The Experts below are selected from a list of 2997 Experts worldwide ranked by ideXlab platform
Heinz Feldmann - One of the best experts on this subject based on the ideXlab platform.
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Ebolavirus an overview of molecular and clinical pathogenesis
2017Co-Authors: Veronica Vine, Dana P Scott, Heinz FeldmannAbstract:Ebolaviruses cause severe, often fatal hemorrhagic fever in Central, East, and West Africa. Until recently, they have been viewed as rare but highly pathogenic infections with regional, but limited, global public health impact. This view has changed with the emergence of the first epidemic of Ebola hemorrhagic fever in West Africa. In this chapter we provide an introduction of the pathogenesis of Ebolaviruses as well as a description of clinical disease features. We also describe the current animal models used in Ebolavirus research, detailing each model's unique strengths and weaknesses. We focus on Ebola virus representing the type species Zaire Ebolavirus of the genus Ebolavirus, as most work relates to this pathogen.
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With Improved Cross-Protective Efficacy
2016Co-Authors: Vesicular Stomatitis, Andrea Marzi, Allison Groseth, Thomas W Geisbert, Hideki Ebihara, Virus–based Ebola Vaccines, Julie Callison, Kinola J. Williams, Heinz FeldmannAbstract:newly discovered Bundibugyo Ebolavirus has been proposed as a 5th species. So far, no cross-neutralization among EBOV species has been described, aggravating progress toward cross-species protective vaccines. With the use of recombinant vesicular stomatitis virus (rVSV)–based vaccines, guinea pigs could be protected against Zaire Ebolavirus (ZEBOV) infection only when immunized with a vector expressing the homologous, but not a heterologous, EBOV glycoprotein (GP). However, infection of guinea pigs with nonadapted wild-type strains of the different species resulted in full protection of all animals against subsequent challenge with guinea pig–adapted ZEBOV, showing that cross-species protection is possible. New vectors were generated that contain EBOV viral protein 40 (VP40) or EBOV nucleoprotein (NP) as a second antigen expressed by the same rVSV vector that encodes the heterologous GP. After applying a 2-dose immunization approach, we observed an improved cross-protection rate, with 5 of 6 guinea pigs surviving the lethal ZEBOV challenge if vaccinated with rVSV-expressing SEBOV-GP and-VP40. Our data demonstrate that cross-protection between the EBOV species can be achieved, although EBOV-GP alone cannot induce the required immune response. In the preceding 3 decades, 4 different Ebola virus (EBOV) species have been identified: Zaire Ebolavirus (ZEBOV), Sudan Ebolavirus (SEBOV), Côte d’Ivoire ebo
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Stat1-Deficient Mice Are Not an Appropriate Model for Efficacy Testing of Recombinant
2016Co-Authors: Vesicular Stomatitis, Lisa Kercher, Joshua Marceau, Anthony York, Julie Callsion, Donald J. Gardner, Andrea Marzi, Thomas W Geisbert, Heinz FeldmannAbstract:Stat1−/ − mice lack a response to interferon α, β, and γ, allowing for replication of nonadapted wild-type (wt) Ebolavirus and Marburgvirus. We sought to establish a mouse model for efficacy testing of live attenuated re-combinant vesicular stomatitis virus (rVSV)–based filovirus vaccine vectors using wt Ebolavirus and Marburg-virus challenge strains. While infection of immunocompetent mice with different rVSV-based filovirus vectors did not cause disease, infection of Stat1−/ − mice with the same vectors resulted in systemic infection and lethal outcome for the majority of tested rVSVs. Despite differences in viral loads, organ tropism was remarkably similar between rVSV filovirus vaccine vectors and rVSVwt, with the exception of the brain. In conclusion, Stat1−/−mice are not an appropriate immunocompromised mouse model for efficacy testing of live attenuated, replication-competent rVSV vaccine vectors. Keywords. Vesicular stomatitis virus; Ebolavirus; Marburgvirus; vaccine; Stat1-deficient mice. Ebolavirus and Marburgvirus, members of the family Filoviridae, cause viral hemorrhagic fever in nonhuman primates and humans [1]. While outbreaks of filovirus hemorrhagic fever have occurred mainly in their en-demic area in Central Africa, currently, the biggest doc-umented Ebola virus (EBOV) outbreak is still ongoing in West African countries such as Guinea, Liberia and Sierra Leone. Not only has the virus spread from there into neighboring Mali, it was also introduced to Sene
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Vesicular Stomatitis Virus-Based Vaccines Protect Nonhuman Primates against Bundibugyo Ebolavirus
2016Co-Authors: Chad E. Mire, Krystle N. Agans, Andrea Marzi, Heinz Feldmann, Joan B Geisbert, Thomas W GeisbertAbstract:Ebola virus (EBOV) causes severe and often fatal hemorrhagic fever in humans and nonhuman primates (NHPs). Currently, there are no licensed vaccines or therapeutics for human use. Recombinant vesicular stomatitis virus (rVSV)-based vaccine vectors, which encode an EBOV glycoprotein in place of the VSV glycoprotein, have shown 100 % efficacy against homologous Sudan Ebolavirus (SEBOV) or Zaire Ebolavirus (ZEBOV) challenge in NHPs. In addition, a single injection of a blend of three rVSV vectors completely protected NHPs against challenge with SEBOV, ZEBOV, the former Côte d’Ivoire Ebolavirus, and Marburg virus. However, recent studies suggest that complete protection against the newly discovered Bundibugyo Ebolavirus (BEBOV) using several different heterologous filovirus vaccines is more difficult and presents a new challenge. As BEBOV caused nearly 50 % mortality in a recent outbreak any filovirus vaccine advanced for human use must be able to protect against this new species. Here, we evaluated several different strategies against BEBOV using rVSV-based vaccines. Groups of cynomolgus macaques were vaccinated with a single injection of a homologous BEBOV vaccine, a single injection of a blended heterologous vaccine (SEBOV/ZEBOV), or a prime-boost using heterologous SEBOV and ZEBOV vectors. Animals were challenged with BEBOV 29–36 days after initial vaccination. Macaques vaccinated with the homologous BEBOV vaccine or the prime-boost showed no overt signs of illness and survived challenge. In contrast, animals vaccinated with the heterologous blended vaccine and unvaccinated control animals developed severe clinical symptom
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Discovery of an antibody for pan-Ebolavirus therapy
2016Co-Authors: Wakako Furuyama, Asuka Nanbo, Junki Maruyama, Hiroko Miyamoto, Osamu Noyori, Andrea Marzi, Manabu Igarashi, Reiko Yoshida, Elaine Haddock, Heinz FeldmannAbstract:During the latest outbreak of Ebola virus disease in West Africa, monoclonal antibody therapy (e.g., ZMapp) was utilized to treat patients. However, due to the antigenic differences among the five Ebolavirus species, the current therapeutic monoclonal antibodies are only effective against viruses of the species Zaire Ebolavirus. Although this particular species has indeed caused the majority of human infections in Central and, recently, West Africa, other Ebolavirus species (e.g., Sudan Ebolavirus and Bundibugyo Ebolavirus) have also repeatedly caused outbreaks in Central Africa and thus should not be neglected in the development of countermeasures against Ebolaviruses. Here we report the generation of an Ebolavirus glycoprotein-specific monoclonal antibody that effectively inhibits cellular entry of representative isolates of all known Ebolavirus species in vitro and show its protective efficacy in mouse models of Ebolavirus infections. This novel neutralizing monoclonal antibody targets a highly conserved internal fusion loop in the glycoprotein molecule and prevents membrane fusion of the viral envelope with cellular membranes. The discovery of this highly cross-neutralizing antibody provides a promising option for broad-acting Ebolavirus antibody therapy and will accelerate the design of improved vaccines that can selectively elicit cross-neutralizing antibodies against multiple species of Ebolaviruses.
Andrea Marzi - One of the best experts on this subject based on the ideXlab platform.
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With Improved Cross-Protective Efficacy
2016Co-Authors: Vesicular Stomatitis, Andrea Marzi, Allison Groseth, Thomas W Geisbert, Hideki Ebihara, Virus–based Ebola Vaccines, Julie Callison, Kinola J. Williams, Heinz FeldmannAbstract:newly discovered Bundibugyo Ebolavirus has been proposed as a 5th species. So far, no cross-neutralization among EBOV species has been described, aggravating progress toward cross-species protective vaccines. With the use of recombinant vesicular stomatitis virus (rVSV)–based vaccines, guinea pigs could be protected against Zaire Ebolavirus (ZEBOV) infection only when immunized with a vector expressing the homologous, but not a heterologous, EBOV glycoprotein (GP). However, infection of guinea pigs with nonadapted wild-type strains of the different species resulted in full protection of all animals against subsequent challenge with guinea pig–adapted ZEBOV, showing that cross-species protection is possible. New vectors were generated that contain EBOV viral protein 40 (VP40) or EBOV nucleoprotein (NP) as a second antigen expressed by the same rVSV vector that encodes the heterologous GP. After applying a 2-dose immunization approach, we observed an improved cross-protection rate, with 5 of 6 guinea pigs surviving the lethal ZEBOV challenge if vaccinated with rVSV-expressing SEBOV-GP and-VP40. Our data demonstrate that cross-protection between the EBOV species can be achieved, although EBOV-GP alone cannot induce the required immune response. In the preceding 3 decades, 4 different Ebola virus (EBOV) species have been identified: Zaire Ebolavirus (ZEBOV), Sudan Ebolavirus (SEBOV), Côte d’Ivoire ebo
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Stat1-Deficient Mice Are Not an Appropriate Model for Efficacy Testing of Recombinant
2016Co-Authors: Vesicular Stomatitis, Lisa Kercher, Joshua Marceau, Anthony York, Julie Callsion, Donald J. Gardner, Andrea Marzi, Thomas W Geisbert, Heinz FeldmannAbstract:Stat1−/ − mice lack a response to interferon α, β, and γ, allowing for replication of nonadapted wild-type (wt) Ebolavirus and Marburgvirus. We sought to establish a mouse model for efficacy testing of live attenuated re-combinant vesicular stomatitis virus (rVSV)–based filovirus vaccine vectors using wt Ebolavirus and Marburg-virus challenge strains. While infection of immunocompetent mice with different rVSV-based filovirus vectors did not cause disease, infection of Stat1−/ − mice with the same vectors resulted in systemic infection and lethal outcome for the majority of tested rVSVs. Despite differences in viral loads, organ tropism was remarkably similar between rVSV filovirus vaccine vectors and rVSVwt, with the exception of the brain. In conclusion, Stat1−/−mice are not an appropriate immunocompromised mouse model for efficacy testing of live attenuated, replication-competent rVSV vaccine vectors. Keywords. Vesicular stomatitis virus; Ebolavirus; Marburgvirus; vaccine; Stat1-deficient mice. Ebolavirus and Marburgvirus, members of the family Filoviridae, cause viral hemorrhagic fever in nonhuman primates and humans [1]. While outbreaks of filovirus hemorrhagic fever have occurred mainly in their en-demic area in Central Africa, currently, the biggest doc-umented Ebola virus (EBOV) outbreak is still ongoing in West African countries such as Guinea, Liberia and Sierra Leone. Not only has the virus spread from there into neighboring Mali, it was also introduced to Sene
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Vesicular Stomatitis Virus-Based Vaccines Protect Nonhuman Primates against Bundibugyo Ebolavirus
2016Co-Authors: Chad E. Mire, Krystle N. Agans, Andrea Marzi, Heinz Feldmann, Joan B Geisbert, Thomas W GeisbertAbstract:Ebola virus (EBOV) causes severe and often fatal hemorrhagic fever in humans and nonhuman primates (NHPs). Currently, there are no licensed vaccines or therapeutics for human use. Recombinant vesicular stomatitis virus (rVSV)-based vaccine vectors, which encode an EBOV glycoprotein in place of the VSV glycoprotein, have shown 100 % efficacy against homologous Sudan Ebolavirus (SEBOV) or Zaire Ebolavirus (ZEBOV) challenge in NHPs. In addition, a single injection of a blend of three rVSV vectors completely protected NHPs against challenge with SEBOV, ZEBOV, the former Côte d’Ivoire Ebolavirus, and Marburg virus. However, recent studies suggest that complete protection against the newly discovered Bundibugyo Ebolavirus (BEBOV) using several different heterologous filovirus vaccines is more difficult and presents a new challenge. As BEBOV caused nearly 50 % mortality in a recent outbreak any filovirus vaccine advanced for human use must be able to protect against this new species. Here, we evaluated several different strategies against BEBOV using rVSV-based vaccines. Groups of cynomolgus macaques were vaccinated with a single injection of a homologous BEBOV vaccine, a single injection of a blended heterologous vaccine (SEBOV/ZEBOV), or a prime-boost using heterologous SEBOV and ZEBOV vectors. Animals were challenged with BEBOV 29–36 days after initial vaccination. Macaques vaccinated with the homologous BEBOV vaccine or the prime-boost showed no overt signs of illness and survived challenge. In contrast, animals vaccinated with the heterologous blended vaccine and unvaccinated control animals developed severe clinical symptom
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Discovery of an antibody for pan-Ebolavirus therapy
2016Co-Authors: Wakako Furuyama, Asuka Nanbo, Junki Maruyama, Hiroko Miyamoto, Osamu Noyori, Andrea Marzi, Manabu Igarashi, Reiko Yoshida, Elaine Haddock, Heinz FeldmannAbstract:During the latest outbreak of Ebola virus disease in West Africa, monoclonal antibody therapy (e.g., ZMapp) was utilized to treat patients. However, due to the antigenic differences among the five Ebolavirus species, the current therapeutic monoclonal antibodies are only effective against viruses of the species Zaire Ebolavirus. Although this particular species has indeed caused the majority of human infections in Central and, recently, West Africa, other Ebolavirus species (e.g., Sudan Ebolavirus and Bundibugyo Ebolavirus) have also repeatedly caused outbreaks in Central Africa and thus should not be neglected in the development of countermeasures against Ebolaviruses. Here we report the generation of an Ebolavirus glycoprotein-specific monoclonal antibody that effectively inhibits cellular entry of representative isolates of all known Ebolavirus species in vitro and show its protective efficacy in mouse models of Ebolavirus infections. This novel neutralizing monoclonal antibody targets a highly conserved internal fusion loop in the glycoprotein molecule and prevents membrane fusion of the viral envelope with cellular membranes. The discovery of this highly cross-neutralizing antibody provides a promising option for broad-acting Ebolavirus antibody therapy and will accelerate the design of improved vaccines that can selectively elicit cross-neutralizing antibodies against multiple species of Ebolaviruses.
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Mapping of conserved and species-specific antibody epitopes on the Ebola virus nucleoprotein.
2013Co-Authors: Katendi Changula, Hiroko Miyamoto, Osamu Noyori, Andrea Marzi, Heinz Feldmann, Reiko Yoshida, Masahiro Kajihara, Mari Ishijima, Ayaka Yokoyama, Aaron S MweeneAbstract:Filoviruses (viruses in the genus Ebolavirus and Marburgvirus in the family Filoviridae) cause severe haemorrhagic fever in humans and nonhuman primates. Rapid, highly sensitive, and reliable filovirus-specific assays are required for diagnostics and outbreak control. Characterisation of antigenic sites in viral proteins can aid in the development of viral antigen detection assays such immunochromatography-based rapid diagnosis. We generated a panel of mouse monoclonal antibodies (mAbs) to the nucleoprotein (NP) of Ebola virus belonging to the species Zaire Ebolavirus. The mAbs were divided into seven groups based on the profiles of their specificity and cross-reactivity to other species in the Ebolavirus genus. Using synthetic peptides corresponding to the Ebola virus NP sequence, the mAb binding sites were mapped to seven antigenic regions in the C-terminal half of the NP, including two highly conserved regions among all five Ebolavirus species currently known. Furthermore, we successfully produced species-specific rabbit antisera to synthetic peptides predicted to represent unique filovirus B-cell epitopes. Our data provide useful information for the development of Ebola virus antigen detection assays.
Kinola J N Williams - One of the best experts on this subject based on the ideXlab platform.
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vesicular stomatitis virus based ebola vaccines with improved cross protective efficacy
2011Co-Authors: Kinola J N Williams, Andrea Marzi, Allison Groseth, Hideki Ebihara, Julie CallisonAbstract:For Ebola virus (EBOV), 4 different species are known: Zaire, Sudan, Cote d'Ivoire, and Reston Ebolavirus. The newly discovered Bundibugyo Ebolavirus has been proposed as a 5th species. So far, no cross-neutralization among EBOV species has been described, aggravating progress toward cross-species protective vaccines. With the use of recombinant vesicular stomatitis virus (rVSV)-based vaccines, guinea pigs could be protected against Zaire Ebolavirus (ZEBOV) infection only when immunized with a vector expressing the homologous, but not a heterologous, EBOV glycoprotein (GP). However, infection of guinea pigs with nonadapted wild-type strains of the different species resulted in full protection of all animals against subsequent challenge with guinea pig-adapted ZEBOV, showing that cross-species protection is possible. New vectors were generated that contain EBOV viral protein 40 (VP40) or EBOV nucleoprotein (NP) as a second antigen expressed by the same rVSV vector that encodes the heterologous GP. After applying a 2-dose immunization approach, we observed an improved cross-protection rate, with 5 of 6 guinea pigs surviving the lethal ZEBOV challenge if vaccinated with rVSV-expressing SEBOV-GP and -VP40. Our data demonstrate that cross-protection between the EBOV species can be achieved, although EBOV-GP alone cannot induce the required immune response.
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Recombinant vesicular stomatitis virus vector mediates postexposure protection against Sudan Ebola hemorrhagic fever in nonhuman primates.
2008Co-Authors: Thomas W Geisbert, Kinola J N Williams, Kathleen M Daddario DiCaprio, Lisa E. Hensley, Friederike Feldmann, Heinz Feldmann, Joan B Geisbert, Anders Leung, Steven M. JonesAbstract:Recombinant vesicular stomatitis virus (VSV) vectors expressing homologous filoviral glycoproteins can completely protect rhesus monkeys against Marburg virus when administered after exposure and can partially protect macaques after challenge with Zaire Ebolavirus. Here, we administered a VSV vector expressing the Sudan Ebolavirus (SEBOV) glycoprotein to four rhesus macaques shortly after exposure to SEBOV. All four animals survived SEBOV challenge, while a control animal that received a nonspecific vector developed fulminant SEBOV hemorrhagic fever and succumbed. This is the first demonstration of complete postexposure protection against an Ebola virus in nonhuman primates and provides further evidence that postexposure vaccination may have utility in treating exposures to filoviruses.
Allison Groseth - One of the best experts on this subject based on the ideXlab platform.
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With Improved Cross-Protective Efficacy
2016Co-Authors: Vesicular Stomatitis, Andrea Marzi, Allison Groseth, Thomas W Geisbert, Hideki Ebihara, Virus–based Ebola Vaccines, Julie Callison, Kinola J. Williams, Heinz FeldmannAbstract:newly discovered Bundibugyo Ebolavirus has been proposed as a 5th species. So far, no cross-neutralization among EBOV species has been described, aggravating progress toward cross-species protective vaccines. With the use of recombinant vesicular stomatitis virus (rVSV)–based vaccines, guinea pigs could be protected against Zaire Ebolavirus (ZEBOV) infection only when immunized with a vector expressing the homologous, but not a heterologous, EBOV glycoprotein (GP). However, infection of guinea pigs with nonadapted wild-type strains of the different species resulted in full protection of all animals against subsequent challenge with guinea pig–adapted ZEBOV, showing that cross-species protection is possible. New vectors were generated that contain EBOV viral protein 40 (VP40) or EBOV nucleoprotein (NP) as a second antigen expressed by the same rVSV vector that encodes the heterologous GP. After applying a 2-dose immunization approach, we observed an improved cross-protection rate, with 5 of 6 guinea pigs surviving the lethal ZEBOV challenge if vaccinated with rVSV-expressing SEBOV-GP and-VP40. Our data demonstrate that cross-protection between the EBOV species can be achieved, although EBOV-GP alone cannot induce the required immune response. In the preceding 3 decades, 4 different Ebola virus (EBOV) species have been identified: Zaire Ebolavirus (ZEBOV), Sudan Ebolavirus (SEBOV), Côte d’Ivoire ebo
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Profile and persistence of the virus-specific neutralizing humoral immune response in human survivors of sudan Ebolavirus (Gulu)
2013Co-Authors: Ariel Sobarzo, Eddie Perelman, Victoria Yavelsky, Majidat A Muhammad, Olga Dolnik, Ana I Kuehne, Julius J Lutwama, Allison Groseth, Robert S. Marks, Stephan Becker, Jolo M Dye, Leslie LobelAbstract:To better understand humoral immunity following Ebolavirus infection, a serological study of the humoral immune response against the individual viral proteins of Sudan Ebolavirus (Gulu) in human survivors was performed. An enzyme-linked immunosorbent assay specific for full-length recombinant viral proteins NP, VP30, VP40, and GP1-649 (GP lacking the transmembrane domain) of Sudan Ebolavirus (Gulu) was used as well as a plaque reduction neutralization test. Serum samples from human survivors, which were collected up to 10 years following recovery, were screened and analyzed. Results demonstrate that samples obtained 10 years following infection contain virus-specific antibodies that can neutralize virus. Neutralization correlates well with immunoreactivity against the viral proteins NP, VP30, and GP1-649. Sera from individuals who died or those with no documented infection but immunoreactive to Ebolavirus did not neutralize. This work provides insight into the duration, profile of immunoreactivity, and neutralization capacity of the humoral immune response in Ebolavirus survivors.
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Inclusion Bodies Are a Site of Ebolavirus Replication
2012Co-Authors: Thomas Hoenen, Olga Dolnik, Allison Groseth, Stephan Becker, Christopher F. Basler, Reed S. Shabman, Astrid Herwig, Michaela Weber, Gordian Schudt, Heinz FeldmannAbstract:Inclusion bodies are a characteristic feature of Ebolavirus infections in cells. They contain large numbers of preformed nucleocapsids, but their biological significance has been debated, and they have been suggested to be aggregates of viral proteins without any further biological function. However, recent data for other viruses that produce similar structures have suggested that inclusion bodies might be involved in genome replication and transcription. In order to study filovirus inclusion bodies, we fused mCherry to the Ebolavirus polymerase L, which is found in inclusion bodies. The resulting L-mCherry fusion protein was functional in minigenome assays and incorporated into virus-like particles. Importantly, L-mCherry fluorescence in transfected cells was readily detectable and distributed in a punctate pattern characteristic for inclusion bodies. A recombinant Ebolavirus encoding L-mCherry instead of L was rescued and showed virtually identical growth kinetics and endpoint titers to those for wild-type virus. Using this virus, we showed that the onset of inclusion body formation corresponds to the onset of viral genome replication, but that viral transcription occurs prior to inclusion body formation. Live-cell imaging further showed that inclusion bodies are highly dynamic structures and that they can undergo dramatic reorganization during cell division. Finally, by labeling nascent RNAs using click technology we showed that inclusion bodies are indeed the site of viral RNA synthesis. Based on these data we conclude that, rather than being inert aggregates of nucleocapsids, Ebolavirus inclusion bodies are in fact complex and dynamic structures and an important site at which viral RNA replication takes place.
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vesicular stomatitis virus based ebola vaccines with improved cross protective efficacy
2011Co-Authors: Kinola J N Williams, Andrea Marzi, Allison Groseth, Hideki Ebihara, Julie CallisonAbstract:For Ebola virus (EBOV), 4 different species are known: Zaire, Sudan, Cote d'Ivoire, and Reston Ebolavirus. The newly discovered Bundibugyo Ebolavirus has been proposed as a 5th species. So far, no cross-neutralization among EBOV species has been described, aggravating progress toward cross-species protective vaccines. With the use of recombinant vesicular stomatitis virus (rVSV)-based vaccines, guinea pigs could be protected against Zaire Ebolavirus (ZEBOV) infection only when immunized with a vector expressing the homologous, but not a heterologous, EBOV glycoprotein (GP). However, infection of guinea pigs with nonadapted wild-type strains of the different species resulted in full protection of all animals against subsequent challenge with guinea pig-adapted ZEBOV, showing that cross-species protection is possible. New vectors were generated that contain EBOV viral protein 40 (VP40) or EBOV nucleoprotein (NP) as a second antigen expressed by the same rVSV vector that encodes the heterologous GP. After applying a 2-dose immunization approach, we observed an improved cross-protection rate, with 5 of 6 guinea pigs surviving the lethal ZEBOV challenge if vaccinated with rVSV-expressing SEBOV-GP and -VP40. Our data demonstrate that cross-protection between the EBOV species can be achieved, although EBOV-GP alone cannot induce the required immune response.
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rna polymerase i driven minigenome system for ebola viruses
2005Co-Authors: Allison Groseth, Heinz Feldmann, Steven Theriault, Gulsah Mehmetoglu, Ramon FlickAbstract:In general, Ebola viruses are well known for their ability to cause severe hemorrhagic fever in both human and nonhuman primates. However, despite substantial sequence homology to other members of the family Filoviridae, Reston Ebolavirus displays reduced pathogenicity for nonhuman primates and has never been demonstrated to cause clinical disease in humans, despite its ability to cause infection. In order to develop a tool to explore potential roles for transcription and replication in the reduced pathogenicity of Reston Ebolavirus, we developed an RNA polymerase I (Pol I)-driven minigenome system. Here we demonstrate successful Reston Ebolavirus minigenome rescue, including encapsidation, transcription, and replication, as well as the packaging of minigenome transcripts into progeny particles. The Pol I-driven Reston Ebolavirus minigenome system provides a higher signal intensity with less background (higher signal-to-noise ratio) than a comparable T7-driven Reston Ebolavirus minigenome system which was developed simultaneously. Successful Reston Ebolavirus minigenome rescue was also achieved by the use of helper plasmids derived from the closely related Zaire Ebolavirus or the more distantly related Lake Victoria marburgvirus. The use of heterologous helper plasmids in the Reston Ebolavirus minigenome system yielded levels of reporter expression which far exceeded the level produced by the homologous helper plasmids. This comparison between minigenomes and helper plasmids from different filovirus species and genera indicates that inherent differences in the transcription and/or replication capacities of the ribonucleoprotein complexes of pathogenic and apathogenic filoviruses may exist, as these observations were confirmed in a Lake Victoria marburgvirus minigenome system.
Hideki Ebihara - One of the best experts on this subject based on the ideXlab platform.
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With Improved Cross-Protective Efficacy
2016Co-Authors: Vesicular Stomatitis, Andrea Marzi, Allison Groseth, Thomas W Geisbert, Hideki Ebihara, Virus–based Ebola Vaccines, Julie Callison, Kinola J. Williams, Heinz FeldmannAbstract:newly discovered Bundibugyo Ebolavirus has been proposed as a 5th species. So far, no cross-neutralization among EBOV species has been described, aggravating progress toward cross-species protective vaccines. With the use of recombinant vesicular stomatitis virus (rVSV)–based vaccines, guinea pigs could be protected against Zaire Ebolavirus (ZEBOV) infection only when immunized with a vector expressing the homologous, but not a heterologous, EBOV glycoprotein (GP). However, infection of guinea pigs with nonadapted wild-type strains of the different species resulted in full protection of all animals against subsequent challenge with guinea pig–adapted ZEBOV, showing that cross-species protection is possible. New vectors were generated that contain EBOV viral protein 40 (VP40) or EBOV nucleoprotein (NP) as a second antigen expressed by the same rVSV vector that encodes the heterologous GP. After applying a 2-dose immunization approach, we observed an improved cross-protection rate, with 5 of 6 guinea pigs surviving the lethal ZEBOV challenge if vaccinated with rVSV-expressing SEBOV-GP and-VP40. Our data demonstrate that cross-protection between the EBOV species can be achieved, although EBOV-GP alone cannot induce the required immune response. In the preceding 3 decades, 4 different Ebola virus (EBOV) species have been identified: Zaire Ebolavirus (ZEBOV), Sudan Ebolavirus (SEBOV), Côte d’Ivoire ebo
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vesicular stomatitis virus based ebola vaccines with improved cross protective efficacy
2011Co-Authors: Kinola J N Williams, Andrea Marzi, Allison Groseth, Hideki Ebihara, Julie CallisonAbstract:For Ebola virus (EBOV), 4 different species are known: Zaire, Sudan, Cote d'Ivoire, and Reston Ebolavirus. The newly discovered Bundibugyo Ebolavirus has been proposed as a 5th species. So far, no cross-neutralization among EBOV species has been described, aggravating progress toward cross-species protective vaccines. With the use of recombinant vesicular stomatitis virus (rVSV)-based vaccines, guinea pigs could be protected against Zaire Ebolavirus (ZEBOV) infection only when immunized with a vector expressing the homologous, but not a heterologous, EBOV glycoprotein (GP). However, infection of guinea pigs with nonadapted wild-type strains of the different species resulted in full protection of all animals against subsequent challenge with guinea pig-adapted ZEBOV, showing that cross-species protection is possible. New vectors were generated that contain EBOV viral protein 40 (VP40) or EBOV nucleoprotein (NP) as a second antigen expressed by the same rVSV vector that encodes the heterologous GP. After applying a 2-dose immunization approach, we observed an improved cross-protection rate, with 5 of 6 guinea pigs surviving the lethal ZEBOV challenge if vaccinated with rVSV-expressing SEBOV-GP and -VP40. Our data demonstrate that cross-protection between the EBOV species can be achieved, although EBOV-GP alone cannot induce the required immune response.
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replication deficient Ebolavirus as a vaccine candidate
2009Co-Authors: Peter Halfmann, Andrea Marzi, Heinz Feldmann, Shinji Watanabe, Gabriele Neumann, Hideki Ebihara, Yasuko Hatta, M SureshAbstract:Ebolavirus causes severe hemorrhagic fever, with case fatality rates as high as 90%. Currently, no licensed vaccine is available against Ebolavirus. We previously generated a replication-deficient, biologically contained Ebolavirus, EbolaDeltaVP30, which lacks the essential VP30 gene, grows only in cells stably expressing this gene product, and is genetically stable. Here, we evaluated the vaccine potential of EbolaDeltaVP30. First, we demonstrated its safety in STAT-1-knockout mice, a susceptible animal model for Ebolavirus infection. We then tested its protective efficacy in two animal models, mice and guinea pigs. Mice immunized twice with EbolaDeltaVP30 were protected from a lethal infection of mouse-adapted Ebolavirus. Virus titers in the serum of vaccinated mice were significantly lower than those in nonvaccinated mice. Protection of mice immunized with EbolaDeltaVP30 was associated with a high antibody response to the Ebolavirus glycoprotein and the generation of an Ebolavirus NP-specific CD8(+) T-cell response. Guinea pigs immunized twice with EbolaDeltaVP30 were also protected from a lethal infection of guinea pig-adapted Ebolavirus. Our study demonstrates the potential of the EbolaDeltaVP30 virus as a new vaccine platform.
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Assembly and Budding of Ebolavirus
2006Co-Authors: Takeshi Noda, Ayato Takada, Heinz Feldmann, Hideki Ebihara, Yukiko Muramoto, Ken Fujii, Hiroshi Sagara, Jin Hyun Kim, Hiroshi Kida, Yoshihiro KawaokaAbstract:Ebolavirus is responsible for highly lethal hemorrhagic fever. Like all viruses, it must reproduce its various components and assemble them in cells in order to reproduce infectious virions and perpetuate itself. To generate infectious Ebolavirus, a viral genome-protein complex called the nucleocapsid (NC) must be produced and transported to the cell surface, incorporated into virions, and then released from cells. To further our understanding of the Ebolavirus life cycle, we expressed the various viral proteins in mammalian cells and examined them ultrastructurally and biochemically. Expression of nucleoprotein alone led to the formation of helical tubes, which likely serve as a core for the NC. The matrix protein VP40 was found to be critical for transport of NCs to the cell surface and for the incorporation of NCs into virions, where interaction between nucleoprotein and the matrix protein VP40 is likely essential for these processes. Examination of virus-infected cells revealed that virions containing NCs mainly emerge horizontally from the cell surface, whereas empty virions mainly bud vertically, suggesting that horizontal budding is the major mode of Ebolavirus budding. These data form a foundation for the identification and development of potential antiviral agents to combat the devastating disease caused by this virus.