Identification of anti-premembrane antibody as a serocomplex-specific marker to discriminate Zika, dengue and West Nile virus infections

2021 ◽  
Author(s):  
Szu-Chia Hsieh ◽  
Wen-Yang Tsai ◽  
Jih-Jin Tsai ◽  
Mars Stone ◽  
Graham Simmons ◽  
...  

Although transmission of Zika virus (ZIKV) in the Americas has greatly declined since late 2017, recent reports of reduced risks of symptomatic Zika by prior dengue virus (DENV) infection and increased risks of severe dengue disease by previous ZIKV or DENV infection underscore a critical need for serological tests that can discriminate past ZIKV, DENV and/or other flavivirus infections and improve our understanding of the immune interactions between these viruses and vaccine strategy in endemic regions. As serological tests for ZIKV primarily focus on envelope (E) and nonstructural protein 1 (NS1), antibodies to other ZIKV proteins have not been explored. Here we employed Western blot analysis using antigens of 6 flaviviruses from 3 serocomplexes to investigate antibody responses following reverse-transcription-polymerase-chain reaction-confirmed ZIKV infection. Panels of 20 primary ZIKV and 20 ZIKV with previous DENV infection recognized E proteins of all 6 flaviviruses and NS1 protein of ZIKV with some cross-reactivity to DENV. While the primary ZIKV panel recognized only the premembrane (prM) protein of ZIKV, the ZIKV with previous DENV panel recognized both ZIKV and DENV prM proteins. Analysis of antibody responses following 42 DENV and 18 West Nile virus infections revealed similar patterns of recognition by anti-E and anti-NS1 antibodies, whereas both panels recognized prM protein of homologous serocomplex but not others. The specificity was further supported by analysis of sequential samples. Together, these findings suggest that anti-prM antibody is a flavivirus serocomplex-specific marker and can be used to delineate current and past flavivirus infections in endemic areas. IMPORTANCE Despite a decline in Zika virus (ZIKV) transmission since late 2017, questions regarding its surveillance, potential re-emergence, and interactions with other flaviviruses in endemic regions remain unanswered. Recent studies have reported reduced risks of symptomatic Zika by prior dengue virus (DENV) infection and increased risks of severe dengue disease by previous ZIKV or DENV infection, highlighting a need for better serological tests to discriminate past ZIKV, DENV and/or other flavivirus infections and improved understanding of the immune interactions and vaccine strategy for these viruses. As most serological tests for ZIKV focused on envelope and nonstructural protein 1, antibodies to other ZIKV proteins including potentially specific antibodies remain understudied. We employed Western blot analysis using antigens of 6 flaviviruses to study antibody responses following well-documented ZIKV, DENV and West Nile virus infections and identified anti-premembrane antibody as a flavivirus serocomplex-specific marker to delineate current and past flavivirus infections in endemic areas.

2007 ◽  
Vol 14 (8) ◽  
pp. 1024-1031 ◽  
Author(s):  
Yoko Kitai ◽  
Mizue Shoda ◽  
Takashi Kondo ◽  
Eiji Konishi

ABSTRACT West Nile virus (WNV) is now widely distributed worldwide, except in most areas of Asia where Japanese encephalitis virus (JEV) is distributed. Considering the movement and migration of reservoir birds, there is concern that WNV may be introduced in Asian countries. Although manuals and guidelines for serological tests have been created in Japan in preparedness for the introduction of WNV, differential diagnosis between WNV and JEV may be complicated by antigenic cross-reactivities between these flaviviruses. Here, we generated a monoclonal antibody specific for the nonstructural protein 1 (NS1) of WNV and established an epitope-blocking enzyme-linked immunosorbent assay that can differentiate WNV from JEV infections in horse sera. Under conditions well suited for our assay system, samples collected from 95 horses in Japan (regarded as negative for WNV antibodies), including those collected from horses naturally infected with JEV, showed a mean inhibition value of 8.2% and a standard deviation (SD) of 6.5%. However, inhibition values obtained with serum used as a positive control (obtained after 28 days from a horse experimentally infected with WNV) in nine separate experiments showed a mean of 54.4% and an SD of 7.1%. We tentatively determined 27.6% (mean + 3 × SD obtained with 95 negative samples) as the cutoff value to differentiate positive from negative samples. Under this criterion, two horses experimentally infected with WNV were diagnosed as positive at 12 and 14 days, respectively, after infection.


2015 ◽  
Vol 55 (2) ◽  
pp. 87
Author(s):  
Ni Made Adi Purnami ◽  
Mohammad Juffrie ◽  
Made Gde Dwi Lingga Utama

Background Dengue infection is one of the main cause ofmorbidity and mortality in children in Indonesia. Since it is knownthat earlier treatment and supportive therapies can decreased casefatality rate from dengue hemorrhagic fever (DHF), identificationof children who have risks to develop to DHF must be quicklyidentified, mainly in areas of endemic.Objective To find a correlation between increased quantitativesecreted nonstructural protein-1 (sNS1) with clinical course ofsevere dengue infections.Methods This was a cross-sectional study conducted on childrenwith dengue infections in Tropical Infections Division of ChildHealth Department, Sanglah Hospital, Denpasar. Detection ofthe dengue antigen was made by examining sNS1 quantitativeimmuno-assay. Analysis correlation of Spearman test was used tolook the relationship between increased quantitative sNS1 withclinical course of severe dengue infections.Results There was a positive relationship between quantitativesNS1 and clinical course of severe dengue infections with a valueof r = 0.903, P=0.001. Increased sNS1 level had a positivecorrelation with more severe dengue infections.Conclusions Quantitative sNS1 titer has a strong positivecorrelation with clinical course of severe dengue infections.


2014 ◽  
Vol 53 (2) ◽  
pp. 557-566 ◽  
Author(s):  
Day-Yu Chao ◽  
Jedhan Ucat Galula ◽  
Wen-Fan Shen ◽  
Brent S. Davis ◽  
Gwong-Jen J. Chang

IgM antibody- and IgG antibody-capture enzyme-linked immunosorbent assays (MAC/GAC-ELISAs) targeted at envelope protein (E) of dengue viruses (DENV), West Nile virus, and Japanese encephalitis virus (JEV) are widely used as serodiagnostic tests for presumptive confirmation of viral infection. Antibodies directed against the flavivirus nonstructural protein 1 (NS1) have been proposed as serological markers of natural infections among vaccinated populations. The aim of the current study is to optimize an IgM and IgG antibody-capture ELISA (MAC/GAC-ELISA) to detect anti-NS1 antibodies and compare it with anti-E MAC/GAC-ELISA. Plasmids to express premembrane/envelope (prM/E) or NS1 proteins of six medically important flaviviruses, including dengue viruses (DENV-1 to DENV-4), West Nile virus (WNV), and Japanese encephalitis virus (JEV), were constructed. These plasmids were used for the production of prM/E-containing virus-like particles (VLPs) and secreted NS1 (sNS1) from COS-1 cells. Archived clinical specimens from patients with confirmed DENV, JEV, and WNV infections, along with naive sera, were subjected to NS1-MAC/GAC-ELISAs before or after depletion of anti-prM/E antibodies by preabsorption with or without VLPs. Human serum specimens from previously confirmed DENV infections showed significantly enhanced positive-to-negative (P/N) ratios for NS1-MAC/GAC-ELISAs after the depletion of anti-prM/E antibodies. No statistical differences in sensitivities and specificities were found between the newly developed NS1- and VLP-MAC/GAC-ELISAs. Further application of the assays to WNV- and JEV-infected serum panels showed similar results. A novel approach to perform MAC/GAC-ELISAs for NS1 antibody detection was successfully developed with great potential to differentiate antibodies elicited by the tetravalent chimeric yellow fever-17D/dengue vaccine or DENV infection.


2010 ◽  
Vol 84 (16) ◽  
pp. 8332-8341 ◽  
Author(s):  
Dong Jiang ◽  
Jessica M. Weidner ◽  
Min Qing ◽  
Xiao-Ben Pan ◽  
Haitao Guo ◽  
...  

ABSTRACT Interferons (IFNs) are key mediators of the host innate antiviral immune response. To identify IFN-stimulated genes (ISGs) that instigate an antiviral state against two medically important flaviviruses, West Nile virus (WNV) and dengue virus (DENV), we tested 36 ISGs that are commonly induced by IFN-α for antiviral activity against the two viruses. We discovered that five ISGs efficiently suppressed WNV and/or DENV infection when they were individually expressed in HEK293 cells. Mechanistic analyses revealed that two structurally related cell plasma membrane proteins, IFITM2 and IFITM3, disrupted early steps (entry and/or uncoating) of the viral infection. In contrast, three IFN-induced cellular enzymes, viperin, ISG20, and double-stranded-RNA-activated protein kinase, inhibited steps in viral proteins and/or RNA biosynthesis. Our results thus imply that the antiviral activity of IFN-α is collectively mediated by a panel of ISGs that disrupt multiple steps of the DENV and WNV life cycles.


2021 ◽  
Author(s):  
Alex W. Wessel ◽  
Kimberly A. Dowd ◽  
Scott B. Biering ◽  
Ping Zhang ◽  
Melissa A. Edeling ◽  
...  

Dengue (DENV) and West Nile (WNV) viruses are arthropod-transmitted flaviviruses that respectively cause systemic vascular leakage and encephalitis syndromes in humans. However, the viral factors contributing to these specific clinical disorders are not completely understood. Flavivirus nonstructural protein 1 (NS1) is required for replication, expressed on the cell surface, and secreted as a soluble glycoprotein, reaching high levels in the blood of infected individuals. Extracellular DENV and WNV NS1 interact with host proteins and cells, have immune evasion functions, and promote endothelial dysfunction in a tissue-specific manner. To characterize how differences in DENV and WNV NS1 might function in pathogenesis, we generated WNV NS1 variants with substitutions corresponding to residues found in DENV NS1. We discovered that the substitution NS1-P101K led to reduced WNV infectivity of the brain and attenuated lethality in infected mice, although the virus replicated efficiently in cell culture and peripheral organs and bound at wild-type levels to brain endothelial cells and complement components. The P101K substitution resulted in reduced NS1 antigenemia in mice, and this was associated with reduced WNV spread to the brain. As exogenous administration of NS1 protein rescued WNV brain infectivity in mice, we conclude that circulating WNV NS1 facilitates viral dissemination into the central nervous system and impacts disease outcome. IMPORTANCE Flavivirus NS1 serves as an essential scaffolding molecule during virus replication but also is expressed on the cell surface and secreted as a soluble glycoprotein that circulates in the blood of infected individuals. Although extracellular forms of NS1 are implicated in immune modulation and in promoting endothelial dysfunction at blood-tissue barriers, it has been challenging to study specific effects of NS1 on pathogenesis without disrupting its key role in virus replication. Here we assessed West Nile virus (WNV) NS1 variants that do not affect virus replication and evaluated their effects on pathogenesis in mice. Our characterization of WNV NS1-P101K suggests that the levels of NS1 in circulation facilitate WNV dissemination to the brain and disease outcome. Our findings help understand the role of NS1 during flavivirus infection and support antiviral strategies for targeting circulating forms of NS1.


2017 ◽  
Vol 91 (18) ◽  
Author(s):  
Hong-Lei Zhang ◽  
Han-Qing Ye ◽  
Si-Qing Liu ◽  
Cheng-Lin Deng ◽  
Xiao-Dan Li ◽  
...  

ABSTRACT West Nile virus (WNV) is a mosquito-borne flavivirus that causes epidemics of encephalitis and viscerotropic disease worldwide. This virus has spread rapidly and has posed a significant public health threat since the outbreak in New York City in 1999. The interferon (IFN)-mediated antiviral response represents an important component of virus-host interactions and plays an essential role in regulating viral replication. Previous studies have suggested that multifunctional nonstructural proteins encoded by flaviviruses antagonize the host IFN response via various means in order to establish efficient viral replication. In this study, we demonstrated that the nonstructural protein 1 (NS1) of WNV antagonizes IFN-β production, most likely through suppression of retinoic acid-inducible gene I (RIG-I)-like receptor (RLR) activation. In a dual-luciferase reporter assay, WNV NS1 significantly inhibited the activation of the IFN-β promoter after Sendai virus infection or poly(I·C) treatment. NS1 also suppressed the activation of the IFN-β promoter when it was stimulated by interferon regulatory factor 3 (IRF3)/5D or its upstream molecules in the RLR signaling pathway. Furthermore, NS1 blocked the phosphorylation and nuclear translocation of IRF3 upon stimulation by various inducers. Mechanistically, WNV NS1 targets RIG-I and melanoma differentiation-associated gene 5 (MDA5) by interacting with them and subsequently causing their degradation by the proteasome. Furthermore, WNV NS1 inhibits the K63-linked polyubiquitination of RIG-I, thereby inhibiting the activation of downstream sensors in the RLR signaling pathway. Taken together, our results reveal a novel mechanism by which WNV NS1 interferes with the host antiviral response. IMPORTANCE WNV Nile virus (WNV) has received increased attention since its introduction to the United States. However, the pathogenesis of this virus is poorly understood. This study demonstrated that the nonstructural protein 1 (NS1) of WNV antagonizes the induction of interferon beta (IFN-β) by interacting with and degrading retinoic acid-inducible gene I (RIG-I) and melanoma differentiation-associated gene 5 (MDA5), which are crucial viral sensors in the host innate immune system. Further experiments suggested that NS1-mediated inhibition of the RIG-I-like receptor (RLR) signaling pathway involves inhibition of RIG-I K63-linked polyubiquitination and that the proteasome plays a role in RIG-I degradation. This study provides new insights into the regulation of WNV NS1 in the RLR signaling pathway and reveals a novel mechanism by which WNV evades the host innate immune response. The novel findings may guide us to discover new therapeutic targets and develop effective vaccines for WNV infections.


2011 ◽  
Vol 18 (6) ◽  
pp. 978-983 ◽  
Author(s):  
Elizabeth Hunsperger ◽  
Manuela Beltran ◽  
Luz Nereida Acosta ◽  
Jorge Jordan-Munoz ◽  
Jomil Torres ◽  
...  

ABSTRACTA laboratory testing algorithm was evaluated to confirm West Nile virus (WNV) infection in human serum following the introduction of the virus in Puerto Rico in 2007. This testing algorithm used two standard diagnostic assays, the IgM antibody capture enzyme-linked immunosorbent assay (MAC ELISA) and real-time reverse transcriptase PCR (RT-PCR), along with two nonconventional assays, the nonstructural protein 1 (NS1) ELISA and a 90%-plaque-reduction neutralization test (PRNT90) with IgG depletion for dengue virus (DENV) and WNV. A total of 2,321 serum samples from suspected WNV human cases were submitted for testing. Approximately one-third (867, 37%) were cross-reactive for DENV and WNV by MAC ELISA and had negative RT-PCR results for both viruses. Of a subset of 43 samples tested, 31 (72%) of these cases were identified as positive for DENV in the PRNT90with IgG depletion and 8 (19%) were positive in the DENV NS1 antigen ELISA. These two assays combined differentiated 36 (84%) of the samples that could not be diagnosed using the standard diagnostic testing methods.


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