scholarly journals Site-specific N-glycosylation analysis of animal cell culture-derived Zika virus proteins

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Alexander Pralow ◽  
Alexander Nikolay ◽  
Arnaud Leon ◽  
Yvonne Genzel ◽  
Erdmann Rapp ◽  
...  
Keyword(s):  
Zika Virus ◽  
Animal Cell ◽  
Gradient Centrifugation ◽  
Viral Envelope ◽  
Protein Glycosylation ◽  
High Yield ◽  
Structural Protein ◽  
Site Specific ◽  
E Protein ◽  
The Impact

AbstractHere, we present for the first time, a site-specific N-glycosylation analysis of proteins from a Brazilian Zika virus (ZIKV) strain. The virus was propagated with high yield in an embryo-derived stem cell line (EB66, Valneva SE), and concentrated by g-force step-gradient centrifugation. Subsequently, the sample was proteolytically digested with different enzymes, measured via a LC–MS/MS-based workflow, and analyzed in a semi-automated way using the in-house developed glyXtoolMS software. The viral non-structural protein 1 (NS1) was glycosylated exclusively with high-mannose structures on both potential N-glycosylation sites. In case of the viral envelope (E) protein, no specific N-glycans could be identified with this method. Nevertheless, N-glycosylation could be proved by enzymatic de-N-glycosylation with PNGase F, resulting in a strong MS-signal of the former glycopeptide with deamidated asparagine at the potential N-glycosylation site N444. This confirmed that this site of the ZIKV E protein is highly N-glycosylated but with very high micro-heterogeneity. Our study clearly demonstrates the progress made towards site-specific N-glycosylation analysis of viral proteins, i.e. for Brazilian ZIKV. It allows to better characterize viral isolates, and to monitor glycosylation of major antigens. The method established can be applied for detailed studies regarding the impact of protein glycosylation on antigenicity and human pathogenicity of many viruses including influenza virus, HIV and corona virus.

scholarly journals Envelope Protein Glycosylation Mediates Zika Virus Pathogenesis

2019 ◽  
Vol 93 (12) ◽  
Author(s):  
Derek L. Carbaugh ◽  
Ralph S. Baric ◽  
Helen M. Lazear
Keyword(s):  
Zika Virus ◽  
Envelope Protein ◽  
Glycosylation Site ◽  
Viral Envelope ◽  
Protein Glycosylation ◽  
Guillain Barre Syndrome ◽  
Viral Loads ◽  
E Protein ◽  
Guillain Barré Syndrome ◽  
Guillain Barré

ABSTRACT Zika virus (ZIKV) is an emerging mosquito-borne flavivirus. Recent ZIKV outbreaks have produced serious human disease, including neurodevelopmental malformations (congenital Zika syndrome) and Guillain-Barré syndrome. These outcomes were not associated with ZIKV infection prior to 2013, raising the possibility that viral genetic changes could contribute to new clinical manifestations. All contemporary ZIKV isolates encode an N-linked glycosylation site in the envelope (E) protein (N154), but this glycosylation site is absent in many historical ZIKV isolates. Here, we investigated the role of E protein glycosylation in ZIKV pathogenesis using two contemporary Asian-lineage strains (H/PF/2013 and PRVABC59) and the historical African-lineage strain (MR766). We found that glycosylated viruses were highly pathogenic in Ifnar1−/− mice. In contrast, nonglycosylated viruses were attenuated, producing lower viral loads in the serum and brain when inoculated subcutaneously but remaining neurovirulent when inoculated intracranially. These results suggest that E glycosylation is advantageous in the periphery but not within the brain. Accordingly, we found that glycosylation facilitated infection of cells expressing the lectins dendritic cell-specific intercellular adhesion molecule-3-grabbing nonintegrin (DC-SIGN) or DC-SIGN-related (DC-SIGNR), suggesting that inefficient infection of lectin-expressing leukocytes could contribute to the attenuation of nonglycosylated ZIKV in mice. IMPORTANCE It is unclear why the ability of Zika virus (ZIKV) to cause serious disease, including Guillain-Barré syndrome and birth defects, was not recognized until recent outbreaks. One contributing factor could be genetic differences between contemporary ZIKV strains and historical ZIKV strains. All isolates from recent outbreaks encode a viral envelope protein that is glycosylated, whereas many historical ZIKV strains lack this glycosylation. We generated nonglycosylated ZIKV mutants from contemporary and historical strains and evaluated their virulence in mice. We found that nonglycosylated viruses were attenuated and produced lower viral loads in serum and brains. Our studies suggest that envelope protein glycosylation contributes to ZIKV pathogenesis, possibly by facilitating attachment to and infection of lectin-expressing leukocytes.

scholarly journals N-glycosylation in the Pre-Membrane Protein Is Essential for the Zika Virus Life Cycle

Viruses ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 925
Author(s):  
Yong-Dae Gwon ◽  
Eva Zusinaite ◽  
Andres Merits ◽  
Anna K. Överby ◽  
Magnus Evander
Keyword(s):  
Zika Virus ◽  
Protein Trafficking ◽  
Nuclear Translocation ◽  
Infectious Clone ◽  
Glycosylation Site ◽  
Protein Glycosylation ◽  
Cell Trafficking ◽  
Virion Assembly ◽  
E Protein ◽  
The Impact

Asparagine (N)-linked protein glycosylation plays an important role in protein synthesis and modification. Two Zika virus (ZIKV) structural proteins, the pre-membrane (prM) and envelope (E) protein are N-glycosylated. The prM protein of all ZIKV strains contains a single N-linked glycosylation site, while not all strains contain an N-linked site in the E protein. Our aim was to examine the impact of prM and E N-linked glycosylation on ZIKV infectivity and cell trafficking. Using a ZIKV infectious clone, we found that when the N-glycan sites were removed, the prM- and the prM/E-double mutants did not produce an infectious virus in the supernatant. Further, by using ZIKV prME constructs, we found that N-glycosylation was necessary for effective secretion of ZIKV virions. The absence of the N-glycan on prM or E caused protein aggregation in the rough endoplasmatic reticulum (ER) compartment. The aggregation was more pronounced for the prM-mutation, and the mutant virus lost the ER-Golgi intermediate compartment (ERGIC) localization. In addition, lack of the N-glycan on prM induced nuclear translocation of CCAAT-enhancer-binding protein homologous protein (CHOP), an ER stress marker. To conclude, we show that the prM N-glycan is essential for the ZIKV infectious cycle, and plays an important role in viral protein trafficking, protein folding, and virion assembly.

scholarly journals Two Genetic Differences between Closely Related Zika Virus Strains Determine Pathogenic Outcome in Mice

2020 ◽  
Vol 94 (20) ◽  
Author(s):  
Derek L. Carbaugh ◽  
Shuntai Zhou ◽  
Wes Sanders ◽  
Nathaniel J. Moorman ◽  
Ronald Swanstrom ◽  
...  
Keyword(s):  
Amino Acid ◽  
Mouse Models ◽  
Zika Virus ◽  
Clinical Manifestations ◽  
Amino Acid Sequences ◽  
Viral Envelope ◽  
Laboratory Research ◽  
Balanced Polymorphism ◽  
E Protein ◽  
Virus Strains

ABSTRACT Recent Zika virus (ZIKV) outbreaks and unexpected clinical manifestations of ZIKV infection have prompted an increase in ZIKV-related research. Here, we identify two strain-specific determinants of ZIKV virulence in mice. We found that strain H/PF/2013 caused 100% lethality in Ifnar1−/− mice, whereas PRVABC59 caused no lethality; both strains caused 100% lethality in Ifnar1−/− Ifngr1−/− double-knockout (DKO) mice. Deep sequencing revealed a high-frequency variant in PRVABC59 not present in H/PF/2013: a G-to-T change at nucleotide 1965 producing a Val-to-Leu substitution at position 330 of the viral envelope (E) protein. We show that the V330 variant is lethal on both virus strain backgrounds, whereas the L330 variant is attenuating only on the PRVABC59 background. These results identify a balanced polymorphism in the E protein that is sufficient to attenuate the PRVABC59 strain but not H/PF/2013. The consensus sequences of H/PF/2013 and PRVABC59 differ by 3 amino acids, but these were not responsible for the difference in virulence between the two strains. H/PF/2013 and PRVABC59 differ by an additional 31 noncoding or silent nucleotide changes. We made a panel of chimeric viruses with identical amino acid sequences but nucleotide sequences derived from H/PF/2013 or PRVABC59. We found that 6 nucleotide differences in the 3′ quarter of the H/PF/2013 genome were sufficient to confer virulence in Ifnar1−/− mice. Altogether, our work identifies a large and previously unreported difference in virulence between two commonly used ZIKV strains, in two widely used mouse models of ZIKV pathogenesis (Ifnar1−/− and Ifnar1−/− Ifngr1−/− DKO mice). IMPORTANCE Contemporary ZIKV strains are closely related and often used interchangeably in laboratory research. Here, we identify two strain-specific determinants of ZIKV virulence that are evident in only Ifnar1−/− mice but not Ifnar1−/− Ifngr1−/− DKO mice. These results identify a balanced polymorphism in the E protein that is sufficient to attenuate the PRVABC59 strain but not H/PF/2013. We further identify a second virulence determinant in the H/PF/2013 strain, which is driven by the viral nucleotide sequence but not the amino acid sequence. Altogether, our work identifies a large and previously unreported difference in virulence between two commonly used ZIKV strains, in two widely used mouse models of ZIKV pathogenesis. Our results highlight that even very closely related virus strains can produce significantly different pathogenic phenotypes in common laboratory models.

scholarly journals N-Linked Glycosylation of West Nile Virus Envelope Proteins Influences Particle Assembly and Infectivity

2005 ◽  
Vol 79 (21) ◽  
pp. 13262-13274 ◽  
Author(s):  
Sheri L. Hanna ◽  
Theodore C. Pierson ◽  
Melissa D. Sanchez ◽  
Asim A. Ahmed ◽  
Mariam M. Murtadha ◽  
...  
Keyword(s):  
West Nile Virus ◽  
Envelope Proteins ◽  
Glycosylation Site ◽  
Protein Glycosylation ◽  
E Proteins ◽  
Virus Envelope ◽  
West Nile ◽  
Particle Assembly ◽  
E Protein ◽  
The Impact

ABSTRACT West Nile virus (WNV) encodes two envelope proteins, premembrane (prM) and envelope (E). While the prM protein of all WNV strains contains a single N-linked glycosylation site, not all strains contain an N-linked site in the E protein. The presence of N-linked glycosylation on flavivirus E proteins has been linked to virus production, pH sensitivity, and neuroinvasiveness. Therefore, we examined the impact of prM and E glycosylation on WNV assembly and infectivity. Similar to other flaviviruses, expression of WNV prM and E resulted in the release of subviral particles (SVPs). Removing the prM glycosylation site in a lineage I or II strain decreased SVP release, as did removal of the glycosylation site in a lineage I E protein. Addition of the E protein glycosylation site in a lineage II strain that lacked this site increased SVP production. Similar results were obtained in the context of either reporter virus particles (RVPs) or infectious lineage II WNV. RVPs or virions bearing combinations of glycosylated and nonglycosylated forms of prM and E could infect mammalian, avian, and mosquito cells (BHK-21, QT6, and C6/36, respectively). Those particles lacking glycosylation on the E protein were modestly more infectious per genome copy on BHK-21 and QT6 cells, while this absence greatly enhanced the infection of C6/36 cells. Thus, glycosylation of WNV prM and E proteins can affect the efficiency of virus release and infection in a manner that is cell type and perhaps species dependent. This suggests a multifaceted role for envelope N-linked glycosylation in WNV biology and tropism.

scholarly journals A Linkage-specific Sialic Acid Labeling Strategy Reveals Different Site-specific Glycosylation Patterns in SARS-CoV-2 Spike Protein Produced in CHO and HEK Cell Substrates

2021 ◽  
Vol 9 ◽  
Author(s):  
Qiong Wang ◽  
Yan Wang ◽  
Shuang Yang ◽  
Changyi Lin ◽  
Lateef Aliyu ◽  
...  
Keyword(s):  
Immune System ◽  
Sialic Acid ◽  
Viral Envelope ◽  
Site Specific ◽  
S Protein ◽  
Hek Cells ◽  
High Mannose ◽  
The Impact ◽  
S Proteins ◽  
Spike Proteins

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus utilizes the extensively glycosylated spike (S) protein protruding from the viral envelope to bind to angiotensin-converting enzyme-related carboxypeptidase (ACE2) as its primary receptor to mediate host-cell entry. Currently, the main recombinant S protein production hosts are Chinese hamster ovary (CHO) and human embryonic kidney (HEK) cells. In this study, a recombinant S protein truncated at the transmembrane domain and engineered to express a C-terminal trimerization motif was transiently produced in CHO and HEK cell suspensions. To further evaluate the sialic acid linkages presenting on S protein, a two-step amidation process, employing dimethylamine and ammonium hydroxide reactions in a solid support system, was developed to differentially modify the sialic acid linkages on the glycans and glycopeptides from the S protein. The process also adds a charge to Asp and Glu which aids in ionization. We used MALDI-TOF and LC-MS/MS with electron-transfer/higher-energy collision dissociation (EThcD) fragmentation to determine global and site-specific N-linked glycosylation patterns. We identified 21 and 19 out of the 22 predicted N-glycosites of the SARS-CoV-2 S proteins produced in CHO and HEK, respectively. It was found that the N-glycosite at 1,158 position (N1158) and at 122, 282 and 1,158 positions (N122, N282 and N1158) were absent on S from CHO and HEK cells, respectively. The structural mapping of glycans of recombinant human S proteins reveals that CHO-Spike exhibits more complex and higher sialylation (α2,3-linked) content while HEK-Spike exhibits more high-mannose and a small amount of α2,3- and α2,6-linked sialic acids. The N74 site represents the most abundant glycosite on both spike proteins. The relatively higher amount of high-mannose abundant sites (N17, N234, N343, N616, N709, N717, N801, and N1134) on HEK-Spike suggests that glycan-shielding may differ among the two constructs. HEK-Spike can also provide different host immune system interaction profiles based on known immune system active lectins. Collectively, these data underscore the importance of characterizing the site-specific glycosylation of recombinant human spike proteins from HEK and CHO cells in order to better understand the impact of the production host on this complex and important protein used in research, diagnostics and vaccines.

scholarly journals The Ablation of Envelope Protein Glycosylation Enhances the Neurovirulence of ZIKV and Cell Apoptosis in Newborn Mice

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Yanqing Guo ◽  
Linlin Bao ◽  
Yanfeng Xu ◽  
Fengdi Li ◽  
Qi Lv ◽  
...  
Keyword(s):  
Cell Apoptosis ◽  
Serial Passage ◽  
Causal Link ◽  
Protein Glycosylation ◽  
Fourth Generation ◽  
Supporting Evidence ◽  
Newborn Mouse ◽  
Newborn Mice ◽  
E Protein ◽  
The Impact

Zika virus (ZIKV) has attracted the wide global attention due to its causal link to microcephaly. In this study, two amino acid (aa) mutation (E143K and R3394K) were identified at the fourth generation (named ZKC2P4) during the serial passage of ZIKV-Asian lineage ZKC2/2016 strain in the newborn mouse brain, while another seven aa deletions in envelope (E) protein were detected in ZKC2P6. ZKC2P6 is a novel nonglycosylated E protein Asian ZIKV we first identified and provides the first direct supporting evidence that glycosylation motif could be lost during the passage in neonatal mice. To study the impact of E protein glycosylation ablation, we compared the pathogenicity of ZKC2P6 with that of ZKC2P4. The results showed that the loss of E protein glycosylation accelerated the disease progression, as evidenced by an earlier weight loss and death, a thinner cerebral cortex, and more serious tissue lesions and inflammation/necrosis. Furthermore, ZKC2P6 exhibited a greater ability to replicate and caused severer cell apoptosis than that of ZKC2P4. Therefore, the ablation of E glycosylation generally enhances the neurovirulence of ZIKV and cell apoptosis in newborn mice.

scholarly journals Large-scale analysis of B-cell epitopes of envelope: Implications for Zika vaccine and immunotherapeutic development

F1000Research ◽  
2019 ◽  
Vol 7 ◽  
pp. 1624
Author(s):  
Iman Almansour ◽  
Rahaf Alfares ◽  
Halah Aljofi
Keyword(s):  
B Cell ◽  
Zika Virus ◽  
Large Scale ◽  
Human Mabs ◽  
Bioinformatics Analyses ◽  
Multiple Sequence ◽  
B Cell Epitopes ◽  
E Protein ◽  
The Impact

Background:Cases of the re-emergence of Zika virus in 2015 were associated with severe neurologic complications, including Gillien-Barre syndrome in adults and congenital Zika syndrome in newborns. The major structural determinant of immunity to the Zika virus is the E protein. Although B-cell epitopes of Zika E protein were recently identified, data regarding epitope variations among Zika strains in pre-epidemic and epidemic periods are lacking.Methods:Here, we conducted systematic bioinformatics analyses of Zika strains isolated between 1968 and 2017. Multiple sequence alignment of E protein as well as B-cell epitopes annotations were performed. In addition, homology-based approach was utilized to construct three-dimensional structures of monomeric E glycoproteins to annotate epitope variations. Lastly, prediction of ofN-glycosylation patterns and prediction of protein stability upon mutations were also investigated.Results:Our analyses indicates that epitopes recognized by human mAbs ZIKV-117, ZIKV-15, and ZIKV-19 were highly conserved, suggesting as attractive targets for the development of vaccines and immunotherapeutics directed against diverse Zika strains. In addition, the epitope recognized by ZIKV-E-2A10G6 mAb derived from immunized mice was mostly conserved across Zika strains.Conclusions:Our data provide new insights regarding antigenic similarities between Zika strains circulating worldwide. These data are essential for understanding the impact of evolution on antigenic cross-reactivity between Zika lineages and strains. Furtherin-vitroanalyses are needed to determine how mutationsat predefined epitopes could impact the development of vaccines that can effectively neutralize Zika viruses.

scholarly journals Large-scale analysis of B-cell epitopes of envelope: Implications for Zika vaccine and immunotherapeutic development

F1000Research ◽  
2018 ◽  
Vol 7 ◽  
pp. 1624 ◽  
Author(s):  
Iman Almansour ◽  
Rahaf Alfares ◽  
Halah Aljofi
Keyword(s):  
B Cell ◽  
Zika Virus ◽  
Large Scale ◽  
Human Mabs ◽  
Bioinformatics Analyses ◽  
Multiple Sequence ◽  
B Cell Epitopes ◽  
E Protein ◽  
The Impact

Background:Cases of the re-emergence of Zika virus in 2015 were associated with severe neurologic complications, including Gillien-Barre syndrome in adults and congenital Zika syndrome in newborns. The major structural determinant of immunity to the Zika virus is the E protein. Although B-cell epitopes of Zika E protein were recently identified, data regarding epitope variations among Zika strains in pre-epidemic and epidemic periods are lacking.Methods:Here, we conducted systematic bioinformatics analyses of Zika strains isolated between 1968 and 2017. Multiple sequence alignment of E protein as well as B-cell epitopes annotations were performed. In addition, homology-based approach was utilized to construct three-dimensional structures of monomeric E glycoproteins to annotate epitope variations. Lastly, ofN-glycosylation patterns and prediction of protein stability upon mutations were also investigated.Results:Our analyses indicates that epitopes recognized by human mAbs ZIKV-117, ZIKV-15, and ZIKV-119 were highly conserved, suggesting as attractive targets for the development of vaccines and immunotherapeutics directed against diverse Zika strains. In addition, the epitope recognized by ZIKV-E-2A10G6 mAb derived from immunized mice was highly conserved across Zika strains.Conclusions:Our data provide new insights regarding antigenic similarities between Zika strains circulating worldwide. These data are essential for understanding the impact of evolution on antigenic cross-reactivity between Zika lineages and strains. Furtherin-vitroanalyses are needed to determine how mutations could impact the development of vaccines that can effectively neutralize Zika viruses.

scholarly journals A Measles Virus-Based Vaccine Candidate Mediates Protection against Zika Virus in an Allogeneic Mouse Pregnancy Model

2018 ◽  
Vol 93 (3) ◽  
Author(s):  
Cindy Nürnberger ◽  
Bianca S. Bodmer ◽  
Anna H. Fiedler ◽  
Gülsah Gabriel ◽  
Michael D. Mühlebach
Keyword(s):  
Immune Responses ◽  
Vaccine Strain ◽  
Zika Virus ◽  
Measles Virus ◽  
Vaccine Candidate ◽  
Vaccine Platform ◽  
Cellular Immune Responses ◽  
E Protein ◽  
Cellular Immune ◽  
The Impact

ABSTRACTThe impact of the Zika virus (ZIKV) epidemic highlights the need for vaccines that reduce or prevent infection and reliably prevent teratogenic complications. The live-attenuated measles virus (MV) vaccine strains are a promising vaccine platform, since they induce robust humoral and cellular immune responses against additional antigens and have an excellent safety record. To explore its potential to protect against ZIKV, we compared a recombinant Schwarz strain MV that encodes ZIKV prM and soluble E proteins (MV-Zika-sE) with a prototypic alum-adjuvanted whole inactivated ZIKV particle vaccine. Analysis of MV-Zika-sE-infected cells confirmed antigen expression, and the virus replicated with vaccine strain characteristics. Immunized IFNAR−/−-CD46Ge mice developed E protein-specific and neutralizing antibodies, and ZIKV E-specific cellular immune responses were observed by gamma interferon (IFN-γ) enzyme-linked immunospot (ELISpot) andin vitroT cell proliferation assays. To analyze protective efficacy, vaccinated female mice were challenged with ZIKV after allogeneic mating. In MV-Zika-sE-vaccinated mice, weight gain was similar to that in uninfected mice, while no plasma viremia was detectable in the majority of the animals. In contrast, infected control animals gained less weight and experienced about 100-fold higher viremia over at least 3 days. Moreover, vaccination with MV-Zika-sE reduced the ZIKV load in different organs and the placentas and prevented infection of the fetus. Consequently, no fetal growth retardation, anemia, or death due to ZIKV infection was seen in MV-Zika-sE-vaccinated dams. In contrast, the inactivated ZIKV vaccine had little to no effect in our studies. Therefore, the MV-derived ZIKV vaccine is a promising candidate for further preclinical and clinical development.IMPORTANCEZika virus (ZIKV) is a mosquito-borne flavivirus that causes a variety of neurological complications, including congenital birth defects. Despite the urgent need, no ZIKV vaccine has yet been licensed. Recombinant vaccine strain-derived measles viruses (MV) constitute a promising vector platform to induce immunity against foreign pathogens by expressing antigens from additional transcription units while at the same time possessing a remarkable safety profile. This concept has already been validated against different pathogens, including at least 3 other flaviviruses, and our data show that vaccination with MV expressing soluble ZIKV E protein significantly diminishes infection and prevents fetal loss or damage in an allogeneic mouse pregnancy model. It can thus be regarded as a promising emergency vaccine candidate with the potential for inclusion in routine vaccination settings in areas of endemicity to prevent teratogenic effects of circulating ZIKV during pregnancy, comparable to standard rubella virus vaccination.

scholarly journals A single nonsynonymous mutation on gene encoding E protein of Zika virus leads to increased neurovirulence in vivo

2020 ◽  
Author(s):  
Zhihua Liu ◽  
Yawei Zhang ◽  
Mengli Cheng ◽  
Ningning Ge ◽  
Jiayi Shu ◽  
...  
Keyword(s):  
Zika Virus ◽  
Viral Envelope ◽  
Sequencing Analysis ◽  
Viral Envelope Protein ◽  
Nonsynonymous Mutation ◽  
Genetic Characteristics ◽  
Neonatal Mice ◽  
E Protein ◽  
Wide Range

AbstractZika virus can infect a wide range of tissues including the developmental brain of human fetuses, causing from mild to severe clinical diseases. Whether its genetic characteristics impacts on viral pathogenesis is incompletely understood. We have obtained viral variants through serially passage of a clinical Zika virus isolate (SW01) in neonatal mice in vivo and found some of which exhibited markedly increased virulence and neurotropism. By deep sequencing analysis, the more pathogenic viral variants were found to contain four dominant nonsynonymous nucleotide mutations on genes encoding E and NS2A proteins. Further investigation using molecularly cloned viruses revealed that a single 67D (Aspatic acid) to N (Asparagine) substitution on E protein is sufficient to confer the increased virulence and neurotropism. These findings provide new insight into Zika virus pathogenesis and suggest novel targets for the development of therapeutics.Author SummaryRecent large outbreaks of Zika virus infection worldwide have revealed an association between the viral infection and increased cases of specific neurological problems including Congenital Zika Syndrome (including microcephaly) and adult Guillain–Barré Syndrome. However, the determinants of the increased neurovirulence of Zika virus remain uncertain. One hypothesis is that some unique changes across the Zika viral genome have led to the occurrence of these neurological diseases. To test this hypothesis, we continuously propagated a clinical isolate of contemporary Zika virus (SW01) in neonatal mice brain for 11 times to obtain an mouse central nervous system (CNS) adapted Zika virus (MA-SW01) that showed significantly increased neurovirulence in vivo. We then discovered that a single G to A nucleotide substitution at the 1069 site of Zika virus open reading frame leading to a D (aspartic acid) to N (asparagine) in viral Envelope protein is responsible for the increased neurovirulence. These findings improve our understanding of the neurological pathogenesis of Zika virus and provide clues for the development of antiviral strategy.

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