scholarly journals Fetal Brain Infection Is Not a Unique Characteristic of Brazilian Zika Viruses

Viruses ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 541 ◽  
Author(s):  
Yin Setoh ◽  
Nias Peng ◽  
Eri Nakayama ◽  
Alberto Amarilla ◽  
Natalie Prow ◽  
...  
Keyword(s):  
De Novo ◽  
Sequence Data ◽  
Fetal Brain ◽  
Vero Cells ◽  
Neurological Complications ◽  
Interferon Α ◽  
Brain Infection ◽  
Recent Emergence ◽  
Congenital Zika Syndrome

The recent emergence of Zika virus (ZIKV) in Brazil was associated with an increased number of fetal brain infections that resulted in a spectrum of congenital neurological complications known as congenital Zika syndrome (CZS). Herein, we generated de novo from sequence data an early Asian lineage ZIKV isolate (ZIKV-MY; Malaysia, 1966) not associated with microcephaly and compared the in vitro replication kinetics and fetal brain infection in interferon α/β receptor 1 knockout (IFNAR1−/−) dams of this isolate and of a Brazilian isolate (ZIKV-Natal; Natal, 2015) unequivocally associated with microcephaly. The replication efficiencies of ZIKV-MY and ZIKV-Natal in A549 and Vero cells were similar, while ZIKV-MY replicated more efficiently in wild-type (WT) and IFNAR−/− mouse embryonic fibroblasts. Viremias in IFNAR1−/− dams were similar after infection with ZIKV-MY or ZIKV-Natal, and importantly, infection of fetal brains was also not significantly different. Thus, fetal brain infection does not appear to be a unique feature of Brazilian ZIKV isolates.

scholarly journals MERS-coronavirus replication induces severe in vitro cytopathology and is strongly inhibited by cyclosporin A or interferon-α treatment

2013 ◽  
Vol 94 (8) ◽  
pp. 1749-1760 ◽  
Author(s):  
Adriaan H. de Wilde ◽  
V. Stalin Raj ◽  
Diede Oudshoorn ◽  
Theo M. Bestebroer ◽  
Stefan van Nieuwkoop ◽  
...  
Keyword(s):  
Cyclosporin A ◽  
Rna Synthesis ◽  
Nuclear Translocation ◽  
Fatal Outcome ◽  
Membrane Vesicles ◽  
Vero Cells ◽  
Interferon Α ◽  
Antiviral Compound ◽  
Compound Screening

Coronavirus (CoV) infections are commonly associated with respiratory and enteric disease in humans and animals. The 2003 outbreak of severe acute respiratory syndrome (SARS) highlighted the potentially lethal consequences of CoV-induced disease in humans. In 2012, a novel CoV (Middle East Respiratory Syndrome coronavirus; MERS-CoV) emerged, causing 49 human cases thus far, of which 23 had a fatal outcome. In this study, we characterized MERS-CoV replication and cytotoxicity in human and monkey cell lines. Electron microscopy of infected Vero cells revealed extensive membrane rearrangements, including the formation of double-membrane vesicles and convoluted membranes, which have been implicated previously in the RNA synthesis of SARS-CoV and other CoVs. Following infection, we observed rapidly increasing viral RNA synthesis and release of high titres of infectious progeny, followed by a pronounced cytopathology. These characteristics were used to develop an assay for antiviral compound screening in 96-well format, which was used to identify cyclosporin A as an inhibitor of MERS-CoV replication in cell culture. Furthermore, MERS-CoV was found to be 50–100 times more sensitive to alpha interferon (IFN-α) treatment than SARS-CoV, an observation that may have important implications for the treatment of MERS-CoV-infected patients. MERS-CoV infection did not prevent the IFN-induced nuclear translocation of phosphorylated STAT1, in contrast to infection with SARS-CoV where this block inhibits the expression of antiviral genes. These findings highlight relevant differences between these distantly related zoonotic CoVs in terms of their interaction with and evasion of the cellular innate immune response.

‘Piggy-Back’ Transport of Xenopus Hyaluronan Synthase (XHAS1) via the Secretory Pathway to the Plasma Membrane

2003 ◽  
Vol 384 (1) ◽  
pp. 175-182 ◽  
Author(s):  
J. Müllegger ◽  
A. Rustom ◽  
G. Kreil ◽  
H.-H. Gerdes ◽  
G. Lepperdinger
Keyword(s):  
Plasma Membrane ◽  
Secretory Pathway ◽  
Fluorescent Protein ◽  
De Novo ◽  
Signal Sequence ◽  
Vero Cells ◽  
In Vitro Translation ◽  
Hyaluronan Synthase ◽  
Microsomal Membranes

AbstractHyaluronan is the sole glycosaminoglycan whose biosynthesis takes place directly at the plasma membrane. The mechanism by which hyaluronan synthase (HAS) becomes inserted there, as well as the question of how the enzyme discriminates between particular membrane species in polarized cells, are largely unknown. In vitro translation of HAS suggested that the nascent protein becomes stabilized in the presence of microsomal membranes, but would not insert spontaneously into membranes after being translated in the absence of those. We therefore monitored the membrane attachment of enzymatically active fusion proteins consisting of Xenopus HAS1 and green fluorescent protein shortly after de novo synthesis in Vero cells. Our data strongly suggest that HAS proteins are directly translated on the ER membrane without exhibiting an N-terminal signal sequence. From there the inactive protein is transferred to the plasma membrane via the secretory pathway. For unknown reasons, HAS inserted into membranes other than the plasma membrane remains inactive.

scholarly journals Viral RNA-Dependent RNA Polymerase Inhibitor 7-Deaza-2′-C-Methyladenosine Prevents Death in a Mouse Model of West Nile Virus Infection

2019 ◽  
Vol 63 (3) ◽  
Author(s):  
Luděk Eyer ◽  
Martina Fojtíková ◽  
Radim Nencka ◽  
Ivo Rudolf ◽  
Zdeněk Hubálek ◽  
...  
Keyword(s):  
West Nile Virus ◽  
West Nile Virus Infection ◽  
Antiviral Effect ◽  
Vero Cells ◽  
Modified Nucleosides ◽  
West Nile ◽  
Brain Infection ◽  
Highly Effective ◽  
Time Of Infection

ABSTRACTWest Nile virus (WNV) is a medically important emerging arbovirus causing serious neuroinfections in humans and against which no approved antiviral therapy is currently available. In this study, we demonstrate that 2′-C-methyl- or 4′-azido-modified nucleosides are highly effective inhibitors of WNV replication, showing nanomolar or low micromolar anti-WNV activity and negligible cytotoxicity in cell culture. One representative ofC2′-methylated nucleosides, 7-deaza-2′-C-methyladenosine, significantly protected WNV-infected mice from disease progression and mortality. Twice daily treatment at 25 mg/kg starting at the time of infection resulted in 100% survival of the mice. This compound was highly effective, even if the treatment was initiated 3 days postinfection, at the time of a peak of viremia, which resulted in a 90% survival rate. However, the antiviral effect of 7-deaza-2′-C-methyladenosine was absent or negligible when the treatment was started 8 days postinfection (i.e., at the time of extensive brain infection). The 4′-azido moiety appears to be another important determinant for highly efficient inhibition of WNV replicationin vitro. However, the strong anti-WNV effect of 4′-azidocytidine and 4′-azido-aracytidine was cell type dependent and observed predominantly in porcine kidney stable (PS) cells. The effect was much less pronounced in Vero cells. Our results indicate that 2′-C-methylated or 4′-azidated nucleosides merit further investigation as potential therapeutic agents for treating WNV infections as well as infections caused by other medically important flaviviruses.

scholarly journals Network analysis of genome-wide selective constraint reveals a gene network active in early fetal brain intolerant of mutation

2015 ◽  
Author(s):  
Jinmyung Choi ◽  
Parisa Shooshtari ◽  
Kaitlin E Samocha ◽  
Mark J Daly ◽  
Chris Cotsapas
Keyword(s):  
De Novo ◽  
Sequence Data ◽  
Fetal Brain ◽  
Selective Constraint ◽  
Adverse Outcomes ◽  
Integrated Analysis ◽  
Disease Genes ◽  
De Novo Mutations ◽  
Strong Constraint ◽  
Genome Wide

Using robust, integrated analysis of multiple genomic datasets, we show that genes depleted for non-synonymous de novo mutations form a subnetwork of 72 members under strong selective constraint. We further show this subnetwork is preferentially expressed in the early development of the human hippocampus and is enriched for genes mutated in neurological, but not other, Mendelian disorders. We thus conclude that carefully orchestrated developmental processes are under strong constraint in early brain development, and perturbations caused by mutation have adverse outcomes subject to strong purifying selection. Our findings demonstrate that selective forces can act on groups of genes involved in the same process, supporting the notion that adaptation can act coordinately on multiple genes. Our approach provides a statistically robust, interpretable way to identify the tissues and developmental times where groups of disease genes are active. Our findings highlight the importance of considering the interactions between genes when analyzing genome-wide sequence data.

scholarly journals Viral RNA-dependent RNA polymerase inhibitor 7-deaza-2′-C-methyladenosine prevents death in a mouse model of West Nile virus infection

2018 ◽  
Author(s):  
Luděk Eyer ◽  
Martina Fojtíková ◽  
Radim Nencka ◽  
Ivo Rudolf ◽  
Zdeněk Hubálek ◽  
...  
Keyword(s):  
West Nile Virus ◽  
Post Infection ◽  
West Nile Virus Infection ◽  
Antiviral Effect ◽  
Vero Cells ◽  
Modified Nucleosides ◽  
West Nile ◽  
Brain Infection ◽  
Highly Effective

AbstractWest Nile virus (WNV) is a medically important emerging arbovirus causing serious neuroinfections in humans against which no approved antiviral therapy is currently available. In this study, we demonstrate that 2′-C- methyl- or 4′-azido-modified nucleosides are highly effective inhibitors of WNV replication, showing nanomolar or low micromolar anti-WNV activity and negligible cytotoxicity in cell culture. One representative ofC2′-methylated nucleosides, 7-deaza-2′-C- methyladenosine, significantly protected WNV-infected mice from disease progression and mortality. Twice daily treatment at 25 mg/kg starting at the time of infection resulted in 100% survival of the mice. This compound was highly effective, even if the treatment was initiated 3 days post-infection, at the time of a peak of viremia, which resulted in a 90% survival rate. However, the antiviral effect of 7-deaza-2′-C- methyladenosine was absent or negligible when the treatment was started 8 days post-infection (i.e., at the time of extensive brain infection). The 4′-azido moiety appears to be another important determinant for highly efficient inhibition of WNV replication in vitro. However, the strong anti-WNV effect of 4′-azidocytidine and 4′-azido-aracytidine was cell type-dependent and observed predominantly in PS cells. The effect was much less pronounced in Vero cells. Our results indicate that 2′-C- methylated or 4′-azidated nucleosides merit further investigation as potential therapeutic agents for treating WNV infections, as well as infections caused by other medically important flaviviruses.

scholarly journals Zika virus infects pericytes in the choroid plexus and enters the central nervous system through the blood-cerebrospinal fluid barrier

2019 ◽  
Author(s):  
Jihye Kim ◽  
Michal Hetman ◽  
Eyas M. Hattab ◽  
Joshua Joiner ◽  
Brian Alejandro ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Cerebrospinal Fluid ◽  
Choroid Plexus ◽  
Zika Virus ◽  
Neurological Complications ◽  
Brain Infection ◽  
The Central Nervous System ◽  
The Brain ◽  
Host Brain

ABSTRACTZika virus (ZIKV) can infect and cause microcephaly and Zika-associated neurological complications in the developing fetal and adult brains. In terms of pathogenesis, a critical question is how ZIKV overcomes the barriers separating the brain from the circulation and gains access to the central nervous system (CNS). Despite the importance of ZIKV pathogenesis, the route ZIKV utilizes to cross CNS barriers remains unclear.Here we show that in mouse models, ZIKV-infected cells initially appeared in the periventricular regions of the brain, including the choroid plexus and the meninges, prior to infection of the cortex. The appearance of ZIKV in cerebrospinal fluid (CSF) preceded infection of the brain parenchyma. We show that ZIKV infects pericytes in the choroid plexus, and that ZIKV infection of pericytes is dependent on AXL receptor tyrosine kinase. Using an in vitro Transwell system, we highlight the possibility of ZIKV to move from the blood side to CSF side, across the choroid plexus epithelial layers, via a nondestructive pathway (e.g., transcytosis). Finally, we demonstrate that brain infection is significantly attenuated by neutralization of the virus in the CSF, indicating that ZIKV in the CSF at the early stage of infection might be responsible for establishing a lethal infection of the brain. Taken together, our results suggest that ZIKV invades the host brain by exploiting the blood-CSF barrier rather than the blood-brain barrier.AUTHOR SUMMARYZika virus invades the human brains and causes Zika-associated neurological complications; however, the mechanism(s) by which Zika virus accesses the central nerves system remain unclear. Understanding of the cellular and molecular mechanisms will shed light on development of novel therapeutic and prophylactic targets for Zika virus and other neurotropic viruses. Here we use in vivo and in vitro models to understand how Zika virus enters the brain. In mouse models, we found that Zika virus infects pericytes in the choroid plexus at very early stages of infection and neutralization of Zika virus in the cerebrospinal fluid significantly attenuate the brain infection. Further we show evidence that Zika virus can cross the epithelial cell layers in the choroid plexus from the blood side. Our research highlights that ZIKV invades the host brain by exploiting the blood-CSF barrier rather than the blood-brain barrier.

scholarly journals Coding and noncoding variants in EBF3 are involved in HADDS and simplex autism

2021 ◽  
Vol 15 (1) ◽  
Author(s):  
Evin M. Padhi ◽  
Tristan J. Hayeck ◽  
Zhang Cheng ◽  
Sumantra Chatterjee ◽  
Brandon J. Mannion ◽  
...  
Keyword(s):  
De Novo ◽  
Fetal Brain ◽  
Neuronal Cell ◽  
The Body ◽  
Whole Genome Sequencing Data ◽  
Loss Of Function ◽  
Sequencing Data ◽  
Enhancer Activity ◽  
Genome Wide

Abstract Background Previous research in autism and other neurodevelopmental disorders (NDDs) has indicated an important contribution of protein-coding (coding) de novo variants (DNVs) within specific genes. The role of de novo noncoding variation has been observable as a general increase in genetic burden but has yet to be resolved to individual functional elements. In this study, we assessed whole-genome sequencing data in 2671 families with autism (discovery cohort of 516 families, replication cohort of 2155 families). We focused on DNVs in enhancers with characterized in vivo activity in the brain and identified an excess of DNVs in an enhancer named hs737. Results We adapted the fitDNM statistical model to work in noncoding regions and tested enhancers for excess of DNVs in families with autism. We found only one enhancer (hs737) with nominal significance in the discovery (p = 0.0172), replication (p = 2.5 × 10−3), and combined dataset (p = 1.1 × 10−4). Each individual with a DNV in hs737 had shared phenotypes including being male, intact cognitive function, and hypotonia or motor delay. Our in vitro assessment of the DNVs showed they all reduce enhancer activity in a neuronal cell line. By epigenomic analyses, we found that hs737 is brain-specific and targets the transcription factor gene EBF3 in human fetal brain. EBF3 is genome-wide significant for coding DNVs in NDDs (missense p = 8.12 × 10−35, loss-of-function p = 2.26 × 10−13) and is widely expressed in the body. Through characterization of promoters bound by EBF3 in neuronal cells, we saw enrichment for binding to NDD genes (p = 7.43 × 10−6, OR = 1.87) involved in gene regulation. Individuals with coding DNVs have greater phenotypic severity (hypotonia, ataxia, and delayed development syndrome [HADDS]) in comparison to individuals with noncoding DNVs that have autism and hypotonia. Conclusions In this study, we identify DNVs in the hs737 enhancer in individuals with autism. Through multiple approaches, we find hs737 targets the gene EBF3 that is genome-wide significant in NDDs. By assessment of noncoding variation and the genes they affect, we are beginning to understand their impact on gene regulatory networks in NDDs.

scholarly journals Local assembly of long reads enables phylogenomics of transposable elements in a polyploid cell line

2022 ◽  
Author(s):  
Shunhua Han ◽  
Guilherme B. Dias ◽  
Preston J. Basting ◽  
Raghuvir Viswanatha ◽  
Norbert Perrimon ◽  
...  
Keyword(s):  
Cell Culture ◽  
Transposable Elements ◽  
Cell Line ◽  
Cell Lines ◽  
De Novo ◽  
Sequence Data ◽  
Animal Cell ◽  
Polyploid Cell ◽  
Long Read

Animal cell lines cultured for extended periods often undergo extreme genome restructuring events, including polyploidy and segmental aneuploidy that can impede de novo whole-genome assembly (WGA). In Drosophila, many established cell lines also exhibit massive proliferation of transposable elements (TEs) relative to wild-type flies. To better understand the role of transposition during long-term animal somatic cell culture, we sequenced the genome of the tetraploid Drosophila S2R+ cell line using long-read and linked-read technologies. Relative to comparable data from inbred whole flies, WGAs for S2R+ were highly fragmented and generated variable estimates of TE content across sequencing and assembly technologies. We therefore developed a novel WGA-independent bioinformatics method called "TELR" that identifies, locally assembles, and estimates allele frequency of TEs from long-read sequence data (https://github.com/bergmanlab/telr). Application of TELR to a ~130x PacBio dataset for S2R+ revealed many haplotype-specific TE insertions that arose by somatic transposition in cell culture after initial cell line establishment and subsequent tetraploidization. Local assemblies from TELR also allowed phylogenetic analysis of paralogous TE copies within the S2R+ genome, which revealed that proliferation of different TE families during cell line evolution in vitro can be driven by single or multiple source lineages. Our work provides a model for the analysis of TEs in complex heterozygous or polyploid genomes that are not amenable to WGA and yields new insights into the mechanisms of genome evolution in animal cell culture.

scholarly journals A Zika Vaccine Generated Using the Chimeric Insect-Specific Binjari Virus Platform Protects against Fetal Brain Infection in Pregnant Mice

Vaccines ◽  
2020 ◽  
Vol 8 (3) ◽  
pp. 496
Author(s):  
Jessamine E. Hazlewood ◽  
Daniel J. Rawle ◽  
Bing Tang ◽  
Kexin Yan ◽  
Laura J. Vet ◽  
...  
Keyword(s):  
Fetal Brain ◽  
Target Population ◽  
Maternal Blood ◽  
The Novel ◽  
Brain Infection ◽  
Child Bearing ◽  
Congenital Zika Syndrome ◽  
Pregnant Mice ◽  
Potential Vaccine ◽  
Flavivirus Vaccine

Zika virus (ZIKV) is the etiological agent of congenital Zika syndrome (CZS), a spectrum of birth defects that can lead to life-long disabilities. A range of vaccines are in development with the target population including pregnant women and women of child-bearing age. Using a recently described chimeric flavivirus vaccine technology based on the novel insect-specific Binjari virus (BinJV), we generated a ZIKV vaccine (BinJ/ZIKA-prME) and illustrate herein its ability to protect against fetal brain infection. Female IFNAR−/− mice were vaccinated once with unadjuvanted BinJ/ZIKA-prME, were mated, and at embryonic day 12.5 were challenged with ZIKVPRVABC59. No infectious ZIKV was detected in maternal blood, placenta, or fetal heads in BinJ/ZIKA-prME-vaccinated mice. A similar result was obtained when the more sensitive qRT PCR methodology was used to measure the viral RNA. BinJ/ZIKA-prME vaccination also did not result in antibody-dependent enhancement of dengue virus infection or disease. BinJ/ZIKA-prME thus emerges as a potential vaccine candidate for the prevention of CSZ.

scholarly journals De Novo Generation and Characterization of New Zika Virus Isolate Using Sequence Data from a Microcephaly Case

mSphere ◽  
2017 ◽  
Vol 2 (3) ◽  
Author(s):  
Yin Xiang Setoh ◽  
Natalie A. Prow ◽  
Nias Peng ◽  
Leon E. Hugo ◽  
Gregor Devine ◽  
...  
Keyword(s):  
Deep Sequencing ◽  
Zika Virus ◽  
De Novo ◽  
Sequence Data ◽  
Fetal Brain ◽  
Congenital Defects ◽  
Cdna Clones ◽  
Adaptive Mutations ◽  
Positive Strand Rna ◽  
Viral Isolates

ABSTRACT Zika virus (ZIKV) has recently emerged and is the etiological agent of congenital Zika syndrome (CZS), a spectrum of congenital abnormalities arising from neural tissue infections in utero. Herein, we describe the de novo generation of a new ZIKV isolate, ZIKVNatal, using a modified circular polymerase extension reaction protocol and sequence data obtained from a ZIKV-infected fetus with microcephaly. ZIKVNatal thus has no laboratory passage history and is unequivocally associated with CZS. ZIKVNatal could be used to establish a fetal brain infection model in IFNAR−/− mice (including intrauterine growth restriction) without causing symptomatic infections in dams. ZIKVNatal was also able to be transmitted by Aedes aegypti mosquitoes. ZIKVNatal thus retains key aspects of circulating pathogenic ZIKVs and illustrates a novel methodology for obtaining an authentic functional viral isolate by using data from deep sequencing of infected tissues. IMPORTANCE The major complications of an ongoing Zika virus outbreak in the Americas and Asia are congenital defects caused by the virus’s ability to cross the placenta and infect the fetal brain. The ability to generate molecular tools to analyze viral isolates from the current outbreak is essential for furthering our understanding of how these viruses cause congenital defects. The majority of existing viral isolates and infectious cDNA clones generated from them have undergone various numbers of passages in cell culture and/or suckling mice, which is likely to result in the accumulation of adaptive mutations that may affect viral properties. The approach described herein allows rapid generation of new, fully functional Zika virus isolates directly from deep sequencing data from virus-infected tissues without the need for prior virus passaging and for the generation and propagation of full-length cDNA clones. The approach should be applicable to other medically important flaviviruses and perhaps other positive-strand RNA viruses.

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