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Viruses Feb 2012Ebolavirus (EBOV) and Marburgvirus (MARV) that compose the filovirus family of negative strand RNA viruses infect a broad range of mammalian cells. Recent studies... (Review)
Review
Ebolavirus (EBOV) and Marburgvirus (MARV) that compose the filovirus family of negative strand RNA viruses infect a broad range of mammalian cells. Recent studies indicate that cellular entry of this family of viruses requires a series of cellular protein interactions and molecular mechanisms, some of which are unique to filoviruses and others are commonly used by all viral glycoproteins. Details of this entry pathway are highlighted here. Virus entry into cells is initiated by the interaction of the viral glycoprotein(1) subunit (GP(1)) with both adherence factors and one or more receptors on the surface of host cells. On epithelial cells, we recently demonstrated that TIM-1 serves as a receptor for this family of viruses, but the cell surface receptors in other cell types remain unidentified. Upon receptor binding, the virus is internalized into endosomes primarily via macropinocytosis, but perhaps by other mechanisms as well. Within the acidified endosome, the heavily glycosylated GP(1) is cleaved to a smaller form by the low pH-dependent cellular proteases Cathepsin L and B, exposing residues in the receptor binding site (RBS). Details of the molecular events following cathepsin-dependent trimming of GP(1) are currently incomplete; however, the processed GP(1) specifically interacts with endosomal/lysosomal membranes that contain the Niemann Pick C1 (NPC1) protein and expression of NPC1 is required for productive infection, suggesting that GP/NPC1 interactions may be an important late step in the entry process. Additional events such as further GP(1) processing and/or reducing events may also be required to generate a fusion-ready form of the glycoprotein. Once this has been achieved, sequences in the filovirus GP(2) subunit mediate viral/cellular membrane fusion via mechanisms similar to those previously described for other enveloped viruses. This multi-step entry pathway highlights the complex and highly orchestrated path of internalization and fusion that appears unique for filoviruses.
Topics: Animals; Ebolavirus; Endocytosis; Host-Pathogen Interactions; Humans; Mammals; Marburgvirus; Receptors, Virus; Viral Envelope Proteins; Virus Internalization
PubMed: 22470835
DOI: 10.3390/v4020258 -
Journal of Virology Mar 2022Ebola virus (EBOV) and Marburg virus (MARV) continue to emerge and cause severe hemorrhagic disease in humans. A comprehensive understanding of the filovirus-host...
Ebola virus (EBOV) and Marburg virus (MARV) continue to emerge and cause severe hemorrhagic disease in humans. A comprehensive understanding of the filovirus-host interplay will be crucial for identifying and developing antiviral strategies. The filoviral VP40 matrix protein drives virion assembly and egress, in part by recruiting specific WW domain-containing host interactors via its conserved PPxY late (L) domain motif to positively regulate virus egress and spread. In contrast to these positive regulators of virus budding, a growing list of WW domain-containing interactors that negatively regulate virus egress and spread have been identified, including BAG3, YAP/TAZ, and WWOX. In addition to host WW domain regulators of virus budding, host PPxY-containing proteins also contribute to regulating this late stage of filovirus replication. For example, angiomotin (AMOT) is a multi-PPxY-containing host protein that functionally interacts with many of the same WW domain-containing proteins that regulate virus egress and spread. In this report, we demonstrate that host WWOX, which negatively regulates egress of VP40 virus-like particles (VLPs) and recombinant vesicular stomatitis virus (VSV) M40 virus, interacts with and suppresses the expression of AMOT. We found that WWOX disrupts AMOT's scaffold-like tubular distribution and reduces AMOT localization at the plasma membrane via lysosomal degradation. In sum, our findings reveal an indirect and novel mechanism by which modular PPxY-WW domain interactions between AMOT and WWOX regulate PPxY-mediated egress of filovirus VP40 VLPs. A better understanding of this modular network and competitive nature of protein-protein interactions will help to identify new antiviral targets and therapeutic strategies. Filoviruses (Ebola virus [EBOV] and Marburg virus [MARV]) are zoonotic, emerging pathogens that cause outbreaks of severe hemorrhagic fever in humans. A fundamental understanding of the virus-host interface is critical for understanding the biology of these viruses and for developing future strategies for therapeutic intervention. Here, we reveal a novel mechanism by which host proteins WWOX and AMOTp130 interact with each other and with the filovirus matrix protein VP40 to regulate VP40-mediated egress of virus-like particles (VLPs). Our results highlight the biological impact of competitive interplay of modular virus-host interactions on both the virus life cycle and the host cell.
Topics: Angiomotins; Ebolavirus; Humans; Marburgvirus; Viral Matrix Proteins; Virus Release; WW Domain-Containing Oxidoreductase
PubMed: 35107375
DOI: 10.1128/jvi.02026-21 -
Methods in Molecular Biology (Clifton,... 2017Pseudotyping lentivirus-based vectors is a strategy used to study conferred vector tropism and mechanisms of envelope glycoprotein function. Lentiviruses and filoviruses...
Pseudotyping lentivirus-based vectors is a strategy used to study conferred vector tropism and mechanisms of envelope glycoprotein function. Lentiviruses and filoviruses both assemble at the plasma membrane and have homotrimeric structural envelope glycoproteins that mediate both receptor binding and fusion. Such similarities help foster efficient pseudotyping. Importantly, filovirus glycoprotein pseudotyping of lentiviral vectors allows investigators to study virus entry at substantially less restrictive levels of biosafety containment than that required for wild-type filovirus work (biosafety level-2 vs. biosafety level-4, respectively). Standard lentiviral vector production involves transient transfection of viral component expression plasmids into producer cells, supernatant collection, and centrifuge concentration. Because the envelope glycoprotein expression plasmid is provided in trans, wild type or variant filoviral glycoproteins from marburgvirus or ebolavirus species may be used for pseudotyping and compared side-by-side. In this chapter we discuss the manufacture of pseudotyped lentiviral vector with an emphasis on small-scale laboratory grade production.
Topics: Animals; Genetic Therapy; Genetic Vectors; Humans; Lentivirus; Membrane Glycoproteins; Plasmids; Transfection; Viral Envelope Proteins; Viral Tropism; Virus Internalization
PubMed: 28573611
DOI: 10.1007/978-1-4939-7116-9_5 -
Bioscience Trends Sep 2022Two cases of the deadly Marburgvirus were reported in Ghana, which might be a new global virus alert following COVID-19 and novel monkeypox. Thus far, there is no...
Two cases of the deadly Marburgvirus were reported in Ghana, which might be a new global virus alert following COVID-19 and novel monkeypox. Thus far, there is no vaccine or treatment for Marburg virus disease, which is a disease with a mortality rate as high as that of Ebola. Although now human infections with Marburgvirus occurred mainly in Africa, outbreaks were twice reported in Europe over the past 55 years. A concern is that globalization might promote its global viral transmission, just like what happened with COVID-19. The current study has briefly summarized the etiology, epidemiology, and clinical symptoms of the Marburgvirus as well as vaccine development and experimental treatments in order to prevent and control this virus.
Topics: Animals; COVID-19; Disease Outbreaks; Hemorrhagic Fever, Ebola; Humans; Marburg Virus Disease; Marburgvirus
PubMed: 35908851
DOI: 10.5582/bst.2022.01333 -
Journal of Virology Feb 2018Previous studies demonstrated that a single intramuscular (i.m.) dose of an attenuated recombinant vesicular stomatitis virus (rVSV) vector (VesiculoVax vector platform;...
Previous studies demonstrated that a single intramuscular (i.m.) dose of an attenuated recombinant vesicular stomatitis virus (rVSV) vector (VesiculoVax vector platform; rVSV-N4CT1) expressing the glycoprotein (GP) from the Mayinga strain of (EBOV) protected nonhuman primates (NHPs) from lethal challenge with EBOV strains Kikwit and Makona. Here, we studied the immunogenicities of an expanded range of attenuated rVSV vectors expressing filovirus GP in mice. Based on data from those studies, an optimal attenuated trivalent rVSV vector formulation was identified that included rVSV vectors expressing EBOV, (SUDV), and the Angola strain of (MARV) GPs. NHPs were vaccinated with a single dose of the trivalent formulation, followed by lethal challenge 28 days later with each of the three corresponding filoviruses. At day 14 postvaccination, a serum IgG response specific for all three GPs was detected in all the vaccinated macaques. A modest and balanced cell-mediated immune response specific for each GP was also detected in a majority of the vaccinated macaques. No matter the level of total GP-specific immune response detected postvaccination, all the vaccinated macaques were protected from disease and death following lethal challenge with each of the three filoviruses. These findings indicate that vaccination with a single dose of attenuated rVSV-N4CT1 vectors each expressing a single filovirus GP may provide protection against the filoviruses most commonly responsible for outbreaks of hemorrhagic fever in sub-Saharan Africa. The West African Ebola virus Zaire outbreak in 2013 showed that the disease was not only a regional concern, but a worldwide problem, and highlighted the need for a safe and efficacious vaccine to be administered to the populace. However, other endemic pathogens, like Ebola virus Sudan and Marburg, also pose an important health risk to the public and therefore require development of a vaccine prior to the occurrence of an outbreak. The significance of our research was the development of a blended trivalent filovirus vaccine that elicited a balanced immune response when administered as a single dose and provided complete protection against a lethal challenge with all three filovirus pathogens.
Topics: Animals; Antibodies, Viral; Ebolavirus; Glycoproteins; Hemorrhagic Fever, Ebola; Immunoglobulin G; Injections, Intramuscular; Macaca fascicularis; Marburg Virus Disease; Marburgvirus; Mice; Vaccination; Vaccines, Attenuated; Vaccines, Synthetic; Vesiculovirus; Viral Proteins; Viral Vaccines
PubMed: 29142131
DOI: 10.1128/JVI.01190-17 -
Journal of Virology Sep 2011With the exception of Reston and Lloviu viruses, filoviruses (marburgviruses, ebolaviruses, and "cuevaviruses") cause severe viral hemorrhagic fevers in humans....
With the exception of Reston and Lloviu viruses, filoviruses (marburgviruses, ebolaviruses, and "cuevaviruses") cause severe viral hemorrhagic fevers in humans. Filoviruses use a class I fusion protein, GP(1,2), to bind to an unknown, but shared, cell surface receptor to initiate virus-cell fusion. In addition to GP(1,2), ebolaviruses and cuevaviruses, but not marburgviruses, express two secreted glycoproteins, soluble GP (sGP) and small soluble GP (ssGP). All three glycoproteins have identical N termini that include the receptor-binding region (RBR) but differ in their C termini. We evaluated the effect of the secreted ebolavirus glycoproteins on marburgvirus and ebolavirus cell entry, using Fc-tagged recombinant proteins. Neither sGP-Fc nor ssGP-Fc bound to filovirus-permissive cells or inhibited GP(1,2)-mediated cell entry of pseudotyped retroviruses. Surprisingly, several Fc-tagged Δ-peptides, which are small C-terminal cleavage products of sGP secreted by ebolavirus-infected cells, inhibited entry of retroviruses pseudotyped with Marburg virus GP(1,2), as well as Marburg virus and Ebola virus infection in a dose-dependent manner and at low molarity despite absence of sequence similarity to filovirus RBRs. Fc-tagged Δ-peptides from three ebolaviruses (Ebola virus, Sudan virus, and Taï Forest virus) inhibited GP(1,2)-mediated entry and infection of viruses comparably to or better than the Fc-tagged RBRs, whereas the Δ-peptide-Fc of an ebolavirus nonpathogenic for humans (Reston virus) and that of an ebolavirus with lower lethality for humans (Bundibugyo virus) had little effect. These data indicate that Δ-peptides are functional components of ebolavirus proteomes. They join cathepsins and integrins as novel modulators of filovirus cell entry, might play important roles in pathogenesis, and could be exploited for the synthesis of powerful new antivirals.
Topics: Animals; Antiviral Agents; Biological Products; Cell Line; Ebolavirus; Humans; Immunoglobulin Fc Fragments; Marburgvirus; Recombinant Fusion Proteins; Viral Proteins; Virus Internalization
PubMed: 21697477
DOI: 10.1128/JVI.02600-10 -
Viruses Aug 2023A new filovirus named Měnglà virus was found in bats in southern China in 2015. This species has been assigned to the new genus and has only been detected in China....
A new filovirus named Měnglà virus was found in bats in southern China in 2015. This species has been assigned to the new genus and has only been detected in China. In this article, we report the detection of filoviruses in bats captured in Vietnam. We studied 248 bats of 15 species caught in the provinces of Lai Chau and Son La in northern Vietnam and in the province of Dong Thap in the southern part of the country. Filovirus RNA was found in four and one from Lai Chau Province. Phylogenetic analysis of the polymerase gene fragment showed that three positive samples belong to , and two samples form a separate clade closer to . An enzyme-linked immunosorbent assay showed that 9% of , 13% of , and 10% of bats had antibodies to the glycoprotein of marburgviruses.
Topics: Animals; Filoviridae; Chiroptera; Vietnam; Phylogeny; Marburgvirus
PubMed: 37766193
DOI: 10.3390/v15091785 -
Emerging Infectious Diseases Aug 2019We detected Marburg virus genome in Egyptian fruit bats (Rousettus aegyptiacus) captured in Zambia in September 2018. The virus was closely related phylogenetically to...
We detected Marburg virus genome in Egyptian fruit bats (Rousettus aegyptiacus) captured in Zambia in September 2018. The virus was closely related phylogenetically to the viruses that previously caused Marburg outbreaks in the Democratic Republic of the Congo. This finding demonstrates that Zambia is at risk for Marburg virus disease.
Topics: Animals; Chiroptera; Genes, Viral; Humans; Marburg Virus Disease; Marburgvirus; Phylogeny; Prevalence; Public Health Surveillance; RNA, Viral; Zambia
PubMed: 31146800
DOI: 10.3201/eid2508.190268 -
The Journal of Veterinary Medical... Nov 2022Some filoviruses such as ebolaviruses and marburgviruses, cause hemorrhagic fever in humans and nonhuman primates. Pigs are suggested to play a potential role in the...
Some filoviruses such as ebolaviruses and marburgviruses, cause hemorrhagic fever in humans and nonhuman primates. Pigs are suggested to play a potential role in the filovirus ecology. We investigated the seroprevalence of filovirus infection in pigs in Ghana. Using a viral glycoprotein (GP)-based enzyme-linked immunosorbent assay, we detected filovirus-specific immunoglobulin G antibodies in 5 of 139 samples. These positive sera showed specificities to four different filovirus species. Particularly, two of the positive sera reacted to GPs of two African ebolaviruses (i.e., Ebola virus and Taï Forest virus) in Western blotting. Our results suggest that these Ghanaian pigs were exposed to multiple filoviruses and emphasize the importance of continuous monitoring of filovirus infection in pig populations in West African countries.
Topics: Swine; Humans; Animals; Ebolavirus; Ghana; Hemorrhagic Fever, Ebola; Seroepidemiologic Studies; Antibodies, Viral; Filoviridae Infections; Swine Diseases
PubMed: 36123040
DOI: 10.1292/jvms.22-0186 -
Journal of Virology Jul 2006In March 2005, the Centers for Disease Control and Prevention (CDC) investigated a large hemorrhagic fever (HF) outbreak in Uige Province in northern Angola, West...
In March 2005, the Centers for Disease Control and Prevention (CDC) investigated a large hemorrhagic fever (HF) outbreak in Uige Province in northern Angola, West Africa. In total, 15 initial specimens were sent to CDC, Atlanta, Ga., for testing for viruses associated with viral HFs known to be present in West Africa, including ebolavirus. Marburgvirus was also included despite the fact that the origins of all earlier outbreaks were linked directly to East Africa. Surprisingly, marburgvirus was confirmed (12 of 15 specimens) as the cause of the outbreak. The outbreak likely began in October 2004 and ended in July 2005, and it included 252 cases and 227 (90%) fatalities (report from the Ministry of Health, Republic of Angola, 2005), making it the largest Marburg HF outbreak on record. A real-time quantitative reverse transcription-PCR assay utilized and adapted during the outbreak proved to be highly sensitive and sufficiently robust for field use. Partial marburgvirus RNA sequence analysis revealed up to 21% nucleotide divergence among the previously characterized East African strains, with the most distinct being Ravn from Kenya (1987). The Angolan strain was less different ( approximately 7%) from the main group of East African marburgviruses than one might expect given the large geographic separation. To more precisely analyze the virus genetic differences between outbreaks and among viruses within the Angola outbreak itself, a total of 16 complete virus genomes were determined, including those of the virus isolates Ravn (Kenya, 1987) and 05DRC, 07DRC, and 09DRC (Democratic Republic of Congo, 1998) and the reference Angolan virus isolate (Ang1379v). In addition, complete genome sequences were obtained from RNAs extracted from 10 clinical specimens reflecting various stages of the disease and locations within the Angolan outbreak. While the marburgviruses exhibit high overall genetic diversity (up to 22%), only 6.8% nucleotide difference was found between the West African Angolan viruses and the majority of East African viruses, suggesting that the virus reservoir species in these regions are not substantially distinct. Remarkably few nucleotide differences were found among the Angolan clinical specimens (0 to 0.07%), consistent with an outbreak scenario in which a single (or rare) introduction of virus from the reservoir species into the human population was followed by person-to-person transmission with little accumulation of mutations. This is in contrast to the 1998 to 2000 marburgvirus outbreak, where evidence of several virus genetic lineages (with up to 21% divergence) and multiple virus introductions into the human population was found.
Topics: Angola; Base Sequence; Disease Outbreaks; Female; Genome, Viral; History, 21st Century; Humans; Kenya; Male; Marburg Virus Disease; Marburgvirus; Molecular Sequence Data; Mutation; Reverse Transcriptase Polymerase Chain Reaction; Sequence Analysis, RNA; Species Specificity
PubMed: 16775337
DOI: 10.1128/JVI.00069-06