scholarly journals Interferon-Induced HERC5 Inhibits Ebola Virus Particle Production and Is Antagonized by Ebola Glycoprotein

Cells ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 2399
Author(s):  
Ermela Paparisto ◽  
Nina R. Hunt ◽  
Daniel S. Labach ◽  
Macon D. Coleman ◽  
Eric J. Di Gravio ◽  
...  
Keyword(s):  
Particle Production ◽  
Ebola Virus ◽  
Marburg Virus ◽  
Antiviral Protein ◽  
Virus Like Particle ◽  
Ebov Infection ◽  
Necessary And Sufficient ◽  
Virus Particle Production ◽  
Transcription And Replication

Survival following Ebola virus (EBOV) infection correlates with the ability to mount an early and robust interferon (IFN) response. The host IFN-induced proteins that contribute to controlling EBOV replication are not fully known. Among the top genes with the strongest early increases in expression after infection in vivo is IFN-induced HERC5. Using a transcription- and replication-competent VLP system, we showed that HERC5 inhibits EBOV virus-like particle (VLP) replication by depleting EBOV mRNAs. The HERC5 RCC1-like domain was necessary and sufficient for this inhibition and did not require zinc finger antiviral protein (ZAP). Moreover, we showed that EBOV (Zaire) glycoprotein (GP) but not Marburg virus GP antagonized HERC5 early during infection. Our data identify a novel ‘protagonist–antagonistic’ relationship between HERC5 and GP in the early stages of EBOV infection that could be exploited for the development of novel antiviral therapeutics.

scholarly journals In vivo single-cell profiling of lncRNAs during Ebola virus infection

2022 ◽  
Author(s):  
Luisa Santus ◽  
Raquel García-Pérez ◽  
Maria Sopena-Rios ◽  
Aaron E Lin ◽  
Gordon C Adams ◽  
...  
Keyword(s):  
Viral Infection ◽  
Single Cell ◽  
Ebola Virus ◽  
Cell Type ◽  
Protein Coding ◽  
Expression Variation ◽  
Lncrna Expression ◽  
Ebov Infection ◽  
Cell Type Specific

Long non-coding RNAs (lncRNAs) are pivotal mediators of systemic immune response to viral infection, yet most studies concerning their expression and functions upon immune stimulation are limited to in vitro bulk cell populations. This strongly constrains our understanding of how lncRNA expression varies at single-cell resolution, and how their cell-type specific immune regulatory roles may differ compared to protein-coding genes. Here, we perform the first in-depth characterization of lncRNA expression variation at single-cell resolution during Ebola virus (EBOV) infection in vivo. Using bulk RNA-sequencing from 119 samples and 12 tissue types, we significantly expand the current macaque lncRNA annotation. We then profile lncRNA expression variation in immune circulating single-cells during EBOV infection and find that lncRNAs' expression in fewer cells is a major differentiating factor from their protein-coding gene counterparts. Upon EBOV infection, lncRNAs present dynamic and mostly cell-type specific changes in their expression profiles especially in monocytes, the main cell type targeted by EBOV. Such changes are associated with gene regulatory modules related to important innate immune responses such as interferon response and purine metabolism. Within infected cells, several lncRNAs have positively and negatively correlated expression with viral load, suggesting that expression of some of these lncRNAs might be directly hijacked by EBOV to attack host cells. This study provides novel insights into the roles that lncRNAs play in the host response to acute viral infection and paves the way for future lncRNA studies at single-cell resolution.

scholarly journals Exchange Protein Directly Activated by cAMP Modulates Ebola Virus Uptake into Vascular Endothelial Cells

Viruses ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 563 ◽  
Author(s):  
Aleksandra Drelich ◽  
Barbara Judy ◽  
Xi He ◽  
Qing Chang ◽  
Shangyi Yu ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Ebola Virus ◽  
Vascular Endothelial Cells ◽  
Ex Vivo ◽  
Marburg Virus ◽  
Dependent Manner ◽  
Vascular Endothelial ◽  
Ultrastructural Studies ◽  
Ebov Infection ◽  
Exchange Protein

Members of the family Filoviridae, including Ebola virus (EBOV) and Marburg virus (MARV), cause severe hemorrhagic fever in humans and nonhuman primates. Given their high lethality, a comprehensive understanding of filoviral pathogenesis is urgently needed. In the present studies, we revealed that the exchange protein directly activated by cAMP 1 (EPAC1) gene deletion protects vasculature in ex vivo explants from EBOV infection. Importantly, pharmacological inhibition of EPAC1 using EPAC-specific inhibitors (ESIs) mimicked the EPAC1 knockout phenotype in the ex vivo model. ESI treatment dramatically decreased EBOV infectivity in both ex vivo vasculature and in vitro vascular endothelial cells (ECs). Furthermore, postexposure protection of ECs against EBOV infection was conferred using ESIs. Protective efficacy of ESIs in ECs was observed also in MARV infection. Additional studies using a vesicular stomatitis virus pseudotype that expresses EBOV glycoprotein (EGP-VSV) confirmed that ESIs reduced infection in ECs. Ultrastructural studies suggested that ESIs blocked EGP-VSV internalization via inhibition of macropinocytosis. The inactivation of EPAC1 affects the early stage of viral entry after viral binding to the cell surface, but before early endosome formation, in a phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K)-dependent manner. Our study delineated a new critical role of EPAC1 during EBOV uptake into ECs.

scholarly journals DC-SIGN and DC-SIGNR Interact with the Glycoprotein of Marburg Virus and the S Protein of Severe Acute Respiratory Syndrome Coronavirus

2004 ◽  
Vol 78 (21) ◽  
pp. 12090-12095 ◽  
Author(s):  
Andrea Marzi ◽  
Thomas Gramberg ◽  
Graham Simmons ◽  
Peggy Möller ◽  
Andrew J. Rennekamp ◽  
...  
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Viral Infection ◽  
Ebola Virus ◽  
Marburg Virus ◽  
S Protein ◽  
Viral Dissemination

ABSTRACT The lectins DC-SIGN and DC-SIGNR can augment viral infection; however, the range of pathogens interacting with these attachment factors is incompletely defined. Here we show that DC-SIGN and DC-SIGNR enhance infection mediated by the glycoprotein (GP) of Marburg virus (MARV) and the S protein of severe acute respiratory syndrome coronavirus and might promote viral dissemination. SIGNR1, a murine DC-SIGN homologue, also enhanced infection driven by MARV and Ebola virus GP and could be targeted to assess the role of attachment factors in filovirus infection in vivo.

scholarly journals Inhibition of Filovirus Replication by the Zinc Finger Antiviral Protein

2006 ◽  
Vol 81 (5) ◽  
pp. 2391-2400 ◽  
Author(s):  
Stefanie Müller ◽  
Peggy Möller ◽  
Matthew J. Bick ◽  
Stephanie Wurr ◽  
Stephan Becker ◽  
...  
Keyword(s):  
Zinc Finger ◽  
Sindbis Virus ◽  
Time Course ◽  
Ebola Virus ◽  
Leukemia Virus ◽  
Inhibitory Effect ◽  
Marburg Virus ◽  
Moloney Murine Leukemia Virus ◽  
Zinc Finger Motif ◽  
Antiviral Protein

ABSTRACT The zinc finger antiviral protein (ZAP) was recently shown to inhibit Moloney murine leukemia virus and Sindbis virus replication. We tested whether ZAP also acts against Ebola virus (EBOV) and Marburg virus (MARV). Antiviral effects were observed after infection of cells expressing the N-terminal part of ZAP fused to the product of the zeocin resistance gene (NZAP-Zeo) as well as after infection of cells inducibly expressing full-length ZAP. EBOV was inhibited by up to 4 log units, whereas MARV was inhibited between 1 to 2 log units. The activity of ZAP was dependent on the integrity of the second and fourth zinc finger motif, as tested with cell lines expressing NZAP-Zeo mutants. Heterologous expression of EBOV- and MARV-specific sequences fused to a reporter gene suggest that ZAP specifically targets L gene sequences. The activity of NZAP-Zeo in this assay was also dependent on the integrity of the second and fourth zinc finger motif. Time-course experiments with infectious EBOV showed that ZAP reduces the level of L mRNA before the level of genomic or antigenomic RNA is affected. Transient expression of ZAP decreased the activity of an EBOV replicon system by up to 95%. This inhibitory effect could be partially compensated for by overexpression of L protein. In conclusion, the data demonstrate that ZAP exhibits antiviral activity against filoviruses, presumably by decreasing the level of viral mRNA.

scholarly journals TIM-1 Serves as a Nonredundant Receptor for Ebola Virus, Enhancing Viremia and Pathogenesis

2018 ◽  
Author(s):  
Bethany Brunton ◽  
Kai Rogers ◽  
Elisabeth K. Phillips ◽  
Rachel B. Brouillette ◽  
Ruayda Bouls ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Ebola Virus ◽  
Apoptotic Bodies ◽  
Virus Load ◽  
Ebov Infection ◽  
Model Virus ◽  
Deficient Mice

AbstractBackground.T cell immunoglobulin mucin domain-1 (TIM-1) is a phosphatidylserine (PS) receptor, mediating filovirus entry into cells through interactions with PS on virions. TIM-1 expression has been implicated in Ebola virus (EBOV) pathogenesis; however, it remains unclear whether this is due to TIM-1 serving as a filovirus receptor in vivo or, as others have suggested, TIM-1 induces a cytokine storm elicited by T cell/virion interactions. Here, we use a BSL2 model virus that expresses EBOV glycoprotein and demonstrate the importance of TIM-1 as a virus receptor late during in vivo infection.Methodology/Principal findings.We used an infectious, recombinant vesicular stomatitis virus expressing EBOV glycoprotein (EBOV GP/rVSV) to assess the role of TIM-1 during in vivo infection. TIM-1-sufficient or TIM-1-deficient BALB/c interferon α/β receptor-/-mice were challenged with EBOV GP/rVSV-GFP or G/rVSV-GFP. While G/rVSV caused profound morbidity and mortality in both mouse strains, TIM-1-deficient mice had significantly better survival than TIM-1-expressing mice following EBOV GP/rVSV challenge. EBOV GP/rVSV load in spleen was high and unaffected by expression of TIM-1. However, infectious virus in serum, liver, kidney and adrenal gland was reduced late in infection in the TIM-1-deficient mice, suggesting that virus entry via this receptor contributes to virus load. Consistent with higher virus loads, proinflammatory chemokines trended higher in organs from infected TIM-1-sufficient mice compared to the TIM-1-deficient mice, but proinflammatory cytokines were more modestly affected. To assess the role of T cells in EBOV GP/rVSV pathogenesis, T cells were depleted in TIM-1-sufficient and -deficient mice and the mice were challenged with virus. Depletion of T cells did not alter the pathogenic consequences of virus infection.Conclusions.Our studies provide evidence that at late times during EBOV GP/rVSV infection, TIM-1 increased virus load and associated mortality, consistent with an important role of this receptor in virus entry. This work suggests that inhibitors which block TIM-1/virus interaction may serve as effective antivirals, reducing virus load at late times during EBOV infection.Author summaryT cell immunoglobulin mucin domain-1 (TIM-1) is one of a number of phosphatidylserine (PS) receptors that mediate clearance of apoptotic bodies by binding PS on the surface of dead or dying cells. Enveloped viruses mimic apoptotic bodies by exposing PS on the outer leaflet of the viral membrane. While TIM-1 has been shown to serve as an adherence factor/receptor for filoviruses in tissue culture, limited studies have investigated the role of TIM-1 as a receptor in vivo. Here, we sought to determine if TIM-1 was critical for Ebola virus glycoprotein-mediated infection using a BSL2 model virus. We demonstrate that loss of TIM-1 expression results in decreased virus load late during infection and significantly reduced virus-elicited mortality. These findings provide evidence that TIM-1 serves as an important receptor for Ebola virus in vivo. Blocking TIM-1/EBOV interactions may be effective antiviral strategy to reduce viral load and pathogenicity at late times of EBOV infection.

scholarly journals Late Assembly Domain Function Can Exhibit Context Dependence and Involves Ubiquitin Residues Implicated in Endocytosis

2002 ◽  
Vol 76 (11) ◽  
pp. 5472-5479 ◽  
Author(s):  
Bettina Strack ◽  
Arianna Calistri ◽  
Heinrich G. Göttlinger
Keyword(s):  
Particle Production ◽  
Ebola Virus ◽  
Point Mutations ◽  
Core Motif ◽  
Virus Particles ◽  
Virus Like Particle ◽  
Immunodeficiency Virus ◽  
Late Assembly Domain ◽  
Hiv 1

ABSTRACT Retroviral Gag polyproteins contain regions that promote the separation of virus particles from the plasma membrane and from each other. These Gag regions are often referred to as late assembly (L) domains. The L domain of human immunodeficiency virus type 1 (HIV-1) is in the C-terminal p6 gag domain and harbors an essential P(T/S)APP motif, whereas the L domains of oncoretroviruses are in the N-terminal half of the Gag precursor and have a PPXY core motif. We recently observed that L domains induce the ubiquitination of a minimal HIV-1 Gag construct and that point mutations which abolish L domain activity prevent Gag ubiquitination. In that study, a peptide from the Ebola virus L domain with overlapping P(T/S)APP and PPXY motifs showed exceptional activity in promoting Gag ubiquitination and the release of virus-like particles. We now show that a substitution which disrupts the PPXY motif but leaves the P(T/S)APP motif intact abolishes L domain activity in the minimal Gag context, but not in the context of a near full-length HIV-1 Gag precursor. Our results reveal that the P(T/S)APP motif does not function autonomously and indicate that the HIV-1 nucleocapsid-p1 region, which is proximal to p6 gag , can cooperate with the conserved L domain core motif. We have also examined the effects of ubiquitin mutants on virus-like particle production, and the results indicate that residues required for the endocytosis function of ubiquitin are also involved in virus budding.

scholarly journals Comparison of the Transcription and Replication Strategies of Marburg Virus and Ebola Virus by Using Artificial Replication Systems

1999 ◽  
Vol 73 (3) ◽  
pp. 2333-2342 ◽  
Author(s):  
Elke Mühlberger ◽  
Michael Weik ◽  
Viktor E. Volchkov ◽  
Hans-Dieter Klenk ◽  
Stephan Becker
Keyword(s):  
Gene Expression ◽  
Reporter Gene ◽  
Ebola Virus ◽  
Expression System ◽  
Protein Composition ◽  
Marburg Virus ◽  
Reporter Gene Expression ◽  
Lower Efficiency ◽  
Replication Systems ◽  
Transcription And Replication

ABSTRACT The members of the family Filoviridae, Marburg virus (MBGV) and Ebola virus (EBOV), are very similar in terms of morphology, genome organization, and protein composition. To compare the replication and transcription strategies of both viruses, an artificial replication system based on the vaccinia virus T7 expression system was established for EBOV. Specific transcription and replication of an artificial monocistronic minireplicon was demonstrated by reporter gene expression and detection of the transcribed and replicated RNA species. As it was shown previously for MBGV, three of the four EBOV nucleocapsid proteins, NP, VP35, and L, were essential and sufficient for replication. In contrast to MBGV, EBOV-specific transcription was dependent on the presence of the fourth nucleocapsid protein, VP30. When EBOV VP30 was replaced by MBGV VP30, EBOV-specific transcription was observed but with lower efficiency. Exchange of NP, VP35, and L between the two replication systems did not lead to detectable reporter gene expression. It was further observed that neither MBGV nor EBOV were able to replicate the heterologous minigenomes. A chimeric minigenome, however, containing the EBOV leader and the MBGV trailer was encapsidated, replicated, transcribed, and packaged by both viruses.

scholarly journals The Marburg Virus 3′ Noncoding Region Structurally and Functionally Differs from That of Ebola Virus

2009 ◽  
Vol 83 (9) ◽  
pp. 4508-4519 ◽  
Author(s):  
Sven Enterlein ◽  
Kristina M. Schmidt ◽  
Michael Schümann ◽  
Dominik Conrad ◽  
Verena Krähling ◽  
...  
Keyword(s):  
Secondary Structure ◽  
Rna Structure ◽  
Rna Secondary Structure ◽  
Ebola Virus ◽  
Gene Mutations ◽  
Replication Initiation ◽  
Marburg Virus ◽  
Noncoding Region ◽  
Nontranslated Region ◽  
Transcription And Replication

ABSTRACT We have previously shown that the first transcription start signal (TSS) of Zaire Ebola virus (ZEBOV) is involved in formation of an RNA secondary structure regulating VP30-dependent transcription activation. Interestingly, transcription of Marburg virus (MARV) minigenomes occurs independently of VP30. In this study, we analyzed the structure of the MARV 3′ noncoding region and its influence on VP30 necessity. Secondary structure formation of the TSS of the first gene was experimentally determined and showed substantial differences from the structure formed by the ZEBOV TSS. Chimeric MARV minigenomes mimicking the ZEBOV-specific RNA secondary structure were neither transcribed nor replicated. Mapping of the MARV genomic replication promoter revealed that the region homologous to the sequence involved in formation of the regulatory ZEBOV RNA structure is part of the MARV promoter. The MARV promoter is contained within the first 70 nucleotides of the genome and consists of two elements separated by a spacer region, comprising the TSS of the first gene. Mutations within the spacer abolished transcription activity and led to increased replication, indicating competitive transcription and replication initiation. The second promoter element is located within the nontranslated region of the first gene and consists of a stretch of three UN5 hexamers. Recombinant full-length MARV clones, in which the three conserved U residues were substituted, could not be rescued, underlining the importance of the UN5 hexamers for replication activity. Our data suggest that differences in the structure of the genomic replication promoters might account for the different transcription strategies of Marburg and Ebola viruses.

scholarly journals Identification and characterization of defective viral genomes in Ebola virus infected rhesus macaques

2021 ◽  
Author(s):  
Rebecca I. Johnson ◽  
Beata Boczkowska ◽  
Kendra Alfson ◽  
Taylor Weary ◽  
Heather Menzie ◽  
...  
Keyword(s):  
Nonhuman Primates ◽  
Ebola Virus ◽  
Sequence Data ◽  
Rna Virus ◽  
Hemorrhagic Fever ◽  
Marburg Virus ◽  
Immunostimulatory Activity ◽  
Viral Genomes

Ebola virus (EBOV), of the family Filoviridae, is an RNA virus that can cause hemorrhagic fever with a high mortality rate. Defective viral genomes (DVGs) are truncated genomes that have been observed during multiple RNA virus infections, including  in vitro EBOV infection, and have previously been associated with viral persistence and immunostimulatory activity. As DVGs have been detected in cells persistently infected with EBOV, we hypothesized that DVGs may also accumulate during viral replication in filovirus-infected hosts. Therefore, we interrogated sequence data from serum and tissues using a bioinformatics tool in order to identify the presence of DVGs in nonhuman primates (NHPs) infected with EBOV, Sudan virus (SUDV) or Marburg virus (MARV). Multiple 5’ copy-back DVGs (cbDVGs) were detected in NHP serum during the acute phase of filovirus infection. While the relative abundance of total DVGs in most animals was low, serum collected during acute EBOV and SUDV infections, but not MARV infection, contained a higher proportion of short trailer sequence cbDVGs than the challenge stock. This indicated an accumulation of these DVGs throughout infection, potentially due to the preferential replication of short DVGs over the longer viral genome. Using RT-PCR and deep sequencing, we also confirmed the presence of 5’ cbDVGs in EBOV-infected NHP testes, which is of interest due to EBOV persistence in semen of male survivors of infection. This work suggests that DVGs play a role in EBOV infection in vivo and further study will lead to a better understanding of EBOV pathogenesis. Importance The study of filovirus pathogenesis is critical for understanding the consequences of infection and the development of strategies to ameliorate future outbreaks. Defective viral genomes (DVGs) have been detected during EBOV infections in vitro , however their presence in in vivo infections remains unknown. In this study, DVGs were detected in samples collected from EBOV- and SUDV-infected nonhuman primates (NHPs). The accumulation of these DVGs in the trailer region of the genome during infection indicates a potential role in EBOV and SUDV pathogenesis. In particular, the presence of DVGs in the testes of infected NHPs requires further investigation as it may be linked to the establishment of persistence.

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