of dengue disease. The hypotheses concerning the pathogenesis of thrombocytopenia include decreased production and increased destruction or consumption of platelets. We previously suggested a mechanism of molecular mimicry in which antibodies (Abs) directed against dengue virus (DENV) nonstructural protein 1 (NS1) cross-react with platelets. Furthermore, several lines of evidence show activation of endothelial cells (ECs) and macrophages are related to dengue disease severity. Previous studies also suggested that Ab-opsonised platelets facilitate the engulfment of platelets by macrophages. Here we show that TNF-α-activated ECs upregulate adhesion molecule expression to enhance the binding of platelets and macrophages and lead to anti-DENV NS1 Ab-mediated platelet phagocytosis. We further demonstrate that the interaction between macrophages and TNF-α-activated ECs requires binding of FcγR with the Fc region of platelet-bound anti-DENV NS1 Abs. Importantly, the binding of anti-DENV NS1 Abs to platelets did not interfere with platelet adhesion to ECs. The adhesion molecules ICAM-1 and β3 integrin expressed on ECs as well as the FcγR expressed on macrophages were critical in anti-DENV NS1 Ab-mediated platelet phagocytosis on activated ECs. Moreover, anti-DENV NS1 Abs dramatically enhanced platelet engulfment by macrophages in a murine model of DENV infection. Our study provides evidence for a novel role for anti-DENV NS1 Abs in the pathogenesis of thrombocytopenia in dengue disease by enhancing platelet phagocytosis by macrophages.

Antibodies against thrombin in dengue patients contain both anti-thrombotic and pro-fibrinolytic activities

2013 ◽  
Vol 110 (08) ◽  
pp. 358-365 ◽  
Author(s):  
Yung-Chun Chuang ◽  
Yee-Shin Lin ◽  
Hsiao-Sheng Liu ◽  
Jen-Reng Wang ◽  
Trai-Ming Yeh
Keyword(s):  
Nonstructural Protein ◽  
Protein A ◽  
Denv Infection ◽  
Functional Studies ◽  
Nonstructural Protein 1 ◽  
Dengue Patient ◽  
Human Thrombin ◽  
Life Threatening ◽  
Human Plasminogen

SummaryDengue virus (DENV) infection may result in severe life-threatening Dengue haemorrhagic fever (DHF). The mechanisms causing haemorrhage in those with DHF are unclear. In this study, we demonstrated that antibodies against human thrombin were increased in the sera of Dengue patients but not in that of patients infected with other viruses. To further characterise the properties of these antibodies, affinity-purified anti-thrombin antibodies (ATAs) were collected from Dengue patient sera by thrombin and protein A/L affinity columns. Most of the ATAs belonged to the IgG class and recognized DENV nonstructural protein 1 (NS1). In addition, we found that dengue patient ATAs also cross-reacted with human plasminogen (Plg). Functional studies in vitro indicated that Dengue patient ATAs could inhibit thrombin activity and enhance Plg activation. Taken together, these results suggest that DENV NS1-induced thrombin and Plg cross-reactive antibodies may contribute to the development of haemorrhage in patients with DHF by interfering with coagulation and fibrinolysis.

scholarly journals Structure of nonstructural protein 1 from SARS-CoV-2

2020 ◽  
Author(s):  
Lauren K. Clark ◽  
Todd J. Green ◽  
Chad M. Petit
Keyword(s):  
Crystal Structure ◽  
High Resolution ◽  
Nonstructural Protein ◽  
Critical Role ◽  
Structure And Function ◽  
Health Concern ◽  
Future Studies ◽  
Nonstructural Protein 1 ◽  
And Function ◽  
Viral Lifecycle

ABSTRACTThe periodic emergence of novel coronaviruses (CoVs) represents an ongoing public health concern with significant health and financial burden worldwide. The most recent occurrence originated in the city of Wuhan, China where a novel coronavirus (SARS-CoV-2) emerged causing severe respiratory illness and pneumonia. The continual emergence of novel coronaviruses underscores the importance of developing effective vaccines as well as novel therapeutic options that target either viral functions or host factors recruited to support coronavirus replication. The CoV nonstructural protein 1 (nsp1) has been shown to promote cellular mRNA degradation, block host cell translation, and inhibit the innate immune response to virus infection. Interestingly, deletion of the nsp1-coding region in infectious clones prevented the virus from productively infecting cultured cells. Because of nsp1’s importance in the CoV lifecycle, it has been highlighted as a viable target for both antiviral therapy and vaccine development. However, the fundamental molecular and structural mechanisms that underlie nsp1 function remain poorly understood, despite its critical role in the viral lifecycle. Here we report the high-resolution crystal structure of the amino, globular portion of SARS-CoV-2 nsp1 (residues 10 – 127) at 1.77Å resolution. A comparison of our structure with the SARS-CoV-1 nsp1 structure reveals how mutations alter the conformation of flexible loops, inducing the formation of novel secondary structural elements and new surface features. Paired with the recently published structure of the carboxyl end of nsp1 (residues 148 – 180), our results provide the groundwork for future studies focusing on SARS-CoV-2 nsp1 structure and function during the viral lifecycle.IMPORTANCEThe Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) is the causative agent for the COVID-19 pandemic. One protein known to play a critical role in the coronavirus lifecycle is nonstructural protein1 (nsp1). As such, it has been highlighted in numerous studies as a target for both the development of antivirals and for the design of live-attenuated vaccines. Here we report the high-resolution crystal structure of nsp1 derived from SARS-CoV-2 at 1.77Å resolution. This structure will facilitate future studies focusing on understanding the relationship between structure and function for nsp1. In turn, understanding these structure-function relationships will allow nsp1 to be fully exploited as a target for both antiviral development and vaccine design.

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