Characterization of mutations in West Nile virus NS4B protein identifies proline residue 54 as a determinant of attenuation
Ontology highlight
ABSTRACT:
INSTRUMENT(S): Illumina HiSeq 1500
ORGANISM(S): Yellow fever virus
SUBMITTER: Kassandra Carpio
PROVIDER: E-MTAB-9408 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
Similar Datasets
Project description:West Nile virus (WNV), a member of the Flavivirus genus and currently one of the most common arboviruses worldwide, is associated with severe neurological disease in humans. Its high potential to reemerge and rapidly disseminate makes it a bona fide global public health problem. The surface membrane glycoprotein (M) has been associated with Flavivirus-induced pathogenesis. Here, we identified a key amino acid residue at position 36 of the M protein whose mutation impacts WNV secretion and promotes viral attenuation. We also identified a compensatory site at position M-43 whose mutation stabilizes M-36 substitution both in vitro and in vivo Moreover, we found that introduction of the two mutations together confers a full attenuation phenotype and protection against wild-type WNV lethal challenge, eliciting potent neutralizing-antibody production in mice. Our study thus establishes the M protein as a new viral target for rational design of attenuated WNV strains.IMPORTANCE West Nile virus (WNV) is a worldwide (re)emerging mosquito-transmitted Flavivirus causing fatal neurological diseases in humans. However, no human vaccine has been yet approved. One of the most effective live-attenuated vaccines was empirically obtained by serial passaging of wild-type yellow fever Flavivirus However, such an approach is not acceptable nowadays, and the development of a rationally designed vaccine is necessary. Generating molecular infectious clones and mutating specific residues known to be involved in Flavivirus virulence constitute a powerful tool to promote viral attenuation. WNV membrane glycoprotein is thought to carry such essential determinants. Here, we identified two residues of this protein whose substitutions are key to the full and stable attenuation of WNV in vivo, most likely through inhibition of secretion and possible alteration of morphology. Applied to other flaviviruses, this approach should help in designing new vaccines against these viruses, which are an increasing threat to global human health.
| S-EPMC7307099 | biostudies-literature
Project description:West Nile virus (WNV) is a mosquito-borne RNA flavivirus and the cause of more than 31,000 cases in the USA from 1999-2011 including 1, 262 fatalities. WNV infections are typically asymptomatic, but some patients, especially the elderly and immunocompromised, may experience severe neurological disease and even death. Control of WNV infection by the immune system is multifactorial. We profiled antibody, cytokine responses and gene expression from a stratified cohort of WNV subjects to define immune responses that contribute to disease severity and outcome. Differential gene expression by human PBMCs from asymptomatic and severe patients with WNV infection were generated by microarray.
2012-12-29 | E-GEOD-43190 | biostudies-arrayexpress
Project description:Background: West Nile virus is an emerging infection of biodefense concern and there are no available treatments or vaccines. Here we used a high-throughput method based on a novel gene expression analysis, RNA-Seq, to give a global picture of differential gene expression by primary human macrophages of 10 healthy donors infected in vitro with WNV. Results: From a total of 50 million reads per sample, we employed a Bayesian hierarchical mixture model to identify 4,026 transcripts that were differentially expressed after infection. Both predicted and novel gene changes were detected, as were gene isoforms, and while many of the genes were expressed by all donors, some were unique. Knock-down of genes not previously known to be associated with WNV resistance identified their critical role in control of viral infection. Conclusions: Our study distinguishes both common gene pathways as well as novel cellular responses. Such analysis will be valuable for translational studies of susceptible and resistant individuals -- and for targeting therapeutics -- in multiple biological settings. Differential gene expression by primary human macrophages of 10 healthy donors infected in vitro with WNV were generated by RNA-Seq.
2014-01-08 | E-GEOD-40718 | biostudies-arrayexpress
Project description:We studied the cause-effect relationships between the transcriptomics and phenotypic outcomes within the CC-F1 population, which allowed us to identify novel genetic signatures. Our results indicate that Oas1b status as wild type or mutant, and overall Oas1b gene dosage, link with novel innate immune gene signatures that impact specific biological pathways for the control of flavivirus infection and immunity.
2017-01-03 | GSE91003 | GEO
Project description:West Nile virus (WNV) is a mosquito-borne RNA flavivirus which has caused more than 31,000 cases in the USA from 1999-2011 including 1,262 fatalities. WNV infections are typically asymptomatic, but some patients, especially the elderly and immunocompromised, may experience severe neurological disease and even death. Control of WNV infection by the immune system is multifactorial. We profiled antibody and cytokine responses from a stratified cohort of WNV subjects to define immune responses that contribute to disease severity. While antibody levels were not significantly different between asymptomatic and severely ill subjects in our cohort, subjects with severe infections had lower levels of serum IL-4. Further, we detected 158 genes that were differentially expressed by asymptomatic and severely infected cohorts and using cluster analysis correlated WNV susceptibility with IL-4 related gene expression pathways. Our results suggest an important contribution for IL4 in more severe responses to WNV.
2012-12-29 | GSE43190 | GEO
Project description:The goal of this study is to determine if infection with flavivirus (West Nile virus) and action of proinflamatory cytokine interferon alter incorporation of host RNAs into extracellular vesicles secreted by human cells.
2019-05-20 | GSE114008 | GEO
Project description:Neurotropic flavivirus Japanese encephalitis virus (JEV) and West Nile virus (WNV) are amongst the leading causes of encephalitis. Using label-free quantitative proteomics, we identified proteins differentially expressed upon JEV (gp-3, RP9) or WNV (IS98) infection of human neuroblastoma cells. Both viruses were associated with the up-regulation of immune response (IFIT1/3/5, ISG15, OAS, STAT1, IRF9) and the down-regulation of SSBP2, involved in gene expression, as well as PAM, involved in neuropeptide amidation. Proteins associated to membranes, involved in extracellular matrix organization and collagen metabolism represented major clusters down-regulated by JEV and WNV. Moreover, transcription regulation and mRNA processing clusters were also heavily regulated by both neurotropic flaviviruses. If the proteome of neuroblastoma cells infected by JEV or WNV was significantly modulated in the presence of mosquito saliva, both viruses showed distinct patterns. Mosquito saliva favored the modulation of proteins associated with gene regulation in JEV infected neuroblastoma cells while it was the modulation of proteins associated with protein maturation, signal transduction and ion transporters in the case of WNV infected neuroblastoma cells.
2020-05-14 | PXD016805 | Pride
Project description:West Nile virus (WNV) is a neurotropic flavivirus and the leading cause of mosquito-borne encephalitis in the United States. Recent studies in humans have found that dysfunctional T cell responses strongly correlate with development of severe WNV neuroinvasive disease. However, the contributions of human dendritic cells (DCs) in priming WNV-specific T cell immunity remains poorly understood. Here, we demonstrate that human monocyte derived DCs (moDCs) support productive viral replication following infection with a pathogenic strain of WNV. Antiviral effector gene transcription was strongly induced during the log-phase viral growth, while secretion of type I interferons (IFN) occurred with delayed kinetics. Activation of RIG-I like receptor (RLR) or type I IFN signaling prior to log-phase viral growth significantly diminished viral replication, suggesting that early activation of antiviral programs can block WNV infection. In contrast to the induction of antiviral responses, WNV infection did not promote transcription or secretion of pro-inflammatory (IL-6, GM-CSF, CCL3, CCL5, CXCL9) or T cell modulatory cytokines (IL-4, IL-12, IL-15). There was also minimal induction of molecules associated with antigen presentation and T cell priming, including the co-stimulatory molecules CD80, CD86, and CD40. Functionally, WNV-infected moDCs dampened allogenic CD4 and CD8 T cell activation and proliferation. Combined, we propose a model where WNV subverts human DC activation to compromise priming of WNV-specific T cell immunity.
2019-09-06 | GSE136342 | GEO
Project description:High rates of error-prone replication result in the rapid accumulation of genetic diversity of RNA viruses. Recent studies suggest that mutation rates are selected for optimal viral fitness and that modest variations in replicase fidelity may be associated with viral attenuation. Arthropod-borne viruses (arboviruses) are unique in their requirement for host cycling and may necessitate substantial genetic and phenotypic plasticity. In order to more thoroughly investigate the correlates, mechanisms and consequences of arbovirus fidelity, we selected fidelity variants of West Nile virus (WNV; Flaviviridae, Flavivirus) utilizing selection in the presence of a mutagen. We identified two mutations in the WNV RNA-dependent RNA polymerase associated with increased fidelity, V793I and G806R, and a single mutation in the WNV methyltransferase, T248I, associated with decreased fidelity. Both deep-sequencing and in vitro biochemical assays confirmed strain-specific differences in both fidelity and mutational bias. WNV fidelity variants demonstrated host-specific alterations to replicative fitness in vitro, with modest attenuation in mosquito but not vertebrate cell culture. Experimental infections of colonized and field populations of Cx. quinquefaciatus demonstrated that WNV fidelity alterations are associated with a significantly impaired capacity to establish viable infections in mosquitoes. Taken together, these studies (i) demonstrate the importance of allosteric interactions in regulating mutation rates, (ii) establish that mutational spectra can be both sequence and strain-dependent, and (iii) display the profound phenotypic consequences associated with altered replication complex function of flaviviruses.
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Project description:Greater than 50% of patients who survive neuroinvasive West Nile virus (WNV), a mosquito-borne, positive-sense strand flavivirus, exhibit cognitive sequelae including memory impairments which may last several years. High survival rates from WNV neuroinvasive disease (WNND) (>90%) have led to hundreds to thousands of cases of WNV-mediated neurologic impairment accruing annually, yet underlying mechanisms responsible for these impairments have not been investigated. Here, we established a novel murine model of recovery from WNND in which intracranial inoculation of a mutant WNV (WNV-NS5-E218A) leads to rates of survival and cognitive dysfunction that mirror human WNND. WNV-NS5-E218A-recovered mice exhibit impaired spatial learning and persistently phagocytic microglia without significant loss of hippocampal neurons or brain volume. Whole transcriptome analysis of hippocampi from WNV-NS5-E218A-recovered mice with poor spatial learning was performed in order to identify target pathways and molecules underlying cognitive impairments during WNND recovery. Total RNA obtained from isolated murine hippocampus at 25 days post-mock or WNV-NS5-E218A intracranial infection.
2016-06-27 | E-GEOD-72139 | biostudies-arrayexpress