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1

Ebola virus.  

PubMed

Ebola virus was first identified as a filovirus in 1976, following epidemics of severe haemorrhagic fever in sub-Saharan Africa. Further outbreaks have occurred since, but, despite extensive and continued investigations, the natural reservoir for the virus remains unknown. The mortality rate is high and there is no cure for Ebola virus infection. Molecular technology is proving useful in extending our knowledge of the virus. Identification of the host reservoir, control and prevention of further outbreaks, rapid diagnosis of infection, and vaccine development remain areas of continued interest in the fight against this biosafety level-four pathogen. PMID:10795373

Streether, L A

1999-01-01

2

Ebola Virus Disease  

MedlinePLUS

Ebola virus disease Fact sheet N°103 Updated September 2014 Key facts Ebola virus disease (EVD), formerly ... 7 weeks after recovery from illness. Symptoms of Ebola virus disease The incubation period, that is, the ...

3

Ebola virus-like particles prevent lethal Ebola virus infection  

E-print Network

... successfully immunized mice against Ebola virus using virus-like particles ... exposed to lethal doses of Ebola . The work could serve as ... basis for developing countermeasures to Ebola , which causes hemorrhagic fever with ...

4

Ebola virus disease epidemic.  

PubMed

The Ebola virus disease epidemic now constitutes an international public health emergency. Occupational and environmental health nurses can collaborate with international colleagues to halt Ebola virus transmission within Africa, protect workers from exposures, and prevent another pandemic. [Workplace Health Saf 2014;62(11):484.]. PMID:25373029

Phillips, Jennan A

2014-11-01

5

Ebola virus (image)  

MedlinePLUS

Ebola is a virus-caused disease limited to parts of Africa. Within a week, a raised rash, often hemorrhagic (bleeding), spreads over the body. Bleeding from the mucous membranes is typical causing apparent bleeding from the mouth, ...

6

Écosystèmes forestiers et virus Ebola  

Microsoft Academic Search

Summary: Ebola virus and forest ecosystem. Despite data collected since the emergence of the Ebola virus in 1976, its natural transmission cycle and especially the nature of its reservoirs and means of transmission are still an enigma. This means that effective epidemiological surveillance and prevention are difficult to implement. The location of outbreak areas has suggested that the reservoir and

J. M. Morvan; E. Nakouné; V. Deubel; M. Colyn

7

Ebola Virus Antibodies in Fruit Bats, Bangladesh  

PubMed Central

To determine geographic range for Ebola virus, we tested 276 bats in Bangladesh. Five (3.5%) bats were positive for antibodies against Ebola Zaire and Reston viruses; no virus was detected by PCR. These bats might be a reservoir for Ebola or Ebola-like viruses, and extend the range of filoviruses to mainland Asia. PMID:23343532

Islam, Ariful; Yu, Meng; Anthony, Simon J.; Epstein, Jonathan H.; Khan, Shahneaz Ali; Khan, Salah Uddin; Crameri, Gary; Wang, Lin-Fa; Lipkin, W. Ian; Luby, Stephen P.; Daszak, Peter

2013-01-01

8

The ecology of Ebola virus.  

PubMed

Since Ebola virus was first identified more than 30 years ago, tremendous progress has been made in understanding the molecular biology and pathogenesis of this virus. However, the means by which Ebola virus is maintained and transmitted in nature remains unclear despite dedicated efforts to answer these questions. Recent work has provided new evidence that fruit bats might have a role as a reservoir species, but it is not clear whether other species are also involved or how transmission to humans or apes takes place. Two opposing hypotheses for Ebola emergence have surfaced; one of long-term local persistence in a cryptic and infrequently contacted reservoir, versus another of a more recent introduction of the virus and directional spread through susceptible populations. Nevertheless, with the increasing frequency of human filovirus outbreaks and the tremendous impact of infection on the already threatened great ape populations, there is an urgent need to better understand the ecology of Ebola virus in nature. PMID:17698361

Groseth, Allison; Feldmann, Heinz; Strong, James E

2007-09-01

9

Frequently Asked Questions on Ebola Virus Disease  

MedlinePLUS

Frequently asked questions on Ebola virus disease Updated 8 August 2014 1. What is Ebola virus disease? Download the FAQ on Ebola in pdf format ... in detail. Should patients with suspected or confirmed Ebola virus be separated from other patients? Isolating patients ...

10

Packaging of actin into Ebola virus VLPs  

Microsoft Academic Search

The actin cytoskeleton has been implicated in playing an important role assembly and budding of several RNA virus families including retroviruses and paramyxoviruses. In this report, we sought to determine whether actin is incorporated into Ebola VLPs, and thus may play a role in assembly and\\/or budding of Ebola virus. Our results indicated that actin and Ebola virus VP40 strongly

Ziying Han; Ronald N Harty

2005-01-01

11

Fruit bats as reservoirs of Ebola virus  

Microsoft Academic Search

The first recorded human outbreak of Ebola virus was in 1976, but the wild reservoir of this virus is still unknown. Here we test for Ebola in more than a thousand small vertebrates that were collected during Ebola outbreaks in humans and great apes between 2001 and 2003 in Gabon and the Republic of the Congo. We find evidence of

Eric M. Leroy; Brice Kumulungui; Xavier Pourrut; Pierre Rouquet; Alexandre Hassanin; Philippe Yaba; André Délicat; Janusz T. Paweska; Jean-Paul Gonzalez; Robert Swanepoel

2005-01-01

12

Gene Research Yields Insights into Ebola Virus  

MedlinePLUS

... please enable JavaScript. Gene Research Yields Insights Into Ebola Virus Strain tied to West Africa outbreak has ... 2014) Thursday, August 28, 2014 Related MedlinePlus Pages Ebola Genes and Gene Therapy THURSDAY, Aug. 28, 2014 ( ...

13

Ebola virus infection: an overview.  

PubMed

The current outbreak of the Ebola virus infection in Africa has yet again proven that highly dangerous diseases that are transmitted via the blood-borne route may be endemic in some parts of the world and may emerge as sporadic outbreaks causing worldwide concern. Health care professionals are at the forefront of combatting these diseases and treating infected individuals. Though dental professionals are unlikely to be directly involved in the management of such acute infections, with very high mortality rates, they may encounter patients seeking dental treatment who are either from, or who have recently toured the endemic disease areas. This overview, therefore, is a thumb nail sketch of the Ebola virus infection and its implications for dentistry. PMID:8935292

Samaranayake, L P; Peiris, J S; Scully, C

1996-04-01

14

Characteristics of Filoviridae: Marburg and Ebola Viruses  

NASA Astrophysics Data System (ADS)

Filoviruses are enveloped, nonsegmented negative-stranded RNA viruses. The two species, Marburg and Ebola virus, are serologically, biochemically, and genetically distinct. Marburg virus was first isolated during an outbreak in Europe in 1967, and Ebola virus emerged in 1976 as the causative agent of two simultaneous outbreaks in southern Sudan and northern Zaire. Although the main route of infection is known to be person-to-person transmission by intimate contact, the natural reservoir for filoviruses still remains a mystery.

Beer, Brigitte; Kurth, Reinhard; Bukreyev, Alexander

15

Characteristics of Filoviridae: Marburg and Ebola viruses.  

PubMed

Filoviruses are enveloped, nonsegmented negative-stranded RNA viruses. The two species, Marburg and Ebola virus, are serologically, biochemically, and genetically distinct. Marburg virus was first isolated during an outbreak in Europe in 1967, and Ebola virus emerged in 1976 as the causative agent of two simultaneous outbreaks in southern Sudan and northern Zaire. Although the main route of infection is known to be person-to-person transmission by intimate contact, the natural reservoir for filoviruses still remains a mystery. PMID:10024977

Beer, B; Kurth, R; Bukreyev, A

1999-01-01

16

Care of patients with ebola virus disease.  

PubMed

Caring for patients with Ebola virus disease requires strict biosafety protocols to eliminate exposure and ensure containment. Training and competency verification were critical to creation of a safe environment for nursing staff involved in the direct care of two patients with Ebola virus disease at Emory University Hospital. J Contin Educ Nurs. 2014;45(11):479-481. PMID:25365183

Smith, Elaine L; Rice, Karen L; Feistritzer, Nancye R; Hill, Carolyn; Vanairsdale, Sharon; Gentry, Janice

2014-11-01

17

Virion nucleic acid of Ebola virus.  

PubMed Central

The virion nucleic acid of Ebola virus consists of a single-stranded RNA with a molecular weight of approximately 4.0 x 10(6). The virion RNA did not bind to oligodeoxythymidylic acid-cellulose under conditions known to bind RNAs rich in polyadenylic acid and was not infectious under conditions which yielded infectious RNA from Sindbis virus, suggesting that Ebola virus virion nucleic acid is a negative-stranded RNA. PMID:7431486

Regnery, R L; Johnson, K M; Kiley, M P

1980-01-01

18

[Forest ecosystems and Ebola virus].  

PubMed

Despite data collected since the emergence of the Ebola virus in 1976, its natural transmission cycle and especially the nature of its reservoirs and means of transmission are still an enigma. This means that effective epidemiological surveillance and prevention are difficult to implement. The location of outbreak areas has suggested that the reservoir and the transmission cycle of the Ebola virus are closely linked to the rainforest ecosystem. The fact that outbreaks seldom occur suggests the presence of a rare animal reservoir having few contacts with man. Paradoxically, various serological investigations have shown a high prevalence in human beings, especially in forest areas of the Central African Republic (CAR), with no pathology associated. This would appear to suggest a circulation of both pathogenic and non-pathogenic strains as well as frequent contacts with man. The ecological changes resulting from human activity (agriculture and logging) account for the modification of the fauna (movement of rainforest fauna, introduction of savannah species) and could explain a multiplication of contacts. Likewise, it is interesting to note that the centre of outbreaks has always been in areas bordering on forests (ecotone foreset-savannah in the Democratic Republic of Congo, savannah in Sudan). All these considerations have led us to establish a permanent "watch" in areas bordering on forests in the CAR, involving a multidisciplinary approach to the virological study (strain isolation, molecular biology) of the biodiversity of small terrestrial mammals. The results of a study conducted on 947 small mammals has shown for the first time the presence of the Ebola virus genome in two species of rodents and one species of shrew living in forest border areas. These animals must be considered as intermediary hosts and research should now focus on reservoirs in the ecosystem of forest border areas where contacts with man are likely to be more frequent. PMID:11030051

Morvan, J M; Nakouné, E; Deubel, V; Colyn, M

2000-07-01

19

[Ebola virus disease].  

PubMed

The current Ebola outbreak in Western Africa differs from previous ones due to its extent. Serious shortcomings in the on-site management in Africa are obvious. In addition to the situation in the countries affected media and medical interests also focus on detection and management of imported cases in Germany. From the experience with such patients already treated in Germany the existing medical concepts have been updated and expanded. This overview addresses not only the latest clinical knowledge and epidemiological developments but also outlines the key measures as well as the practical procedure when there is a suspected case. PMID:25423458

Grünewald, Th

2014-12-01

20

Ebola Virus Antibody Prevalence in Dogs  

E-print Network

observed that several dogs were highly exposed to Ebola virus by eating infected dead animals. To examine whether these animals became infected with Ebola virus, we sampled 439 dogs and screened them by Ebola virus–specific immunoglobulin (Ig) G assay, antigen detection, and viral polymerase chain reaction amplification. Seven (8.9%) of 79 samples from the 2 main towns, 15 (15.2%) of 99 samples from Mekambo, and 40 (25.2%) of 159 samples from villages in the Ebola virus–epidemic area had detectable Ebola virus–IgG, compared to only 2 (2%) of 102 samples from France. Among dogs from villages with both infected animal carcasses and human cases, seroprevalence was 31.8%. A significant positive direct association existed between seroprevalence and the distances to the Ebola virus–epidemic area. This study suggests that dogs can be infected by Ebola virus and that the putative infection is asymptomatic. *Centre International de Recherches Médicales de Franceville,

Human Risk; Loïs Allela; Olivier Bourry; Régis Pouillot; André Délicat; Brice Kumulungui; Pierre Rouquet; Jean-paul Gonzalez; Eric M. Leroy

21

Ebola Virus Disease The current outbreak of Ebola Virus Disease (EVD) in West Africa has involved the  

E-print Network

Ebola Virus Disease The current outbreak of Ebola Virus Disease (EVD) in West Africa has involved the countries of Sierra Leone, Liberia, Guinea, and Nigeria. This has become the largest outbreak of Ebola want to make sure you have the most accurate information about this illness. What is Ebola Virus

MacAdam, Keith

22

[Ebola virus reproduction in cell cultures].  

PubMed

Ebola-Zaire virus production in Vero and BGM cells was studied. The CPE developed in both cell cultures. The cell monolayer destruction by 80-90% was seen at a low multiplicity of infection in 7-8 days after virus inoculation. An overlay composition was developed for virus titration using plaque assay. The plaque production was shown to be directly proportional to the virus dose. The curve of Ebola virus production in Vero cell culture fluid was determined. At a multiplicity of infection of 0.01 PFU/cell, the maximum virus titer of 10(6.4) PFU/ml was reached in 7 days postinfection. Specific antisera were generated by inoculation of guinea pigs. Indirect immunofluorescent assay was used for testing of virus-specific antigen and antibody. PMID:1279896

Titenko, A M; Novozhilov, S S; Andaev, E I; Borisova, T I; Kulikova, E V

1992-01-01

23

Comprehensive Analysis of Ebola Virus GP1 in Viral Entry  

Microsoft Academic Search

Ebola virus infection is initiated by interactions between the viral glycoprotein GP1 and its cognate recep- tor(s), but little is known about the structure and function of GP1 in viral entry, partly due to the concern about safety when working with the live Ebola virus and the difficulty of manipulating the RNA genome of Ebola virus. In this study, we

Balaji Manicassamy; Jizhen Wang; Haiqing Jiang; Lijun Rong

2005-01-01

24

Ebola virus (EboV) infection causes fatal  

E-print Network

Ebola virus (EboV) infection causes fatal haemorrhagic fever with mortality rates exceeding 75 Carette, J. E. et al. Ebola virus entry requires the cholesterol transporter Niemann­Pick C1. Nature 24 is essential for Ebola virus infection. Nature 24 Aug 2011 (doi:10.1038/nature10380) ANTIVIRALS Achilles heel

Chandran, Kartik

25

Therapy and prophylaxis of Ebola virus infections.  

PubMed

The first cases of Ebola hemorrhagic fever were reported from Sudan and Zaire (now Democratic Republic of the Congo) in 1976, but the virus has only received significant attention since 1995. Until recently, the development of therapeutics or vaccines was not considered a priority. The knowledge gained during the past decade on the biology and pathogenesis of Ebola virus has led to the development of therapeutic strategies that are currently being investigated. Considering the aggressive nature of Ebola infections, in particular the rapid and overwhelming viral burdens, early diagnosis will play a significant role in determining the success of any intervention strategy. Advanced understanding of the immune response has produced several vaccine candidates of which a few can be considered for further evaluation. This review will summarize and discuss the current therapeutic and prophylactic strategies for Ebola hemorrhagic fever. PMID:16121689

Feldmann, Heinz; Jones, Steven M; Schnittler, Hans-Joachim; Geisbert, Thomas

2005-08-01

26

[The properties of Ebola virus proteins].  

PubMed

The paper describes the structure and functions of Ebola virus properties. It also presents information on the role of structural (NP, VP40, VP35, GP, VP30, VP24, and L) and secreted (sGP, delta-peptide, GP1, GP(1,2delta), ssGP) proteins in the viral replication cycle and in the pathogenesis of Ebola hemorrhagic fever. PMID:17214074

Subbotina, E L; Kachko, A V; Chepurnov, A A

2006-01-01

27

A System for Functional Analysis of Ebola Virus Glycoprotein  

Microsoft Academic Search

Ebola virus causes hemorrhagic fever in humans and nonhuman primates, resulting in mortality rates of up to 90%. Studies of this virus have been hampered by its extraordinary pathogenicity, which requires biosafety level 4 containment. To circumvent this problem, we developed a novel complementation system for functional analysis of Ebola virus glycoproteins. It relies on a recombinant vesicular stomatitis virus

Ayato Takada; Clinton Robison; Hideo Goto; Anthony Sanchez; K. Gopal Murti; Michael A. Whitt; Yoshihiro Kawaoka

1997-01-01

28

Ebola Virus: Immune Mechanisms of Protection and Vaccine Development  

Microsoft Academic Search

Vaccination is one of our most powerful antiviral strategies. Despite the emergence of deadly viruses such as Ebola virus, vaccination efforts have focused mainly on childhood communicable diseases. Although Ebola virus was once believed to be limited to isolated outbreaks in distant lands, forces of globalization potentiate outbreaks anywhere in the world through incidental transmission. Moreover, since this virus has

Adeline M. Nyamathi; John L. Fahey; Heather Sands; Adrian M. Casillas

2003-01-01

29

Ebola Virus Defective Interfering Particles and Persistent Infection  

Microsoft Academic Search

Ebola virus (Zaire subtype) is associated with high mortality disease outbreaks that commonly involve human to human transmission. Surviving patients can show evidence of prolonged virus persistence. The potential for Ebola virus to generate defective interfering (DI) particles and establish persistent infections in tissue culture was investigated. It was found that serial undiluted virus passages quickly resulted in production of

Philippe Calain; Martha C. Monroe; Stuart T. Nichol

1999-01-01

30

Packaging of actin into Ebola virus VLPs.  

PubMed

The actin cytoskeleton has been implicated in playing an important role assembly and budding of several RNA virus families including retroviruses and paramyxoviruses. In this report, we sought to determine whether actin is incorporated into Ebola VLPs, and thus may play a role in assembly and/or budding of Ebola virus. Our results indicated that actin and Ebola virus VP40 strongly co-localized in transfected cells as determined by confocal microscopy. In addition, actin was packaged into budding VP40 VLPs as determined by a functional budding assay and protease protection assay. Co-expression of a membrane-anchored form of Ebola virus GP enhanced the release of both VP40 and actin in VLPs. Lastly, disruption of the actin cytoskeleton with latrunculin-A suggests that actin may play a functional role in budding of VP40/GP VLPs. These data suggest that VP40 may interact with cellular actin, and that actin may play a role in assembly and/or budding of Ebola VLPs. PMID:16367999

Han, Ziying; Harty, Ronald N

2005-01-01

31

Ebola virus-like particles protect from lethal Ebola virus infection.  

PubMed

The filovirus Ebola causes hemorrhagic fever with 70-80% human mortality. High case-fatality rates, as well as known aerosol infectivity, make Ebola virus a potential global health threat and possible biological warfare agent. Development of an effective vaccine for use in natural outbreaks, response to biological attack, and protection of laboratory workers is a higher national priority than ever before. Coexpression of the Ebola virus glycoprotein (GP) and matrix protein (VP40) in mammalian cells results in spontaneous production and release of virus-like particles (VLPs) that resemble the distinctively filamentous infectious virions. VLPs have been tested and found efficacious as vaccines for several viruses, including papillomavirus, HIV, parvovirus, and rotavirus. Herein, we report that Ebola VLPs (eVLPs) were immunogenic in vitro as eVLPs matured and activated mouse bone marrow-derived dendritic cells, assessed by increases in cell-surface markers CD40, CD80, CD86, and MHC class I and II and secretion of IL-6, IL-10, macrophage inflammatory protein (MIP)-1alpha, and tumor necrosis factor alpha by the dendritic cells. Further, vaccinating mice with eVLPs activated CD4+ and CD8+ T cells, as well as CD19+ B cells. After vaccination with eVLPs, mice developed high titers of Ebola virus-specific antibodies, including neutralizing antibodies. Importantly, mice vaccinated with eVLPs were 100% protected from an otherwise lethal Ebola virus inoculation. Together, our data suggest that eVLPs represent a promising vaccine candidate for protection against Ebola virus infections and a much needed tool to examine the genesis and nature of immune responses to Ebola virus. PMID:14673108

Warfield, Kelly L; Bosio, Catharine M; Welcher, Brent C; Deal, Emily M; Mohamadzadeh, Mansour; Schmaljohn, Alan; Aman, M Javad; Bavari, Sina

2003-12-23

32

Ebola Virus: Identification of Virion Structural Proteins  

Microsoft Academic Search

SUMMARY Polyacrylamide gel electrophoresis of purified Ebola virus revealed the presence of four major virion structural proteins which we have designated VPI, VP2, VP3 and VP4. Vesicular stomatitis virus (VSV) proteins were used as mol. wt. markers, and the virion proteins were found to have tool. wt. of 125ooo (VPI), IO4OOO (VP2), 40000 (VP3) and 26ooo (VP4). VPI was labelled

MICHAEL P. KILEY; RUSSELL L. REGNERY; KARL M. JOHNSON

1980-01-01

33

[Research progress of prevention and treatment of Ebola virus infection].  

PubMed

Starting from February 2014, the Ebola virus outbreak had spread across West African countries within a few months and caused great concerns of the World Health Organization. Currently no effective vaccines or drugs have been available for prevention and treatment of Ebola virus infection. This paper gives a brief review of the epidemics and pandemics, the biological characteristics of Ebola virus, the potential antiviral drug targets, and research progress of vaccine and drug development against the virus. PMID:25345954

Wu, Wen-Jiao; Liu, Shu-Wen

2014-10-01

34

[Molecular mechanisms of Ebola virus reproduction].  

PubMed

The review presents recent data on the molecular mechanisms of the stages of an Ebola virus replication cycle, on the interaction of viral and cellular components at each stage, as well as on the mechanisms responsible for he realization of viral genetic information in the infected cell. PMID:17338228

Subbotina, E L; Chepurnov, A A

2007-01-01

35

Ebola virus: from discovery to vaccine  

Microsoft Academic Search

Ebola virus, being highly pathogenic for humans and non-human primates and the subject of former weapons programmes, is now one of the most feared pathogens worldwide. In addition, the lack of pre- and post-exposure interventions makes the development of rapid diagnostics, new antiviral agents and protective vaccines a priority for many nations. Further insight into the ecology, immunology and pathogenesis

Steven Jones; Hans-Dieter Klenk; Hans-Joachim Schnittler; Heinz Feldmann

2003-01-01

36

Endosomal Proteolysis of the Ebola Virus Glycoprotein Is  

E-print Network

Endosomal Proteolysis of the Ebola Virus Glycoprotein Is Necessary for Infection Kartik Chandran,1 Nancy J. Sullivan,2 Ute Felbor,3 Sean P. Whelan,4 James M. Cunningham1,4 * Ebola virus (EboV) causes the multiplication of infectious EboV-Zaire in cultured cells and may merit investigation as anti- EboV drugs. Ebola

Chandran, Kartik

37

DISPATCHES Ebola Virus Antibodies in Fruit Bats, Bangladesh  

E-print Network

To determine geographic range for Ebola virus, we tested 276 bats in Bangladesh. Five (3.5%) bats were positive for antibodies against Ebola Zaire and Reston viruses; no virus was detected by PCR. These bats might be a reservoir for Ebola or Ebola-like viruses, and extend the range of filoviruses to mainland Asia. Filoviruses are zoonotic pathogens that cause episodic, lethal, hemorrhagic outbreaks among humans and nonhuman primates and case-fatality rates up to 80 % (1). The family Filoviridae contains 2 genera: Marburgvirus, which contains Marburg virus (MARV), and Ebolavirus, which

Kevin J. Olival; Ariful Islam; Meng Yu; Simon J. Anthony; Jonathan H. Epstein; Shahneaz Ali Khan; Salah Uddin Khan; Gary Crameri; Lin-fa Wang; W. Ian Lipkin; Stephen P. Luby; Peter Daszak; Ebola Virus; Lloviu Ebola Virus

38

Ebola virus: identification of virion structural proteins.  

PubMed

Polyacrylamide gel electrophoresis of purified Ebola virus revealed the presence of four major virion structural proteins which we have designated VP1, VP2, VP3 and VP4. Vesicular stomatitis virus (VSV) proteins were used as mol. wt. markers, and the virion proteins were found to have mol. wt. of 125000 (VP1), 104000 (VP2), 40000 (VP3) and 26000 (VP4). VP1 was labelled with glucosamine and is probably a glycoprotein. The density of the Ebola virion was approx. 1.14g/ml in potassium tartrate. Virus nucleocapsids with a density of 1.32g/ml in caesium chloride were released when virions were treated with detergents. Proteins VP2 and VP3 were consistently associated with released nucleocapsids and are probably the major structural nucleocapsid proteins analogous to the N protein of VSV. Protein VP4 was reduced or absent in released nucleocapsids and is probably analogous to the membrane (M) protein of VSV and similar viruses. The glycoprotein (VP1) is larger than the glycoprotein of any known negative-strand RNA virus and is not labelled well with 35S-methionine. VP1 is solubilized by detergent treatment, suggesting that it is a component of the virion spikes and analogous to the G protein of VSV. Our results, in conjunction with analysis of Ebola virion RNA (Regnery et al. 1980), strongly suggest that the virus is a negative-strand RNA virus and, along with marburg virus, may constitute a new taxon within this group. PMID:7441205

Kiley, M P; Regnery, R L; Johnson, K M

1980-08-01

39

Infectivity-Enhancing Antibodies to Ebola Virus Glycoprotein  

Microsoft Academic Search

Ebola virus causes severe hemorrhagic fever in primates, resulting in mortality rates of up to 100%, yet there are no satisfactory biologic explanations for this extreme virulence. Here we show that antisera produced by DNA immunization with a plasmid encoding the surface glycoprotein (GP) of the Zaire strain of Ebola virus enhances the infectivity of vesicular stomatitis virus pseudotyped with

AYATO TAKADA; SHINJI WATANABE; KATSUNORI OKAZAKI; HIROSHI KIDA; Y. Kawaoka

2001-01-01

40

Emergence of Subtype Zaire Ebola Virus in Gabon  

Microsoft Academic Search

Gabon has recently been struck three times by Ebola hemorrhagic fever. The first isolate originating from the 1994 outbreak has been subjected to molecular characterization of its GP and VP24 genes. Sequence analysis demonstrates that the agent, Gabon-94 virus, belongs to subtype Zaire of Ebola virus. The isolate is closely related to the Kikwit-95 isolate, and both viruses seem to

Viktor Volchkov; Valentina Volchkova; Carina Eckel; Hans-Dieter Klenk; Michele Bouloy; Bernard LeGuenno; Heinz Feldmann

1997-01-01

41

Successful Topical Respiratory Tract Immunization of Primates against Ebola Virus  

Microsoft Academic Search

Ebola virus causes outbreaks of severe viral hemorrhagic fever with high mortality in humans. The virus is highly contagious and can be transmitted by contact and by the aerosol route. These features make Ebola virus a potential weapon for bioterrorism and biological warfare. Therefore, a vaccine that induces both systemic and local immune responses in the respiratory tract would be

Alexander Bukreyev; Pierre E. Rollin; Mallory K. Tate; Lijuan Yang; Sherif R. Zaki; Wun-Ju Shieh; Brian R. Murphy; Peter L. Collins; Anthony Sanchez

2007-01-01

42

Ebola Anxiety: a Bigger Threat Now Than the Virus Itself  

MedlinePLUS

... sharing features on this page, please enable JavaScript. Ebola Anxiety: A Bigger Threat Now Than the Virus ... Tuesday, October 21, 2014 Related MedlinePlus Pages Anxiety Ebola TUESDAY, Oct. 21, 2014 (HealthDay News) -- Headlines remain ...

43

[Ebola virus three years later (author's transl)].  

PubMed

Sporadic cases and data from serologic surveys give evidence that Ebola virus is still active in Northern Zaïre after the first outbreak in 1976. It is also active in Southern Sudan where it is, from August 1979, responsible of a new epidemic focus. In addition, serological surveys demonstrate that its dispersion area comprises several other african countries. Physicians practising in central Africa must be aware of this fact. Serological test is necessary to confirm the diagnosis. This confirmation is necessary to obtain convalescent patient plasma, the only specific treatment. The clinical, epidemiological and virological aspects of Ebola virus disease are reviewed as well as precautionary measures to be taken by medical and nursing staff to avoid infection. PMID:119124

Courtois, D

1979-01-01

44

virus  

E-print Network

The nucleotide sequences of the L gene and 5 ? trailer region of Ebola virus strain Mayinga (subtype Zaire) have been determined, thus completing the sequence of the Ebola virus genome. The putative transcription start signal of the L gene was identical to the determined 5 ? terminus of the L mRNA (5 ? GAGGAAGAUUAA) and showed a high degree of similarity to the corresponding regions of other Ebola virus genes. The 3 ? end of the L mRNA terminated with 5 ? AUUAUAAAAAA, a sequence which is distinct from the proposed transcription termination signals of other genes. The 5 ? trailer sequence of the Ebola virus genomic RNA consisted of 676 nt and revealed a selfcomplementary sequence at the extreme end which may play an important role in virus replication. The L gene contained a single ORF encoding a polypeptide of 2212 aa. The deduced amino acid sequence showed identities of about 73 and 44 % to the L proteins of Ebola virus strain Maleo (subtype Sudan) and Marburg virus, respectively. Sequence comparison studies of the Ebola virus L proteins with several corresponding proteins of other non-segmented, negative-strand RNA viruses, including Marburg viruses, confirmed a close relationship between filoviruses and members of the Paramyxovirinae. The presence of several conserved linear domains commonly found within L proteins of other members of the order Mononegavirales identified this protein as the RNA-dependent RNA polymerase of Ebola virus.

Viktor E. Volchkov; Valentina A. Volchkova; R A. Chepurnov; Vladimir M. Blinov; Olga Dolnik; Sergej V. Netesov; Heinz Feldmann

45

[Ebola and Marburg viruses: the humans strike back].  

PubMed

Ebola and Marburg viruses are the causative agents of rapidly progressive hemorrhagic fevers with high mortality rates. Pre- or post-exposure treatments against the diseases are currently not available for human use. In the field, establishment of strict quarantine measures preventing further virus transmission are still the only way to fight the infections. However, our knowledge of Ebola and Marburg viruses has markedly increased as a result of two recent discoveries discussed in this review. Chandran et al. have elucidated the mechanism by which Ebola GP is converted to a fusion-active form. Infectivity of Ebola virus was shown to be dependent on the cleavage of GP by cellular endosomal proteases, cathepsin B and L, thus opening new therapeutic approaches options. As for Jones SM et al., they have successfully vaccinated monkeys with recombinant vesicular stomatitis virus expressing Ebola or Marburg virus surface glycoprotein GP, a promising vaccine approach. PMID:16597410

Alazard-Dany, Nathalie; Ottmann Terrangle, Michèle; Volchkov, Viktor

2006-04-01

46

Ebola virus defective interfering particles and persistent infection.  

PubMed

Ebola virus (Zaire subtype) is associated with high mortality disease outbreaks that commonly involve human to human transmission. Surviving patients can show evidence of prolonged virus persistence. The potential for Ebola virus to generate defective interfering (DI) particles and establish persistent infections in tissue culture was investigated. It was found that serial undiluted virus passages quickly resulted in production of an evolving population of virus minireplicons possessing both deletion and copyback type DI genome rearrangements. The tenth undiluted virus passage resulted in the establishment of virus persistently infected cell lines. Following one or two crises, these cells were stably maintained for several months with continuous shedding of infectious virus. An analysis of the estimated genome lengths of a selected set of the Ebola virus minireplicons and standard filoviruses revealed no obvious genome length rule, such as "the rule of six" found for the phylogenetically related Paramyxovirinae subfamily viruses. Minimal promoters for Ebola virus replication were found to be contained within 156 and 177 nucleotide regions of the genomic and antigenomic RNA 3' termini, respectively, based on the length of authentic termini retained in the naturally occurring minireplicons analyzed. In addition, using UV-irradiated preparations of virus released from persistently infected cells, it was demonstrated that Ebola virus DI particles could potentially be used as natural minireplicons to assay standard virus support functions. PMID:10489346

Calain, P; Monroe, M C; Nichol, S T

1999-09-15

47

The origin and evolution of Ebola and Marburg viruses.  

PubMed

Molecular evolutionary analyses for Ebola and Marburg viruses were conducted with the aim of elucidating evolutionary features of these viruses. In particular, the rate of nonsynonymous substitutions for the glycoprotein gene of Ebola virus was estimated to be, on the average, 3.6 x 10(-5) per site per year. Marburg virus was also suggested to be evolving at a similar rate. Those rates were a hundred times slower than those of retroviruses and human influenza A virus, but were of the same order of magnitude as that of the hepatitis B virus. When these rates were applied to the degree of sequence divergence, the divergence time between Ebola and Marburg viruses was estimated to be more than several thousand years ago. Moreover, most of the nucleotide substitutions were transitions and synonymous for Marburg virus. This suggests that purifying selection has operated on Marburg virus during evolution. PMID:9254917

Suzuki, Y; Gojobori, T

1997-08-01

48

Ebola Virus Disease: Essential Public Health Principles for Clinicians  

E-print Network

index.html. for Suspected Ebola Cases, 2014. Available at:investigate, and manage Ebola cases. ” Enormous mediaEbola Virus Disease According to CDC, as of September 25, 2014, there have been at least 6,263 suspected and confirmed cases

Koenig, Kristi L.; Majestic, Cassondra; Burns, Michael J

2014-01-01

49

Release of Viral Glycoproteins during Ebola Virus Infection  

Microsoft Academic Search

Maturation and release of the Ebola virus glycoprotein GP were studied in cells infected with either Ebola or recombinant vaccinia viruses. Significant amounts of GP were found in the culture medium in nonvirion forms. The major form represented the large subunit GP1that was shed after release of its disulfide linkage to the smaller transmembrane subunit GP2. The minor form were

Viktor E. Volchkov; Valentina A. Volchkova; Werner Slenczka; Hans-Dieter Klenk; Heinz Feldmann

1998-01-01

50

New hope in the search for ebola virus treatments.  

PubMed

Because of its lethality, the Ebola virus often appears to be an invincible adversary. In Nature, Qiu et al. (2014) recently described the complete protection of nonhuman primates from deadly Ebola virus disease, even when treatment was begun as late as 5 days after infection. PMID:25367568

Basler, Christopher F

2014-10-16

51

Antibody-Dependent Enhancement of Ebola Virus Infection  

Microsoft Academic Search

Most strains of Ebola virus cause a rapidly fatal hemorrhagic disease in humans, yet there are still no biologic explanations that adequately account for the extreme virulence of these emerging pathogens. Here we show that Ebola Zaire virus infection in humans induces antibodies that enhance viral infectivity. Plasma or serum from convalescing patients enhanced the infection of primate kidney cells

Ayato Takada; Heinz Feldmann; Thomas G. Ksiazek; Yoshihiro Kawaoka

2003-01-01

52

Ultrastructure of Ebola virus particles in human liver  

Microsoft Academic Search

Electron microscopy of tissues from two necropsies carried out in the Sudan on patients with Ebola virus infection identified virus particles in lung and spleen, but the main concentrations of Ebola particles were seen in liver sections. Viral precursor proteins and cores were found in functional liver cells, often aligned in membrane-bound aggregations. Complete virions, usually found only extracellularly, were

D S Ellis; I H Simpson; D P Francis; J Knobloch; E T Bowen; P Lolik; I M Deng

1978-01-01

53

Protective efficacy of neutralizing antibodies against Ebola virus infection  

Microsoft Academic Search

Ebola virus causes lethal hemorrhagic fever in humans and nonhuman primates, but no effective antiviral compounds are available for the treatment of this infection. The surface glycoprotein (GP) of Ebola virus is an important target of neutralizing antibodies. Although passive transfer of GP-specific antibodies has been evaluated in mouse and guinea pig models, protection was achieved only by treatment shortly

Ayato Takada; Hideki Ebihara; Steven Jones; Heinz Feldmann; Yoshihiro Kawaoka

2007-01-01

54

Persistent Infection with Ebola Virus under Conditions of Partial Immunity  

Microsoft Academic Search

Ebola hemorrhagic fever in humans is associated with high mortality; however, some infected hosts clear the virus and recover. The mechanisms by which this occurs and the correlates of protective immunity are not well defined. Using a mouse model, we determined the role of the immune system in clearance of and protection against Ebola virus. All CD8 T-cell-deficient mice succumbed

Manisha Gupta; Siddhartha Mahanty; Patricia Greer; Jonathan S. Towner; Wun-Ju Shieh; Sherif R. Zaki; Rafi Ahmed; Pierre E. Rollin

2004-01-01

55

Proteolytic Processing of the Ebola Virus Glycoprotein Is Not Critical for Ebola Virus Replication in Nonhuman Primates  

Microsoft Academic Search

Enveloped viruses often require cleavage of a surface glycoprotein by a cellular endoprotease such as furin for infectivity and virulence. Previously, we showed that Ebola virus glycoprotein does not require the furin cleavage motif for virus replication in cell culture. Here, we show that there are no appreciable differences in disease progression, hematology, serum biochemistry, virus titers, or lethality in

Gabriele Neumann; Thomas W. Geisbert; Hideki Ebihara; Joan B. Geisbert; Kathleen M. Daddario-DiCaprio; Heinz Feldmann; Yoshihiro Kawaoka

2007-01-01

56

Successful topical respiratory tract immunization of primates against Ebola virus.  

PubMed

Ebola virus causes outbreaks of severe viral hemorrhagic fever with high mortality in humans. The virus is highly contagious and can be transmitted by contact and by the aerosol route. These features make Ebola virus a potential weapon for bioterrorism and biological warfare. Therefore, a vaccine that induces both systemic and local immune responses in the respiratory tract would be highly beneficial. We evaluated a common pediatric respiratory pathogen, human parainfluenza virus type 3 (HPIV3), as a vaccine vector against Ebola virus. HPIV3 recombinants expressing the Ebola virus (Zaire species) surface glycoprotein (GP) alone or in combination with the nucleocapsid protein NP or with the cytokine adjuvant granulocyte-macrophage colony-stimulating factor were administered by the respiratory route to rhesus monkeys--in which HPIV3 infection is mild and asymptomatic--and were evaluated for immunogenicity and protective efficacy against a highly lethal intraperitoneal challenge with Ebola virus. A single immunization with any construct expressing GP was moderately immunogenic against Ebola virus and protected 88% of the animals against severe hemorrhagic fever and death caused by Ebola virus. Two doses were highly immunogenic, and all of the animals survived challenge and were free of signs of disease and of detectable Ebola virus challenge virus. These data illustrate the feasibility of immunization via the respiratory tract against the hemorrhagic fever caused by Ebola virus. To our knowledge, this is the first study in which topical immunization through respiratory tract achieved prevention of a viral hemorrhagic fever infection in a primate model. PMID:17428868

Bukreyev, Alexander; Rollin, Pierre E; Tate, Mallory K; Yang, Lijuan; Zaki, Sherif R; Shieh, Wun-Ju; Murphy, Brian R; Collins, Peter L; Sanchez, Anthony

2007-06-01

57

Reidentification of Ebola Virus E718 and ME as Ebola Virus/H.sapiens-tc/COD/1976/Yambuku-Ecran  

PubMed Central

Ebola virus (EBOV) was discovered in 1976 around Yambuku, Zaire. A lack of nomenclature standards resulted in a variety of designations for each isolate, leading to confusion in the literature and databases. We sequenced the genome of isolate E718/ME/Ecran and unified the various designations under Ebola virus/H.sapiens-tc/COD/1976/Yambuku-Ecran. PMID:25414499

Lofts, Loreen L.; Kugelman, Jeffrey R.; Smither, Sophie J.; Lever, Mark S.; van der Groen, Guido; Johnson, Karl M.; Radoshitzky, Sheli R.; Bavari, Sina; Jahrling, Peter B.; Towner, Jonathan S.; Nichol, Stuart T.; Palacios, Gustavo

2014-01-01

58

Proteolysis of the Ebola Virus Glycoproteins Enhances Virus Binding and Infectivity  

Microsoft Academic Search

Cellular cathepsins are required for Ebola virus infection and are believed to proteolytically process the Ebola virus glycoprotein (GP) during entry. However, the significance of cathepsin cleavage during infection remains unclear. Here we demonstrate a role for cathepsin L (CatL) cleavage of Ebola virus GP in the generation of a stable 18-kDa GP1 viral intermediate that exhibits increased binding to

Rachel L. Kaletsky; Graham Simmons; Paul Bates

2007-01-01

59

Generation of biologically contained Ebola viruses.  

PubMed

Ebola virus (EBOV), a public health concern in Africa and a potential biological weapon, is classified as a biosafety level-4 agent because of its high mortality rate and the lack of approved vaccines and antivirals. Basic research into the mechanisms of EBOV pathogenicity and the development of effective countermeasures are restricted by the current biosafety classification of EBOVs. We therefore developed biologically contained EBOV that express a reporter gene instead of the VP30 gene, which encodes an essential transcription factor. A Vero cell line that stably expresses VP30 provides this essential protein in trans and biologically confines the virus to its complete replication cycle in this cell line. This complementation approach is highly efficient because biologically contained EBOVs lacking the VP30 gene grow to titers similar to those obtained with wild-type virus. Moreover, EBOVs lacking the VP30 gene are indistinguishable in their morphology from wild-type virus and are genetically stable, as determined by sequence analysis after seven serial passages in VP30-expressing Vero cells. We propose that this system provides a safe means to handle EBOV outside a biosafety level-4 facility and will stimulate critical studies on the EBOV life cycle as well as large-scale screening efforts for compounds with activity against this lethal virus. PMID:18212124

Halfmann, Peter; Kim, Jin Hyun; Ebihara, Hideki; Noda, Takeshi; Neumann, Gabriele; Feldmann, Heinz; Kawaoka, Yoshihiro

2008-01-29

60

Protection from Ebola Virus Mediated by Cytotoxic T Lymphocytes Specific for the Viral Nucleoprotein  

Microsoft Academic Search

Cytotoxic T lymphocytes (CTLs) are proposed to be critical for protection from intracellular pathogens such as Ebola virus. However, there have been no demonstrations that protection against Ebola virus is mediated by Ebola virus-specific CTLs. Here, we report that C57BL\\/6 mice vaccinated with Venezuelan equine enceph- alitis virus replicons encoding the Ebola virus nucleoprotein (NP) survived lethal challenge with Ebola

JULIE A. WILSON; MARY KATE HART

2001-01-01

61

Antigenic analysis of strains of Ebola virus: identification of two Ebola virus serotypes.  

PubMed

A sensitive radioimmunoassay has been adapted for Ebola virus antigens and antibodies to them. It uses 125I-labeled staphylococcal protein A and a specially designed filter manifold. The assay is applicable to the sera of humans and to a wide range of animal sera. Virus isolates from two discrete outbreaks of Ebola hemorrhagic fever that occurred in 1976 were shown by this assay to be antigenically distinct. This lack of identity was further confirmed by cross-absorbing antisera to each isolate with antigens of the heterologous virus strain. The advantages of this assay include the use of noninfectious antigens, the requirement for only small quantities of serum, the capability of screening large numbers of sera, the speed of execution, and the objectivity of end point determination. PMID:6827143

Richman, D D; Cleveland, P H; McCormick, J B; Johnson, K M

1983-02-01

62

Dispatches Experimental Inoculation of Plants and Animals with Ebola Virus  

E-print Network

Thirty-three varieties of 24 species of plants and 19 species of vertebrates and invertebrates were experimentally inoculated with Ebola Zaire virus. Fruit and insectivorous bats supported replication and circulation of high titers of virus without necessarily becoming ill; deaths occurred only among bats that had not adapted to the diet fed in the laboratory. The taxonomy of the Filoviridae is in a state of flux; the family includes viruses currently designated Marburg, Ebola Zaire, Ebola Sudan, and Ebola Ivory Coast, which are believed to be endemic to Africa, and Ebola Reston, which putatively originates in the Philippines (1,2). The viruses are known particularly for their propensity to cause fatal hemorrhagic disease of humans with person-to-person spread, but their pathogenicity

unknown authors

63

Ebola Virus Antibody Prevalence in Dogs and Human Risk  

PubMed Central

During the 2001–2002 outbreak in Gabon, we observed that several dogs were highly exposed to Ebola virus by eating infected dead animals. To examine whether these animals became infected with Ebola virus, we sampled 439 dogs and screened them by Ebola virus–specific immunoglobulin (Ig) G assay, antigen detection, and viral polymerase chain reaction amplification. Seven (8.9%) of 79 samples from the 2 main towns, 15 (15.2%) of 14 the 99 samples from Mekambo, and 40 (25.2%) of 159 samples from villages in the Ebola virus–epidemic area had detectable Ebola virus–IgG, compared to only 2 (2%) of 102 samples from France. Among dogs from villages with both infected animal carcasses and human cases, seroprevalence was 31.8%. A significant positive direct association existed between seroprevalence and the distances to the Ebola virus–epidemic area. This study suggests that dogs can be infected by Ebola virus and that the putative infection is asymptomatic. PMID:15757552

Allela, Lois; Bourry, Olivier; Pouillot, Regis; Delicat, Andre; Yaba, Philippe; Kumulungui, Brice; Rouquet, Pierre; Gonzalez, Jean-Paul

2005-01-01

64

Ebola virus antibody prevalence in dogs and human risk.  

PubMed

During the 2001-2002 outbreak in Gabon, we observed that several dogs were highly exposed to Ebola virus by eating infected dead animals. To examine whether these animals became infected with Ebola virus, we sampled 439 dogs and screened them by Ebola virus-specific immunoglobulin (Ig) G assay, antigen detection, and viral polymerase chain reaction amplification. Seven (8.9%) of 79 samples from the 2 main towns, 15 (15.2%) of 99 samples from Mekambo, and 40 (25.2%) of 159 samples from villages in the Ebola virus-epidemic area had detectable Ebola virus-IgG, compared to only 2 (2%) of 102 samples from France. Among dogs from villages with both infected animal carcasses and human cases, seroprevalence was 31.8%. A significant positive direct association existed between seroprevalence and the distances to the Ebola virus-epidemic area. This study suggests that dogs can be infected by Ebola virus and that the putative infection is asymptomatic. PMID:15757552

Allela, Loïs; Boury, Olivier; Pouillot, Régis; Délicat, André; Yaba, Philippe; Kumulungui, Brice; Rouquet, Pierre; Gonzalez, Jean-Paul; Leroy, Eric M

2005-03-01

65

Immunopathology of highly virulent pathogens: insights from Ebola virus  

Microsoft Academic Search

Ebola virus is a highly virulent pathogen capable of inducing a frequently lethal hemorrhagic fever syndrome. Accumulating evidence indicates that the virus actively subverts both innate and adaptive immune responses and triggers harmful inflammatory responses as it inflicts direct tissue damage. The host immune system is ultimately overwhelmed by a combination of inflammatory factors and virus-induced cell damage, particularly in

Carisa A Zampieri; Nancy J Sullivan; Gary J Nabel

2007-01-01

66

Recombinant vesicular stomatitis virus-based vaccines against Ebola and Marburg virus infections.  

PubMed

The filoviruses, Marburg virus and Ebola virus, cause severe hemorrhagic fever with a high mortality rate in humans and nonhuman primates. Among the most-promising filovirus vaccines under development is a system based on recombinant vesicular stomatitis virus (rVSV) that expresses a single filovirus glycoprotein (GP) in place of the VSV glycoprotein (G). Importantly, a single injection of blended rVSV-based filovirus vaccines was shown to completely protect nonhuman primates against Marburg virus and 3 different species of Ebola virus. These rVSV-based vaccines have also shown utility when administered as a postexposure treatment against filovirus infections, and a rVSV-based Ebola virus vaccine was recently used to treat a potential laboratory exposure. Here, we review the history of rVSV-based vaccines and pivotal animal studies showing their utility in combating Ebola and Marburg virus infections. PMID:21987744

Geisbert, Thomas W; Feldmann, Heinz

2011-11-01

67

Downregulation of ?1 Integrins by Ebola Virus Glycoprotein: Implication for Virus Entry  

Microsoft Academic Search

Filoviruses, including Ebola virus, are cytotoxic. To investigate the role of the Ebola virus glycoprotein (GP) in this cytopathic effect, we transiently expressed the GP in human kidney 293T cells. Expression of wild-type GP, but not the secretory form of the molecule lacking a membrane anchor, induced rounding and detachment of the cells, as did a chimeric GP containing its

Ayato Takada; Shinji Watanabe; Hiroshi Ito; Katsunori Okazaki; Hiroshi Kida; Yoshihiro Kawaoka

2000-01-01

68

Immunopathology of highly virulent pathogens: insights from Ebola virus.  

PubMed

Ebola virus is a highly virulent pathogen capable of inducing a frequently lethal hemorrhagic fever syndrome. Accumulating evidence indicates that the virus actively subverts both innate and adaptive immune responses and triggers harmful inflammatory responses as it inflicts direct tissue damage. The host immune system is ultimately overwhelmed by a combination of inflammatory factors and virus-induced cell damage, particularly in the liver and vasculature, often leading to death from septic shock. We summarize the mechanisms of immune dysregulation and virus-mediated cell damage in Ebola virus-infected patients. Future approaches to prevention and treatment of infection will be guided by answers to unresolved questions about interspecies transmission, molecular mechanisms of pathogenesis, and protective adaptive and innate immune responses to Ebola virus. PMID:17952040

Zampieri, Carisa A; Sullivan, Nancy J; Nabel, Gary J

2007-11-01

69

Unconventional Secretion of Ebola Virus Matrix Protein VP40  

PubMed Central

The Ebola virus matrix protein VP40 plays an essential role in virus assembly and budding. In this study we reveal that transient VP40 expression results in the release into the culture medium of substantial amounts of soluble monomeric VP40 in addition to the release of virus-like particles containing an oligomeric form of this protein as previously described. We show that VP40 secretion is endoplasmic reticulum/Golgi–independent and is not associated with cell death. Soluble VP40 was observed during Ebola virus infection of cells and was also found in the serum of virus-infected animals albeit in lower amounts. Unconventional secretion of VP40 may therefore play a role in Ebola virus pathogenicity. PMID:21987759

Reynard, Olivier; Reid, St. Patrick; Page, Audrey; Mateo, Mathieu; Alazard-Dany, Nathalie; Raoul, Herve; Basler, Christopher F.

2011-01-01

70

Unconventional secretion of Ebola virus matrix protein VP40.  

PubMed

The Ebola virus matrix protein VP40 plays an essential role in virus assembly and budding. In this study we reveal that transient VP40 expression results in the release into the culture medium of substantial amounts of soluble monomeric VP40 in addition to the release of virus-like particles containing an oligomeric form of this protein as previously described. We show that VP40 secretion is endoplasmic reticulum/Golgi-independent and is not associated with cell death. Soluble VP40 was observed during Ebola virus infection of cells and was also found in the serum of virus-infected animals albeit in lower amounts. Unconventional secretion of VP40 may therefore play a role in Ebola virus pathogenicity. PMID:21987759

Reynard, Olivier; Reid, St Patrick; Page, Audrey; Mateo, Mathieu; Alazard-Dany, Nathalie; Raoul, Hervé; Basler, Christopher F; Volchkov, Viktor E

2011-11-01

71

Molecular Dynamics Simulations of Folding and Insertion of the Ebola Virus Fusion Peptide into a  

E-print Network

Molecular Dynamics Simulations of Folding and Insertion of the Ebola Virus Fusion Peptide- residue Ebola virus fusion peptide into a membrane bilayer. We applied a multi-resolution computational-energy landscape, virus-host interactions 1 Introduction Ebola and Marburg viruses are nonsegmented, negative

72

Nurses are in the forefront of Ebola virus disease outbreak.  

PubMed

The outbreak of Ebola virus disease in West Africa is a global threat. It is of particular concern that many front line medical personnel are being infected, with nurses who have close contact with patients at particular risk. PMID:25294483

Wiwanitkit, Viroj

2014-10-01

73

Ebola virus disease in west Africa - clinical manifestations and management.  

PubMed

The cumulative clinical observations of physicians who cared for more than 700 patients with Ebola virus disease in Liberia between August and October of this year support a rational approach to EVD management in resource-limited settings. PMID:25372854

Chertow, Daniel S; Kleine, Christian; Edwards, Jeffrey K; Scaini, Roberto; Giuliani, Ruggero; Sprecher, Armand

2014-11-27

74

Ebola virus vaccines: an overview of current approaches.  

PubMed

Ebola hemorrhagic fever is one of the most fatal viral diseases worldwide affecting humans and nonhuman primates. Although infections only occur frequently in Central Africa, the virus has the potential to spread globally and is classified as a category A pathogen that could be misused as a bioterrorism agent. As of today there is no vaccine or treatment licensed to counteract Ebola virus infections. DNA, subunit and several viral vector approaches, replicating and non-replicating, have been tested as potential vaccine platforms and their protective efficacy has been evaluated in nonhuman primate models for Ebola virus infections, which closely resemble disease progression in humans. Though these vaccine platforms seem to confer protection through different mechanisms, several of them are efficacious against lethal disease in nonhuman primates attesting that vaccination against Ebola virus infections is feasible. PMID:24575870

Marzi, Andrea; Feldmann, Heinz

2014-04-01

75

Reemerging Sudan Ebola virus disease in Uganda, 2011.  

PubMed

Two large outbreaks of Ebola hemorrhagic fever occurred in Uganda in 2000 and 2007. In May 2011, we identified a single case of Sudan Ebola virus disease in Luwero District. The establishment of a permanent in-country laboratory and cooperation between international public health entities facilitated rapid outbreak response and control activities. PMID:22931687

Shoemaker, Trevor; MacNeil, Adam; Balinandi, Stephen; Campbell, Shelley; Wamala, Joseph Francis; McMullan, Laura K; Downing, Robert; Lutwama, Julius; Mbidde, Edward; Ströher, Ute; Rollin, Pierre E; Nichol, Stuart T

2012-09-01

76

Reemerging Sudan Ebola Virus Disease in Uganda, 2011  

PubMed Central

Two large outbreaks of Ebola hemorrhagic fever occurred in Uganda in 2000 and 2007. In May 2011, we identified a single case of Sudan Ebola virus disease in Luwero District. The establishment of a permanent in-country laboratory and cooperation between international public health entities facilitated rapid outbreak response and control activities. PMID:22931687

Shoemaker, Trevor; Balinandi, Stephen; Campbell, Shelley; Wamala, Joseph Francis; McMullan, Laura K.; Downing, Robert; Lutwama, Julius; Mbidde, Edward; Stroher, Ute; Rollin, Pierre E.; Nichol, Stuart T.

2012-01-01

77

Marburg and Ebola viruses as aerosol threats.  

PubMed

Ebola and Marburg viruses are the sole members of the genus Filovirus in the family Filoviridae. There has been considerable media attention and fear generated by outbreaks of filoviruses because they can cause a severe viral hemorrhagic fever (VHF) syndrome that has a rapid onset and high mortality. Although they are not naturally transmitted by aerosol, they are highly infectious as respirable particles under laboratory conditions. For these and other reasons, filoviruses are classified as category A biological weapons. However, there is very little data from animal studies with aerosolized filoviruses. Animal models of filovirus exposure are not well characterized, and there are discrepancies between these models and what has been observed in human outbreaks. Building on published results from aerosol studies, as well as a review of the history, epidemiology, and disease course of naturally occurring outbreaks, we offer an aerobiologist's perspective on the threat posed by aerosolized filoviruses. PMID:15588056

Leffel, Elizabeth K; Reed, Douglas S

2004-01-01

78

Disease modeling for Ebola and Marburg viruses.  

PubMed

The filoviruses Ebola and Marburg are zoonotic agents that are classified as both biosafety level 4 and category A list pathogens. These viruses are pathogenic in humans and cause isolated infections or epidemics of viral hemorrhagic fever, mainly in Central Africa. Their natural reservoir has not been definitely identified, but certain species of African bat have been associated with Ebola and Marburg infections. Currently, there are no licensed options available for either treatment or prophylaxis. Different animal models have been developed for filoviruses including mouse, guinea pig and nonhuman primates. The 'gold standard' animal models for pathogenesis, treatment and vaccine studies are rhesus and cynomolgus macaques. This article provides a brief overview of the clinical picture and the pathology/pathogenesis of human filovirus infections. The current animal model options are discussed and compared with regard to their value in different applications. In general, the small animal models, in particular the mouse, are the most feasible for high biocontainment facilities and they offer the most options for research owing to the greater availability of immunologic and genetic tools. However, their mimicry of the human diseases as well as their predictive value for therapeutic efficacy in primates is limited, thereby making them, at best, valuable initial screening tools for pathophysiology, treatment and vaccine studies. PMID:19132113

Bente, Dennis; Gren, Jason; Strong, James E; Feldmann, Heinz

2009-01-01

79

[Immunobiological properties of vp24 protein of Ebola virus expressed by recombinant vaccinia virus].  

PubMed

Immunological and biochemical parameters were studied in guinea pigs immunized with recombinant vaccinia virus containing full-sized gene of Ebola virus vp24 protein and then infected with virulent strain of Ebola virus. The majority of the studied parameters changed similarly in guinea pigs immunized with recombinant vaccinia virus and control guinea pigs inoculated with vaccinia virus both before and after challenge with Ebola virus. However, in animals immunized with recombinant vaccinia virus producing vp24 some biochemical parameters, the mean life span after challenge with Ebola virus, the level of antibodies to the virus, and the phagocytic activity of neutrophils indicated the development of immunological processes other than in controls, namely, the development of immune response to vp24. Although these processes did not eventually lead to the survival of animals, they prolonged the mean life span and resulted in the production of anti-Ebola antibodies, though the level thereof was low. These data demonstrate that recombinant vaccines against Ebola fever are a promising trend of research. PMID:9297340

Chepurnov, A A; Ternovo?, V A; Dadaeva, A A; Dmitriev, I P; Sizikova, L P; Volchkov, V E; Kudoiarova, N M; Rudzevich, T N; Netesov, S V

1997-01-01

80

Infectivity-enhancing antibodies to Ebola virus glycoprotein.  

PubMed

Ebola virus causes severe hemorrhagic fever in primates, resulting in mortality rates of up to 100%, yet there are no satisfactory biologic explanations for this extreme virulence. Here we show that antisera produced by DNA immunization with a plasmid encoding the surface glycoprotein (GP) of the Zaire strain of Ebola virus enhances the infectivity of vesicular stomatitis virus pseudotyped with the GP. Substantially weaker enhancement was observed with antiserum to the GP of the Reston strain, which is much less pathogenic in humans than the Ebola Zaire and Sudan viruses. The enhancing activity was abolished by heat but was increased in the presence of complement system inhibitors, suggesting that heat-labile factors other than the complement system are required for this effect. We also generated an anti-Zaire GP monoclonal antibody that enhanced viral infectivity and another that neutralized it, indicating the presence of distinct epitopes for these properties. Our findings suggest that antibody-dependent enhancement of infectivity may account for the extreme virulence of the virus. They also raise issues about the development of Ebola virus vaccines and the use of passive prophylaxis or therapy with Ebola virus GP antibodies. PMID:11160735

Takada, A; Watanabe, S; Okazaki, K; Kida, H; Kawaoka, Y

2001-03-01

81

[Ebola virus: what the practitioner needs to know].  

PubMed

The Ebola virus is an RNA virus of Filoviridae family. The earliest documented fatal epidemic of Ebola hemorrhagic occurred in 1976. There are four genetically different subtypes of Ebola virus. The virus remains in the blood for several weeks, can maintain its infectivity for several weeks at 20 degrees C outside the body, and survives for several weeks in corpses. Isolation of Ebola virus requires level 4 laboratory security conditions. Specimens are obtained by culturing mammal cells. Identification is achieved using reference serums. Serologic diagnosis is made using mainly ELISA technique for immunocapture of IgM or EBO Ag. The natural reservoir for Ebola virus is unknown. One possibility is that each isolated strain has a different reservoir. In recorded outbreaks, the index case has often had a history of contact with non-human primates. However since these animals are also highly sensitive to the virus, they cannot be considered as reservoirs but only as intermediate hosts. Transmission requires close contact such as occurs in association with health care, local customs, or funeral rites. In humans, infection causes hemorrhagic fever that progresses to diarrhea within 5 to 10 days. Recovery is observed in only 25% of cases. During outbreaks containment depends on implementation of simple precautions including isolation of suspected cases, appropriate protective clothing, disinfection with hypochlorite solutions, and proper waste disposal. PMID:9791600

Georges, A J; Baize, S; Leroy, E M; Georges-Courbot, M C

1998-01-01

82

A system for functional analysis of Ebola virus glycoprotein.  

PubMed

Ebola virus causes hemorrhagic fever in humans and nonhuman primates, resulting in mortality rates of up to 90%. Studies of this virus have been hampered by its extraordinary pathogenicity, which requires biosafety level 4 containment. To circumvent this problem, we developed a novel complementation system for functional analysis of Ebola virus glycoproteins. It relies on a recombinant vesicular stomatitis virus (VSV) that contains the green fluorescent protein gene instead of the receptor-binding G protein gene (VSVDeltaG*). Herein we show that Ebola Reston virus glycoprotein (ResGP) is efficiently incorporated into VSV particles. This recombinant VSV with integrated ResGP (VSVDeltaG*-ResGP) infected primate cells more efficiently than any of the other mammalian or avian cells examined, in a manner consistent with the host range tropism of Ebola virus, whereas VSVDeltaG* complemented with VSV G protein (VSVDeltaG*-G) efficiently infected the majority of the cells tested. We also tested the utility of this system for investigating the cellular receptors for Ebola virus. Chemical modification of cells to alter their surface proteins markedly reduced their susceptibility to VSVDeltaG*-ResGP but not to VSVDeltaG*-G. These findings suggest that cell surface glycoproteins with N-linked oligosaccharide chains contribute to the entry of Ebola viruses, presumably acting as a specific receptor and/or cofactor for virus entry. Thus, our VSV system should be useful for investigating the functions of glycoproteins from highly pathogenic viruses or those incapable of being cultured in vitro. PMID:9405687

Takada, A; Robison, C; Goto, H; Sanchez, A; Murti, K G; Whitt, M A; Kawaoka, Y

1997-12-23

83

Isolation and partial characterisation of a new strain of Ebola We have isolated a new strain of Ebola virus from a non-  

E-print Network

1271 Isolation and partial characterisation of a new strain of Ebola virus Summary We have isolated a new strain of Ebola virus from a non- fatal human case infected during the autopsy of a wild about the natural reservoir of the Ebola virus. Lancet 1995; 345: 1271-74 Introduction Ebola virus

84

Update: ebola virus disease outbreak - west Africa, october 2014.  

PubMed

CDC is assisting ministries of health and working with other organizations to control and end the ongoing outbreak of Ebola virus disease (Ebola) in West Africa. The updated data in this report were compiled from situation reports from the Guinea Interministerial Committee for Response Against the Ebola Virus and the World Health Organization, the Liberia Ministry of Health and Social Welfare, and the Sierra Leone Ministry of Health and Sanitation. Total case counts include all suspected, probable, and confirmed cases as defined by each country. These data reflect reported cases, which make up an unknown proportion of all actual cases and reporting delays that vary from country to country. PMID:25356606

2014-10-31

85

Update: ebola virus disease epidemic - west Africa, november 2014.  

PubMed

CDC is assisting ministries of health and working with other organizations to end the ongoing epidemic of Ebola virus disease (Ebola) in West Africa. The updated data in this report were compiled from situation reports from the Guinea Interministerial Committee for Response Against the Ebola Virus and the World Health Organization, the Liberia Ministry of Health and Social Welfare, and the Sierra Leone Ministry of Health and Sanitation. Total case counts include all suspected, probable, and confirmed cases, which are defined similarly by each country. These data reflect reported cases, which make up an unknown proportion of all cases, and reporting delays that vary from country to country. PMID:25412064

System Ebola Epidemiology Team, Incident Management

2014-11-21

86

How Ebola virus counters the interferon system.  

PubMed

Zoonotic transmission of Ebola virus (EBOV) to humans causes a severe haemorrhagic fever in afflicted individuals with high case-fatality rates. Neither vaccines nor therapeutics are at present available to combat EBOV infection, making the virus a potential threat to public health. To devise antiviral strategies, it is important to understand which components of the immune system could be effective against EBOV infection. The interferon (IFN) system constitutes a key innate defence against viral infections and prevents development of lethal disease in mice infected with EBOV strains not adapted to this host. Recent research revealed that expression of the host cell IFN-inducible transmembrane proteins 1-3 (IFITM1-3) and tetherin is induced by IFN and restricts EBOV infection, at least in cell culture model systems. IFITMs, tetherin and other effector molecules of the IFN system could thus pose a potent barrier against EBOV spread in humans. However, EBOV interferes with signalling events required for human cells to express these proteins. Here, we will review the strategies employed by EBOV to fight the IFN system, and we will discuss how IFITM proteins and tetherin inhibit EBOV infection. PMID:22958256

Kühl, A; Pöhlmann, S

2012-09-01

87

Lethal Experimental Infections of Rhesus Monkeys by Aerosolized Ebola Virus.  

National Technical Information Service (NTIS)

The potential of aerogenic infection by Ebola virus was established by using a head-only exposure aerosol system. Virus-containing droplets of 0.8-1.2 urn were generated and administered into the respiratory tract of rhesus monkeys via inhalation. Inhalat...

E. Johnson, N. Jaax, J. White, P. Jahrling

1994-01-01

88

Association of Ebola Virus Matrix Protein VP40 with Microtubules  

Microsoft Academic Search

Viruses exploit a variety of cellular components to complete their life cycles, and it has become increasingly clear that use of host cell microtubules is a vital part of the infection process for many viruses. A variety of viral proteins have been identified that interact with microtubules, either directly or via a microtubule-associated motor protein. Here, we report that Ebola

Gordon Ruthel; Gretchen L. Demmin; George Kallstrom; Melodi P. Javid; Shirin S. Badie; Amy B. Will; Timothy Nelle; Rowena Schokman; Tam L. Nguyen; John H. Carra; Sina Bavari; M. Javad Aman

2005-01-01

89

Experimental inoculation of plants and animals with Ebola virus.  

PubMed Central

Thirty-three varieties of 24 species of plants and 19 species of vertebrates and invertebrates were experimentally inoculated with Ebola Zaire virus. Fruit and insectivorous bats supported replication and circulation of high titers of virus without necessarily becoming ill; deaths occurred only among bats that had not adapted to the diet fed in the laboratory. PMID:8969248

Swanepoel, R.; Leman, P. A.; Burt, F. J.; Zachariades, N. A.; Braack, L. E.; Ksiazek, T. G.; Rollin, P. E.; Zaki, S. R.; Peters, C. J.

1996-01-01

90

Ebola virus disease: potential use of melatonin as a treatment.  

PubMed

The purpose of this report is to emphasize the potential utility for the use of melatonin in the treatment of individuals who are infected with the Ebola virus. The pathological changes associated with an Ebola infection include, most notably, endothelial disruption, disseminated intravascular coagulation and multiple organ hemorrhage. Melatonin has been shown to target these alterations. Numerous similarities between Ebola virus infection and septic shock have been recognized for more than a decade. Moreover, melatonin has been successfully employed for the treatment of sepsis in many experimental and clinical studies. Based on these factors, as the number of treatments currently available is limited and the useable products are not abundant, the use of melatonin for the treatment of Ebola virus infection is encouraged. Additionally, melatonin has a high safety profile, is readily available and can be orally self-administered; thus, the use of melatonin is compatible with the large scale of this serious outbreak. PMID:25262626

Tan, Dun-Xian; Korkmaz, Ahmet; Reiter, Russel J; Manchester, Lucien C

2014-11-01

91

Kunjin Virus Replicon-Based Vaccines Expressing Ebola Virus Glycoprotein GP Protect the Guinea Pig Against Lethal Ebola Virus Infection  

PubMed Central

Pre- or postexposure treatments against the filoviral hemorrhagic fevers are currently not available for human use. We evaluated, in a guinea pig model, the immunogenic potential of Kunjin virus (KUN)–derived replicons as a vaccine candidate against Ebola virus (EBOV). Virus like particles (VLPs) containing KUN replicons expressing EBOV wild-type glycoprotein GP, membrane anchor-truncated GP (GP/Ctr), and mutated GP (D637L) with enhanced shedding capacity were generated and assayed for their protective efficacy. Immunization with KUN VLPs expressing full-length wild-type and D637L-mutated GPs but not membrane anchor–truncated GP induced dose-dependent protection against a challenge of a lethal dose of recombinant guinea pig-adapted EBOV. The surviving animals showed complete clearance of the virus. Our results demonstrate the potential for KUN replicon vectors as vaccine candidates against EBOV infection. PMID:21987742

Reynard, O.; Mokhonov, V.; Mokhonova, E.; Leung, J.; Page, A.; Mateo, M.; Pyankova, O.; Georges-Courbot, M. C.; Raoul, H.; Khromykh, A. A.

2011-01-01

92

Kunjin virus replicon-based vaccines expressing Ebola virus glycoprotein GP protect the guinea pig against lethal Ebola virus infection.  

PubMed

Pre- or postexposure treatments against the filoviral hemorrhagic fevers are currently not available for human use. We evaluated, in a guinea pig model, the immunogenic potential of Kunjin virus (KUN)-derived replicons as a vaccine candidate against Ebola virus (EBOV). Virus like particles (VLPs) containing KUN replicons expressing EBOV wild-type glycoprotein GP, membrane anchor-truncated GP (GP/Ctr), and mutated GP (D637L) with enhanced shedding capacity were generated and assayed for their protective efficacy. Immunization with KUN VLPs expressing full-length wild-type and D637L-mutated GPs but not membrane anchor-truncated GP induced dose-dependent protection against a challenge of a lethal dose of recombinant guinea pig-adapted EBOV. The surviving animals showed complete clearance of the virus. Our results demonstrate the potential for KUN replicon vectors as vaccine candidates against EBOV infection. PMID:21987742

Reynard, O; Mokhonov, V; Mokhonova, E; Leung, J; Page, A; Mateo, M; Pyankova, O; Georges-Courbot, M C; Raoul, H; Khromykh, A A; Volchkov, V E

2011-11-01

93

Comprehensive analysis of ebola virus GP1 in viral entry.  

PubMed

Ebola virus infection is initiated by interactions between the viral glycoprotein GP1 and its cognate receptor(s), but little is known about the structure and function of GP1 in viral entry, partly due to the concern about safety when working with the live Ebola virus and the difficulty of manipulating the RNA genome of Ebola virus. In this study, we have used a human immunodeficiency virus-based pseudotyped virus as a surrogate system to dissect the role of Ebola virus GP1 in viral entry. Analysis of more than 100 deletion and amino acid substitution mutants of GP1 with respect to protein expression, processing, viral incorporation, and viral entry has allowed us to map the region of GP1 responsible for viral entry to the N-terminal 150 residues. Furthermore, six amino acids in this region have been identified as critical residues for early events in Ebola virus entry, and among these, three are clustered and are implicated as part of a potential receptor-binding pocket. In addition, substitutions of some 30 residues in GP1 are shown to adversely affect GP1 expression, processing, and viral incorporation, suggesting that these residues are involved in the proper folding and/or overall conformation of GP. Sequence comparison of the GP1 proteins suggests that the majority of the critical residues for GP folding and viral entry identified in Ebola virus GP1 are conserved in Marburg virus. These results provide information for elucidating the structural and functional roles of the filoviral glycoproteins and for developing potential therapeutics to block viral entry. PMID:15795265

Manicassamy, Balaji; Wang, Jizhen; Jiang, Haiqing; Rong, Lijun

2005-04-01

94

Designed protein mimics of the Ebola virus glycoprotein GP2 -helical bundle: stability  

E-print Network

Designed protein mimics of the Ebola virus glycoprotein GP2 -helical bundle: stability and p.lai@einstein.yu.edu Running Title: Mimicry of the Ebola virus GP2 -helical bundle. (This manuscript contains 25 total pages, 1

Chandran, Kartik

95

Ebola GP-Specific Monoclonal Antibodies Protect Mice and Guinea Pigs from Lethal Ebola Virus Infection  

Microsoft Academic Search

Ebola virus (EBOV) causes acute hemorrhagic fever in humans and non-human primates with mortality rates up to 90%. So far there are no effective treatments available. This study evaluates the protective efficacy of 8 monoclonal antibodies (MAbs) against Ebola glycoprotein in mice and guinea pigs. Immunocompetent mice or guinea pigs were given MAbs i.p. in various doses individually or as

Xiangguo Qiu; Lisa Fernando; P. Leno Melito; Jonathan Audet; Heinz Feldmann; Gary Kobinger; Judie B. Alimonti; Steven M. Jones

2012-01-01

96

Inactivation of Lassa, Marburg, and Ebola viruses by gamma irradiation  

Microsoft Academic Search

Because of the cumbersome conditions experienced in a maximum containment laboratory, methods for inactivating highly pathogenic viruses were investigated. The infectivity of Lassa, Marburg, and Ebola viruses was inactivated without altering the immunological activity after radiation with ⁶°Co gamma rays. At 4 degrees C, Lassa virus was the most difficult to inactivate with a rate of 5.3 X 10(-6) log

L. H. Elliott; J. B. McCormick; K. M. Johnson

1982-01-01

97

Inactivation of Lassa, Marburg, and Ebola viruses by gamma irradiation  

Microsoft Academic Search

Because of the cumbersome conditions experienced in a maximum containment laboratory, methods for inactivating highly pathogenic viruses were investigated. The infectivity of Lassa, Marburg, and Ebola viruses was inactivated without altering the immunological activity after radiation with ⁶°CO gamma rays. At 4 degrees C, Lassa virus was the most difficult to inactivate with a rate of 5.3 X 10(-6) log

L. H. Elliott; J. B. McCormick; K. M. Johnson

1982-01-01

98

Rapid Detection and Quantification of RNA of Ebola and Marburg Viruses, Lassa Virus, Crimean-Congo Hemorrhagic Fever Virus, Rift Valley Fever Virus, Dengue Virus, and Yellow Fever Virus by Real-Time Reverse Transcription-PCR  

Microsoft Academic Search

Viral hemorrhagic fevers (VHFs) are acute infections with high case fatality rates. Important VHF agents are Ebola and Marburg viruses (MBGV\\/EBOV), Lassa virus (LASV), Crimean-Congo hemorrhagic fever virus (CCHFV), Rift Valley fever virus (RVFV), dengue virus (DENV), and yellow fever virus (YFV). VHFs are clinically difficult to diagnose and to distinguish; a rapid and reliable laboratory diagnosis is required in

Christian Drosten; Stephan Göttig; Stefan Schilling; Marcel Asper; Marcus Panning; Herbert Schmitz; Stephan Günther

2002-01-01

99

Release of cellular proteases into the acidic extracellular milieu exacerbates Ebola virus-induced cell damage  

Microsoft Academic Search

Ebola virus is highly cytopathic through mechanisms that are largely unknown. We present evidence that progressive acidification of the extracellular milieu by Ebola virus-infected cells combined with reduced levels of natural cysteine protease inhibitor makes the cells vulnerable to uncontrolled proteolysis of extracellular matrix components by released active endosomal cathepsins, thereby exacerbating Ebola virus-induced cell destruction. The cell surface microenvironment

Laura G. Barrientos; Pierre E. Rollin

2007-01-01

100

The Ebola virus glycoprotein mediates entry via a non-classical dynamin-dependent macropinocytic pathway  

E-print Network

The Ebola virus glycoprotein mediates entry via a non-classical dynamin-dependent macropinocytic for revision 21 June 2011 Accepted 8 August 2011 Available online 9 September 2011 Keywords: Ebola virus Endocytosis Macropinocytosis Pak-1 Dynamin Antigen presenting cells Monocytes Dendritic cells Ebola virus

Chandran, Kartik

101

Ebola virus: immune mechanisms of protection and vaccine development.  

PubMed

Vaccination is one of our most powerful antiviral strategies. Despite the emergence of deadly viruses such as Ebola virus, vaccination efforts have focused mainly on childhood communicable diseases. Although Ebola virus was once believed to be limited to isolated outbreaks in distant lands, forces of globalization potentiate outbreaks anywhere in the world through incidental transmission. Moreover, since this virus has already been transformed into weapon-grade material, the potential exists for it to be used as a biological weapon with catastrophic consequences for any population vulnerable to attack. Ebola hemorrhagic fever (EHF) is a syndrome that can rapidly lead to death within days of symptom onset. The disease directly affects the immune system and vascular bed, with correspondingly high mortality rates. Patients with severe disease produce dangerously high levels of inflammatory cytokines, which destroy normal tissue and microcirculation, leading to profound capillary leakage, renal failure, and disseminated intravascular coagulation. Vaccine development has been fraught with obstacles, primarily of a biosafety nature. Case reports of acutely ill patients with EHF showing improvement with the transfusion of convalescent plasma are at odds with animal studies demonstrating further viral replication with the same treatment. Using mRNA extracted from bone marrow of Ebola survivors, human monoclonal antibodies against Ebola virus surface protein have been experimentally produced and now raise the hope for the development of a safe vaccine. PMID:12698920

Nyamathi, Adeline M; Fahey, John L; Sands, Heather; Casillas, Adrian M

2003-04-01

102

The VP35 protein of Ebola virus impairs dendritic cell maturation induced by virus and lipopolysaccharide.  

PubMed

Ebola virus causes rapidly progressive haemorrhagic fever, which is associated with severe immuosuppression. In infected dendritic cells (DCs), Ebola virus replicates efficiently and inhibits DC maturation without inducing cytokine expression, leading to impaired T-cell proliferation. However, the underlying mechanism remains unclear. In this study, we report that Ebola virus VP35 impairs the maturation of mouse DCs. When expressed in mouse immature DCs, Ebola virus VP35 prevents virus-stimulated expression of CD40, CD80, CD86 and major histocompatibility complex class II. Further, it suppresses the induction of cytokines such as interleukin (IL)-6, IL-12, tumour necrosis factor alpha and alpha/beta interferon (IFN-alpha/beta). Notably, Ebola VP35 attenuates the ability of DCs to stimulate the activation of CD4(+) T cells. Addition of type I IFN to mouse DCs only partially reverses the inhibitory effects of VP35. Moreover, VP35 perturbs mouse DC functions induced by lipopolysaccharide, an agonist of Toll-like receptor 4. Deletion of the amino terminus abolishes its activity, whereas a mutation in the RNA binding motif has no effect. Our work highlights a critical role of VP35 in viral interference in DC function with resultant deficiency in T-cell function, which may contribute to the profound virulence of Ebola virus infection. PMID:19828757

Jin, Huali; Yan, Zhipeng; Prabhakar, Bellur S; Feng, Zongdi; Ma, Yijie; Verpooten, Dustin; Ganesh, Balaji; He, Bin

2010-02-01

103

Characterization of the Ebola virus nucleoprotein-RNA complex.  

PubMed

When Ebola virus nucleoprotein (NP) is expressed in mammalian cells, it assembles into helical structures. Here, the recombinant NP helix purified from cells expressing NP was characterized biochemically and morphologically. We found that the recombinant NP helix is associated with non-viral RNA, which is not protected from RNase digestion and that the morphology of the helix changes depending on the environmental salt concentration. The N-terminal 450 aa residues of NP are sufficient for these properties. However, digestion of the NP-associated RNA eliminates the plasticity of the helix, suggesting that this RNA is an essential structural component of the helix, binding to individual NP molecules via the N-terminal 450 aa. These findings enhance our knowledge of Ebola virus assembly and understanding of the Ebola virus life cycle. PMID:20164259

Noda, Takeshi; Hagiwara, Kyoji; Sagara, Hiroshi; Kawaoka, Yoshihiro

2010-06-01

104

Characterization of the Ebola virus nucleoprotein-RNA complex  

PubMed Central

When Ebola virus nucleoprotein (NP) is expressed in mammalian cells, it assembles into helical structures. Here, the recombinant NP helix purified from cells expressing NP was characterized biochemically and morphologically. We found that the recombinant NP helix is associated with non-viral RNA, which is not protected from RNase digestion and that the morphology of the helix changes depending on the environmental salt concentration. The N-terminal 450 aa residues of NP are sufficient for these properties. However, digestion of the NP-associated RNA eliminates the plasticity of the helix, suggesting that this RNA is an essential structural component of the helix, binding to individual NP molecules via the N-terminal 450 aa. These findings enhance our knowledge of Ebola virus assembly and understanding of the Ebola virus life cycle. PMID:20164259

Noda, Takeshi; Hagiwara, Kyoji; Sagara, Hiroshi; Kawaoka, Yoshihiro

2010-01-01

105

Chimeric human parainfluenza virus bearing the Ebola virus glycoprotein as the sole surface protein is immunogenic and highly protective against Ebola virus challenge  

Microsoft Academic Search

We generated a new live-attenuated vaccine against Ebola virus (EBOV) based on a chimeric virus HPIV3\\/?F-HN\\/EboGP that contains the EBOV glycoprotein (GP) as the sole transmembrane envelope protein combined with the internal proteins of human parainfluenza virus type 3 (HPIV3). Electron microscopy analysis of the virus particles showed that they have an envelope and surface spikes resembling those of EBOV

Alexander Bukreyev; Andrea Marzi; Friederike Feldmann; Liqun Zhang; Lijuan Yang; Jerrold M. Ward; David W. Dorward; Raymond J. Pickles; Brian R. Murphy; Heinz Feldmann; Peter L. Collins

2009-01-01

106

Protection against lethal challenge by Ebola virus-like particles produced in insect cells  

Microsoft Academic Search

Ebola virus-like particles (VLPs) were produced in insect cells using a recombinant baculovirus expression system and their efficacy for protection against Ebola virus infection was investigated. Two immunizations with 50 ?g Ebola VLPs (high dose) induced a high level of antibodies against Ebola GP that exhibited strong neutralizing activity against GP-mediated virus infection and conferred complete protection of vaccinated mice against

Yuliang Sun; Ricardo Carrion Jr.; Ling Ye; Zhiyuan Wen; Young-Tae Ro; Kathleen Brasky; Anysha E. Ticer; E. Ellen Schwegler; Jean L. Patterson; Richard W. Compans; Chinglai Yang

2009-01-01

107

GP mRNA of Ebola Virus Is Edited by the Ebola Virus Polymerase and by T7 and Vaccinia Virus Polymerases 1  

Microsoft Academic Search

The glycoprotein gene of Ebola virus contains a translational stop codon in the middle, thus preventing synthesis of full-length glycoprotein. Twenty percent of the mRNA isolated from Ebola virus-infected cells was shown to be edited, containing one additional nontemplate A in a stretch of seven consecutive A residues. Only the edited mRNA species encoded full-length glycoprotein, whereas the exact copies

VIKTOR E. VOLCHKOV; STEPHAN BECKER; VALENTINA A. VOLCHKOVA; VLADIMIR A. TERNOVOJ; ALEKSANDR N. KOTOV; SERGEJ V. NETESOV; HANS-DIETER KLENK

1995-01-01

108

Marburg Virus Evades Interferon Responses by a Mechanism Distinct from Ebola Virus  

Microsoft Academic Search

Previous studies have demonstrated that Marburg viruses (MARV) and Ebola viruses (EBOV) inhibit interferon (IFN)-?\\/? signaling but utilize different mechanisms. EBOV inhibits IFN signaling via its VP24 protein which blocks the nuclear accumulation of tyrosine phosphorylated STAT1. In contrast, MARV infection inhibits IFN?\\/? induced tyrosine phosphorylation of STAT1 and STAT2. MARV infection is now demonstrated to inhibit not only IFN?\\/?

Charalampos Valmas; Melanie N. Grosch; Michael Schümann; Judith Olejnik; Osvaldo Martinez; Sonja M. Best; Verena Krähling; Christopher F. Basler; Elke Mühlberger

2010-01-01

109

The Marburg Virus 3' Noncoding Region Structurally and Functionally Differs from That of Ebola Virus  

Microsoft Academic Search

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

Sven Enterlein; Kristina M. Schmidt; Michael Schumann; Dominik Conrad; Verena Krahling; Judith Olejnik; Elke Muhlberger

2009-01-01

110

Phosphoinositide3 Kinase-Akt Pathway Controls Cellular Entry of Ebola Virus  

Microsoft Academic Search

The phosphoinositide-3 kinase (PI3K) pathway regulates diverse cellular activities related to cell growth, migration, survival, and vesicular trafficking. It is known that Ebola virus requires endocytosis to establish an infection. However, the cellular signals that mediate this uptake were unknown for Ebola virus as well as many other viruses. Here, the involvement of PI3K in Ebola virus entry was studied.

Mohammad F. Saeed; Andrey A. Kolokoltsov; Alexander N. Freiberg; Michael R. Holbrook; Robert A. Davey

2008-01-01

111

Role of natural killer cells in innate protection against lethal Ebola virus infection  

Microsoft Academic Search

Ebola virus is a highly lethal human pathogen and is rapidly driving many wild primate popula- tions toward extinction. Several lines of evidence suggest that innate, nonspecific host factors are potentially critical for survival after Ebola virus infection. Here, we show that nonreplicating Ebola virus-like particles (VLPs), containing the glycoprotein (GP) and matrix protein virus pro- tein (VP)40, administered 1-3

Kelly L. Warfield; Jeremy G. Perkins; Dana L. Swenson; Emily M. Deal; Catharine M. Bosio; M. Javad Aman; Wayne M. Yokoyama; Howard A. Young; Sina Bavari

2004-01-01

112

Control of ebola virus disease - firestone district, liberia, 2014.  

PubMed

On March 30, 2014, the Ministry of Health and Social Welfare (MOHSW) of Liberia alerted health officials at Firestone Liberia, Inc. (Firestone) of the first known case of Ebola virus disease (Ebola) inside the Firestone rubber tree plantation of Liberia. The patient, who was the wife of a Firestone employee, had cared for a family member with confirmed Ebola in Lofa County, the epicenter of the Ebola outbreak in Liberia during March-April 2014. To prevent a large outbreak among Firestone's 8,500 employees, their dependents, and the surrounding population, the company responded by 1) establishing an incident management system, 2) instituting procedures for the early recognition and isolation of Ebola patients, 3) enforcing adherence to standard Ebola infection control guidelines, and 4) providing differing levels of management for contacts depending on their exposure, including options for voluntary quarantine in the home or in dedicated facilities. In addition, Firestone created multidisciplinary teams to oversee the outbreak response, address case detection, manage cases in a dedicated unit, and reintegrate convalescent patients into the community. The company also created a robust risk communication, prevention, and social mobilization campaign to boost community awareness of Ebola and how to prevent transmission. During August 1-September 23, a period of intense Ebola transmission in the surrounding areas, 71 cases of Ebola were diagnosed among the approximately 80,000 Liberians for whom Firestone provides health care (cumulative incidence = 0.09%). Fifty-seven (80%) of the cases were laboratory confirmed; 39 (68%) of these cases were fatal. Aspects of Firestone's response appear to have minimized the spread of Ebola in the local population and might be successfully implemented elsewhere to limit the spread of Ebola and prevent transmission to health care workers (HCWs). PMID:25340914

Reaves, Erik J; Mabande, Lyndon G; Thoroughman, Douglas A; Arwady, M Allison; Montgomery, Joel M

2014-10-24

113

A case of Ebola virus infection  

Microsoft Academic Search

In November 1976 an investigator at the Microbiological Research Establishment accidentally inoculated himself while processing material from patients in Africa who had been suffering from a haemorrhagic fever of unknown cause. He developed an illness closely resembling Marburg disease, and a virus was isolated from his blood that resembled Marburg virus but was distinct serologically. The course of the illness

R T Emond; B Evans; Etw Bowen; G Lloyd

1977-01-01

114

A Replicating Cytomegalovirus-Based Vaccine Encoding a Single Ebola Virus Nucleoprotein CTL Epitope Confers Protection against Ebola Virus  

Microsoft Academic Search

BackgroundHuman outbreaks of Ebola virus (EBOV) are a serious human health concern in Central Africa. Great apes (gorillas\\/chimpanzees) are an important source of EBOV transmission to humans due to increased hunting of wildlife including the ‘bush-meat’ trade. Cytomegalovirus (CMV) is an highly immunogenic virus that has shown recent utility as a vaccine platform. CMV-based vaccines also have the unique potential

Yoshimi Tsuda; Patrizia Caposio; Christopher J. Parkins; Sara Botto; Ilhem Messaoudi; Luka Cicin-Sain; Heinz Feldmann; Michael A. Jarvis

2011-01-01

115

Ebola Virus VP30 Is an RNA Binding Protein  

Microsoft Academic Search

The Ebola virus (EBOV) genome encodes for several proteins that are necessary and sufficient for replication and transcription of the viral RNAs in vitro; NP, VP30, VP35, and L. VP30 acts in trans with an RNA secondary structure upstream of the first transcriptional start site to modulate transcription. Using a bioinformatics approach, we identified a region within the N terminus

Sinu P. John; Tan Wang; Scott Steffen; Sonia Longhi; Connie S. Schmaljohn; Colleen B. Jonsson

2007-01-01

116

How Ebola and Marburg viruses battle the immune system  

Microsoft Academic Search

The filoviruses Ebola and Marburg have emerged in the past decade from relative obscurity to serve now as archetypes for some of the more intriguing and daunting challenges posed by such agents. Public imagination is captured by deadly outbreaks of these viruses and reinforced by the specter of bioterrorism. As research on these agents has accelerated, it has been found

Lieping Chen; Mansour Mohamadzadeh; Alan L. Schmaljohn

2007-01-01

117

Role of Ebola Virus VP30 in Transcription Reinitiation  

Microsoft Academic Search

VP30 is a phosphoprotein essential for the initiation of Ebola virus transcription. In this work, we have studied the effect of mutations in VP30 phosphorylation sites on the ebolavirus replication cycle by using a reverse genetics system. We demonstrate that VP30 is involved in reinitiation of gene transcription and that this activity is affected by mutations at the phosphorylation sites.

M. J. Martinez; Nadine Biedenkopf; Valentina Volchkova; Bettina Hartlieb; Nathalie Alazard-Dany; Olivier Reynard; Stephan Becker; Viktor Volchkov

2008-01-01

118

Inactivation of Ebola virus with a surfactant nanoemulsion  

Microsoft Academic Search

Hemorrhagic fever caused by Ebola virus (EBO) is a highly contagious infection. This necessitates that the contaminated instruments, clothes, and hospital premises must be completely disinfected. Nanoemulsions are a new form of disinfectant composed of detergents and vegetable oil suspended in water. The antiviral activity of nanoemulsion ATB has been investigated against EBO. The nanoemulsion was tested against two preparations

A. A Chepurnov; L. F Bakulina; A. A Dadaeva; E. N Ustinova; T. S Chepurnova; J. R Baker

2003-01-01

119

RNA Polymerase I-Driven Minigenome System for Ebola Viruses  

Microsoft Academic Search

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

Allison Groseth; Heinz Feldmann; Steven Theriault; Gulsah Mehmetoglu; Ramon Flick

2005-01-01

120

Evaluation in Nonhuman Primates of Vaccines against Ebola Virus  

Microsoft Academic Search

Ebola virus (EBOV) causes acute hemorrhagic fever that is fatal in up to 90% of cases in both humans and nonhuman primates. No vaccines or treatments are available for human use. We evaluated the effects in nonhuman primates of vaccine strategies that had protected mice or guinea pigs from lethal EBOV infec- tion. The following immunogens were used: RNA replicon

Thomas W. Geisbert; Peter Pushko; Kevin Anderson; Jonathan Smith; Kelly J. Davis; Peter B. Jahrling

2002-01-01

121

Proportion of Deaths and Clinical Features in Bundibugyo Ebola Virus Infection, Uganda  

PubMed Central

The first known Ebola hemorrhagic fever (EHF) outbreak caused by Bundibugyo Ebola virus occurred in Bundibugyo District, Uganda, in 2007. Fifty-six cases of EHF were laboratory confirmed. Although signs and symptoms were largely nonspecific and similar to those of EHF outbreaks caused by Zaire and Sudan Ebola viruses, proportion of deaths among those infected was lower (?40%). PMID:21122234

Farnon, Eileen C.; Wamala, Joseph; Okware, Sam; Cannon, Deborah L.; Reed, Zachary; Towner, Jonathan S.; Tappero, Jordan W.; Lutwama, Julius; Downing, Robert; Nichol, Stuart T.; Ksiazek, Thomas G.; Rollin, Pierre E.

2010-01-01

122

Histopathological and Immunohistochemical Studies of Lesions Associated with Ebola Virus in a Naturally Infected Chimpanzee  

E-print Network

S54 Histopathological and Immunohistochemical Studies of Lesions Associated with Ebola Virus'Ivoire Lesions caused by the Co^te d'Ivoire subtype of Ebola virus in a naturally infected young chimpan- zee, so perti-A new subtype of Ebola (EBO) filovirus designated EBO nent laboratory analyses were done

123

LETTER doi:10.1038/nature10348 Ebola virus entry requires the cholesterol transporter  

E-print Network

LETTER doi:10.1038/nature10348 Ebola virus entry requires the cholesterol transporter Niemann { Infections by the Ebola and Marburg filoviruses cause a rapidly fatal haemorrhagic fever in humans for which cells to identify host factors required for Ebola virus entry. Our screen uncovered 67 mutations

Gleeson, Joseph G.

124

Information regarding Ebola Virus Disease (EVD) for Campus Personnel and Visitors September 5, 2014  

E-print Network

Information regarding Ebola Virus Disease (EVD) for Campus Personnel and Visitors September 5, 2014 You are likely very much aware of the ongoing attention focused on the Ebola Virus Disease (EVD Control and Prevention (CDC) considers Ebola to pose little risk to persons in the U.S. at this time. We

Gerdes, J. Christian

125

A reconstituted replication and transcription system for Ebola virus Reston and comparison with Ebola virus Zaire.  

PubMed

The only known filovirus, which presumably is not pathogenic for humans, is Ebola virus (EBOV) Reston. When EBOV Reston and the highly pathogenic EBOV Zaire were grown in cell culture, comparison of the replication kinetics showed a clear growth impairment of EBOV Reston, indicating that the replication cycle of EBOV Reston might be delayed. In addition, the cytopathic effect caused by the virus was much milder with EBOV Reston than with EBOV Zaire. To compare replication and transcription of EBOV Reston and Zaire, a reconstituted minigenomic replication and transcription system based on reverse genetics has been established for EBOV Reston. This system was used to exchange the EBOV Zaire and EBOV Reston nucleocapsid (NC) proteins NP, VP35, VP30, and L, which catalyze replication and transcription. Furthermore, chimeric minigenomes were constructed containing the cis-acting replication signals of EBOV Zaire combined with those of EBOV Reston. Surprisingly, the cis-acting signals as well as almost all NC proteins could be exchanged between EBOV Reston and Zaire, suggesting a high degree of functional homology of the replication/transcription complexes of EBOV Zaire and EBOV Reston. Only the combination of EBOV Zaire VP35 and EBOV Reston L did not result in replication and transcription activity. Although these two proteins did not constitute an active polymerase complex, it was shown by immunofluorescence analysis that they were still able to interact. PMID:15661171

Boehmann, Yannik; Enterlein, Sven; Randolf, Anke; Mühlberger, Elke

2005-02-01

126

Contribution of Ebola Virus Glycoprotein, Nucleoprotein, and VP24 to Budding of VP40 Virus-Like Particles  

Microsoft Academic Search

The VP40 matrix protein of Ebola virus buds from cells in the form of virus-like particles (VLPs) and plays a central role in virus assembly and budding. In this study, we utilized a functional budding assay and cotransfection experiments to examine the contributions of the glycoprotein (GP), nucleoprotein (NP), and VP24 of Ebola virus in facilitating release of VP40 VLPs.

Jillian M. Licata; Reed F. Johnson; Ziying Han; Ronald N. Harty

2004-01-01

127

Modeling The Lifecycle Of Ebola Virus Under Biosafety Level 2 Conditions With Virus-like Particles Containing Tetracistronic Minigenomes.  

PubMed

Ebola viruses cause severe hemorrhagic fevers in humans and non-human primates, with case fatality rates as high as 90%. There are no approved vaccines or specific treatments for the disease caused by these viruses, and work with infectious Ebola viruses is restricted to biosafety level 4 laboratories, significantly limiting the research on these viruses. Lifecycle modeling systems model the virus lifecycle under biosafety level 2 conditions; however, until recently such systems have been limited to either individual aspects of the virus lifecycle, or a single infectious cycle. Tetracistronic minigenomes, which consist of Ebola virus non-coding regions, a reporter gene, and three Ebola virus genes involved in morphogenesis, budding, and entry (VP40, GP1,2, and VP24), can be used to produce replication and transcription-competent virus-like particles (trVLPs) containing these minigenomes. These trVLPs can continuously infect cells expressing the Ebola virus proteins responsible for genome replication and transcription, allowing us to safely model multiple infectious cycles under biosafety level 2 conditions. Importantly, the viral components of this systems are solely derived from Ebola virus and not from other viruses (as is, for example, the case in systems using pseudotyped viruses), and VP40, GP1,2 and VP24 are not overexpressed in this system, making it ideally suited for studying morphogenesis, budding and entry, although other aspects of the virus lifecycle such as genome replication and transcription can also be modeled with this system. Therefore, the tetracistronic trVLP assay represents the most comprehensive lifecycle modeling system available for Ebola viruses, and has tremendous potential for use in investigating the biology of Ebola viruses in future. Here, we provide detailed information on the use of this system, as well as on expected results. PMID:25285674

Hoenen, Thomas; Watt, Ari; Mora, Anita; Feldmann, Heinz

2014-01-01

128

Epidemiology of the Ebola Virus: Facts and Hypotheses.  

PubMed

Marburg and Ebola viruses are emerging pathogens recognized since 1967, and in 1976, when they were first identified. These viruses are the only members of the Filoviridae family. They cause severe, frequently fatal, hemorrhagic fever. Each genus includes some serotypes with the distinctive characteristics to cause high mortality rate during outbreaks. The Ebola-Zaire subtype is the most lethal variant. The epidemiology of human pathogenic filovirus is reviewed in this paper considering the most relevant facts. Primary human cases arise probably through close contact with infected primates. This point may be the key to preventing the introduction of these viruses in human populations. Once introduced in humans, the infection may spread through close contact with infected individuals or their body fluids, particularly in hospital environments. A main feature of filovirus outbreaks is the occurrence of cycles of secondary infection. PMID:11103018

Portela Câmara F

1998-12-01

129

Dispatches Isolation and Phylogenetic Characterization of Ebola Viruses Causing Different Outbreaks in Gabon  

E-print Network

Three outbreaks of Ebola hemorrhagic fever have recently occurred in Gabon. Virus has been isolated from clinical materials from all three outbreaks, and nucleotide sequence analysis of the glycoprotein gene of the isolates and virus present in clinical samples has been carried out. These data indicate that each of the three outbreaks should be considered an independent emergence of a different Ebola virus of the Zaire subtype. As in earlier Ebola virus outbreaks, no genetic variability was detected between virus samples taken during an individual outbreak. Since the first recognized outbreaks of human Ebola virus hemorrhagic fever in Africa in the 1970s, biological and genetic differences have been described among the four distinct Ebola viruses isolated: Zaire, Sudan, and Côte d’Ivoire, all isolated from humans, and Reston virus isolated from macaque monkeys from the Philippines (1-5). Serologic evidence has suggested the presence

unknown authors

130

Protection against lethal challenge by Ebola virus-like particles produced in insect cells.  

PubMed

Ebola virus-like particles (VLPs) were produced in insect cells using a recombinant baculovirus expression system and their efficacy for protection against Ebola virus infection was investigated. Two immunizations with 50 microg Ebola VLPs (high dose) induced a high level of antibodies against Ebola GP that exhibited strong neutralizing activity against GP-mediated virus infection and conferred complete protection of vaccinated mice against lethal challenge by a high dose of mouse-adapted Ebola virus. In contrast, two immunizations with 10 microg Ebola VLPs (low dose) induced 5-fold lower levels of antibodies against GP and these mice were not protected against lethal Ebola virus challenge, similar to control mice that were immunized with 50 microg SIV Gag VLPs. However, the antibody responses against GP were boosted significantly after a third immunization with 10 microg Ebola VLPs to similar levels as those induced by two immunizations with 50 microg Ebola VLPs, and vaccinated mice were also effectively protected against lethal Ebola virus challenge. Furthermore, serum viremia levels in protected mice were either below the level of detection or significantly lower compared to the viremia levels in control mice. These results show that effective protection can be achieved by immunization with Ebola VLPs produced in insect cells, which give high production yields, and lend further support to their development as an effective vaccine strategy against Ebola virus. PMID:18986663

Sun, Yuliang; Carrion, Ricardo; Ye, Ling; Wen, Zhiyuan; Ro, Young-Tae; Brasky, Kathleen; Ticer, Anysha E; Schwegler, E Ellen; Patterson, Jean L; Compans, Richard W; Yang, Chinglai

2009-01-01

131

Man Treated for Ebola in Atlanta Now 'Free' of the Virus  

MedlinePLUS

... this page, please enable JavaScript. Man Treated for Ebola in Atlanta Now 'Free' of the Virus Unidentified ... 2015) Monday, October 20, 2014 Related MedlinePlus Page Ebola MONDAY, Oct. 20, 2014 (HealthDay News) -- An unidentified ...

132

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

Microsoft Academic Search

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 tran- scription 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

ELKE MUHLBERGER; MICHAEL WEIK; VIKTOR E. VOLCHKOV; HANS-DIETER KLENK; STEPHAN BECKER

1999-01-01

133

Distinct Mechanisms of Entry by Envelope Glycoproteins of Marburg and Ebola (Zaire) Viruses  

Microsoft Academic Search

Since the Marburg (MBG) and Ebola (EBO) viruses have sequence homology and cause similar diseases, we hypothesized that they associate with target cells by similar mechanisms. Pseudotype viruses prepared with a luciferase-containing human immunodeficiency virus type 1 backbone and packaged by the MBG virus or the Zaire subtype EBO virus glycoproteins (GP) mediated infection of a comparable wide range of

STEPHEN Y. CHAN; ROBERTO F. SPECK; MELISSA C. MA; MARK A. GOLDSMITH

2000-01-01

134

Ebola virus disease outbreak - Nigeria, july-september 2014.  

PubMed

On July 20, 2014, an acutely ill traveler from Liberia arrived at the international airport in Lagos, Nigeria, and was confirmed to have Ebola virus disease (Ebola) after being admitted to a private hospital. This index patient potentially exposed 72 persons at the airport and the hospital. The Federal Ministry of Health, with guidance from the Nigeria Centre for Disease Control (NCDC), declared an Ebola emergency. Lagos, (pop. 21 million) is a regional hub for economic, industrial, and travel activities and a setting where communicable diseases can be easily spread and transmission sustained. Therefore, implementing a rapid response using all available public health assets was the highest priority. On July 23, the Federal Ministry of Health, with the Lagos State government and international partners, activated an Ebola Incident Management Center as a precursor to the current Emergency Operations Center (EOC) to rapidly respond to this outbreak. The index patient died on July 25; as of September 24, there were 19 laboratory-confirmed Ebola cases and one probable case in two states, with 894 contacts identified and followed during the response. Eleven patients with laboratory-confirmed Ebola had been discharged, an additional patient was diagnosed at convalescent stage, and eight patients had died (seven with confirmed Ebola; one probable). The isolation wards were empty, and 891 (all but three) contacts had exited follow-up, with the remainder due to exit on October 2. No new cases had occurred since August 31, suggesting that the Ebola outbreak in Nigeria might be contained. The EOC, established quickly and using an Incident Management System (IMS) to coordinate the response and consolidate decision making, is largely credited with helping contain the Nigeria outbreak early. National public health emergency preparedness agencies in the region, including those involved in Ebola responses, should consider including the development of an EOC to improve the ability to rapidly respond to urgent public health threats. PMID:25275332

Shuaib, Faisal; Gunnala, Rajni; Musa, Emmanuel O; Mahoney, Frank J; Oguntimehin, Olukayode; Nguku, Patrick M; Nyanti, Sara Beysolow; Knight, Nancy; Gwarzo, Nasir Sani; Idigbe, Oni; Nasidi, Abdulsalam; Vertefeuille, John F

2014-10-01

135

Enhanced Protection against Ebola Virus Mediated by an Improved Adenovirus-Based Vaccine  

Microsoft Academic Search

BackgroundThe Ebola virus is transmitted by direct contact with bodily fluids of infected individuals, eliciting death rates as high as 90% among infected humans. Currently, replication defective adenovirus-based Ebola vaccine is being studied in a phase I clinical trial. Another Ebola vaccine, based on an attenuated vesicular stomatitis virus has shown efficacy in post-exposure treatment of nonhuman primates to Ebola

Jason S. Richardson; Michel K. Yao; Kaylie N. Tran; Maria A. Croyle; James E. Strong; Heinz Feldmann; Gary P. Kobinger; Olivier Schwartz

2009-01-01

136

Inactivation of Lassa, Marburg, and Ebola viruses by gamma irradiation  

SciTech Connect

Because of the cumbersome conditions experienced in a maximum containment laboratory, methods for inactivating highly pathogenic viruses were investigated. The infectivity of Lassa, Marburg, and Ebola viruses was inactivated without altering the immunological activity after radiation with /sup 60/CO gamma rays. At 4 degrees C, Lassa virus was the most difficult to inactivate with a rate of 5.3 X 10(-6) log 50% tissue culture infective dose per rad of /sup 60/CO radiation, as compared with 6.8 X 10(-6) log 50% tissue culture infective dose per rad for Ebola virus and 8.4 X 10(-6) log 50% tissue culture infective dose per rad for Marburg virus. Experimental inactivation curves, as well as curves giving the total radiation needed to inactivate a given concentration of any of the three viruses, are presented. The authors found this method of inactivation to be superior to UV light or beta-propiolactone inactivation and now routinely use it for preparation of material for protein-chemistry studies or for preparation of immunological reagents.

Elliott, L.H.; McCormick, J.B.; Johnson, K.M.

1982-10-01

137

Inactivation of Lassa, Marburg, and Ebola viruses by gamma irradiation  

SciTech Connect

Because of the cumbersome conditions experienced in a maximum containment laboratory, methods for inactivating highly pathogenic viruses were investigated. The infectivity of Lassa, Marburg, and Ebola viruses was inactivated without altering the immunological activity after radiation with /sup 60/Co gamma rays. At 4 degrees C, Lassa virus was the most difficult to inactivate with a rate of 5.3 X 10(-6) log 50% tissue culture infective dose per rad of /sup 60/Co radiation, as compared with 6.8 X 10(-6) log 50% tissue culture infective dose per rad for Ebola virus and 8.4 X 10(-6) log 50% tissue culture infective dose per rad for Marburg virus. Experimental inactivation curves, as well as curves giving the total radiation needed to inactivate a given concentration of any of the three viruses, are presented. We found this method of inactivation to be superior to UV light or beta-propiolactone inactivation and now routinely use it for preparation of material for protein-chemistry studies or for preparation of immunological reagents.

Elliott, L.H.; McCormick, J.B.; Johnson, K.M.

1982-10-01

138

Inactivation of Lassa, Marburg, and Ebola viruses by gamma irradiation.  

PubMed

Because of the cumbersome conditions experienced in a maximum containment laboratory, methods for inactivating highly pathogenic viruses were investigated. The infectivity of Lassa, Marburg, and Ebola viruses was inactivated without altering the immunological activity after radiation with Co60 gamma rays. At 4 degrees C, Lassa virus was the most difficult to inactivate with a rate of 5.3 X 10(-6) log 50% tissue culture infective dose per rad of CO60 radiation, as compared with 6.8 X 10(-6) log 50% tissue culture infective dose per rad for Ebola virus and 8.4 X 10(-6) log 50% tissue culture infective dose per rad for Marburg virus. Experimental inactivation curves, as well as curves giving the total radiation needed to inactivate a given concentration of any of the three viruses, are presented. We found this method of inactivation to be superior to UV light or beta-propiolactone inactivation and now routinely use it for preparation of material for protein-chemistry studies or for preparation of immunological reagents. PMID:7153317

Elliott, L H; McCormick, J B; Johnson, K M

1982-10-01

139

Identification of Protective Epitopes on Ebola Virus Glycoprotein at the Single Amino Acid Level by Using Recombinant Vesicular Stomatitis Viruses  

Microsoft Academic Search

Ebola virus causes lethal hemorrhagic fever in humans, but currently there are no effective vaccines or antiviral compounds for this infectious disease. Passive transfer of monoclonal antibodies (MAbs) protects mice from lethal Ebola virus infection (J. A. Wilson, M. Hevey, R. Bakken, S. Guest, M. Bray, A. L. Schmaljohn, and M. K. Hart, Science 287:1664-1666, 2000). However, the epitopes responsible

Ayato Takada; Heinz Feldmann; Ute Stroeher; Mike Bray; Shinji Watanabe; Hiroshi Ito; Martha McGregor; Yoshihiro Kawaoka

2003-01-01

140

Ebola virus disease outbreak - west Africa, september 2014.  

PubMed

CDC is assisting ministries of health and working with other organizations to control and end the ongoing outbreak of Ebola virus disease (Ebola) in West Africa. The updated data in this report were compiled from ministry of health situation reports and World Health Organization (WHO) sources. Total case counts include all suspected, probable, and confirmed cases as defined by each country. These data reflect reported cases, which make up an unknown proportion of all actual cases. The data also reflect reporting delays that might vary from country to country. PMID:25275331

2014-10-01

141

Protective efficacy of neutralizing antibodies against Ebola virus infection.  

PubMed

Ebola virus causes lethal hemorrhagic fever in humans and nonhuman primates, but no effective antiviral compounds are available for the treatment of this infection. The surface glycoprotein (GP) of Ebola virus is an important target of neutralizing antibodies. Although passive transfer of GP-specific antibodies has been evaluated in mouse and guinea pig models, protection was achieved only by treatment shortly before or after virus challenge. Using these animal models, we evaluated the protective efficacy of two monoclonal antibodies whose epitopes are distinct from those of the antibodies tested by others. Treatment of mice with these antibodies 2 days after challenge completely protected most of the animals; even treatment 3 or 4 days after challenge was partially effective. Although antibody treatment in the guinea pig model was not as effective as in the mouse model, single-dose treatment of guinea pigs 1 day before, or 1 or 2 days after challenge did protect some animals. Interestingly, the protective effects seen in these animal models did not correlate with the in vitro neutralizing activity of the antibodies, suggesting different mechanisms of the neutralization by these antibodies. These results underscore the potential therapeutic utility of monoclonal antibodies for postexposure treatment of Ebola virus infections. PMID:17055127

Takada, Ayato; Ebihara, Hideki; Jones, Steven; Feldmann, Heinz; Kawaoka, Yoshihiro

2007-01-22

142

Cell Adhesion Promotes Ebola Virus Envelope Glycoprotein-Mediated Binding and Infection  

Microsoft Academic Search

Ebola virus infects a wide variety of adherent cell types, while nonadherent cells are found to be refractory. To explore this correlation, we compared the ability of pairs of related adherent and nonadherent cells to bind a recombinant Ebola virus receptor binding domain (EboV RBD) and to be infected with Ebola virus glyco- protein (GP)-pseudotyped particles. Both human 293F and

Derek Dube; Kathryn L. Schornberg; Tzanko S. Stantchev; Matthew I. Bonaparte; Sue E. Delos; Amy H. Bouton; Christopher C. Broder; Judith M. White

2008-01-01

143

A case of Ebola virus infection.  

PubMed Central

In November 1976 an investigator at the Microbiological Research Establishment accidentally inoculated himself while processing material from patients in Africa who had been suffering from a haemorrhagic fever of unknown cause. He developed an illness closely resembling Marburg disease, and a virus was isolated from his blood that resembled Marburg virus but was distinct serologically. The course of the illness was mild and may have been modified by treatment with human interferon and convalescent serum. Convalescence was protracted; there was evidence of bone-marrow depression and virus was excreted in low titre for some weeks. Recovery was complete. Infection was contained by barrier-nursing techniques using a negative-pressure plastic isolator and infection did not spread to attendant staff or to the community. PMID:890413

Emond, R T; Evans, B; Bowen, E T; Lloyd, G

1977-01-01

144

A case of Ebola virus infection.  

PubMed

In November 1976 an investigator at the Microbiological Research Establishment accidentally inoculated himself while processing material from patients in Africa who had been suffering from a haemorrhagic fever of unknown cause. He developed an illness closely resembling Marburg disease, and a virus was isolated from his blood that resembled Marburg virus but was distinct serologically. The course of the illness was mild and may have been modified by treatment with human interferon and convalescent serum. Convalescence was protracted; there was evidence of bone-marrow depression and virus was excreted in low titre for some weeks. Recovery was complete. Infection was contained by barrier-nursing techniques using a negative-pressure plastic isolator and infection did not spread to attendant staff or to the community. PMID:890413

Emond, R T; Evans, B; Bowen, E T; Lloyd, G

1977-08-27

145

Ebola  

MedlinePLUS

What Is Ebola? Ebola is a dangerous virus that can cause people to get very sick and even die. The virus ... others is low. What Happens When Someone Has Ebola? Ebola often starts with fever and headache, kind ...

146

In Vivo Replication and Pathogenesis of Vesicular Stomatitis Virus Recombinant M40 Containing Ebola Virus L-Domain Sequences  

PubMed Central

The M40 VSV recombinant was engineered to contain overlapping PTAP and PPxY L-domain motifs and flanking residues from the VP40 protein of Ebola virus. Replication of M40 in cell culture is virtually indistinguishable from that of control viruses. However, the presence of the Ebola PTAP motif in the M40 recombinant enabled this virus to interact with and recruit host Tsg101, which was packaged into M40 virions. In this brief report, we compared replication and the pathogenic profiles of M40 and the parental virus M51R in mice to determine whether the presence of the Ebola L-domains and flanking residues altered in vivo characteristics of the virus. Overall, the in vivo characteristics of M40 were similar to those of the parental M51R virus, indicating that the Ebola sequences did not alter pathogenesis of VSV in this small animal model of infection. PMID:23794798

Irie, Takashi; Carnero, Elena; Garcia-Sastre, Adolfo; Harty, Ronald N.

2013-01-01

147

Generation of vero cells expressing ebola virus glycoprotein.  

PubMed

To establish replication-incompetent Ebola virus (EBOV) lacking its glycoprotein (GP), we attempted to generate a Vero cell line that constitutively expressed GP. We used a retroviral vector to transduce Vero cells with the EBOV GP gene, resulting in a high expression level of GP on the cell surface. The Vero cells expressing EBOV GP complemented the replication cycle of vesicular stomatitis virus, which lacks the essential viral glycoprotein. This cell line might be useful for basic research on EBOV GP as well as for vaccine production. PMID:19420858

Makino, Akiko; Kawaoka, Yoshihiro

2009-04-01

148

Mapping the zoonotic niche of Ebola virus disease in Africa.  

PubMed

Ebola virus disease (EVD) is a complex zoonosis that is highly virulent in humans. The largest recorded outbreak of EVD is ongoing in West Africa, outside of its previously reported and predicted niche. We assembled location data on all recorded zoonotic transmission to humans and Ebola virus infection in bats and primates (1976-2014). Using species distribution models, these occurrence data were paired with environmental covariates to predict a zoonotic transmission niche covering 22 countries across Central and West Africa. Vegetation, elevation, temperature, evapotranspiration, and suspected reservoir bat distributions define this relationship. At-risk areas are inhabited by 22 million people; however, the rarity of human outbreaks emphasises the very low probability of transmission to humans. Increasing population sizes and international connectivity by air since the first detection of EVD in 1976 suggest that the dynamics of human-to-human secondary transmission in contemporary outbreaks will be very different to those of the past. PMID:25201877

Pigott, David M; Golding, Nick; Mylne, Adrian; Huang, Zhi; Henry, Andrew J; Weiss, Daniel J; Brady, Oliver J; Kraemer, Moritz Ug; Smith, David L; Moyes, Catherine L; Bhatt, Samir; Gething, Peter W; Horby, Peter W; Bogoch, Isaac I; Brownstein, John S; Mekaru, Sumiko R; Tatem, Andrew J; Khan, Kamran; Hay, Simon I

2014-01-01

149

Vaccine to Confer to Nonhuman Primates Complete Protection Against Multistrain Ebola and Marburg Virus Infections.  

National Technical Information Service (NTIS)

Filoviruses (Ebola and Marburg viruses) are among the deadliest viruses known to mankind with mortality rates nearing 90%. These pathogens are highly infectious through contact with infected body fluids and can be easily aerosolized. Additionally, there a...

D. Wang, D. L. Swenson, J. Woraratanadharm, K. L. Warfield, M. Luo

2008-01-01

150

Protective Cytotoxic T-Cell Responses Induced by Venezuelan Equine Encephalitis Virus Replicons Expressing Ebola Virus Proteins  

PubMed Central

Infection with Ebola virus causes a severe disease accompanied by high mortality rates, and there are no licensed vaccines or therapies available for human use. Filovirus vaccine research efforts still need to determine the roles of humoral and cell-mediated immune responses in protection from Ebola virus infection. Previous studies indicated that exposure to Ebola virus proteins expressed from packaged Venezuelan equine encephalitis virus replicons elicited protective immunity in mice and that antibody-mediated protection could only be demonstrated after vaccination against the glycoprotein. In this study, the murine CD8+ T-cell responses to six Ebola virus proteins were examined. CD8+ T cells specific for Ebola virus glycoprotein, nucleoprotein, and viral proteins (VP24, VP30, VP35, and VP40) were identified by intracellular cytokine assays using splenocytes from vaccinated mice. The cells were expanded by restimulation with peptides and demonstrated cytolytic activity. Adoptive transfer of the CD8+ cytotoxic T cells protected filovirus naïve mice from challenge with Ebola virus. These data support a role for CD8+ cytotoxic T cells as part of a protective mechanism induced by vaccination against six Ebola virus proteins and provide additional evidence that cytotoxic T-cell responses can contribute to protection from filovirus infections. PMID:16254354

Olinger, Gene G.; Bailey, Michael A.; Dye, John M.; Bakken, Russell; Kuehne, Ana; Kondig, John; Wilson, Julie; Hogan, Robert J.; Hart, Mary Kate

2005-01-01

151

Vesicular Release of Ebola Virus Matrix Protein VP40  

Microsoft Academic Search

We have analysed the expression and cellular localisation of the matrix protein VP40 from Ebola virus. Full-length VP40 and an N-terminal truncated construct missing the first 31 residues [VP40(31–326)] both locate to the plasma membrane of 293T cells when expressed transiently, while a C-terminal truncation of residues 213 to 326 [VP40(31–212)] shows only expression in the cytoplasm, when analysed by

Joanna Timmins; Sandra Scianimanico; Guy Schoehn; Winfried Weissenhorn

2001-01-01

152

A DNA vaccine for the prevention of Ebola virus infection.  

PubMed

The NIH and Vical Inc are developing an intramuscular needle-free DNA vaccine containing plasmids encoding the envelope glycoprotein of Ebola virus (EBOV) from the Sudan and Zaire strains, and the nucleoprotein of EBOV Zaire strain. A phase I clinical trial demonstrated a good safety profile, with most adverse events limited to the site of injection and largely attributable to the delivery. PMID:18535936

Dery, Markalain; Bausch, Daniel G

2008-06-01

153

Role of Ebola virus VP30 in transcription reinitiation.  

PubMed

VP30 is a phosphoprotein essential for the initiation of Ebola virus transcription. In this work, we have studied the effect of mutations in VP30 phosphorylation sites on the ebolavirus replication cycle by using a reverse genetics system. We demonstrate that VP30 is involved in reinitiation of gene transcription and that this activity is affected by mutations at the phosphorylation sites. PMID:18829754

Martínez, Miguel J; Biedenkopf, Nadine; Volchkova, Valentina; Hartlieb, Bettina; Alazard-Dany, Nathalie; Reynard, Olivier; Becker, Stephan; Volchkov, Viktor

2008-12-01

154

Chimpanzee adenovirus vaccine protects against Zaire Ebola virus  

Microsoft Academic Search

This study evaluated the use of a chimpanzee-based adenovirus vaccine in mouse and Guinea pigs models of Zaire Ebola virus (ZEBOV) infection. Vaccine vector expressing the envelope glycoprotein of ZEBOV was created from the molecular clone of chimpanzee adenovirus pan7 (AdC7). AdC7 vaccine stimulated robust T and B cell responses to ZEBOV in naïve mice inducing complete protection to an

Gary P. Kobinger; Heinz Feldmann; Yan Zhi; Gregory Schumer; Guangping Gao; Friederike Feldmann; Steven Jones; James M. Wilson

2006-01-01

155

Persistent Infection with Ebola Virus under Conditions of Partial Immunity  

PubMed Central

Ebola hemorrhagic fever in humans is associated with high mortality; however, some infected hosts clear the virus and recover. The mechanisms by which this occurs and the correlates of protective immunity are not well defined. Using a mouse model, we determined the role of the immune system in clearance of and protection against Ebola virus. All CD8 T-cell-deficient mice succumbed to subcutaneous infection and had high viral antigen titers in tissues, whereas mice deficient in B cells or CD4 T cells cleared infection and survived, suggesting that CD8 T cells, independent of CD4 T cells and antibodies, are critical to protection against subcutaneous Ebola virus infection. B-cell-deficient mice that survived the primary subcutaneous infection (vaccinated mice) transiently depleted or not depleted of CD4 T cells also survived lethal intraperitoneal rechallenge for ?25 days. However, all vaccinated B-cell-deficient mice depleted of CD8 T cells had high viral antigen titers in tissues following intraperitoneal rechallenge and died within 6 days, suggesting that memory CD8 T cells by themselves can protect mice from early death. Surprisingly, vaccinated B-cell-deficient mice, after initially clearing the infection, were found to have viral antigens in tissues later (day 120 to 150 post-intraperitoneal infection). Furthermore, following intraperitoneal rechallenge, vaccinated B-cell-deficient mice that were transiently depleted of CD4 T cells had high levels of viral antigen in tissues earlier (days 50 to 70) than vaccinated undepleted mice. This demonstrates that under certain immunodeficiency conditions, Ebola virus can persist and that loss of primed CD4 T cells accelerates the course of persistent infections. These data show that CD8 T cells play an important role in protection against acute disease, while both CD4 T cells and antibodies are required for long-term protection, and they provide evidence of persistent infection by Ebola virus suggesting that under certain conditions of immunodeficiency a host can harbor virus for prolonged periods, potentially acting as a reservoir. PMID:14694127

Gupta, Manisha; Mahanty, Siddhartha; Greer, Patricia; Towner, Jonathan S.; Shieh, Wun-Ju; Zaki, Sherif R.; Ahmed, Rafi; Rollin, Pierre E.

2004-01-01

156

Characterization of the L gene and 5' trailer region of Ebola virus.  

PubMed

The nucleotide sequences of the L gene and 5' trailer region of Ebola virus strain Mayinga (subtype Zaire) have been determined, thus completing the sequence of the Ebola virus genome. The putative transcription start signal of the L gene was identical to the determined 5' terminus of the L mRNA (5' GAGGAAGAUUAA) and showed a high degree of similarity to the corresponding regions of other Ebola virus genes. The 3' end of the L mRNA terminated with 5' AUUAUAAAAAA, a sequence which is distinct from the proposed transcription termination signals of other genes. The 5' trailer sequence of the Ebola virus genomic RNA consisted of 676 nt and revealed a self-complementary sequence at the extreme end which may play an important role in virus replication. The L gene contained a single ORF encoding a polypeptide of 2212 aa. The deduced amino acid sequence showed identities of about 73 and 44% to the L proteins of Ebola virus strain Maleo (subtype Sudan) and Marburg virus, respectively. Sequence comparison studies of the Ebola virus L proteins with several corresponding proteins of other non-segmented, negative-strand RNA viruses, including Marburg viruses, confirmed a close relationship between filoviruses and members of the Paramyxovirinae. The presence of several conserved linear domains commonly found within L proteins of other members of the order Mononegavirales identified this protein as the RNA-dependent RNA polymerase of Ebola virus. PMID:10073695

Volchkov, V E; Volchkova, V A; Chepurnov, A A; Blinov, V M; Dolnik, O; Netesov, S V; Feldmann, H

1999-02-01

157

Role of Ebola Virus Secreted Glycoproteins and Virus-Like Particles in Activation of Human Macrophages  

Microsoft Academic Search

Ebola virus, a member of the family Filoviridae, causes one of the most severe forms of viral hemorrhagic fever. In the terminal stages of disease, symptoms progress to hypotension, coagulation disorders, and hemorrhages, and there is prominent involvement of the mononuclear phagocytic and reticuloendothelial systems. Cells of the mononuclear phagocytic system are primary target cells and producers of inflammatory mediators.

Victoria Wahl-Jensen; Sabine K. Kurz; Paul R. Hazelton; Hans-Joachim Schnittler; Ute Stroher; Dennis R. Burton; Heinz Feldmann

2005-01-01

158

The Ebola Virus Matrix Protein Penetrates into the Plasma Membrane  

PubMed Central

Ebola, a fatal virus in humans and non-human primates, has no Food and Drug Administration-approved vaccines or therapeutics. The virus from the Filoviridae family causes hemorrhagic fever, which rapidly progresses and in some cases has a fatality rate near 90%. The Ebola genome encodes seven genes, the most abundantly expressed of which is viral protein 40 (VP40), the major Ebola matrix protein that regulates assembly and egress of the virus. It is well established that VP40 assembles on the inner leaflet of the plasma membrane; however, the mechanistic details of plasma membrane association by VP40 are not well understood. In this study, we used an array of biophysical experiments and cellular assays along with mutagenesis of VP40 to investigate the role of membrane penetration in VP40 assembly and egress. Here we demonstrate that VP40 is able to penetrate specifically into the plasma membrane through an interface enriched in hydrophobic residues in its C-terminal domain. Mutagenesis of this hydrophobic region consisting of Leu213, Ile293, Leu295, and Val298 demonstrated that membrane penetration is critical to plasma membrane localization, VP40 oligomerization, and viral particle egress. Taken together, VP40 membrane penetration is an important step in the plasma membrane localization of the matrix protein where oligomerization and budding are defective in the absence of key hydrophobic interactions with the membrane. PMID:23297401

Adu-Gyamfi, Emmanuel; Soni, Smita P.; Xue, Yi; Digman, Michelle A.; Gratton, Enrico; Stahelin, Robert V.

2013-01-01

159

Role of Natural Killer Cells in Innate Protection against Lethal Ebola Virus Infection  

E-print Network

Ebola virus is a highly lethal human pathogen and is rapidly driving many wild primate populations toward extinction. Several lines of evidence suggest that innate, nonspecific host factors are potentially critical for survival after Ebola virus infection. Here, we show that nonreplicating Ebola virus-like particles (VLPs), containing the glycoprotein (GP) and matrix protein virus protein (VP)40, administered 1–3 d before Ebola virus infection rapidly induced protective immunity. VLP injection enhanced the numbers of natural killer (NK) cells in lymphoid tissues. In contrast to live Ebola virus, VLP treatment of NK cells enhanced cytokine secretion and cytolytic activity against NK-sensitive targets. Unlike wild-type mice, treatment of NK-deficient or-depleted mice with VLPs had no protective effect against Ebola virus infection and NK cells treated with VLPs protected against Ebola virus infection when adoptively transferred to naive mice. The mechanism of NK cell–mediated protection clearly depended on perforin, but not interferon-? secretion. Particles containing only VP40 were sufficient to induce NK cell responses and provide protection from infection in the absence of the viral GP. These findings revealed a decisive role for NK cells during lethal Ebola virus infection. This work should open new doors for better understanding

Kelly L. Warfield; Jeremy G. Perkins; Dana L. Swenson; Emily M. Deal; Catharine M. Bosio; M. Javad Aman; Wayne M. Yokoyama; Howard A. Young; Sina Bavari

160

Host IQGAP1 and Ebola Virus VP40 Interactions Facilitate Virus-Like Particle Egress  

PubMed Central

We have identified host IQGAP1 as an interacting partner for Ebola virus (EBOV) VP40, and its expression is required for EBOV VP40 virus-like particle (VLP) budding. IQGAP1 is involved in actin cytoskeletal remodeling during cell migration and formation of filopodia. The physical interaction and the functional requirement for IQGAP1 in EBOV VP40 VLP egress link virus budding to the cytoskeletal remodeling machinery. Consequently, this interaction represents a novel target for development of therapeutics to block budding and transmission of filoviruses. PMID:23637409

Lu, Jianhong; Qu, Yonggang; Liu, Yuliang; Jambusaria, Rakesh; Han, Ziying; Ruthel, Gordon; Freedman, Bruce D.

2013-01-01

161

Downregulation of beta1 integrins by Ebola virus glycoprotein: implication for virus entry.  

PubMed

Filoviruses, including Ebola virus, are cytotoxic. To investigate the role of the Ebola virus glycoprotein (GP) in this cytopathic effect, we transiently expressed the GP in human kidney 293T cells. Expression of wild-type GP, but not the secretory form of the molecule lacking a membrane anchor, induced rounding and detachment of the cells, as did a chimeric GP containing its ectodomain and influenza virus hemagglutinin transmembrane-cytoplasmic domain. These results indicate that the GP ectodomain and its anchorage to the membrane are required for GP-induced morphologic changes in host cells. Since cell rounding and detachment could be associated with reduced levels of cell adhesion molecules, we also studied the expression of integrins, which are major molecules for adhesion to extracellular matrices, and found that the beta1 integrin group is downregulated by the GP. This result was further extended by experiments in which anti-beta1 monoclonal antibodies or purified integrins inhibited the infectivity of vesicular stomatitis virus pseudotyped with the GP. We suggest that integrins, especially the beta1 group, might interact with the GP and perhaps be involved in Ebola virus entry into cells. PMID:11112476

Takada, A; Watanabe, S; Ito, H; Okazaki, K; Kida, H; Kawaoka, Y

2000-12-01

162

Reverse Genetics Demonstrates that Proteolytic Processing of the Ebola Virus Glycoprotein Is Not Essential for Replication in Cell Culture  

Microsoft Academic Search

Ebola virus, a prime example of an emerging pathogen, causes fatal hemorrhagic fever in humans and in nonhuman primates. Identification of major determinants of Ebola virus pathogenicity has been hampered by the lack of effective strategies for experimental mutagenesis. Here we exploit a reverse genetics system that allows the generation of Ebola virus from cloned cDNA to engineer a mutant

Gabriele Neumann; Heinz Feldmann; Shinji Watanabe; Igor Lukashevich; Yoshihiro Kawaoka

2002-01-01

163

Ebola virus outbreaks in Africa: past and present.  

PubMed

Ebola haemorrhagic fever (EHF) is a zoonosis affecting both human and non-human primates (NHP). Outbreaks in Africa occur mainly in the Congo and Nile basins. The first outbreaks of EHF occurred nearly simultaneously in 1976 in the Democratic Republic of the Congo (DRC, former Zaire) and Sudan with very high case fatality rates of 88% and 53%, respectively. The two outbreaks were caused by two distinct species of Ebola virus named Zaire ebolavirus (ZEBOV) and Sudan ebolavirus (SEBOV). The source of transmission remains unknown. After a long period of silence (1980-1993), EHF outbreaks in Africa caused by the two species erupted with increased frequency and new species were discovered, namely Côte d'Ivoire ebolavirus (CIEBOV) in 1994 in the Ivory Coast and Bundibugyo ebolavirus (BEBOV) in 2007 in Uganda. The re-emergence of EHF outbreaks in Gabon and Republic of the Congo were concomitant with an increase in mortality amongst gorillas and chimpanzees infected with ZEBOV. The human outbreaks were related to multiple, unrelated index cases who had contact with dead gorillas or chimpanzees. However, in areas where NHP were rare or absent, as in Kikwit (DRC) in 1995, Mweka (DRC) in 2007, Gulu (Uganda) in 2000 and Yambio (Sudan) in 2004, the hunting and eating of fruit bats may have resulted in the primary transmission of Ebola virus to humans. Human-to-human transmission is associated with direct contact with body fluids or tissues from an infected subject or contaminated objects. Despite several, often heroic field studies, the epidemiology and ecology of Ebola virus, including identification of its natural reservoir hosts, remains a formidable challenge for public health and scientific communities. PMID:23327370

Muyembe-Tamfum, J J; Mulangu, S; Masumu, Justin; Kayembe, J M; Kemp, A; Paweska, Janusz T

2012-01-01

164

Comparison of individual and combination DNA vaccines for B. anthracis, Ebola virus, Marburg virus and Venezuelan equine encephalitis virus  

Microsoft Academic Search

Multiagent DNA vaccines for highly pathogenic organisms offer an attractive approach for preventing naturally occurring or deliberately introduced diseases. Few animal studies have compared the feasibility of combining unrelated gene vaccines. Here, we demonstrate that DNA vaccines to four dissimilar pathogens that are known biowarfare agents, Bacillus anthracis, Ebola (EBOV), Marburg (MARV), and Venezuelan equine encephalitis virus (VEEV), can elicit

Jenny Riemenschneider; Aura Garrison; Joan Geisbert; Peter Jahrling; Michael Hevey; Diane Negley; Alan Schmaljohn; John Lee; Mary Kate Hart; Lorna Vanderzanden; David Custer; Mike Bray; Albert Ruff; Bruce Ivins; Anthony Bassett; Cynthia Rossi; Connie Schmaljohn

2003-01-01

165

Ebola Virus Can Be Effectively Neutralized by Antibody Produced in Natural Human Infection  

Microsoft Academic Search

The activity of antibodies against filoviruses is poorly understood but has important consequences for vaccine design and passive prophylaxis. To investigate this activity, a panel of recombinant human monoclonal antibodies to Ebola virus antigens was isolated from phage display libraries constructed from RNA from donors who recovered from infection in the 1995 Ebola virus outbreak in Kikwit, Democratic Republic of

TOSHIAKI MARUYAMA; LUIS L. RODRIGUEZ; PETER B. JAHRLING; ANTHONY SANCHEZ; ALI S. KHAN; STUART T. NICHOL; C. J. PETERS; PAUL W. H. I. PARREN; DENNIS R. BURTON; Fort Detrick

1999-01-01

166

Ebola Virus Selectively Inhibits Responses to Interferons, but Not to Interleukin1b, in Endothelial Cells  

Microsoft Academic Search

Ebola virus infection is highly lethal and leads to severe immunosuppression. In this study, we demonstrate that infection of human umbilical vein endothelial cells (HUVECs) with Ebola virus Zaire (EZ) suppressed basal expression of the major histocompatibility complex class I (MHC I) family of proteins and inhibited the induction of multiple genes by alpha interferon (IFN-a) and IFN-g, including those

BRIAN H. HARCOURT; ANTHONY SANCHEZ; MARGARET K. OFFERMANN

1999-01-01

167

996. Development of an siRNA Based Therapy for Ebola Virus Infection  

Microsoft Academic Search

Ebola virus infection causes a severe and frequently fatal hemorrhagic fever that is refractory to treatment with currently available antiviral therapeutics. Ebola and the related Marburg virus are of concern as potential bioweapon (BW) threats since they have the potential for aerosol dissemination and weaponization. RNA interference (RNAi) represents a powerful, naturally occurring biological strategy for inhibition of gene expression

Thomas W. Geisbert; Lisa E. Hensley; Kristopher M. Curtis; Joan B. Geisbert; Kathleen M. Daddario; Elliott Kagan; Amy C. H. Lee; Lorne Palmer; Lloyd Jeffs; Ian MacLachlan

2005-01-01

168

Characterization of the L gene and 5« trailer region of Ebola virus  

Microsoft Academic Search

The nucleotide sequences of the L gene and 5« trailer region of Ebola virus strain Mayinga (subtype Zaire) have been determined, thus completing the sequence of the Ebola virus genome. The putative transcription start signal of the L gene was identical to the determined 5« terminus of the L mRNA (5« GAGGAAGAUUAA) and showed a high degree of similarity to

Viktor E. Volchkov; Valentina A. Volchkova; Alexandr A. Chepurnov; Vladimir M. Blinov; Olga Dolnik; Sergej V. Netesov; Heinz Feldmann

1999-01-01

169

Structural and Functional Characterization of Reston Ebola Virus VP35 Interferon Inhibitory Domain  

Microsoft Academic Search

Ebolaviruses are causative agents of lethal hemorrhagic fever in humans and nonhuman primates. Among the filoviruses characterized thus far, Reston Ebola virus (REBOV) is the only Ebola virus that is nonpathogenic to humans despite the fact that REBOV can cause lethal disease in nonhuman primates. Previous studies also suggest that REBOV is less effective at inhibiting host innate immune responses

Daisy W. Leung; Reed S. Shabman; Mina Farahbakhsh; Kathleen C. Prins; Dominika M. Borek; Tianjiao Wang; Elke Mühlberger; Christopher F. Basler; Gaya K. Amarasinghe

2010-01-01

170

Viral Replication and Host Gene Expression in Alveolar Macrophages Infected with Ebola Virus (Zaire Strain)  

Microsoft Academic Search

In order to characterize the cellular response to and identify potential diagnostic markers for the early detection of Ebola virus, an in vitro culture system involving nonhuman primate alveolar macrophages was developed. Ebola virus replication in the alveolar macrophages was characterized by plaque assay, immuno- histochemical analysis, and in situ hybridization. Fluorogenic 5-nuclease assays specific for nonhuman primate proinflammatory cytokines

Tammy R. Gibb; David A. Norwood; N. Woollen; E. A. Henchal

2002-01-01

171

Immune and pathophysiological processes in baboons experimentally infected with Ebola virus adapted to guinea pigs  

Microsoft Academic Search

The dynamics of pathophysiological and immunological parameters monitored in monkeys Papio hamadryas infected with the guinea pig-adapted Ebola virus strain demonstrated that this viral strain preserved its virulence for monkeys and caused the disease with characteristic features similar to those caused by non-adapted Ebola virus. However, certain previously unknown patterns have been observed: (1) prolongation of the febrile period by

George M Ignatiev; Alexandra A Dadaeva; Sergey V Luchko; Alexander A Chepurnov

2000-01-01

172

Production and characterization of monoclonal antibodies against different epitopes of Ebola virus antigens  

Microsoft Academic Search

Ebola virus (EBOV) causes hemorrhagic fever in humans and nonhuman primates with up to 90% mortality rate. In this study, Ebola virus like particles (EVLPs) and the aglycosyl subfragment of glycoprotein (GP(1) subfragment D) were used to generate monoclonal antibodies (MAbs) against different epitopes of the viral antigens. Such MAbs could be useful in diagnostics and potential therapeutics of viral

Soraya Shahhosseini; Dipankar Das; Xiangguo Qiu; Heinz Feldmann; Steven M. Jones; Mavanur R Suresh

2007-01-01

173

Accelerated vaccination for Ebola virus haemorrhagic fever in non-human primates  

Microsoft Academic Search

Containment of highly lethal Ebola virus outbreaks poses a serious public health challenge. Although an experimental vaccine has successfully protected non-human primates against disease, more than six months was required to complete the immunizations, making it impractical to limit an acute epidemic. Here, we report the development of accelerated vaccination against Ebola virus in non-human primates. The antibody response to

Nancy J. Sullivan; Thomas W. Geisbert; Joan B. Geisbert; Ling Xu; Zhi-yong Yang; Mario Roederer; Richard A. Koup; Peter B. Jahrling; Gary J. Nabel

2003-01-01

174

Ebola virus infection in guinea pigs: presumable role of granulomatous inflammation in pathogenesis  

Microsoft Academic Search

Summary An approach combining virology with light and electron microscopy was used to study the organs of guinea pigs during nine serial passages of Ebola virus, strain Zaire. It was observed that the wild type of Ebola virus causes severe granulomatous inflammation in the liver and reproduces in the cells of the mononuclear phagocyte system (MPS). Based on morphological characterization,

E. Ryabchikova; L. Kolesnikova; M. Smolina; V. Tkachev; L. Pereboeva; S. Baranova; A. Grazhdantseva; Y. Rassadkin

1996-01-01

175

Phosphoinositide-3 kinase-Akt pathway controls cellular entry of Ebola virus.  

PubMed

The phosphoinositide-3 kinase (PI3K) pathway regulates diverse cellular activities related to cell growth, migration, survival, and vesicular trafficking. It is known that Ebola virus requires endocytosis to establish an infection. However, the cellular signals that mediate this uptake were unknown for Ebola virus as well as many other viruses. Here, the involvement of PI3K in Ebola virus entry was studied. A novel and critical role of the PI3K signaling pathway was demonstrated in cell entry of Zaire Ebola virus (ZEBOV). Inhibitors of PI3K and Akt significantly reduced infection by ZEBOV at an early step during the replication cycle. Furthermore, phosphorylation of Akt-1 was induced shortly after exposure of cells to radiation-inactivated ZEBOV, indicating that the virus actively induces the PI3K pathway and that replication was not required for this induction. Subsequent use of pseudotyped Ebola virus and/or Ebola virus-like particles, in a novel virus entry assay, provided evidence that activity of PI3K/Akt is required at the virus entry step. Class 1A PI3Ks appear to play a predominant role in regulating ZEBOV entry, and Rac1 is a key downstream effector in this regulatory cascade. Confocal imaging of fluorescently labeled ZEBOV indicated that inhibition of PI3K, Akt, or Rac1 disrupted normal uptake of virus particles into cells and resulted in aberrant accumulation of virus into a cytosolic compartment that was non-permissive for membrane fusion. We conclude that PI3K-mediated signaling plays an important role in regulating vesicular trafficking of ZEBOV necessary for cell entry. Disruption of this signaling leads to inappropriate trafficking within the cell and a block in steps leading to membrane fusion. These findings extend our current understanding of Ebola virus entry mechanism and may help in devising useful new strategies for treatment of Ebola virus infection. PMID:18769720

Saeed, Mohammad F; Kolokoltsov, Andrey A; Freiberg, Alexander N; Holbrook, Michael R; Davey, Robert A

2008-01-01

176

Ebola virus failure to stimulate plasmacytoid dendritic cell interferon responses correlates with impaired cellular entry.  

PubMed

We examined the ability of the Ebola virus to elicit an antiviral response from plasmacytoid dendritic cells (pDCs). Exposure of pDCs to Ebola virus did not result in significantly higher levels of interferon-? production than the levels in mock-infected cells. After inoculation with Ebola virus under the same conditions, conventional dendritic cells expressed viral proteins whereas pDCs did not, suggesting that the latter cells were not infected. Assessment of the entry of Ebola virus-like particles into pDCs revealed that pDCs are highly impaired for viral entry in comparison with conventional dendritic cells. These observations identify a novel means by which Ebola virus can avoid triggering an antiviral response. PMID:21987778

Leung, Lawrence W; Martinez, Osvaldo; Reynard, Olivier; Volchkov, Viktor E; Basler, Christopher F

2011-11-01

177

A search for Ebola virus in animals in the Democratic Republic of the Congo and Cameroon: ecologic, virologic, and serologic surveys, 1979-1980. Ebola Virus Study Teams.  

PubMed

More than 30 years after the first outbreak of Marburg virus disease in Germany and Yugoslavia and 20 years after Ebola hemorrhagic fever first occurred in central Africa, the natural history of filoviruses remains unknown. In 1979 and 1980, animals in the Democratic Republic of the Congo and Cameroon were collected during the dry season near the site of the 1976 Ebola hemorrhagic fever epidemic. The study objectives were to identify local animals and search for evidence of Ebola virus in their tissues. A total of 1664 animals representing 117 species was collected, including >400 bats and 500 rodents. Vero and CV-1 cells and IFA and RIA were used for virus and antibody detection, respectively. No evidence of Ebola virus infection was found. This study was limited in time and animal collections and excluded insects and plants. Long-term, prospective, multidisciplinary comparative studies will yield more information than will repeat short forays on the ecology of filoviruses. PMID:9988177

Breman, J G; Johnson, K M; van der Groen, G; Robbins, C B; Szczeniowski, M V; Ruti, K; Webb, P A; Meier, F; Heymann, D L

1999-02-01

178

Prospects for immunisation against Marburg and Ebola viruses  

PubMed Central

SUMMARY For more than 30 years the filoviruses, Marburg virus and Ebola virus, have been associated with periodic outbreaks of hemorrhagic fever that produce severe and often fatal disease. The filoviruses are endemic primarily in resource-poor regions in Central Africa and are also potential agents of bioterrorism. Although no vaccines or antiviral drugs for Marburg or Ebola are currently available, remarkable progress has been made over the last decade in developing candidate preventive vaccines against filoviruses in nonhuman primate models. Due to the generally remote locations of filovirus outbreaks, a single-injection vaccine is desirable. Among the prospective vaccines that have shown efficacy in nonhuman primate models of filoviral hemorrhagic fever, two candidates, one based on a replication-defective adenovirus serotype 5 and the other on a recombinant VSV (rVSV), were shown to provide complete protection to nonhuman primates when administered as a single injection. The rVSV-based vaccine has also shown utility when administered for postexposure prophylaxis against filovirus infections. A VSV-based Ebola vaccine was recently used to manage a potential laboratory exposure. PMID:20658513

Geisbert, Thomas W.; Bausch, Daniel G.; Feldmann, Heinz

2012-01-01

179

Conservation of the 3' terminal nucleotide sequences of Ebola and Marburg virus.  

PubMed

The 3' RNA base sequences of several Marburg (MBG) and Ebola (EBO) virus isolates have been determined. A comparison of these 3' terminal noncoding sequences with those of other negative strand RNA viruses suggests a unique phylogenic niche for Marburg and Ebola viruses. The translation initiation site and 35 N-terminal amino acids of the 3' proximal coding gene of a Zaire strain of Ebola virus was predicted. In addition, putative leader RNA sequences preceding the first gene are discussed in terms of possible regulatory functions. PMID:3946083

Kiley, M P; Wilusz, J; McCormick, J B; Keene, J D

1986-03-01

180

Ecology of Marburg and Ebola viruses: speculations and directions for future research.  

PubMed

Marburg and virulent Ebola viruses are maintained in hosts that are rare and have little contact with humans or do not readily transmit virus. Bats (particularly solitary microchiropteran species) are leading contenders as reservoir hosts. Virus transfer to humans occurs by contact with the primary reservoir or via an intermediate animal that acquired infection from the reservoir and is, in turn, hunted by humans. An interesting possibility is that filoviruses may be arthropod or plant viruses, with non-blood-feeding arthropods transmitting the virus to intermediate hosts or humans during oral ingestion or envenomation. Paradoxically, in Africa, Ebola virus disease has high lethality and high seroprevalence as determined by the IFA test. If the seroreactivity is confirmed by more specific tests, then the Ebola virus serogroup in Africa probably contains an antigenically cross-reactive, enzootic, nonpathogenic agent(s). Such viruses may have separate life cycles or may give rise to virulent strains by mutation. PMID:9988176

Monath, T P

1999-02-01

181

Productive replication of Ebola virus is regulated by the c-Abl1 tyrosine kinase.  

PubMed

Ebola virus causes a fulminant infection in humans resulting in diffuse bleeding, vascular instability, hypotensive shock, and often death. Because of its high mortality and ease of transmission from human to human, Ebola virus remains a biological threat for which effective preventive and therapeutic interventions are needed. An understanding of the mechanisms of Ebola virus pathogenesis is critical for developing antiviral therapeutics. Here, we report that productive replication of Ebola virus is modulated by the c-Abl1 tyrosine kinase. Release of Ebola virus-like particles (VLPs) in a cell culture cotransfection system was inhibited by c-Abl1-specific small interfering RNA (siRNA) or by Abl-specific kinase inhibitors and required tyrosine phosphorylation of the Ebola matrix protein VP40. Expression of c-Abl1 stimulated an increase in phosphorylation of tyrosine 13 (Y(13)) of VP40, and mutation of Y(13) to alanine decreased the release of Ebola VLPs. Productive replication of the highly pathogenic Ebola virus Zaire strain was inhibited by c-Abl1-specific siRNAs or by the Abl-family inhibitor nilotinib by up to four orders of magnitude. These data indicate that c-Abl1 regulates budding or release of filoviruses through a mechanism involving phosphorylation of VP40. This step of the virus life cycle therefore may represent a target for antiviral therapy. PMID:22378924

García, Mayra; Cooper, Arik; Shi, Wei; Bornmann, William; Carrion, Ricardo; Kalman, Daniel; Nabel, Gary J

2012-02-29

182

Association of ebola virus matrix protein VP40 with microtubules.  

PubMed

Viruses exploit a variety of cellular components to complete their life cycles, and it has become increasingly clear that use of host cell microtubules is a vital part of the infection process for many viruses. A variety of viral proteins have been identified that interact with microtubules, either directly or via a microtubule-associated motor protein. Here, we report that Ebola virus associates with microtubules via the matrix protein VP40. When transfected into mammalian cells, a fraction of VP40 colocalized with microtubule bundles and VP40 coimmunoprecipitated with tubulin. The degree of colocalization and microtubule bundling in cells was markedly intensified by truncation of the C terminus to a length of 317 amino acids. Further truncation to 308 or fewer amino acids abolished the association with microtubules. Both the full-length and the 317-amino-acid truncation mutant stabilized microtubules against depolymerization with nocodazole. Direct physical interaction between purified VP40 and tubulin proteins was demonstrated in vitro. A region of moderate homology to the tubulin binding motif of the microtubule-associated protein MAP2 was identified in VP40. Deleting this region resulted in loss of microtubule stabilization against drug-induced depolymerization. The presence of VP40-associated microtubules in cells continuously treated with nocodazole suggested that VP40 promotes tubulin polymerization. Using an in vitro polymerization assay, we demonstrated that VP40 directly enhances tubulin polymerization without any cellular mediators. These results suggest that microtubules may play an important role in the Ebola virus life cycle and potentially provide a novel target for therapeutic intervention against this highly pathogenic virus. PMID:15795257

Ruthel, Gordon; Demmin, Gretchen L; Kallstrom, George; Javid, Melodi P; Badie, Shirin S; Will, Amy B; Nelle, Timothy; Schokman, Rowena; Nguyen, Tam L; Carra, John H; Bavari, Sina; Aman, M Javad

2005-04-01

183

Incubation Period of Ebola Hemorrhagic Virus Subtype Zaire  

PubMed Central

Objectives Ebola hemorrhagic fever has killed over 1300 people, mostly in equatorial Africa. There is still uncertainty about the natural reservoir of the virus and about some of the factors involved in disease transmission. Until now, a maximum incubation period of 21 days has been assumed. Methods We analyzed data collected during the Ebola outbreak (subtype Zaire) in Kikwit, Democratic Republic of the Congo, in 1995 using maximum likelihood inference and assuming a log-normally distributed incubation period. Results The mean incubation period was estimated to be 12.7 days (standard deviation 4.31 days), indicating that about 4.1% of patients may have incubation periods longer than 21 days. Conclusion If the risk of new cases is to be reduced to 1% then 25 days should be used when investigating the source of an outbreak, when determining the duration of surveillance for contacts, and when declaring the end of an outbreak. PMID:24159443

Eichner, Martin; Dowell, Scott F.; Firese, Nina

2011-01-01

184

Application of real-time PCR for testing antiviral compounds against Lassa virus, SARS coronavirus and Ebola virus in vitro  

Microsoft Academic Search

This report describes the application of real-time PCR for testing antivirals against highly pathogenic viruses such as Lassa virus, SARS coronavirus and Ebola virus. The test combines classical cell culture with a quantitative real-time PCR read-out. The assay for Lassa virus was validated with ribavirin, which showed an IC50 of 9?g\\/ml. Small-scale screening identified a class of imidazole nucleoside\\/nucleotide analogues

Stephan Günther; Marcel Asper; Christina Röser; Luciano K. S. Luna; Christian Drosten; Beate Becker-Ziaja; Peter Borowski; Huan-Ming Chen; Ramachandra S. Hosmane

2004-01-01

185

In vivo oligomerization and raft localization of Ebola virus protein VP40 during vesicular budding  

Microsoft Academic Search

The matrix protein VP40 plays a critical role in Ebola virus assembly and budding, a process that utilizes specialized membrane domains known as lipid rafts. Previous studies with purified protein suggest a role for oligomerization of VP40 in this process. Here, we demonstrate VP40 oligomers in lipid rafts of mammalian cells, virus-like particles, and in the authentic Ebola virus. By

Rekha G. Panchal; Gordon Ruthel; Tara A. Kenny; George H. Kallstrom; Shirin S. Badie; Limin Li; Sina Bavari; M. Javad Aman

2003-01-01

186

3-Deazaneplanocin A induces massively increased interferon-? production in Ebola virus-infected mice  

Microsoft Academic Search

3-Deazaneplanocin A, an analog of adenosine, is a potent inhibitor of Ebola virus replication. A single dose early in infection prevents illness and death in Ebola virus-infected mice. The ability of this and similar compounds to block both RNA and DNA viruses has been attributed to the inhibition of a cellular enzyme, S-adenosylhomocysteine hydrolase (SAH), indirectly resulting in reduced methylation

Mike Bray; Jo Lynne Raymond; Tom Geisbert; Robert O Baker

2002-01-01

187

595. Nasal Delivery of Adenovirus Expressing the Ebola Glycoprotein Protects Mice Against Ebola Virus in the Presence of Preexisting Immunity to the Vaccine Carrier  

Microsoft Academic Search

The Ebola hemorrhagic fever virus has drawn increasing interest in the past years due to an augmentation in the number of natural outbreaks and its potential use as a bioterror agent. To date, only vaccine based on Vesicular Stomatitis virus and Adenovirus as the vaccine carrier have successfully protected nonhuman primates against a lethal dose of Ebola virus. Adenovirus vector

Maria Croyle; Heinz Feldmann; Steven Jones; James M. Wilson; Gary P. Kobinger

2006-01-01

188

Recombinant RNA replicons derived from attenuated Venezuelan equine encephalitis virus protect guinea pigs and mice from Ebola hemorrhagic fever virus  

Microsoft Academic Search

RNA replicons derived from an attenuated strain of Venezuelan equine encephalitis virus (VEE), an alphavirus, were configured as candidate vaccines for Ebola hemorrhagic fever. The Ebola nucleoprotein (NP) or glycoprotein (GP) genes were introduced into the VEE RNA downstream from the VEE 26S promoter in place of the VEE structural protein genes. The resulting recombinant replicons, expressing the NP or

Peter Pushko; Mike Bray; George V Ludwig; Michael Parker; Alan Schmaljohn; Anthony Sanchez; Peter B Jahrling; Jonathan F Smith

2000-01-01

189

Serological evidence of Ebola virus infection in Indonesian orangutans.  

PubMed

Ebola virus (EBOV) and Marburg virus (MARV) belong to the family Filoviridae and cause severe hemorrhagic fever in humans and nonhuman primates. Despite the discovery of EBOV (Reston virus) in nonhuman primates and domestic pigs in the Philippines and the serological evidence for its infection of humans and fruit bats, information on the reservoirs and potential amplifying hosts for filoviruses in Asia is lacking. In this study, serum samples collected from 353 healthy Bornean orangutans (Pongo pygmaeus) in Kalimantan Island, Indonesia, during the period from December 2005 to December 2006 were screened for filovirus-specific IgG antibodies using a highly sensitive enzyme-linked immunosorbent assay (ELISA) with recombinant viral surface glycoprotein (GP) antigens derived from multiple species of filoviruses (5 EBOV and 1 MARV species). Here we show that 18.4% (65/353) and 1.7% (6/353) of the samples were seropositive for EBOV and MARV, respectively, with little cross-reactivity among EBOV and MARV antigens. In these positive samples, IgG antibodies to viral internal proteins were also detected by immunoblotting. Interestingly, while the specificity for Reston virus, which has been recognized as an Asian filovirus, was the highest in only 1.4% (5/353) of the serum samples, the majority of EBOV-positive sera showed specificity to Zaire, Sudan, Cote d'Ivoire, or Bundibugyo viruses, all of which have been found so far only in Africa. These results suggest the existence of multiple species of filoviruses or unknown filovirus-related viruses in Indonesia, some of which are serologically similar to African EBOVs, and transmission of the viruses from yet unidentified reservoir hosts into the orangutan populations. Our findings point to the need for risk assessment and continued surveillance of filovirus infection of human and nonhuman primates, as well as wild and domestic animals, in Asia. PMID:22815803

Nidom, Chairul A; Nakayama, Eri; Nidom, Reviany V; Alamudi, Mohamad Y; Daulay, Syafril; Dharmayanti, Indi N L P; Dachlan, Yoes P; Amin, Mohamad; Igarashi, Manabu; Miyamoto, Hiroko; Yoshida, Reiko; Takada, Ayato

2012-01-01

190

Serological Evidence of Ebola Virus Infection in Indonesian Orangutans  

PubMed Central

Ebola virus (EBOV) and Marburg virus (MARV) belong to the family Filoviridae and cause severe hemorrhagic fever in humans and nonhuman primates. Despite the discovery of EBOV (Reston virus) in nonhuman primates and domestic pigs in the Philippines and the serological evidence for its infection of humans and fruit bats, information on the reservoirs and potential amplifying hosts for filoviruses in Asia is lacking. In this study, serum samples collected from 353 healthy Bornean orangutans (Pongo pygmaeus) in Kalimantan Island, Indonesia, during the period from December 2005 to December 2006 were screened for filovirus-specific IgG antibodies using a highly sensitive enzyme-linked immunosorbent assay (ELISA) with recombinant viral surface glycoprotein (GP) antigens derived from multiple species of filoviruses (5 EBOV and 1 MARV species). Here we show that 18.4% (65/353) and 1.7% (6/353) of the samples were seropositive for EBOV and MARV, respectively, with little cross-reactivity among EBOV and MARV antigens. In these positive samples, IgG antibodies to viral internal proteins were also detected by immunoblotting. Interestingly, while the specificity for Reston virus, which has been recognized as an Asian filovirus, was the highest in only 1.4% (5/353) of the serum samples, the majority of EBOV-positive sera showed specificity to Zaire, Sudan, Cote d’Ivoire, or Bundibugyo viruses, all of which have been found so far only in Africa. These results suggest the existence of multiple species of filoviruses or unknown filovirus-related viruses in Indonesia, some of which are serologically similar to African EBOVs, and transmission of the viruses from yet unidentified reservoir hosts into the orangutan populations. Our findings point to the need for risk assessment and continued surveillance of filovirus infection of human and nonhuman primates, as well as wild and domestic animals, in Asia. PMID:22815803

Nidom, Reviany V.; Alamudi, Mohamad Y.; Daulay, Syafril; Dharmayanti, Indi N. L. P.; Dachlan, Yoes P.; Amin, Mohamad; Igarashi, Manabu; Miyamoto, Hiroko; Yoshida, Reiko; Takada, Ayato

2012-01-01

191

Persistence in darkness of virulent alphaviruses, Ebola virus, and Lassa virus deposited on solid surfaces  

Microsoft Academic Search

Ebola, Lassa, Venezuelan equine encephalitis, and Sindbis viruses were dried onto solid surfaces, incubated for various time\\u000a periods under controlled conditions of temperature and relative humidity, and quantitatively eluted from surfaces, and viral\\u000a titers in the recovered samples were determined. The viral inactivation kinetics that were obtained indicated that viral\\u000a resistance to natural inactivation in the dark follows (in decreasing

Jose-Luis Sagripanti; Amanda M. Rom; Louis E. Holland

2010-01-01

192

Ebola virus disease. Recognizing the face of a rare killer.  

PubMed

Because of international travel and immigration, US physicians should be aware of the signs and symptoms of Ebola virus disease. It should be suspected in any recent traveler who presents with manifestations of viral hemorrhagic fever and in laboratory workers exposed to animals from endemic areas who show symptoms. Infected persons should be given supportive care to help them survive the acute phase of infection. Fortunately, adequate preventive measures are already in place in US hospitals and laboratories because of the prevalence of AIDS and hepatitis. However, aid should be provided to the World Health Organization and developing countries such as Zaire to support further research into the epidemiology and natural history of the virus, which may help prevent future deadly epidemics. PMID:8650097

Sodhi, A

1996-05-01

193

[Evaluation of Ebola virus reproduction in adult ICR white mice].  

PubMed

The investigators studied the ability of adult ICR mice (a laboratory model that was most approximated to the wildtype populations of mice) to maintain Ebola virus (EV) reproduction in the organism. The adult ICR mice inoculated with EV during 23 passages were shown to maintain viral reproduction in the liver. The elevated levels of platelets and the early generation of fibrin and fibrinogen degradation products suggested there were hemostatic changes that did not, however, progress to severe coagulopathy. The animals were in appearance apparently, other than adynamia observed on days 5-7. Thus, the susceptibility of the adult ICR mice to EV is characterized by their ability to maintain virus reproduction in the liver without evident signs of the infection. This pattern of susceptibility in the mice shows a possible role of this rodent species in the transmissive cycle of EV. PMID:20886711

Chepurnov, A A; Sizikova, L P; Shalemba-Chepurnova, A A; Shestopalova, L V

2010-01-01

194

Conformational plasticity of the Ebola virus matrix protein.  

PubMed

Filoviruses are the causative agents of a severe and often fatal hemorrhagic fever with repeated outbreaks in Africa. They are negative sense single stranded enveloped viruses that can cross species barriers from its natural host bats to primates including humans. The small size of the genome poses limits to viral adaption, which may be partially overcome by conformational plasticity. Here we review the different conformational states of the Ebola virus (EBOV) matrix protein VP40 that range from monomers, to dimers, hexamers, and RNA-bound octamers. This conformational plasticity that is required for the viral life cycle poses a unique opportunity for development of VP40 specific drugs. Furthermore, we compare the structure to homologous matrix protein structures from Paramyxoviruses and Bornaviruses and we predict that they do not only share the fold but also the conformational flexibility of EBOV VP40. PMID:25159197

Radzimanowski, Jens; Effantin, Gregory; Weissenhorn, Winfried

2014-11-01

195

Application of real-time PCR for testing antiviral compounds against Lassa virus, SARS coronavirus and Ebola virus in vitro.  

PubMed

This report describes the application of real-time PCR for testing antivirals against highly pathogenic viruses such as Lassa virus, SARS coronavirus and Ebola virus. The test combines classical cell culture with a quantitative real-time PCR read-out. The assay for Lassa virus was validated with ribavirin, which showed an IC(50) of 9 micrograms/ml. Small-scale screening identified a class of imidazole nucleoside/nucleotide analogues with antiviral activity against Lassa virus. The analogues contained either dinitrile or diester groups at the imidazole 4,5-positions, and many of which possessed an acyclic sugar or sugar phosphonate moiety at the imidazole 1-position. The IC(50) values of the most active compounds ranged from 5 to 21 micrograms/ml. The compounds also inhibited replication of SARS coronavirus and Ebola virus in analogous assays, although to a lesser extent than Lassa virus. PMID:15451189

Günther, Stephan; Asper, Marcel; Röser, Christina; Luna, Luciano K S; Drosten, Christian; Becker-Ziaja, Beate; Borowski, Peter; Chen, Huan-Ming; Hosmane, Ramachandra S

2004-09-01

196

Ebola GP-specific monoclonal antibodies protect mice and guinea pigs from lethal Ebola virus infection.  

PubMed

Ebola virus (EBOV) causes acute hemorrhagic fever in humans and non-human primates with mortality rates up to 90%. So far there are no effective treatments available. This study evaluates the protective efficacy of 8 monoclonal antibodies (MAbs) against Ebola glycoprotein in mice and guinea pigs. Immunocompetent mice or guinea pigs were given MAbs i.p. in various doses individually or as pools of 3-4 MAbs to test their protection against a lethal challenge with mouse- or guinea pig-adapted EBOV. Each of the 8 MAbs (100 µg) protected mice from a lethal EBOV challenge when administered 1 day before or after challenge. Seven MAbs were effective 2 days post-infection (dpi), with 1 MAb demonstrating partial protection 3 dpi. In the guinea pigs each MAb showed partial protection at 1 dpi, however the mean time to death was significantly prolonged compared to the control group. Moreover, treatment with pools of 3-4 MAbs completely protected the majority of animals, while administration at 2-3 dpi achieved 50-100% protection. This data suggests that the MAbs generated are capable of protecting both animal species against lethal Ebola virus challenge. These results indicate that MAbs particularly when used as an oligoclonal set are a potential therapeutic for post-exposure treatment of EBOV infection. PMID:22448295

Qiu, Xiangguo; Fernando, Lisa; Melito, P Leno; Audet, Jonathan; Feldmann, Heinz; Kobinger, Gary; Alimonti, Judie B; Jones, Steven M

2012-01-01

197

Ebola GP-Specific Monoclonal Antibodies Protect Mice and Guinea Pigs from Lethal Ebola Virus Infection  

PubMed Central

Ebola virus (EBOV) causes acute hemorrhagic fever in humans and non-human primates with mortality rates up to 90%. So far there are no effective treatments available. This study evaluates the protective efficacy of 8 monoclonal antibodies (MAbs) against Ebola glycoprotein in mice and guinea pigs. Immunocompetent mice or guinea pigs were given MAbs i.p. in various doses individually or as pools of 3–4 MAbs to test their protection against a lethal challenge with mouse- or guinea pig-adapted EBOV. Each of the 8 MAbs (100 µg) protected mice from a lethal EBOV challenge when administered 1 day before or after challenge. Seven MAbs were effective 2 days post-infection (dpi), with 1 MAb demonstrating partial protection 3 dpi. In the guinea pigs each MAb showed partial protection at 1 dpi, however the mean time to death was significantly prolonged compared to the control group. Moreover, treatment with pools of 3–4 MAbs completely protected the majority of animals, while administration at 2–3 dpi achieved 50–100% protection. This data suggests that the MAbs generated are capable of protecting both animal species against lethal Ebola virus challenge. These results indicate that MAbs particularly when used as an oligoclonal set are a potential therapeutic for post-exposure treatment of EBOV infection. PMID:22448295

Qiu, Xiangguo; Fernando, Lisa; Melito, P. Leno; Audet, Jonathan; Feldmann, Heinz; Kobinger, Gary; Alimonti, Judie B.; Jones, Steven M.

2012-01-01

198

Ebola Virus Glycoprotein: Proteolytic Processing, Acylation, Cell Tropism, and Detection of Neutralizing Antibodies  

Microsoft Academic Search

Using the vesicular stomatitis virus (VSV) pseudotype system, we studied the functional properties of the Ebola virus glycoprotein (GP). Amino acid substitutions at the GP cleavage site, which reduce glycoprotein cleavability and viral infectivity in some viruses, did not appreciably change the infectivity of VSV pseudotyped with GP. Likewise, removal of two acylated cysteine residues in the transmembrane region of

HIROSHI ITO; SHINJI WATANABE; AYATO TAKADA; YOSHIHIRO KAWAOKA

2001-01-01

199

Folate Receptor-? Is a Cofactor for Cellular Entry by Marburg and Ebola Viruses  

Microsoft Academic Search

Human infections by Marburg (MBG) and Ebola (EBO) viruses result in lethal hemorrhagic fever. To identify cellular entry factors employed by MBG virus, noninfectible cells transduced with an expression library were challenged with a selectable pseudotype virus packaged by MBG glycoproteins (GP). A cDNA encoding the folate receptor-? (FR-?) was recovered from cells exhibiting reconstitution of viral entry. A FR-?

Stephen Y. Chan; Cyril J. Empig; Frank J. Welte; Roberto F. Speck; Alan Schmaljohn; Jason F. Kreisberg; Mark A. Goldsmith

2001-01-01

200

A paramyxovirus-vectored intranasal vaccine against Ebola virus is immunogenic in vector-immune animals  

Microsoft Academic Search

Ebola virus (EBOV) causes outbreaks of a highly lethal hemorrhagic fever in humans. The virus can be transmitted by direct contact as well as by aerosol and is considered a potential bioweapon. Because direct immunization of the respiratory tract should be particularly effective against infection of mucosal surfaces, we previously developed an intranasal vaccine based on replication-competent human parainfluenza virus

Lijuan Yang; Anthony Sanchez; Jerrold M. Ward; Brian R. Murphy; Peter L. Collins; Alexander Bukreyev

2008-01-01

201

The Cytoprotective Enzyme Heme Oxygenase-1 Suppresses Ebola Virus Replication  

PubMed Central

Ebola virus (EBOV) is the causative agent of a severe hemorrhagic fever in humans with reported case fatality rates as high as 90%. There are currently no licensed vaccines or antiviral therapeutics to combat EBOV infections. Heme oxygenase-1 (HO-1), an enzyme that catalyzes the rate-limiting step in heme degradation, has antioxidative properties and protects cells from various stresses. Activated HO-1 was recently shown to have antiviral activity, potently inhibiting the replication of viruses such as hepatitis C virus and human immunodeficiency virus. However, the effect of HO-1 activation on EBOV replication remains unknown. To determine whether the upregulation of HO-1 attenuates EBOV replication, we treated cells with cobalt protoporphyrin (CoPP), a selective HO-1 inducer, and assessed its effects on EBOV replication. We found that CoPP treatment, pre- and postinfection, significantly suppressed EBOV replication in a manner dependent upon HO-1 upregulation and activity. In addition, stable overexpression of HO-1 significantly attenuated EBOV growth. Although the exact mechanism behind the antiviral properties of HO-1 remains to be elucidated, our data show that HO-1 upregulation does not attenuate EBOV entry or budding but specifically targets EBOV transcription/replication. Therefore, modulation of the cellular enzyme HO-1 may represent a novel therapeutic strategy against EBOV infection. PMID:24109237

Hill-Batorski, Lindsay; Halfmann, Peter; Neumann, Gabriele

2013-01-01

202

Generation and epitope mapping of a monoclonal antibody against nucleoprotein of Ebola virus.  

PubMed

Ebola virus (EBOV) causes highly lethal hemorrhagic fever in humans and nonhuman primates and has a significant impact on public health. The nucleoprotein (NP) of EBOV (EBOV-NP) plays a central role in virus replication and has been used as a target molecule for disease diagnosis. In this study, we generated a monoclonal antibody (MAb) against EBOV-NP and mapped the epitope motif required for recognition by the MAb. The MAb generated via immunization of mice with prokaryotically expressed recombinant NP of the Zaire Ebola virus (ZEBOV-NP) was specific to ZEBOV-NP and able to recognize ZEBOV-NP expressed in prokaryotic and eukaryotic cells. The MAb cross-reacted with the NP of the Reston Ebola virus (REBOV), the Cote-d'Ivoire Ebola virus (CIEBOV) and the Bundibugyo Ebola virus (BEBOV) but not with the NP of the Sudan Ebola virus (SEBOV) or the Marburg virus (MARV). The minimal epitope sequence required for recognition by the MAb was the motif PPLESD, which is located between amino acid residues 583 and 588 at the C-terminus of ZEBOV-NP and well conserved among all 16 strains of ZEBOV, CIEBOV and BEBOV deposited in GenBank. The epitope motif is conserved in four out of five strains of REBOV. PMID:23457784

Wang, Xiaodu; Liu, Yang; Wang, Haoting; Shi, Zixue; Zhao, Fanfan; Wei, Jianchao; Shao, Donghua; Ma, Zhiyong

2012-11-01

203

Structural dissection of Ebola virus and its assembly determinants using cryo-electron tomography.  

PubMed

Ebola virus is a highly pathogenic filovirus causing severe hemorrhagic fever with high mortality rates. It assembles heterogenous, filamentous, enveloped virus particles containing a negative-sense, single-stranded RNA genome packaged within a helical nucleocapsid (NC). We have used cryo-electron microscopy and tomography to visualize Ebola virus particles, as well as Ebola virus-like particles, in three dimensions in a near-native state. The NC within the virion forms a left-handed helix with an inner nucleoprotein layer decorated with protruding arms composed of VP24 and VP35. A comparison with the closely related Marburg virus shows that the N-terminal region of nucleoprotein defines the inner diameter of the Ebola virus NC, whereas the RNA genome defines its length. Binding of the nucleoprotein to RNA can assemble a loosely coiled NC-like structure; the loose coil can be condensed by binding of the viral matrix protein VP40 to the C terminus of the nucleoprotein, and rigidified by binding of VP24 and VP35 to alternate copies of the nucleoprotein. Four proteins (NP, VP24, VP35, and VP40) are necessary and sufficient to mediate assembly of an NC with structure, symmetry, variability, and flexibility indistinguishable from that in Ebola virus particles released from infected cells. Together these data provide a structural and architectural description of Ebola virus and define the roles of viral proteins in its structure and assembly. PMID:22371572

Bharat, Tanmay A M; Noda, Takeshi; Riches, James D; Kraehling, Verena; Kolesnikova, Larissa; Becker, Stephan; Kawaoka, Yoshihiro; Briggs, John A G

2012-03-13

204

Euthanasia assessment in ebola virus infected nonhuman primates.  

PubMed

Multiple products are being developed for use against filoviral infections. Efficacy for these products will likely be demonstrated in nonhuman primate models of filoviral disease to satisfy licensure requirements under the Animal Rule, or to supplement human data. Typically, the endpoint for efficacy assessment will be survival following challenge; however, there exists no standardized approach for assessing the health or euthanasia criteria for filovirus-exposed nonhuman primates. Consideration of objective criteria is important to (a) ensure test subjects are euthanized without unnecessary distress; (b) enhance the likelihood that animals exhibiting mild or moderate signs of disease are not prematurely euthanized; (c) minimize the occurrence of spontaneous deaths and loss of end-stage samples; (d) enhance the reproducibility of experiments between different researchers; and (e) provide a defensible rationale for euthanasia decisions that withstands regulatory scrutiny. Historic records were compiled for 58 surviving and non-surviving monkeys exposed to Ebola virus at the US Army Medical Research Institute of Infectious Diseases. Clinical pathology parameters were statistically analyzed and those exhibiting predicative value for survival are reported. These findings may be useful for standardization of objective euthanasia assessments in rhesus monkeys exposed to Ebola virus and may serve as a useful approach for other standardization efforts. PMID:25421892

Warren, Travis K; Trefry, John C; Marko, Shannon T; Chance, Taylor B; Wells, Jay B; Pratt, William D; Johnson, Joshua C; Mucker, Eric M; Norris, Sarah L; Chappell, Mark; Dye, John M; Honko, Anna N

2014-01-01

205

Chimpanzee adenovirus vaccine protects against Zaire Ebola virus.  

PubMed

This study evaluated the use of a chimpanzee-based adenovirus vaccine in mouse and Guinea pigs models of Zaire Ebola virus (ZEBOV) infection. Vaccine vector expressing the envelope glycoprotein of ZEBOV was created from the molecular clone of chimpanzee adenovirus pan7 (AdC7). AdC7 vaccine stimulated robust T and B cell responses to ZEBOV in naïve mice inducing complete protection to an otherwise lethal challenge of ZEBOV. Complete protection to Zaire Ebola virus was also observed in Guinea pigs vaccinated with a relatively low dose of AdC7 (5 x 10(9)/kg). Pre-existing immunity to AdHu5 was generated in mice following pre-exposure to AdHu5 or administration of pooled human immune globulin. Pre-existing immunity to human adenoviruses severely compromised the efficacy of the human AdHu5 vaccine but not the chimpanzee AdC7 vaccine. These results validate further development of Chimpanzee-based vaccine and highlight the impact of pre-existing immunity to the vaccine carrier. PMID:16356525

Kobinger, Gary P; Feldmann, Heinz; Zhi, Yan; Schumer, Gregory; Gao, Guangping; Feldmann, Friederike; Jones, Steven; Wilson, James M

2006-03-15

206

Euthanasia Assessment in Ebola Virus Infected Nonhuman Primates  

PubMed Central

Multiple products are being developed for use against filoviral infections. Efficacy for these products will likely be demonstrated in nonhuman primate models of filoviral disease to satisfy licensure requirements under the Animal Rule, or to supplement human data. Typically, the endpoint for efficacy assessment will be survival following challenge; however, there exists no standardized approach for assessing the health or euthanasia criteria for filovirus-exposed nonhuman primates. Consideration of objective criteria is important to (a) ensure test subjects are euthanized without unnecessary distress; (b) enhance the likelihood that animals exhibiting mild or moderate signs of disease are not prematurely euthanized; (c) minimize the occurrence of spontaneous deaths and loss of end-stage samples; (d) enhance the reproducibility of experiments between different researchers; and (e) provide a defensible rationale for euthanasia decisions that withstands regulatory scrutiny. Historic records were compiled for 58 surviving and non-surviving monkeys exposed to Ebola virus at the US Army Medical Research Institute of Infectious Diseases. Clinical pathology parameters were statistically analyzed and those exhibiting predicative value for survival are reported. These findings may be useful for standardization of objective euthanasia assessments in rhesus monkeys exposed to Ebola virus and may serve as a useful approach for other standardization efforts. PMID:25421892

Warren, Travis K.; Trefry, John C.; Marko, Shannon T.; Chance, Taylor B.; Wells, Jay B.; Pratt, William D.; Johnson, Joshua C.; Mucker, Eric M.; Norris, Sarah L.; Chappell, Mark; Dye, John M.; Honko, Anna N.

2014-01-01

207

Mapping the zoonotic niche of Ebola virus disease in Africa  

PubMed Central

Ebola virus disease (EVD) is a complex zoonosis that is highly virulent in humans. The largest recorded outbreak of EVD is ongoing in West Africa, outside of its previously reported and predicted niche. We assembled location data on all recorded zoonotic transmission to humans and Ebola virus infection in bats and primates (1976–2014). Using species distribution models, these occurrence data were paired with environmental covariates to predict a zoonotic transmission niche covering 22 countries across Central and West Africa. Vegetation, elevation, temperature, evapotranspiration, and suspected reservoir bat distributions define this relationship. At-risk areas are inhabited by 22 million people; however, the rarity of human outbreaks emphasises the very low probability of transmission to humans. Increasing population sizes and international connectivity by air since the first detection of EVD in 1976 suggest that the dynamics of human-to-human secondary transmission in contemporary outbreaks will be very different to those of the past. DOI: http://dx.doi.org/10.7554/eLife.04395.001 PMID:25201877

Pigott, David M; Golding, Nick; Mylne, Adrian; Huang, Zhi; Henry, Andrew J; Weiss, Daniel J; Brady, Oliver J; Kraemer, Moritz UG; Smith, David L; Moyes, Catherine L; Bhatt, Samir; Gething, Peter W; Horby, Peter W; Bogoch, Isaac I; Brownstein, John S; Mekaru, Sumiko R; Tatem, Andrew J; Khan, Kamran; Hay, Simon I

2014-01-01

208

Outbreaks of Ebola virus disease in Africa: the beginnings of a tragic saga.  

PubMed

The tremendous outbreak of Ebola virus disease occurring in West Africa since the end of 2013 surprises by its remoteness from previous epidemics and dramatic extent. This review aims to describe the 27 manifestations of Ebola virus that arose after its discovery in 1976. It provides an update on research on the ecology of Ebola viruses, modes of contamination and human transmission of the disease that are mainly linked to close contact with an infected animal or a patient suffering from the disease. The recommendations to contain the epidemic and challenges to achieve it are reminded. PMID:25320574

Chippaux, Jean-Philippe

2014-01-01

209

Molecular Cell, Vol. 2, 605616, November, 1998, Copyright 1998 by Cell Press Crystal Structure of the Ebola Virus  

E-print Network

of the Ebola Virus Membrane Fusion Subunit, GP2, from the Envelope Glycoprotein Ectodomain (Schnittler et al entry by membrane fusion such as those of the myxovi- ruses, paramyxoviruses, and retroviruses, Ebola activity and to form a stable con- Ebola virus membrane fusion glycoprotein by X-ray crys- formation

Harrison, Stephen C.

210

Vesicular stomatitis virus-based vaccines protect nonhuman primates against aerosol challenge with Ebola and Marburg viruses  

Microsoft Academic Search

Considerable progress has been made over the last decade in developing candidate preventive vaccines that can protect nonhuman primates against Ebola and Marburg viruses. A vaccine based on recombinant vesicular stomatitis virus (VSV) seems to be particularly robust as it can also confer protection when administered as a postexposure treatment. While filoviruses are not thought to be transmitted by aerosol

Thomas W. Geisbert; Kathleen M. Daddario-DiCaprio; Joan B. Geisbert; Douglas S. Reed; Friederike Feldmann; Allen Grolla; Ute Ströher; Elizabeth A. Fritz; Lisa E. Hensley; Steven M. Jones; Heinz Feldmann

2008-01-01

211

Surveillance and preparedness for ebola virus disease - new york city, 2014.  

PubMed

In July 2014, as the Ebola virus disease (Ebola) epidemic expanded in Guinea, Liberia, and Sierra Leone, an air traveler brought Ebola to Nigeria and two American health care workers in West Africa were diagnosed with Ebola and later medically evacuated to a U.S. hospital. New York City (NYC) is a frequent port of entry for travelers from West Africa, a home to communities of West African immigrants who travel back to their home countries, and a home to health care workers who travel to West Africa to treat Ebola patients. Ongoing transmission of Ebolavirus in West Africa could result in an infected person arriving in NYC. The announcement on September 30 of an Ebola case diagnosed in Texas in a person who had recently arrived from an Ebola-affected country further reinforced the need in NYC for local preparedness for Ebola. PMID:25321072

Benowitz, Isaac; Ackelsberg, Joel; Balter, Sharon E; Baumgartner, Jennifer C; Dentinger, Catherine; Fine, Anne D; Harper, Scott A; Jones, Lucretia E; Laraque, Fabienne; Lee, Ellen H; Merizalde, Giselle; Yacisin, Kari A; Varma, Jay K; Layton, Marcelle C

2014-10-17

212

Chimeric human parainfluenza virus bearing the Ebola virus glycoprotein as the sole surface protein is immunogenic and highly protective against Ebola virus challenge  

SciTech Connect

We generated a new live-attenuated vaccine against Ebola virus (EBOV) based on a chimeric virus HPIV3/{delta}F-HN/EboGP that contains the EBOV glycoprotein (GP) as the sole transmembrane envelope protein combined with the internal proteins of human parainfluenza virus type 3 (HPIV3). Electron microscopy analysis of the virus particles showed that they have an envelope and surface spikes resembling those of EBOV and a particle size and shape resembling those of HPIV3. When HPIV3/{delta}F-HN/EboGP was inoculated via apical surface of an in vitro model of human ciliated airway epithelium, the virus was released from the apical surface; when applied to basolateral surface, the virus infected basolateral cells but did not spread through the tissue. Following intranasal (IN) inoculation of guinea pigs, scattered infected cells were detected in the lungs by immunohistochemistry, but infectious HPIV3/{delta}F-HN/EboGP could not be recovered from the lungs, blood, or other tissues. Despite the attenuation, the virus was highly immunogenic, and a single IN dose completely protected the animals against a highly lethal intraperitoneal challenge of guinea pig-adapted EBOV.

Bukreyev, Alexander [National Institute of Allergy and Infectious Diseases, Building 50, Room 6505, NIAID, National Institutes of Health, 50 South Dr. MSC 8007, Bethesda, MD 20892-8007 (United States)], E-mail: abukreyev@nih.gov; Marzi, Andrea; Feldmann, Friederike [Special Pathogens Program, National Microbiology Laboratory, Canadian Science Centre for Human and Animal Health, Winnipeg (Canada); Zhang Liqun [Cystic Fibrosis/Pulmonary Research and Treatment Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina (United States); Yang Lijuan; Ward, Jerrold M. [National Institute of Allergy and Infectious Diseases, Building 50, Room 6505, NIAID, National Institutes of Health, 50 South Dr. MSC 8007, Bethesda, MD 20892-8007 (United States); Dorward, David W. [Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana (United States); Pickles, Raymond J. [Cystic Fibrosis/Pulmonary Research and Treatment Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina (United States); Murphy, Brian R. [National Institute of Allergy and Infectious Diseases, Building 50, Room 6505, NIAID, National Institutes of Health, 50 South Dr. MSC 8007, Bethesda, MD 20892-8007 (United States); Feldmann, Heinz [Special Pathogens Program, National Microbiology Laboratory, Canadian Science Centre for Human and Animal Health, Winnipeg (Canada); Department of Medical Microbiology, University of Manitoba (Canada); Collins, Peter L. [National Institute of Allergy and Infectious Diseases, Building 50, Room 6505, NIAID, National Institutes of Health, 50 South Dr. MSC 8007, Bethesda, MD 20892-8007 (United States)

2009-01-20

213

Chimeric human parainfluenza virus bearing the Ebola virus glycoprotein as the sole surface protein is immunogenic and highly protective against Ebola virus challenge.  

PubMed

We generated a new live-attenuated vaccine against Ebola virus (EBOV) based on a chimeric virus HPIV3/DeltaF-HN/EboGP that contains the EBOV glycoprotein (GP) as the sole transmembrane envelope protein combined with the internal proteins of human parainfluenza virus type 3 (HPIV3). Electron microscopy analysis of the virus particles showed that they have an envelope and surface spikes resembling those of EBOV and a particle size and shape resembling those of HPIV3. When HPIV3/DeltaF-HN/EboGP was inoculated via apical surface of an in vitro model of human ciliated airway epithelium, the virus was released from the apical surface; when applied to basolateral surface, the virus infected basolateral cells but did not spread through the tissue. Following intranasal (IN) inoculation of guinea pigs, scattered infected cells were detected in the lungs by immunohistochemistry, but infectious HPIV3/DeltaF-HN/EboGP could not be recovered from the lungs, blood, or other tissues. Despite the attenuation, the virus was highly immunogenic, and a single IN dose completely protected the animals against a highly lethal intraperitoneal challenge of guinea pig-adapted EBOV. PMID:19010509

Bukreyev, Alexander; Marzi, Andrea; Feldmann, Friederike; Zhang, Liqun; Yang, Lijuan; Ward, Jerrold M; Dorward, David W; Pickles, Raymond J; Murphy, Brian R; Feldmann, Heinz; Collins, Peter L

2009-01-20

214

Chimeric human parainfluenza virus bearing the Ebola virus glycoprotein as the sole surface protein is immunogenic and highly protective against Ebola virus challenge  

PubMed Central

We generated a new live-attenuated vaccine against Ebola virus (EBOV) based on a chimeric virus HPIV3/?F-HN/EboGP that contains the EBOV glycoprotein (GP) as the sole transmembrane envelope protein combined with the internal proteins of human parainfluenza virus type 3 (HPIV3). Electron microscopy analysis of the virus particles showed that they have an envelope and surface spikes resembling those of EBOV and a particle size and shape resembling those of HPIV3. When HPIV3/?F-HN/EboGP was inoculated via apical surface of an in vitro model of human ciliated airway epithelium, the virus was released from the apical surface; when applied to basolateral surface, the virus infected basolateral cells but did not spread through the tissue. Following intranasal (IN) inoculation of guinea pigs, scattered infected cells were detected in the lungs by immunohistochemistry, but infectious HPIV3/?F-HN/EboGP could not be recovered from the lungs, blood, or other tissues. Despite the attenuation, the virus was highly immunogenic, and a single IN dose completely protected the animals against a highly lethal intraperitoneal challenge of guinea pig-adapted EBOV. PMID:19010509

Bukreyev, Alexander; Marzi, Andrea; Feldmann, Friederike; Zhang, Liqun; Yang, Lijuan; Ward, Jerrold M.; Dorward, David W.; Pickles, Raymond J.; Murphy, Brian R.; Feldmann, Heinz; Collins, Peter L.

2009-01-01

215

Phosphoinositide-3 Kinase-Akt Pathway Controls Cellular Entry of Ebola Virus  

E-print Network

The phosphoinositide-3 kinase (PI3K) pathway regulates diverse cellular activities related to cell growth, migration, survival, and vesicular trafficking. It is known that Ebola virus requires endocytosis to establish an infection. However, the cellular signals that mediate this uptake were unknown for Ebola virus as well as many other viruses. Here, the involvement of PI3K in Ebola virus entry was studied. A novel and critical role of the PI3K signaling pathway was demonstrated in cell entry of Zaire Ebola virus (ZEBOV). Inhibitors of PI3K and Akt significantly reduced infection by ZEBOV at an early step during the replication cycle. Furthermore, phosphorylation of Akt-1 was induced shortly after exposure of cells to radiation-inactivated ZEBOV, indicating that the virus actively induces the PI3K pathway and that replication was not required for this induction. Subsequent use of pseudotyped Ebola virus and/or Ebola virus-like particles, in a novel virus entry assay, provided evidence that activity of PI3K/Akt is required at the virus entry step. Class 1A PI3Ks appear to play a predominant role in regulating ZEBOV entry, and Rac1 is a key downstream effector in this regulatory cascade. Confocal imaging of fluorescently labeled ZEBOV indicated that inhibition of PI3K, Akt, or Rac1 disrupted normal uptake of virus particles into cells and resulted in aberrant accumulation of virus into a cytosolic compartment that was non-permissive for membrane fusion. We conclude that PI3K-mediated signaling plays an important role in regulating vesicular trafficking of ZEBOV necessary for cell entry. Disruption of this signaling leads to inappropriate trafficking within the cell and a block in steps leading to membrane

Mohammad F. Saeed; Andrey A. Kolokoltsov; Er N. Freiberg; Michael R. Holbrook; Robert A. Davey

216

[In vitro synthesis of immunoglobulins caused by an inactivated Ebola virus].  

PubMed

An in vitro model Ebola infection was used to study the humoral response of human mononuclear cells to stimulation by purified inactivated Ebola virus antigen. Inactivated Ebola virus was cocultivated with human mononuclear cells in the presence or absence of B-cell mitogen LPS E. coli: B5. An increase in the rate of synthesis of immunoglobulins (both IgG and, to a less extent, other classes) was observed. The Ebola virus proteins were suggested to exert no suppression effect on B-cells. The IgM/IgG synthesis was evaluated by EIA in supernatants after 7 days of cultivation. It was concluded that Ebola fever is accompanied by active humoral immune response, which provides a promising basis for further search of the methods of treatment of this disease. PMID:12608056

Tuzova, M N; Ga?dul', K V; Chepurnov, A A

2003-01-01

217

Persistence and Genetic Stability of Ebola Virus during the Outbreak in Kikwit, Democratic Republic of the Congo, 1995  

Microsoft Academic Search

Ebola virus persistence was examined in body fluids from 12 convalescent patients by virus isolation and reverse transcription - polymerase chain reaction (RT-PCR) during the 1995 Ebola hemorrhagic fever outbreak in Kikwit, Democratic Republic of the Congo. Virus RNA could be detected for up to 33 days in vaginal, rectal, and conjunctival swabs of 1 patient and up to 101

A. De Roo; Y. Guimard; A. Sanchez; D. Bressler; J. Bertolli

1999-01-01

218

The Assembly of Ebola Virus Nucleocapsid Requires Virion-Associated Proteins 35 and 24 and Posttranslational Modification of Nucleoprotein  

Microsoft Academic Search

Ebola virus encodes seven viral structural and regulatory proteins that support its high rates of replication, but little is known about nucleocapsid assembly of this virus in infected cells. We report here that three viral proteins are necessary and sufficient for formation of Ebola virus particles and that intracellular posttranslational modification regulates this process. Expression of the nucleoprotein (NP) and

Yue Huang; Ling Xu; Yongnian Sun; Gary J Nabel

2002-01-01

219

INHIBITION OF EBOLA VIRUS ENTRY BY A C-PEPTIDE TARGETED TO ENDOSOMES Emily Happy Miller1,2  

E-print Network

1 INHIBITION OF EBOLA VIRUS ENTRY BY A C-PEPTIDE TARGETED TO ENDOSOMES Emily Happy Miller1.lai@einstein.yu.edu. Ebola virus (EboV) and Marburg virus (MarV) (filoviruses) are the causative agents of severe hemorrhagic

Chandran, Kartik

220

Ebola Virus Does Not Block Apoptotic Signaling Pathways  

PubMed Central

Since viruses rely on functional cellular machinery for efficient propagation, apoptosis is an important mechanism to fight viral infections. In this study, we sought to determine the mechanism of cell death caused by Ebola virus (EBOV) infection by assaying for multiple stages of apoptosis and hallmarks of necrosis. Our data indicate that EBOV does not induce apoptosis in infected cells but rather leads to a nonapoptotic form of cell death. Ultrastructural analysis confirmed necrotic cell death of EBOV-infected cells. To investigate if EBOV blocks the induction of apoptosis, infected cells were treated with different apoptosis-inducing agents. Surprisingly, EBOV-infected cells remained sensitive to apoptosis induced by external stimuli. Neither receptor- nor mitochondrion-mediated apoptosis signaling was inhibited in EBOV infection. Although double-stranded RNA (dsRNA)-induced activation of protein kinase R (PKR) was blocked in EBOV-infected cells, induction of apoptosis mediated by dsRNA was not suppressed. When EBOV-infected cells were treated with dsRNA-dependent caspase recruiter (dsCARE), an antiviral protein that selectively induces apoptosis in cells containing dsRNA, virus titers were strongly reduced. These data show that the inability of EBOV to block apoptotic pathways may open up new strategies toward the development of antiviral therapeutics. PMID:23468487

Olejnik, Judith; Alonso, Jesus; Schmidt, Kristina M.; Yan, Zhen; Wang, Wei; Marzi, Andrea; Ebihara, Hideki; Yang, Jinghua; Patterson, Jean L.; Ryabchikova, Elena

2013-01-01

221

VP35 Knockdown Inhibits Ebola Virus Amplification and Protects against Lethal Infection in Mice  

Microsoft Academic Search

Phosphorodiamidate morpholino oligomers (PMO) are a class of uncharged single-stranded DNA analogs modified such that each subunit includes a phosphorodiamidate linkage and morpholine ring. PMO antisense agents have been reported to effectively interfere with the replication of several positive-strand RNA viruses in cell culture. The filoviruses, Marburg virus and Ebola virus (EBOV), are negative-strand RNA viruses that cause up to

Sven Enterlein; Kelly L. Warfield; Dana L. Swenson; David A. Stein; Jeffery L. Smith; C. Scott Gamble; Andrew D. Kroeker; Patrick L. Iversen; Sina Bavari; Elke Muhlberger

2006-01-01

222

[Change in biochemical and hemostatic indicators in guinea pigs upon administering Ebola virus preparations].  

PubMed

The biochemical and hemostatic parameters were compared in guinea pigs after inoculation of Ebola virus strains lethal and nonlethal for them and of inactivated antigen of this virus. The time course of the main hemostatic and biochemical parameters in animals challenged with the lethal strain of Ebola virus differed much from that in other groups. This permits us to hypothesize that modification of the virus in the course of adaptation to the host results in the appearance of properties boosting the enzymatic processes and, hence, in depletion and failure of antioxidant and hemostatic defence, which aggravates the pathological process. PMID:9304298

Chepurnov, A A; Dadaeva, A A; Zhukov, V A; Sizikov, L P; Merzlikin, N V

1997-01-01

223

Ebola virus disease cluster in the United States - dallas county, Texas, 2014.  

PubMed

Since March 10, 2014, Guinea, Liberia, and Sierra Leone have experienced the largest known Ebola virus disease (Ebola) epidemic with approximately 13,000 persons infected as of October 28, 2014. Before September 25, 2014, only four patients with Ebola had been treated in the United States; all of these patients had been diagnosed in West Africa and medically evacuated to the United States for care. PMID:25412069

Chevalier, Michelle S; Chung, Wendy; Smith, Jessica; Weil, Lauren M; Hughes, Sonya M; Joyner, Sibeso N; Hall, Emily; Srinath, Divya; Ritch, Julia; Thathiah, Prea; Threadgill, Heidi; Cervantes, Diana; Lakey, David L

2014-11-21

224

Role for Amino Acids 212KLR214 of Ebola Virus VP40 in Assembly and Budding  

Microsoft Academic Search

Received 20 April 2007\\/Accepted 30 July 2007 Ebola virus VP40 is able to produce virus-like particles (VLPs) in the absence of other viral proteins. At least three domains within VP40 are thought to be required for efficient VLP release: the late domain (L-domain), membrane association domain (M-domain), and self-interaction domain (I-domain). While the L-domain of Ebola VP40 has been well

Sarah E. McCarthy; Reed F. Johnson; Yong-An Zhang; J. Oriol Sunyer; Ronald N. Harty

2007-01-01

225

Development of a broad-spectrum antiviral with activity against Ebola virus  

Microsoft Academic Search

We report herein the identification of a small molecule therapeutic, FGI-106, which displays potent and broad-spectrum inhibition of lethal viral hemorrhagic fevers pathogens, including Ebola, Rift Valley and Dengue Fever viruses, in cell-based assays. Using mouse models of Ebola virus, we further demonstrate that FGI-106 can protect animals from an otherwise lethal infection when used either in a prophylactic or

M. Javad Aman; Michael S. Kinch; Kelly Warfield; Travis Warren; Abdul Yunus; Sven Enterlein; Eric Stavale; Peifang Wang; Shaojing Chang; Qingsong Tang; Kevin Porter; Michael Goldblatt; Sina Bavari

2009-01-01

226

LEPTOSPIROSIS AND EBOLA VIRUS INFECTION IN FIVE GOLD-PANNING VILLAGES IN NORTHEASTERN GABON  

Microsoft Academic Search

An exhaustive epidemiologic and serologic survey was carried out in five gold-panning villages situated in northeastern Gabon to estimate the degree of exposure of to leptospirosis and Ebola virus. The seroprevalence was 15.7% for leptospirosis and 10.2% for Ebola virus. Sixty years after the last seroepidemiologic survey of leptospirosis in Gabon, this study demonstrates the persistence of this infection among

ERIC BERTHERAT; ANDRE RENAUT; RENE NABIAS; GUY DUBREUIL; MARIE-CLAUDE GEORGES-COURBOT

1999-01-01

227

Apoptosis in fatal Ebola infection. Does the virus toll the bell for immune system?  

Microsoft Academic Search

In fatal Ebola virus hemorrhagic fever massive intravascular apoptosis develops rapidly following infection and progressing relentlessly until death. While data suggest that T lymphocytes are mainly deleted by apoptosis in PBMC of human fatal cases, experimental Ebola infection in animal models have shown some evidence of destruction of lymphocytes in spleen and lymph nodes probably involving both T and B

S. Baize; E. M. Leroy; E. Mavoungou; S. P. Fisher-Hoch

2000-01-01

228

Analysis of the role of predicted RNA secondary structures in Ebola virus replication  

Microsoft Academic Search

Thermodynamic modeling of Ebola viral RNA predicts the formation of RNA stem-loop structures at the 3? and 5? termini and panhandle structures between the termini of the genomic (or antigenomic) RNAs. Sequence analysis showed a high degree of identity among Ebola Zaire, Sudan, Reston, and Cote d’Ivoire subtype viruses in their 3? and 5? termini (18 nucleotides in length) and

Sharon M Crary; Jonathan S Towner; Jessica E Honig; Trevor R Shoemaker; Stuart T Nichol

2003-01-01

229

Requirements for cell rounding and surface protein down-regulation by Ebola virus glycoprotein  

Microsoft Academic Search

Ebola virus causes an acute hemorrhagic fever that is associated with high morbidity and mortality. The viral glycoprotein is thought to contribute to pathogenesis, though precise mechanisms are unknown. Cellular pathogenesis can be modeled in vitro by expression of the Ebola viral glycoprotein (GP) in cells, which causes dramatic morphological changes, including cell rounding and surface protein down-regulation. These effects

Joseph R. Francica; Meghan K. Matukonis; Paul Bates

2009-01-01

230

Stimulation of Ebola virus production from persistent infection through activation of the Ras\\/MAPK pathway  

Microsoft Academic Search

Human infections with Ebola virus (EBOV) result in a deadly viral disease known as Ebola hemorrhagic fever. Up to 90% of infected patients die, and there is no available treatment or vaccine. The sporadic human outbreaks are believed to result when EBOV ``jumps'' from an infected animal to a person and is subsequently transmitted between persons by direct contact with

James E. Strong; Gary Wong; Shane E. Jones; Allen Grolla; Steven Theriault; Gary P. Kobinger; Heinz Feldmann

2008-01-01

231

Ebola virus disease cases among health care workers not working in ebola treatment units - liberia, june-august, 2014.  

PubMed

West Africa is experiencing the largest Ebola virus disease (Ebola) epidemic in recorded history. Health care workers (HCWs) are at increased risk for Ebola. In Liberia, as of August 14, 2014, a total of 810 cases of Ebola had been reported, including 10 clusters of Ebola cases among HCWs working in facilities that were not Ebola treatment units (non-ETUs). The Liberian Ministry of Health and Social Welfare and CDC investigated these clusters by reviewing surveillance data, interviewing county health officials, HCWs, and contact tracers, and visiting health care facilities. Ninety-seven cases of Ebola (12% of the estimated total) were identified among HCWs; 62 HCW cases (64%) were part of 10 distinct clusters in non-ETU health care facilities, primarily hospitals. Early recognition and diagnosis of Ebola in patients who were the likely source of introduction to the HCWs (i.e., source patients) was missed in four clusters. Inconsistent recognition and triage of cases of Ebola, overcrowding, limitations in layout of physical spaces, lack of training in the use of and adequate supply of personal protective equipment (PPE), and limited supervision to ensure consistent adherence to infection control practices all were observed. Improving infection control infrastructure in non-ETUs is essential for protecting HCWs. Since August, the Liberian Ministry of Health and Social Welfare with a consortium of partners have undertaken collaborative efforts to strengthen infection control infrastructure in non-ETU health facilities. PMID:25412067

Matanock, Almea; Arwady, M Allison; Ayscue, Patrick; Forrester, Joseph D; Gaddis, Bethany; Hunter, Jennifer C; Monroe, Benjamin; Pillai, Satish K; Reed, Christie; Schafer, Ilana J; Massaquoi, Moses; Dahn, Bernice; De Cock, Kevin M

2014-11-21

232

Release of cellular proteases into the acidic extracellular milieu exacerbates Ebola virus-induced cell damage.  

PubMed

Ebola virus is highly cytopathic through mechanisms that are largely unknown. We present evidence that progressive acidification of the extracellular milieu by Ebola virus-infected cells combined with reduced levels of natural cysteine protease inhibitor makes the cells vulnerable to uncontrolled proteolysis of extracellular matrix components by released active endosomal cathepsins, thereby exacerbating Ebola virus-induced cell destruction. The cell surface microenvironment was shown to be crucial in aiding this activity. Blocking the proteolytic activity with the cathepsin inhibitor E64 resulted in remarkable improvements with respect to viral cytopathicity and cell survival despite an overwhelmingly high viral load. We propose that the observed enzymatic matrix degradation, enhanced by an associated protease/inhibitor imbalance and metabolic acidosis, represents an effective viral strategy to boost infection and underlies, in part, the remarkable pathogenesis caused by Ebola virus. Further in vitro and in vivo research will establish whether a cellular protease with hemorrhagic activity is the leading cause of vascular leakage-the hallmark of Ebola virus hemorrhagic fever-and help understand the Ebola virus caused cell death. PMID:16982079

Barrientos, Laura G; Rollin, Pierre E

2007-02-01

233

Development of a broad-spectrum antiviral with activity against Ebola virus.  

PubMed

We report herein the identification of a small molecule therapeutic, FGI-106, which displays potent and broad-spectrum inhibition of lethal viral hemorrhagic fevers pathogens, including Ebola, Rift Valley and Dengue Fever viruses, in cell-based assays. Using mouse models of Ebola virus, we further demonstrate that FGI-106 can protect animals from an otherwise lethal infection when used either in a prophylactic or therapeutic setting. A single treatment, administered 1 day after infection, is sufficient to protect animals from lethal Ebola virus challenge. Cell-based assays also identified inhibitory activity against divergent virus families, which supports a hypothesis that FGI-106 interferes with a common pathway utilized by different viruses. These findings suggest FGI-106 may provide an opportunity for targeting viral diseases. PMID:19523489

Aman, M Javad; Kinch, Michael S; Warfield, Kelly; Warren, Travis; Yunus, Abdul; Enterlein, Sven; Stavale, Eric; Wang, Peifang; Chang, Shaojing; Tang, Qingsong; Porter, Kevin; Goldblatt, Michael; Bavari, Sina

2009-09-01

234

Ebola virus disease in the democratic republic of congo.  

PubMed

Background The seventh reported outbreak of Ebola virus disease (EVD) in the equatorial African country of the Democratic Republic of Congo (DRC) began on July 26, 2014, as another large EVD epidemic continued to spread in West Africa. Simultaneous reports of EVD in equatorial and West Africa raised the question of whether the two outbreaks were linked. Methods We obtained data from patients in the DRC, using the standard World Health Organization clinical-investigation form for viral hemorrhagic fevers. Patients were classified as having suspected, probable, or confirmed EVD or a non-EVD illness. Blood samples were obtained for polymerase-chain-reaction-based diagnosis, viral isolation, sequencing, and phylogenetic analysis. Results The outbreak began in Inkanamongo village in the vicinity of Boende town in Équateur province and has been confined to that province. A total of 69 suspected, probable, or confirmed cases were reported between July 26 and October 7, 2014, including 8 cases among health care workers, with 49 deaths. As of October 7, there have been approximately six generations of cases of EVD since the outbreak began. The reported weekly case incidence peaked in the weeks of August 17 and 24 and has since fallen sharply. Genome sequencing revealed Ebola virus (EBOV, Zaire species) as the cause of this outbreak. A coding-complete genome sequence of EBOV that was isolated during this outbreak showed 99.2% identity with the most closely related variant from the 1995 outbreak in Kikwit in the DRC and 96.8% identity to EBOV variants that are currently circulating in West Africa. Conclusions The current EVD outbreak in the DRC has clinical and epidemiologic characteristics that are similar to those of previous EVD outbreaks in equatorial Africa. The causal agent is a local EBOV variant, and this outbreak has a zoonotic origin different from that in the 2014 epidemic in West Africa. (Funded by the Centre International de Recherches Médicales de Franceville and others.). PMID:25317743

Maganga, Gaël D; Kapetshi, Jimmy; Berthet, Nicolas; Kebela Ilunga, Benoît; Kabange, Felix; Mbala Kingebeni, Placide; Mondonge, Vital; Muyembe, Jean-Jacques T; Bertherat, Eric; Briand, Sylvie; Cabore, Joseph; Epelboin, Alain; Formenty, Pierre; Kobinger, Gary; González-Angulo, Licé; Labouba, Ingrid; Manuguerra, Jean-Claude; Okwo-Bele, Jean-Marie; Dye, Christopher; Leroy, Eric M

2014-11-27

235

ELISA for the detection of antibodies to Ebola viruses.  

PubMed

EIAs for IgG and IgM antibodies directed against Ebola (EBO) viral antigens have been developed and evaluated using sera of animals and humans surviving infection with EBO viruses. The IgM capture assay detected anti-EBO (subtype Reston) antibodies in the sera of 5 of 5 experimentally infected animals at the time they succumbed to lethal infections. IgM antibodies were also detected in the serum of a human who was infected with EBO (subtype Reston) during a postmortem examination of an infected monkey. The antibody was detectable as early as day 6 after infection in experimentally infected animals and persisted for <90 days. The IgG response was less rapid; however, it persisted for >400 days in 3 animals who survived infection, and it persisted for approximately 10 years after infection in the sera of 2 humans. Although these data are limited by the number of sera available for verification, the IgM assay seems to have great promise as a diagnostic tool. Furthermore the long-term persistence of the IgG antibodies measured by this test strongly suggests that the ELISA will be useful in field investigations of EBO virus. PMID:9988184

Ksiazek, T G; West, C P; Rollin, P E; Jahrling, P B; Peters, C J

1999-02-01

236

A replication-deficient rabies virus vaccine expressing Ebola virus glycoprotein is highly attenuated for neurovirulence.  

PubMed

We are developing inactivated and live-attenuated rabies virus (RABV) vaccines expressing Ebola virus (EBOV) glycoprotein for use in humans and endangered wildlife, respectively. Here, we further characterize the pathogenesis of the live-attenuated RABV/EBOV vaccine candidates in mice in an effort to define their growth properties and potential for safety. RABV vaccines expressing GP (RV-GP) or a replication-deficient derivative with a deletion of the RABV G gene (RV?G-GP) are both avirulent after intracerebral inoculation of adult mice. Furthermore, RV?G-GP is completely avirulent upon intracerebral inoculation of suckling mice unlike parental RABV vaccine or RV-GP. Analysis of RV?G-GP in the brain by quantitative PCR, determination of virus titer, and immunohistochemistry indicated greatly restricted virus replication. In summary, our findings indicate that RV-GP retains the attenuation phenotype of the live-attenuated RABV vaccine, and RV?G-GP would appear to be an even safer alternative for use in wildlife or consideration for human use. PMID:22889613

Papaneri, Amy B; Wirblich, Christoph; Cann, Jennifer A; Cooper, Kurt; Jahrling, Peter B; Schnell, Matthias J; Blaney, Joseph E

2012-12-01

237

A replication-deficient rabies virus vaccine expressing Ebola virus glycoprotein is highly attenuated for neurovirulence  

SciTech Connect

We are developing inactivated and live-attenuated rabies virus (RABV) vaccines expressing Ebola virus (EBOV) glycoprotein for use in humans and endangered wildlife, respectively. Here, we further characterize the pathogenesis of the live-attenuated RABV/EBOV vaccine candidates in mice in an effort to define their growth properties and potential for safety. RABV vaccines expressing GP (RV-GP) or a replication-deficient derivative with a deletion of the RABV G gene (RV{Delta}G-GP) are both avirulent after intracerebral inoculation of adult mice. Furthermore, RV{Delta}G-GP is completely avirulent upon intracerebral inoculation of suckling mice unlike parental RABV vaccine or RV-GP. Analysis of RV{Delta}G-GP in the brain by quantitative PCR, determination of virus titer, and immunohistochemistry indicated greatly restricted virus replication. In summary, our findings indicate that RV-GP retains the attenuation phenotype of the live-attenuated RABV vaccine, and RV{Delta}G-GP would appear to be an even safer alternative for use in wildlife or consideration for human use.

Papaneri, Amy B. [Emerging Viral Pathogens Section, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Fort Detrick, MD 21702 (United States)] [Emerging Viral Pathogens Section, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Fort Detrick, MD 21702 (United States); Wirblich, Christoph [Department of Microbiology and Immunology, Jefferson Medical College, Thomas Jefferson University, Philadelphia, PA 19107 (United States)] [Department of Microbiology and Immunology, Jefferson Medical College, Thomas Jefferson University, Philadelphia, PA 19107 (United States); Cann, Jennifer A.; Cooper, Kurt [Integrated Research Facility, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Fort Detrick MD, 21702 (United States)] [Integrated Research Facility, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Fort Detrick MD, 21702 (United States); Jahrling, Peter B. [Emerging Viral Pathogens Section, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Fort Detrick, MD 21702 (United States) [Emerging Viral Pathogens Section, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Fort Detrick, MD 21702 (United States); Integrated Research Facility, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Fort Detrick MD, 21702 (United States); Schnell, Matthias J., E-mail: matthias.schnell@jefferson.edu [Department of Microbiology and Immunology, Jefferson Medical College, Thomas Jefferson University, Philadelphia, PA 19107 (United States); Jefferson Vaccine Center, Jefferson Medical College, Thomas Jefferson University, Philadelphia, PA 19107 (United States); Blaney, Joseph E., E-mail: jblaney@niaid.nih.gov [Emerging Viral Pathogens Section, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Fort Detrick, MD 21702 (United States)

2012-12-05

238

A replication-deficient rabies virus vaccine expressing Ebola virus glycoprotein is highly attenuated for neurovirulence  

PubMed Central

We are developing inactivated and live-attenuated rabies virus (RABV) vaccines expressing Ebola virus (EBOV) glycoprotein for use in humans and endangered wildlife, respectively. Here, we further characterize the pathogenesis of the live-attenuated RABV/EBOV vaccine candidates in mice in an effort to define their growth properties and potential for safety. RABV vaccines expressing GP (RV-GP) or a replication-deficient derivative with a deletion of the RABV G gene (RV?G-GP) are both avirulent after intracerebral inoculation of adult mice. Furthermore, RV?G-GP is completely avirulent upon intracerebral inoculation of suckling mice unlike parental RABV vaccine or RV-GP. Analysis of RV?G-GP in the brain by quantitative PCR, determination of virus titer, and immunohistochemistry indicated greatly restricted virus replication. In summary, our findings indicate that RV-GP retains the attenuation phenotype of the live-attenuated RABV vaccine, and RV?G-GP would appear to be an even safer alternative for use in wildlife or consideration for human use. PMID:22889613

Papaneri, Amy B.; Wirblich, Christoph; Cann, Jennifer A.; Cooper, Kurt; Jahrling, Peter B.; Schnell, Matthias J.; Blaney, Joseph E.

2012-01-01

239

Ebola and Marburg virus-like particles activate human myeloid dendritic cells  

Microsoft Academic Search

The filoviruses, Ebola (EBOV) and Marburg (MARV), are potential global health threats, which cause deadly hemorrhagic fevers. Although both EBOV and MARV logarithmically replicate in dendritic cells (DCs), these viruses do not elicit DC cytokine secretion and fail to activate and mature infected DCs. Here, we employed virus-like particles (VLPs) of EBOV and MARV to investigate whether these genome-free particles

Catharine M Bosio; Brian D Moore; Kelly L Warfield; Gordon Ruthel; Mansour Mohamadzadeh; M. Javad Aman; Sina Bavari

2004-01-01

240

Differential induction of cellular detachment by envelope glycoproteins of Marburg and Ebola (Zaire) viruses  

Microsoft Academic Search

Human infection by Marburg (MBG) or Ebola (EBO) virus is associated with fatal haemorrhagic fevers. While these filoviruses may both incite disease as a result of explosive virus replication, we hypothe- sized that expression of individual viral gene pro- ducts, such as the envelope glycoprotein (GP), may directly alter target cells and contribute to patho- genesis. We found that expression

Stephen Y. Chan; Melissa C. Ma; Mark A. Goldsmith

241

Ebola Virus Matrix Protein VP40 Interaction with Human Cellular Factors Tsg101 and Nedd4  

Microsoft Academic Search

The Ebola virus matrix protein VP40 is a major viral structural protein and plays a central role in virus assembly and budding at the plasma membrane of infected cells. For efficient budding, a full amino terminus of VP40 is required, which includes a PPXY and a PT\\/SAP motif, both of which have been proposed to interact with cellular proteins. Here,

Joanna Timmins; Guy Schoehn; Sylvie Ricard-Blum; Sandra Scianimanico; Thierry Vernet; Rob W. H Ruigrok; Winfried Weissenhorn

2003-01-01

242

Gene-Specific Countermeasures against Ebola Virus Based on Antisense Phosphorodiamidate Morpholino Oligomers  

Microsoft Academic Search

The filoviruses Marburg virus and Ebola virus (EBOV) quickly outpace host immune responses and cause hemorrhagic fever, resulting in case fatality rates as high as 90% in humans and nearly 100% in nonhuman primates. The development of an effective therapeutic for EBOV is a daunting public health challenge and is hampered by a paucity of knowledge regarding filovirus pathogenesis. This

Kelly L. Warfield; Dana L. Swenson; Gene G. Olinger; Donald K. Nichols; William D. Pratt; Robert Blouch; David A. Stein; M. Javad Aman; Patrick L. Iversen; Sina Bavari

2006-01-01

243

Ebola virus infection in man: a serological and epidemiological survey in the Cameroons.  

PubMed

The presence of antibodies to Ebola virus among 1,517 apparently healthy persons in five regions of the Cameroons was tested using indirect immunofluorescence. A positive rate of 9.7% was found, confirming that the virus circulates in the absence of clinical cases. Highest rates were found among Pygmies, young adults, and rain forest farmers. PMID:6650749

Bouree, P; Bergmann, J F

1983-11-01

244

Rapid identification of Ebola virus and related filoviruses in fluid specimens using indirect immunoelectron microscopy  

Microsoft Academic Search

Recent filoviral outbreaks in animal primates have raised public awareness of the potential for filoviruses to become a public health concern; methods that efficiently identify these viruses are therefore of high priority. An indirect immunoelectron microscopy method, which uses homologous guinea pig polyclonal antiserum, successfully identified Ebola-related (Reston) virus particles in serum and tissue culture fluid specimens with infectivity titres

T W Geisbert; J B Rhoderick; P B Jahrling

1991-01-01

245

Neutralizing Antibody Fails to Impact the Course of Ebola Virus Infection in Monkeys  

Microsoft Academic Search

Prophylaxis with high doses of neutralizing antibody typically offers protection against challenge with viruses producing acute infections. In this study, we have investigated the ability of the neutralizing human monoclonal antibody, KZ52, to protect against Ebola virus in rhesus macaques. This antibody was previously shown to fully protect guinea pigs from infection. Four rhesus macaques were given 50 mg\\/kg of

Wendelien B. Oswald; Thomas W. Geisbert; Kelly J. Davis; Joan B. Geisbert; Nancy J. Sullivan; Peter B. Jahrling; Paul W. H. I. Parren; Dennis R. Burton

2007-01-01

246

Ebola and Marburg Viruses Replicate in Monocyle- Derived Dendritic Cells without Inducing the Production of Cytokines and Full Maturation.  

National Technical Information Service (NTIS)

Ebola virus (EBOV) and Marburg virus (MARV) cause rapidly progressive hemorrhagic fever with high mortality and may possess specialized mechanisms to evade immune destruction. We postulated that immune evasion could be due to the ability of EBOV and MARV ...

C. M. Bosio, M. J. Aman, C. Grogan, R. Hogan, G. Ruthel

2003-01-01

247

Activation of Triggering Receptor Expressed on Myeloid Cells-1 on Human Neutrophils by Marburg and Ebola Viruses.  

National Technical Information Service (NTIS)

Marburg virus (MARV) and Ebola virus (EBOV), members of the viral family Filoviridae, cause fatal hemorrhagic fevers in humans and nonhuman primates. High viral burden is coincident with inadequate adaptive immune responses and robust inflammatory respons...

M. Mohamadzadeh, S. S. Coberley, G. G. Olinger, W. V. Kalina, G. Ruthel

2006-01-01

248

Rho GTPases modulate entry of Ebola virus and vesicular stomatitis virus pseudotyped vectors.  

PubMed

To explore mechanisms of entry for Ebola virus (EBOV) glycoprotein (GP) pseudotyped virions, we used comparative gene analysis to identify genes whose expression correlated with viral transduction. Candidate genes were identified by using EBOV GP pseudotyped virions to transduce human tumor cell lines that had previously been characterized by cDNA microarray. Transduction profiles for each of these cell lines were generated, and a significant positive correlation was observed between RhoC expression and permissivity for EBOV vector transduction. This correlation was not specific for EBOV vector alone as RhoC also correlated highly with transduction of vesicular stomatitis virus GP (VSVG) pseudotyped vector. Levels of RhoC protein in EBOV and VSV permissive and nonpermissive cells were consistent with the cDNA gene array findings. Additionally, vector transduction was elevated in cells that expressed high levels of endogenous RhoC but not RhoA. RhoB and RhoC overexpression significantly increased EBOV GP and VSVG pseudotyped vector transduction but had minimal effect on human immunodeficiency virus (HIV) GP pseudotyped HIV or adeno-associated virus 2 vector entry, indicating that not all virus uptake was enhanced by expression of these molecules. RhoB and RhoC overexpression also significantly enhanced VSV infection. Similarly, overexpression of RhoC led to a significant increase in fusion of EBOV virus-like particles. Finally, ectopic expression of RhoC resulted in increased nonspecific endocytosis of fluorescent dextran and in formation of increased actin stress fibers compared to RhoA-transfected cells, suggesting that RhoC is enhancing macropinocytosis. In total, our studies implicate RhoB and RhoC in enhanced productive entry of some pseudovirions and suggest the involvement of actin-mediated macropinocytosis as a mechanism of uptake of EBOV GP and VSVG pseudotyped viral particles. PMID:19625394

Quinn, Kathrina; Brindley, Melinda A; Weller, Melodie L; Kaludov, Nikola; Kondratowicz, Andrew; Hunt, Catherine L; Sinn, Patrick L; McCray, Paul B; Stein, Colleen S; Davidson, Beverly L; Flick, Ramon; Mandell, Robert; Staplin, William; Maury, Wendy; Chiorini, John A

2009-10-01

249

Cathepsin B & L Are Not Required for Ebola Virus Replication  

PubMed Central

Ebola virus (EBOV), family Filoviridae, emerged in 1976 on the African continent. Since then it caused several outbreaks of viral hemorrhagic fever in humans with case fatality rates up to 90% and remains a serious Public Health concern and biothreat pathogen. The most pathogenic and best-studied species is Zaire ebolavirus (ZEBOV). EBOV encodes one viral surface glycoprotein (GP), which is essential for replication, a determinant of pathogenicity and an important immunogen. GP mediates viral entry through interaction with cellular surface molecules, which results in the uptake of virus particles via macropinocytosis. Later in this pathway endosomal acidification activates the cysteine proteases Cathepsin B and L (CatB, CatL), which have been shown to cleave ZEBOV-GP leading to subsequent exposure of the putative receptor-binding and fusion domain and productive infection. We studied the effect of CatB and CatL on in vitro and in vivo replication of EBOV. Similar to previous findings, our results show an effect of CatB, but not CatL, on ZEBOV entry into cultured cells. Interestingly, cell entry by other EBOV species (Bundibugyo, Côte d'Ivoire, Reston and Sudan ebolavirus) was independent of CatB or CatL as was EBOV replication in general. To investigate whether CatB and CatL have a role in vivo during infection, we utilized the mouse model for ZEBOV. Wild-type (control), catB?/? and catL?/? mice were equally susceptible to lethal challenge with mouse-adapted ZEBOV with no difference in virus replication and time to death. In conclusion, our results show that CatB and CatL activity is not required for EBOV replication. Furthermore, EBOV glycoprotein cleavage seems to be mediated by an array of proteases making targeted therapeutic approaches difficult. PMID:23236527

Marzi, Andrea; Reinheckel, Thomas; Feldmann, Heinz

2012-01-01

250

Animal models for Ebola and Marburg virus infections  

PubMed Central

Ebola and Marburg hemorrhagic fevers (EHF and MHF) are caused by the Filoviridae family, Ebolavirus and Marburgvirus (ebolavirus and marburgvirus), respectively. These severe diseases have high mortality rates in humans. Although EHF and MHF are endemic to sub-Saharan Africa. A novel filovirus, Lloviu virus, which is genetically distinct from ebolavirus and marburgvirus, was recently discovered in Spain where filoviral hemorrhagic fever had never been reported. The virulence of this virus has not been determined. Ebolavirus and marburgvirus are classified as biosafety level-4 (BSL-4) pathogens and Category A agents, for which the US government requires preparedness in case of bioterrorism. Therefore, preventive measures against these viral hemorrhagic fevers should be prepared, not only in disease-endemic regions, but also in disease-free countries. Diagnostics, vaccines, and therapeutics need to be developed, and therefore the establishment of animal models for EHF and MHF is invaluable. Several animal models have been developed for EHF and MHF using non-human primates (NHPs) and rodents, which are crucial to understand pathophysiology and to develop diagnostics, vaccines, and therapeutics. Rhesus and cynomolgus macaques are representative models of filovirus infection as they exhibit remarkably similar symptoms to those observed in humans. However, the NHP models have practical and ethical problems that limit their experimental use. Furthermore, there are no inbred and genetically manipulated strains of NHP. Rodent models such as mouse, guinea pig, and hamster, have also been developed. However, these rodent models require adaptation of the virus to produce lethal disease and do not mirror all symptoms of human filovirus infection. This review article provides an outline of the clinical features of EHF and MHF in animals, including humans, and discusses how the animal models have been developed to study pathophysiology, vaccines, and therapeutics. PMID:24046765

Nakayama, Eri; Saijo, Masayuki

2013-01-01

251

Cathepsin B & L are not required for ebola virus replication.  

PubMed

Ebola virus (EBOV), family Filoviridae, emerged in 1976 on the African continent. Since then it caused several outbreaks of viral hemorrhagic fever in humans with case fatality rates up to 90% and remains a serious Public Health concern and biothreat pathogen. The most pathogenic and best-studied species is Zaire ebolavirus (ZEBOV). EBOV encodes one viral surface glycoprotein (GP), which is essential for replication, a determinant of pathogenicity and an important immunogen. GP mediates viral entry through interaction with cellular surface molecules, which results in the uptake of virus particles via macropinocytosis. Later in this pathway endosomal acidification activates the cysteine proteases Cathepsin B and L (CatB, CatL), which have been shown to cleave ZEBOV-GP leading to subsequent exposure of the putative receptor-binding and fusion domain and productive infection. We studied the effect of CatB and CatL on in vitro and in vivo replication of EBOV. Similar to previous findings, our results show an effect of CatB, but not CatL, on ZEBOV entry into cultured cells. Interestingly, cell entry by other EBOV species (Bundibugyo, Côte d'Ivoire, Reston and Sudan ebolavirus) was independent of CatB or CatL as was EBOV replication in general. To investigate whether CatB and CatL have a role in vivo during infection, we utilized the mouse model for ZEBOV. Wild-type (control), catB(-/-) and catL(-/-) mice were equally susceptible to lethal challenge with mouse-adapted ZEBOV with no difference in virus replication and time to death. In conclusion, our results show that CatB and CatL activity is not required for EBOV replication. Furthermore, EBOV glycoprotein cleavage seems to be mediated by an array of proteases making targeted therapeutic approaches difficult. PMID:23236527

Marzi, Andrea; Reinheckel, Thomas; Feldmann, Heinz

2012-01-01

252

Evasion of interferon responses by Ebola and Marburg viruses.  

PubMed

The filoviruses, Ebola virus (EBOV) and Marburg virus (MARV), cause frequently lethal viral hemorrhagic fever. These infections induce potent cytokine production, yet these host responses fail to prevent systemic virus replication. Consistent with this, filoviruses have been found to encode proteins VP35 and VP24 that block host interferon (IFN)-alpha/beta production and inhibit signaling downstream of the IFN-alpha/beta and the IFN-gamma receptors, respectively. VP35, which is a component of the viral nucleocapsid complex and plays an essential role in viral RNA synthesis, acts as a pseudosubstrate for the cellular kinases IKK-epsilon and TBK-1, which phosphorylate and activate interferon regulatory factor 3 (IRF-3) and interferon regulatory factor 7 (IRF-7). VP35 also promotes SUMOylation of IRF-7, repressing IFN gene transcription. In addition, VP35 is a dsRNA-binding protein, and mutations that disrupt dsRNA binding impair VP35 IFN-antagonist activity while leaving its RNA replication functions intact. The phenotypes of recombinant EBOV bearing mutant VP35s unable to inhibit IFN-alpha/beta demonstrate that VP35 IFN-antagonist activity is critical for full virulence of these lethal pathogens. The structure of the VP35 dsRNA-binding domain, which has recently become available, is expected to provide insight into how VP35 IFN-antagonist and dsRNA-binding functions are related. The EBOV VP24 protein inhibits IFN signaling through an interaction with select host cell karyopherin-alpha proteins, preventing the nuclear import of otherwise activated STAT1. It remains to be determined to what extent VP24 may also modulate the nuclear import of other host cell factors and to what extent this may influence the outcome of infection. Notably, the Marburg virus VP24 protein does not detectably block STAT1 nuclear import, and, unlike EBOV, MARV infection inhibits STAT1 and STAT2 phosphorylation. Thus, despite their similarities, there are fundamental differences by which these deadly viruses counteract the IFN system. It will be of interest to determine how these differences influence pathogenesis. PMID:19694547

Basler, Christopher F; Amarasinghe, Gaya K

2009-09-01

253

3-deazaneplanocin A induces massively increased interferon-alpha production in Ebola virus-infected mice.  

PubMed

3-deazaneplanocin A, an analog of adenosine, is a potent inhibitor of Ebola virus replication. A single dose early in infection prevents illness and death in Ebola virus-infected mice. The ability of this and similar compounds to block both RNA and DNA viruses has been attributed to the inhibition of a cellular enzyme, S-adenosylhomocysteine hydrolase (SAH), indirectly resulting in reduced methylation of the 5' cap of viral messenger RNA. However, we found that the protective effect of the drug resulted from massively increased production of interferon-alpha in Ebola-infected, but not uninfected mice. Peak interferon levels increased with the extent of disease at the time of treatment, indicating that production was boosted only in virus-infected cells. Ebola virus has been shown to suppress innate antiviral mechanisms of the type I interferon response. 3-deazaneplanocin A appears to reverse such suppression, restricting viral dissemination. Further development should focus on identifying adenosine analogues that produce a similar effect in Ebola virus-infected primates. PMID:12076759

Bray, Mike; Raymond, Jo Lynne; Geisbert, Tom; Baker, Robert O

2002-07-01

254

Lipid raft microdomains: a gateway for compartmentalized trafficking of Ebola and Marburg viruses  

E-print Network

Spatiotemporal aspects of filovirus entry and release are poorly understood. Lipid rafts act as functional platforms for multiple cellular signaling and trafficking processes. Here, we report the compartmentalization of Ebola and Marburg viral proteins within lipid rafts during viral assembly and budding. Filoviruses released from infected cells incorporated raft-associated molecules, suggesting that viral exit occurs at the rafts. Ectopic expression of Ebola matrix protein and glycoprotein supported raft-dependent release of filamentous, virus-like particles (VLPs), strikingly similar to live virus as revealed by electron microscopy. Our findings also revealed that the entry of filoviruses requires functional rafts, identifying rafts as the site of virus attack. The identification of rafts as the gateway for the entry and exit of filoviruses and raftdependent generation of VLPs have important implications for development of therapeutics and vaccination strategies against infections with Ebola and Marburg viruses.

Sina Bavari; Catharine M. Bosio; Elizabeth Wieg; Gordon Ruthel; Amy B. Will; Thomas W. Geisbert; Michael Hevey; Connie Schmaljohn; Alan Schmaljohn; M. Javad Aman

2002-01-01

255

The spatio-temporal distribution dynamics of Ebola virus proteins and RNA in infected cells  

PubMed Central

Here, we used a biologically contained Ebola virus system to characterize the spatio-temporal distribution of Ebola virus proteins and RNA during virus replication. We found that viral nucleoprotein (NP), the polymerase cofactor VP35, the major matrix protein VP40, the transcription activator VP30, and the minor matrix protein VP24 were distributed in cytoplasmic inclusions. These inclusions enlarged near the nucleus, became smaller pieces, and subsequently localized near the plasma membrane. GP was distributed in the cytoplasm and transported to the plasma membrane independent of the other viral proteins. We also found that viral RNA synthesis occurred within the inclusions. Newly synthesized negative-sense RNA was distributed inside the inclusions, whereas positive-sense RNA was distributed both inside and outside. These findings provide useful insights into Ebola virus replication. PMID:23383374

Nanbo, Asuka; Watanabe, Shinji; Halfmann, Peter; Kawaoka, Yoshihiro

2013-01-01

256

High-dose mannose-binding lectin therapy for Ebola virus infection.  

PubMed

Mannose-binding lectin (MBL) targets diverse microorganisms for phagocytosis and complement-mediated lysis by binding specific surface glycans. Although recombinant human MBL (rhMBL) trials have focused on reconstitution therapy, safety studies have identified no barriers to its use at higher levels. Ebola viruses cause fatal hemorrhagic fevers for which no treatment exists and that are feared as potential biothreat agents. We found that mice whose rhMBL serum concentrations were increased ?7-fold above average human levels survived otherwise fatal Ebola virus infections and became immune to virus rechallenge. Because Ebola glycoproteins potentially model other glycosylated viruses, rhMBL may offer a novel broad-spectrum antiviral approach. PMID:21288816

Michelow, Ian C; Lear, Calli; Scully, Corinne; Prugar, Laura I; Longley, Clifford B; Yantosca, L Michael; Ji, Xin; Karpel, Marshall; Brudner, Matthew; Takahashi, Kazue; Spear, Gregory T; Ezekowitz, R Alan B; Schmidt, Emmett V; Olinger, Gene G

2011-01-15

257

Cell adhesion promotes Ebola virus envelope glycoprotein-mediated binding and infection.  

PubMed

Ebola virus infects a wide variety of adherent cell types, while nonadherent cells are found to be refractory. To explore this correlation, we compared the ability of pairs of related adherent and nonadherent cells to bind a recombinant Ebola virus receptor binding domain (EboV RBD) and to be infected with Ebola virus glycoprotein (GP)-pseudotyped particles. Both human 293F and THP-1 cells can be propagated as adherent or nonadherent cultures, and in both cases adherent cells were found to be significantly more susceptible to both EboV RBD binding and GP-pseudotyped virus infection than their nonadherent counterparts. Furthermore, with 293F cells the acquisition of EboV RBD binding paralleled cell spreading and did not require new mRNA or protein synthesis. PMID:18448524

Dube, Derek; Schornberg, Kathryn L; Stantchev, Tzanko S; Bonaparte, Matthew I; Delos, Sue E; Bouton, Amy H; Broder, Christopher C; White, Judith M

2008-07-01

258

BRIEF REPORT High-Dose Mannose-Binding Lectin Therapy for Ebola Virus Infection  

E-print Network

Mannose-binding lectin (MBL) targets diverse microorganisms for phagocytosis and complement-mediated lysis by binding specific surface glycans. Although recombinant human MBL (rhMBL) trials have focused on reconstitution therapy, safety studies have identified no barriers to its use at higher levels. Ebola viruses cause fatal hemorrhagic fevers for which no treatment exists and that are feared as potential biothreat agents. We found that mice whose rhMBL serum concentrations were increased>7fold above average human levels survived otherwise fatal Ebola virus infections and became immune to virus rechallenge. Because Ebola glycoproteins potentially model other glycosylated viruses, rhMBL may offer a novel broadspectrum antiviral approach. Circulating mannose-binding lectin (MBL) is a first-line host

Ian C. Michelow; Calli Lear; Corinne Scully; Laura I. Prugar; B. Longley; L. Michael Yantosca; Xin Ji; Marshall Karpel; Matthew Brudner; Kazue Takahashi; Gregory T. Spear; R. Alan; B. Ezekowitz; Emmett V. Schmidt; Department Of Pediatrics

2010-01-01

259

High-Dose Mannose-Binding Lectin Therapy for Ebola Virus Infection  

PubMed Central

Mannose-binding lectin (MBL) targets diverse microorganisms for phagocytosis and complement-mediated lysis by binding specific surface glycans. Although recombinant human MBL (rhMBL) trials have focused on reconstitution therapy, safety studies have identified no barriers to its use at higher levels. Ebola viruses cause fatal hemorrhagic fevers for which no treatment exists and that are feared as potential biothreat agents. We found that mice whose rhMBL serum concentrations were increased ?7-fold above average human levels survived otherwise fatal Ebola virus infections and became immune to virus rechallenge. Because Ebola glycoproteins potentially model other glycosylated viruses, rhMBL may offer a novel broad-spectrum antiviral approach. PMID:21288816

Michelow, Ian C.; Lear, Calli; Scully, Corinne; Prugar, Laura I.; Longley, Clifford B.; Yantosca, L. Michael; Ji, Xin; Karpel, Marshall; Brudner, Matthew; Takahashi, Kazue; Spear, Gregory T.; Ezekowitz, R. Alan B.; Olinger, Gene G.

2011-01-01

260

Detection of Cell-Cell Fusion Mediated by Ebola Virus Glycoproteins  

Microsoft Academic Search

Ebola viruses (EboV) are enveloped RNA viruses infecting cells by a pH-dependent process mediated by viral glycoproteins (GP) involving endocytosis of virions and their routing into acidic endosomes. As with well- characterized pH-dependent viral entry proteins, in particular influenza virus hemagglutinin, it is thought that EboV GP require activation by low pH in order to mediate fusion of the viral

Severine Bar; Ayato Takada; Yoshihiro Kawaoka; Marc Alizon

2006-01-01

261

Sensitivity to ultraviolet radiation of Lassa, vaccinia, and Ebola viruses dried on surfaces  

Microsoft Academic Search

Germicidal UV (also known as UVC) provides a means to decontaminate infected environments as well as a measure of viral sensitivity\\u000a to sunlight. The present study determined UVC inactivation slopes (and derived D37 values) of viruses dried onto nonporous (glass) surfaces. The data obtained indicate that the UV resistance of Lassa virus\\u000a is higher than that of Ebola virus. The

Jose-Luis Sagripanti; C. David Lytle

2011-01-01

262

Development of a cAdVax-Based Bivalent Ebola Virus Vaccine That Induces Immune Responses against both the Sudan and Zaire Species of Ebola Virus  

Microsoft Academic Search

Ebola virus (EBOV) causes a severe hemorrhagic fever for which there are currently no vaccines or effective treatments. While lethal human outbreaks have so far been restricted to sub-Saharan Africa, the potential exploitation of EBOV as a biological weapon cannot be ignored. Two species of EBOV, Sudan ebolavirus (SEBOV) and Zaire ebolavirus (ZEBOV), have been responsible for all of the

Danher Wang; Nicholas U. Raja; Charles M. Trubey; Laure Y. Juompan; Min Luo; Jan Woraratanadharm; Stephen B. Deitz; Hong Yu; Benjamin M. Swain; Kevin M. Moore; William D. Pratt; Mary Kate Hart; John Y. Dong

2006-01-01

263

Mutational analysis of the putative fusion domain of Ebola virus glycoprotein.  

PubMed

Ebola viruses contain a single glycoprotein (GP) spike, which functions as a receptor binding and membrane fusion protein. It contains a highly conserved hydrophobic region (amino acids 524 to 539) located 24 amino acids downstream of the N terminus of the Ebola virus GP2 subunit. Comparison of this region with the structural features of the transmembrane subunit of avian retroviral GPs suggests that the conserved Ebola virus hydrophobic region may, in fact, serve as the fusion peptide. To test this hypothesis directly, we introduced conservative (alanine) and nonconservative (arginine) amino acid substitutions at eight positions in this region of the GP2 molecule. The effects of these mutations were deduced from the ability of the Ebola virus GP to complement the infectivity of a vesicular stomatitis virus (VSV) lacking the receptor-binding G protein. Some mutations, such as Ile-to-Arg substitutions at positions 532 (I532R), F535R, G536A, and P537R, almost completely abolished the ability of the GP to support VSV infectivity without affecting the transport of GP to the cell surface and its incorporation into virions or the production of virus particles. Other mutations, such as G528R, L529A, L529R, I532A, and F535A, reduced the infectivity of the VSV-Ebola virus pseudotypes by at least one-half. These findings, together with previous reports of liposome association with a peptide corresponding to positions 524 to 539 in the GP molecule, offer compelling support for a fusion peptide role for the conserved hydrophobic region in the Ebola virus GP. PMID:10482652

Ito, H; Watanabe, S; Sanchez, A; Whitt, M A; Kawaoka, Y

1999-10-01

264

Ebola virus infection of human PBMCs causes massive death of macrophages, CD4 and CD8 T cell sub-populations in vitro  

Microsoft Academic Search

Ebola virus causes an often fatal disease characterized by poor immune response and high inflammatory reaction in the patients. One of the causes for poor immunity is virus-mediated apoptosis of lymphocytes in the host. In this study, we infected human PBMCs with Ebola Zaire virus and study apoptosis of different cell types using flow cytometry. We have shown that Ebola

Manisha Gupta; Christina Spiropoulou; Pierre E. Rollin

2007-01-01

265

A Mutation in the Ebola Virus Envelope Glycoprotein Restricts Viral Entry in a Host Species-and Cell-Type-Specific Manner  

E-print Network

A Mutation in the Ebola Virus Envelope Glycoprotein Restricts Viral Entry in a Host Species, Bronx, New York, USAb Zaire Ebola virus (EBOV) is a zoonotic pathogen that causes severe hemorrhagic APCs. Zaire Ebola virus (EBOV) is an emerging zoonotic pathogen that causes hemorrhagic fever in humans

Chandran, Kartik

266

Current knowledge on lower virulence of Reston Ebola virus (in French: Connaissances actuelles sur la moindre virulence du virus Ebola Reston).  

PubMed

Ebola viruses (EBOV) and Marburg virus belong to the family Filoviridae, order Mononegavirales. The genus Ebolavirus consists of four species: Zaire ebolavirus (ZEBOV), Sudan ebolavirus (SEBOV), Ivory Coast ebolavirus (ICEBOV) and Reston ebolavirus (REBOV). Three species of ebolaviruses, ZEBOV, SEBOV, ICEBOV, and Marburg virus are known to be extremely pathogenic in primates and humans and cause severe hemorrhagic fever leading up to case fatality rate of some 90%, while REBOV is thought to be pathogenic in Asian monkeys but not in African monkeys and humans. Recent studies indicated several factors involved in different virulence between African EBOV and REBOV. This article reviews the history, epidemiology, and virulence of REBOV. PMID:17610952

Morikawa, Shigeru; Saijo, Masayuki; Kurane, Ichiro

2007-09-01

267

Studies of Ebola Virus Glycoprotein-Mediated Entry and Fusion by Using Pseudotyped Human Immunodeficiency Virus Type 1 Virions: Involvement of Cytoskeletal Proteins and Enhancement by Tumor Necrosis Factor Alpha  

Microsoft Academic Search

The Ebola filoviruses are aggressive pathogens that cause severe and often lethal hemorrhagic fever syndromes in humans and nonhuman primates. To date, no effective therapies have been identified. To analyze the entry and fusion properties of Ebola virus, we adapted a human immunodeficiency virus type 1 (HIV-1) virion-based fusion assay by substituting Ebola virus glycoprotein (GP) for the HIV-1 envelope.

Akihito Yonezawa; Marielle Cavrois; Warner C. Greene

2005-01-01

268

Identification of protective epitopes on ebola virus glycoprotein at the single amino acid level by using recombinant vesicular stomatitis viruses.  

PubMed

Ebola virus causes lethal hemorrhagic fever in humans, but currently there are no effective vaccines or antiviral compounds for this infectious disease. Passive transfer of monoclonal antibodies (MAbs) protects mice from lethal Ebola virus infection (J. A. Wilson, M. Hevey, R. Bakken, S. Guest, M. Bray, A. L. Schmaljohn, and M. K. Hart, Science 287:1664-1666, 2000). However, the epitopes responsible for neutralization have been only partially characterized because some of the MAbs do not recognize the short synthetic peptides used for epitope mapping. To identify the amino acids recognized by neutralizing and protective antibodies, we generated a recombinant vesicular stomatitis virus (VSV) containing the Ebola virus glycoprotein-encoding gene instead of the VSV G protein-encoding gene and used it to select escape variants by growing it in the presence of a MAb (133/3.16 or 226/8.1) that neutralizes the infectivity of the virus. All three variants selected by MAb 133/3.16 contained a single amino acid substitution at amino acid position 549 in the GP2 subunit. By contrast, MAb 226/8.1 selected three different variants containing substitutions at positions 134, 194, and 199 in the GP1 subunit, suggesting that this antibody recognized a conformational epitope. Passive transfer of each of these MAbs completely protected mice from a lethal Ebola virus infection. These data indicate that neutralizing antibody cocktails for passive prophylaxis and therapy of Ebola hemorrhagic fever can reduce the possibility of the emergence of antigenic variants in infected individuals. PMID:12502822

Takada, Ayato; Feldmann, Heinz; Stroeher, Ute; Bray, Mike; Watanabe, Shinji; Ito, Hiroshi; McGregor, Martha; Kawaoka, Yoshihiro

2003-01-01

269

Passive Transfer of Antibodies Protects Immunocompetent and Immunodeficient Mice against Lethal Ebola Virus Infection without Complete Inhibition of Viral Replication  

Microsoft Academic Search

Ebola hemorrhagic fever is a severe, usually fatal illness caused by Ebola virus, a member of the filovirus family. The use of nonhomologous immune serum in animal studies and blood from survivors in two anecdotal reports of Ebola hemorrhagic fever in humans has shown promise, but the efficacy of these treatments has not been demonstrated definitively. We have evaluated the

MANISHA GUPTA; SIDDHARTHA MAHANTY; MIKE BRAY; RAFI AHMED; PIERRE E. ROLLIN

2001-01-01

270

Caring for critically ill patients with ebola virus disease. Perspectives from west Africa.  

PubMed

The largest ever Ebola virus disease outbreak is ravaging West Africa. The constellation of little public health infrastructure, low levels of health literacy, limited acute care and infection prevention and control resources, densely populated areas, and a highly transmissible and lethal viral infection have led to thousands of confirmed, probable, or suspected cases thus far. Ebola virus disease is characterized by a febrile severe illness with profound gastrointestinal manifestations and is complicated by intravascular volume depletion, shock, profound electrolyte abnormalities, and organ dysfunction. Despite no proven Ebola virus-specific medical therapies, the potential effect of supportive care is great for a condition with high baseline mortality and one usually occurring in resource-constrained settings. With more personnel, basic monitoring, and supportive treatment, many of the sickest patients with Ebola virus disease do not need to die. Ebola virus disease represents an illness ready for a paradigm shift in care delivery and outcomes, and the profession of critical care medicine can and should be instrumental in helping this happen. PMID:25166884

Fowler, Robert A; Fletcher, Thomas; Fischer, William A; Lamontagne, Francois; Jacob, Shevin; Brett-Major, David; Lawler, James V; Jacquerioz, Frederique A; Houlihan, Catherine; O'Dempsey, Tim; Ferri, Mauricio; Adachi, Takuya; Lamah, Marie-Claire; Bah, Elhadj Ibrahima; Mayet, Thierry; Schieffelin, John; McLellan, Susan L; Senga, Mikiko; Kato, Yasuyuki; Clement, Christophe; Mardel, Simon; Vallenas Bejar De Villar, Rosa Constanza; Shindo, Nahoko; Bausch, Daniel

2014-10-01

271

Search for the Ebola Virus Reservoir in Kikwit, Democratic Republic of the Congo: Reflections on a Vertebrate Collection  

Microsoft Academic Search

A 3-month ecologic investigation was done to identify the reservoir of Ebola virus following the 1995 outbreak in Kikwit, Democratic Republic of the Congo. Efforts focused on the fields where the putative primary case had worked but included other habitats near Kikwit. Samples were collected from 3066 vertebrates and tested for the presence of antibodies to Ebola (subtype Zaire) virus:

Herwig Leirs; Dudu Akaibe; Neal Woollen; George Ludwig

1999-01-01

272

Defective humoral responses and extensive intravascular apoptosis are associated with fatal outcome in Ebola virus-infected patients  

Microsoft Academic Search

Ebola virus is very pathogenic in humans. It induces an acute hemorrhagic fever that leads to death in about 70% of patients. We compared the immune responses of patients who died from Ebola virus disease with those who survived during two large outbreaks in 1996 in Gabon. In survivors, early and increasing levels of IgG, directed mainly against the nucleoprotein

M.-C. Georges-Courbot; Monique Capron; Joseph Lansoud-Soukate; Patrice Debré; Susan P. Fisher-Hoch; Joseph B. McCormick; Alain J. Georges; Sylvain Baize; Eric M. Leroy

1999-01-01

273

Complete genome sequence of an Ebola virus (Sudan species) responsible for a 2000 outbreak of human disease in Uganda  

Microsoft Academic Search

The entire genomic RNA of the Gulu (Uganda 2000) strain of Ebola virus was sequenced and compared to the genomes of other filoviruses. This data represents the first comprehensive genetic analysis for a representative isolate of the Sudan species of Ebola virus. The genome organization of the Sudan species is nearly identical to that of the Zaire species, but the

Anthony Sanchez; Pierre E. Rollin

2005-01-01

274

A New Ebola Virus Nonstructural Glycoprotein Expressed through RNA Editing?  

PubMed Central

Ebola virus (EBOV), an enveloped, single-stranded, negative-sense RNA virus, causes severe hemorrhagic fever in humans and nonhuman primates. The EBOV glycoprotein (GP) gene encodes the nonstructural soluble glycoprotein (sGP) but also produces the transmembrane glycoprotein (GP1,2) through transcriptional editing. A third GP gene product, a small soluble glycoprotein (ssGP), has long been postulated to be produced also as a result of transcriptional editing. To identify and characterize the expression of this new EBOV protein, we first analyzed the relative ratio of GP gene-derived transcripts produced during infection in vitro (in Vero E6 cells or Huh7 cells) and in vivo (in mice). The average percentages of transcripts encoding sGP, GP1,2, and ssGP were approximately 70, 25, and 5%, respectively, indicating that ssGP transcripts are indeed produced via transcriptional editing. N-terminal sequence similarity with sGP, the absence of distinguishing antibodies, and the abundance of sGP made it difficult to identify ssGP through conventional methodology. Optimized 2-dimensional (2D) gel electrophoresis analyses finally verified the expression and secretion of ssGP in tissue culture during EBOV infection. Biochemical analysis of recombinant ssGP characterized this protein as a disulfide-linked homodimer that was exclusively N glycosylated. In conclusion, we have identified and characterized a new EBOV nonstructural glycoprotein, which is expressed as a result of transcriptional editing of the GP gene. While ssGP appears to share similar structural properties with sGP, it does not appear to have the same anti-inflammatory function on endothelial cells as sGP. PMID:21411529

Mehedi, Masfique; Falzarano, Darryl; Seebach, Jochen; Hu, Xiaojie; Carpenter, Michael S.; Schnittler, Hans-Joachim; Feldmann, Heinz

2011-01-01

275

Search for the Ebola virus reservoir in Kikwit, Democratic Republic of the Congo: reflections on a vertebrate collection.  

PubMed

A 3-month ecologic investigation was done to identify the reservoir of Ebola virus following the 1995 outbreak in Kikwit, Democratic Republic of the Congo. Efforts focused on the fields where the putative primary case had worked but included other habitats near Kikwit. Samples were collected from 3066 vertebrates and tested for the presence of antibodies to Ebola (subtype Zaire) virus: All tests were negative, and attempts to isolate Ebola virus were unsuccessful. The investigation was hampered by a lack of information beyond the daily activities of the primary case, a lack of information on Ebola virus ecology, which precluded the detailed study of select groups of animals, and sample-size limitations for rare species. The epidemiology of Ebola hemorrhagic fever suggests that humans have only intermittent contact with the virus, which complicates selection of target species. Further study of the epidemiology of human outbreaks to further define the environmental contact of primary cases would be of great value. PMID:9988179

Leirs, H; Mills, J N; Krebs, J W; Childs, J E; Akaibe, D; Woollen, N; Ludwig, G; Peters, C J; Ksiazek, T G

1999-02-01

276

Immune Protection of Nonhuman Primates against Ebola Virus with Single Low-Dose Adenovirus Vectors Encoding Modified GPs  

Microsoft Academic Search

BackgroundEbola virus causes a hemorrhagic fever syndrome that is associated with high mortality in humans. In the absence of effective therapies for Ebola virus infection, the development of a vaccine becomes an important strategy to contain outbreaks. Immunization with DNA and\\/or replication-defective adenoviral vectors (rAd) encoding the Ebola glycoprotein (GP) and nucleoprotein (NP) has been previously shown to confer specific

Nancy J Sullivan; Thomas W Geisbert; Joan B Geisbert; Devon J Shedlock; Ling Xu; Laurie Lamoreaux; Jerome H. H. V Custers; Paul M Popernack; Zhi-Yong Yang; Maria G Pau; Mario Roederer; Richard A Koup; Jaap Goudsmit; Peter B Jahrling; Gary J Nabel

2006-01-01

277

Neutralizing Antibody Fails to Impact the Course of Ebola Virus Infection in Monkeys  

E-print Network

Prophylaxis with high doses of neutralizing antibody typically offers protection against challenge with viruses producing acute infections. In this study, we have investigated the ability of the neutralizing human monoclonal antibody, KZ52, to protect against Ebola virus in rhesus macaques. This antibody was previously shown to fully protect guinea pigs from infection. Four rhesus macaques were given 50 mg/kg of neutralizing human monoclonal antibody KZ52 intravenously 1 d before challenge with 1,000 plaque-forming units of Ebola virus, followed by a second dose of 50 mg/kg antibody 4 d after challenge. A control animal was exposed to virus in the absence of antibody treatment. Passive transfer of the neutralizing human monoclonal antibody not only failed to protect macaques against challenge with Ebola virus but also had a minimal effect on the explosive viral replication following infection. We show that the inability of antibody to impact infection was not due to neutralization escape. It appears that Ebola virus has a mechanism of infection propagation in vivo in macaques that is uniquely insensitive even to high concentrations of neutralizing antibody.

Wendelien B. Oswald; Thomas W. Geisbert; Kelly J. Davis ¤a; Joan B. Geisbert; Nancy J. Sullivan; Peter B. Jahrling ¤b; Dennis R. Burton

278

Disulfide bond assignment of the Ebola virus secreted glycoprotein SGP.  

PubMed

The non-structural glycoprotein (SGP) of Ebola virus (EboV) is secreted in large amounts from infected cells as a disulfide-linked homodimer. In this communication, highly purified SGP, derived from Vero E6 cultures infected with the Zaire species of EboV, was used to determine the correct localization of inter- and intrachain disulfide bonds. Matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry analysis of proteolytic cleavage fragments indicates that all cysteines (six per monomeric unit) form unique disulfide bonds. Monomers of the SGP homodimer are joined in a parallel manner by two intersubunit disulfide bonds formed between paired N-terminal and C-terminal cysteines (C53-C53' and C306-C306'). The remaining cysteines are involved in intrachain disulfide bonding (paired as C108-C135 and C121-C147), which resembles the disulfide bond topology of fibronectin type II domains. The findings presented here provide the foundation for future studies aimed at defining the structural and functional properties of SGP. PMID:15369806

Barrientos, Laura G; Martin, Amy M; Rollin, Pierre E; Sanchez, Anthony

2004-10-15

279

Inhibition of Lassa virus and Ebola virus infection in host cells treated with the kinase inhibitors genistein and tyrphostin.  

PubMed

Arenaviruses and filoviruses are capable of causing hemorrhagic fever syndrome in humans. Limited therapeutic and/or prophylactic options are available for humans suffering from viral hemorrhagic fever. In this report, we demonstrate that pre-treatment of host cells with the kinase inhibitors genistein and tyrphostin AG1478 leads to inhibition of infection or transduction in cells infected with Ebola virus, Marburg virus, and Lassa virus. In all, the results demonstrate that a kinase inhibitor cocktail consisting of genistein and tyrphostin AG1478 is a broad-spectrum antiviral that may be used as a therapeutic or prophylactic against arenavirus and filovirus hemorrhagic fever. PMID:21947546

Kolokoltsov, Andrey A; Adhikary, Shramika; Garver, Jennifer; Johnson, Lela; Davey, Robert A; Vela, Eric M

2012-01-01

280

In vivo oligomerization and raft localization of Ebola virus protein VP40 during vesicular budding.  

PubMed

The matrix protein VP40 plays a critical role in Ebola virus assembly and budding, a process that utilizes specialized membrane domains known as lipid rafts. Previous studies with purified protein suggest a role for oligomerization of VP40 in this process. Here, we demonstrate VP40 oligomers in lipid rafts of mammalian cells, virus-like particles, and in the authentic Ebola virus. By mutagenesis, we identify several critical C-terminal sequences that regulate oligomerization at the plasma membrane, association with detergent-resistant membranes, and vesicular release of VP40, directly linking these phenomena. Furthermore, we demonstrate the active recruitment of TSG101 into lipid rafts by VP40. We also report the successful application of the biarsenic fluorophore, FlAsH, combined with a tetracysteine tag for imaging of Ebola VP40 in live cells. PMID:14673115

Panchal, Rekha G; Ruthel, Gordon; Kenny, Tara A; Kallstrom, George H; Lane, Douglas; Badie, Shirin S; Li, Limin; Bavari, Sina; Aman, M Javad

2003-12-23

281

Functional characterization of Ebola virus L-domains using VSV recombinants.  

PubMed

VSV recombinants containing the overlapping L-domain sequences from Ebola virus VP40 (PTAPPEY) were recovered by reverse-genetics. Replication kinetics of M40-WT, M40-P24L, and M40-Y30A were indistinguishable from VSV-WT in BHK-21 cells, whereas the double mutant (M40-P2728A) was defective in budding. Insertion of the Ebola L-domain region into VSV M protein was sufficient to alter the dependence on host proteins for efficient budding. Indeed, M40 recombinants containing a functional PTAP motif specifically incorporated endogenous tsg101 into budding virions and were dependent on tsg101 expression for efficient budding. Thus, VSV represents an excellent negative-sense RNA virus model for elucidating the functional aspects and diverse host interactions associated with the L-domains of Ebola virus. PMID:15892969

Irie, Takashi; Licata, Jillian M; Harty, Ronald N

2005-06-01

282

Commentary Reemergence of Ebola Virus in Africa Members of the family Filoviridae, which currently  

E-print Network

severe and often fatal hemorrhagic fevers in humans and nonhuman primates. The recent isolation and identification of a new Ebola virus from a single nonfatal human case in Côte d’Ivoire (1) and the more recent outbreak of Ebola hemorrhagic fever in and around Kikwit, Zaire (2, 3), have raised concerns about the public health threat of these human pathogens. Filoviruses are classified as biosafety level 4 agents because of the extreme pathogenicity of certain strains and the lack of a protective vaccine or effective antiviral drug. Moreover, filoviruses are among the most mysterious groups of viruses known because their natural history and reservoirs remain undefined and their pathogenesis is poorly understood. Ebola virus infections were first recognized in

Consists Of Ebola; Marburg Viruses

283

A Replicating Cytomegalovirus-Based Vaccine Encoding a Single Ebola Virus Nucleoprotein CTL Epitope Confers Protection against Ebola Virus  

PubMed Central

Background Human outbreaks of Ebola virus (EBOV) are a serious human health concern in Central Africa. Great apes (gorillas/chimpanzees) are an important source of EBOV transmission to humans due to increased hunting of wildlife including the ‘bush-meat’ trade. Cytomegalovirus (CMV) is an highly immunogenic virus that has shown recent utility as a vaccine platform. CMV-based vaccines also have the unique potential to re-infect and disseminate through target populations regardless of prior CMV immunity, which may be ideal for achieving high vaccine coverage in inaccessible populations such as great apes. Methodology/Principal Findings We hypothesize that a vaccine strategy using CMV-based vectors expressing EBOV antigens may be ideally suited for use in inaccessible wildlife populations. To establish a ‘proof-of-concept’ for CMV-based vaccines against EBOV, we constructed a mouse CMV (MCMV) vector expressing a CD8+ T cell epitope from the nucleoprotein (NP) of Zaire ebolavirus (ZEBOV) (MCMV/ZEBOV-NPCTL). MCMV/ZEBOV-NPCTL induced high levels of long-lasting (>8 months) CD8+ T cells against ZEBOV NP in mice. Importantly, all vaccinated animals were protected against lethal ZEBOV challenge. Low levels of anti-ZEBOV antibodies were only sporadically detected in vaccinated animals prior to ZEBOV challenge suggesting a role, at least in part, for T cells in protection. Conclusions/Significance This study demonstrates the ability of a CMV-based vaccine approach to protect against an highly virulent human pathogen, and supports the potential for ‘disseminating’ CMV-based EBOV vaccines to prevent EBOV transmission in wildlife populations. PMID:21858240

Tsuda, Yoshimi; Caposio, Patrizia; Parkins, Christopher J.; Botto, Sara; Messaoudi, Ilhem; Cicin-Sain, Luka; Feldmann, Heinz; Jarvis, Michael A.

2011-01-01

284

Protection of Nonhuman Primates against Two Species of Ebola Virus Infection with a Single Complex Adenovirus Vector?  

PubMed Central

Ebola viruses are highly pathogenic viruses that cause outbreaks of hemorrhagic fever in humans and other primates. To meet the need for a vaccine against the several types of Ebola viruses that cause human diseases, we developed a multivalent vaccine candidate (EBO7) that expresses the glycoproteins of Zaire ebolavirus (ZEBOV) and Sudan ebolavirus (SEBOV) in a single complex adenovirus-based vector (CAdVax). We evaluated our vaccine in nonhuman primates against the parenteral and aerosol routes of lethal challenge. EBO7 vaccine provided protection against both Ebola viruses by either route of infection. Significantly, protection against SEBOV given as an aerosol challenge, which has not previously been shown, could be achieved with a boosting vaccination. These results demonstrate the feasibility of creating a robust, multivalent Ebola virus vaccine that would be effective in the event of a natural virus outbreak or biological threat. PMID:20181765

Pratt, William D.; Wang, Danher; Nichols, Donald K.; Luo, Min; Woraratanadharm, Jan; Dye, John M.; Holman, David H.; Dong, John Y.

2010-01-01

285

Mannose-binding lectin binds to Ebola and Marburg envelope glycoproteins, resulting in blocking of virus interaction with DC-SIGN and complement-mediated virus neutralization.  

PubMed

Mannose-binding lectin (MBL), a serum lectin that mediates innate immune functions including activation of the lectin complement pathway, binds to carbohydrates expressed on some viral glycoproteins. In this study, the ability of MBL to bind to virus particles pseudotyped with Ebola and Marburg envelope glycoproteins was evaluated. Virus particles bearing either Ebola (Zaire strain) or Marburg (Musoke strain) envelope glycoproteins bound at significantly higher levels to immobilized MBL compared with virus particles pseudotyped with vesicular stomatitis virus glycoprotein or with no virus glycoprotein. As observed in previous studies, Ebola-pseudotyped virus bound to cells expressing the lectin DC-SIGN (dendritic cell-specific intercellular adhesion molecule 3-grabbing non-integrin). However, pre-incubation of virus with MBL blocked DC-SIGN-mediated binding to cells, suggesting that the two lectins bind at the same or overlapping sites on the Ebola glycoprotein. Neutralization experiments showed that virus pseudotyped with Ebola or Marburg (Musoke) glycoprotein was neutralized by complement, while the Marburg (Ravn strain) glycoprotein-pseudotyped virus was less sensitive to neutralization. Neutralization was partially mediated through the lectin complement pathway, since a complement source deficient in MBL was significantly less effective at neutralizing viruses pseudotyped with filovirus glycoproteins and addition of purified MBL to the MBL-deficient complement increased neutralization. These experiments demonstrated that MBL binds to filovirus envelope glycoproteins resulting in important biological effects and suggest that MBL can interact with filoviruses during infection in humans. PMID:16099912

Ji, Xin; Olinger, Gene G; Aris, Sheena; Chen, Ying; Gewurz, Henry; Spear, Gregory T

2005-09-01

286

CD8-mediated protection against Ebola virus infection is perforin dependent.  

PubMed

CD8 T cells have been shown to play an important role in the clearance and protection against fatal Ebola virus infection. In this study, we examined the mechanisms by which CD8 T cells mediate this protection. Our data demonstrate that all normal mice infected s.c. with a mouse-adapted Ebola virus survived the infection, as did 100% of mice deficient in Fas and 90% of those deficient in IFN-gamma. In contrast, perforin-deficient mice uniformly died after s.c. challenge. Perforin-deficient mice failed to clear viral infection even though they developed normal levels of neutralizing anti-Ebola Abs and 5- to 10-fold higher levels of IFN-gamma than control mice. Using MHC class I tetramers, we have also shown that perforin-deficient mice have 2- to 4-fold higher numbers of Ebola-specific CD8s than control mice. These findings suggest that the clearance of Ebola virus is perforin-dependent and provide an additional example showing that this basic immunologic mechanism is not limited to the clearance of noncytopathic viruses. PMID:15778381

Gupta, Manisha; Greer, Patricia; Mahanty, Siddhartha; Shieh, Wun-Ju; Zaki, Sherif R; Ahmed, Rafi; Rollin, Pierre E

2005-04-01

287

Functional importance of the coiled-coil of the Ebola virus glycoprotein.  

PubMed

Ebola virus contains a single glycoprotein (GP) that is responsible for receptor binding and membrane fusion and is proteolytically cleaved into disulfide-linked GP1 and GP2 subunits. The GP2 subunit possesses a coiled-coil motif, which plays an important role in the oligomerization and fusion activity of other viral GPs. To determine the functional significance of the coiled-coil motif of GP2, we examined the effects of peptides corresponding to the coiled-coil motif of GP2 on the infectivity of a mutant vesicular stomatitis virus (lacking the receptor-binding/fusion protein) pseudotyped with the Ebola virus GP. A peptide corresponding to the C-terminal helix reduced the infectivity of the pseudotyped virus. We next introduced alanine substitutions into hydrophobic residues in the coiled-coil motif to identify residues important for GP function. None of the substitutions affected GP oligomerization, but some mutations, two in the N-terminal helix and all in the C-terminal helix, reduced the ability of GP to confer infectivity to the mutant vesicular stomatitis virus without affecting the transport of GP to the cell surface, its incorporation into virions, and the production of virus particles. These results indicate that the coiled-coil motif of GP2 plays an important role in facilitating the entry of Ebola virus into host cells and that peptides corresponding to this region could act as efficient antiviral agents. PMID:11024148

Watanabe, S; Takada, A; Watanabe, T; Ito, H; Kida, H; Kawaoka, Y

2000-11-01

288

Ebola and Marburg virus antibody prevalence in selected populations of the Central African Republic.  

PubMed

With the natural history of the filovirus family seemingly unknown, filovirus ecology in its natural environment remains a rudimentary field of research. In order to investigate the maintenance cycle of filovirus in Central Africa, a study was conducted within the rain forest of the Central African Republic. The epidemiological study determines the frequency and distribution of filovirus seroprevalence in a selected human population. Using an ELISA, serum samples from Pygmy and non-Pygmy populations were tested for Ebola-Zaire virus and Marburg (MBG) virus antibody. Filovirus antibody reacting sera were found in all zones investigated, and in all populations studied (Ebola virus IgG 5.3%; Marburg virus IgG 2.4%). Pygmies appeared to have a significantly higher seroprevalence (P < 0.03) against Ebola-Zaire virus (7.02%) than non-Pygmies (4.2%). MBG virus or related unknown filovirus strains also seem to be present in the western part of Central Africa. MBG virus antibodies were present in different Pygmy groups (ranging from 0.7 to 5.6%, mean 2.05%) and in several non-Pygmy populations (ranging from 0.0 to 3.9%, mean 3.4%) without an overall significant difference between the two groups (P = 0.14). The potentialities of nonpathogenic filovirus strains circulating in the Central African Republic are discussed. PMID:10717539

Gonzalez, J P; Nakoune, E; Slenczka, W; Vidal, P; Morvan, J M

2000-01-01

289

The Ebola Virus Matrix Protein VP40 Selectively Induces Vesiculation from Phosphatidylserine-enriched Membranes.  

PubMed

Ebola virus is from the Filoviridae family of viruses and is one of the most virulent pathogens known with ?60% clinical fatality. The Ebola virus negative sense RNA genome encodes seven proteins including viral matrix protein 40 (VP40), which is the most abundant protein found in the virions. Within infected cells VP40 localizes at the inner leaflet of the plasma membrane (PM), binds lipids, and regulates formation of new virus particles. Expression of VP40 in mammalian cells is sufficient to form virus-like particles that are nearly indistinguishable from the authentic virions. However, how VP40 interacts with the PM and forms virus-like particles is for the most part unknown. To investigate VP40 lipid specificity in a model of viral egress we employed giant unilamellar vesicles with different lipid compositions. The results demonstrate VP40 selectively induces vesiculation from membranes containing phosphatidylserine (PS) at concentrations of PS that are representative of the PM inner leaflet content. The formation of intraluminal vesicles was not significantly detected in the presence of other important PM lipids including cholesterol and polyvalent phosphoinositides, further demonstrating PS selectivity. Taken together, these studies suggest that PM phosphatidylserine may be an important component of Ebola virus budding and that VP40 may be able to mediate PM scission. PMID:25315776

Soni, Smita P; Stahelin, Robert V

2014-11-28

290

Identification of the Ebola virus glycoprotein as the main viral determinant of vascular cell cytotoxicity and injury  

Microsoft Academic Search

Here we defined the main viral determinant of Ebola virus pathogenicity; synthesis of the virion glycoprotein (GP) of Ebola virus Zaire induced cytotoxic effects in human endothelial cells in vitro and in vivo. This effect mapped to a serine–threonine-rich, mucin-like domain of this type I transmembrane glycoprotein, one of seven gene products of the virus. Gene transfer of GP into

Zhi-yong Yang; Henricus J. Duckers; Nancy J. Sullivan; Anthony Sanchez; Elizabeth G. Nabel; Gary J. Nabel

2000-01-01

291

Pre- and postexposure prophylaxis of Ebola virus infection in an animal model by passive transfer of a neutralizing human antibody.  

PubMed

A neutralizing human monoclonal antibody, KZ52, protects guinea pigs from lethal Ebola Zaire virus challenge. Administration before or up to 1 h after challenge resulted in dose-dependent protection by the antibody. Interestingly, some antibody-treated animals survived despite developing high-level viremia, suggesting that the mechanism of protection by KZ52 may extend beyond reduction of viremia by virus neutralization. KZ52 is a promising candidate for immunoprophylaxis of Ebola virus infection. PMID:12021376

Parren, Paul W H I; Geisbert, Tom W; Maruyama, Toshiaki; Jahrling, Peter B; Burton, Dennis R

2002-06-01

292

Protection from lethal infection is determined by innate immune responses in a mouse model of Ebola virus infection  

Microsoft Academic Search

A mouse-adapted strain of Ebola Zaire virus produces a fatal infection when BALB\\/cj mice are infected intraperitoneally (ip) but subcutaneous (sc) infection with the same virus fails to produce illness and confers long-term protection from lethal ip rechallenge. To identify immune correlates of protection in this model, we compared viral replication and cytokine\\/chemokine responses to Ebola virus in mice infected

Siddhartha Mahanty; Manisha Gupta; Jason Paragas; Mike Bray; Rafi Ahmed; Pierre E Rollin

2003-01-01

293

Development of a preventive vaccine for Ebola virus infection in primates.  

PubMed

Outbreaks of haemorrhagic fever caused by the Ebola virus are associated with high mortality rates that are a distinguishing feature of this human pathogen. The highest lethality is associated with the Zaire subtype, one of four strains identified to date. Its rapid progression allows little opportunity to develop natural immunity, and there is currently no effective anti-viral therapy. Therefore, vaccination offers a promising intervention to prevent infection and limit spread. Here we describe a highly effective vaccine strategy for Ebola virus infection in non-human primates. A combination of DNA immunization and boosting with adenoviral vectors that encode viral proteins generated cellular and humoral immunity in cynomolgus macaques. Challenge with a lethal dose of the highly pathogenic, wild-type, 1976 Mayinga strain of Ebola Zaire virus resulted in uniform infection in controls, who progressed to a moribund state and death in less than one week. In contrast, all vaccinated animals were asymptomatic for more than six months, with no detectable virus after the initial challenge. These findings demonstrate that it is possible to develop a preventive vaccine against Ebola virus infection in primates. PMID:11117750

Sullivan, N J; Sanchez, A; Rollin, P E; Yang, Z Y; Nabel, G J

2000-11-30

294

RNA polymerase I-driven minigenome system for Ebola viruses.  

PubMed

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. PMID:15767442

Groseth, Allison; Feldmann, Heinz; Theriault, Steven; Mehmetoglu, Gülsah; Flick, Ramon

2005-04-01

295

Ebola virus VP30 is an RNA binding protein.  

PubMed

The Ebola virus (EBOV) genome encodes for several proteins that are necessary and sufficient for replication and transcription of the viral RNAs in vitro; NP, VP30, VP35, and L. VP30 acts in trans with an RNA secondary structure upstream of the first transcriptional start site to modulate transcription. Using a bioinformatics approach, we identified a region within the N terminus of VP30 with sequence features that typify intrinsically disordered regions and a putative RNA binding site. To experimentally assess the ability of VP30 to directly interact with the viral RNA, we purified recombinant EBOV VP30 to >90% homogeneity and assessed RNA binding by UV cross-linking and filter-binding assays. VP30 is a strongly acidophilic protein; RNA binding became stronger as pH was decreased. Zn(2+), but not Mg(2+), enhanced activity. Enhancement of transcription by VP30 requires a RNA stem-loop located within nucleotides 54 to 80 of the leader region. VP30 showed low binding affinity to the predicted stem-loop alone or to double-stranded RNA but showed a good binding affinity for the stem-loop when placed in the context of upstream and downstream sequences. To map the region responsible for interacting with RNA, we constructed, purified, and assayed a series of N-terminal deletion mutations of VP30 for RNA binding. The key amino acids supporting RNA binding activity map to residues 26 to 40, a region rich in arginine. Thus, we show for the first time the direct interaction of EBOV VP30 with RNA and the importance of the N-terminal region for binding RNA. PMID:17567691

John, Sinu P; Wang, Tan; Steffen, Scott; Longhi, Sonia; Schmaljohn, Connie S; Jonsson, Colleen B

2007-09-01

296

Inflammatory responses in Ebola virus-infected patients.  

PubMed

Ebola virus subtype Zaire (Ebo-Z) induces acute haemorrhagic fever and a 60-80% mortality rate in humans. Inflammatory responses were monitored in victims and survivors of Ebo-Z haemorrhagic fever during two recent outbreaks in Gabon. Survivors were characterized by a transient release in plasma of interleukin-1beta (IL-1beta), IL-6, tumour necrosis factor-alpha (TNFalpha), macrophage inflammatory protein-1alpha (MIP-1alpha) and MIP-1beta early in the disease, followed by circulation of IL-1 receptor antagonist (IL-1RA) and soluble receptors for TNFalpha (sTNF-R) and IL-6 (sIL-6R) towards the end of the symptomatic phase and after recovery. Fatal infection was associated with moderate levels of TNFalpha and IL-6, and high levels of IL-10, IL-1RA and sTNF-R, in the days before death, while IL-1beta was not detected and MIP-1alpha and MIP-1beta concentrations were similar to those of endemic controls. Simultaneous massive activation of monocytes/macrophages, the main target of Ebo-Z, was suggested in fatal infection by elevated neopterin levels. Thus, presence of IL-1beta and of elevated concentrations of IL-6 in plasma during the symptomatic phase can be used as markers of non-fatal infection, while release of IL-10 and of high levels of neopterin and IL-1RA in plasma as soon as a few days after the disease onset is indicative of a fatal outcome. In conclusion, recovery from Ebo-Z infection is associated with early and well-regulated inflammatory responses, which may be crucial in controlling viral replication and inducing specific immunity. In contrast, defective inflammatory responses and massive monocyte/macrophage activation were associated with fatal outcome. PMID:11982604

Baize, S; Leroy, E M; Georges, A J; Georges-Courbot, M-C; Capron, M; Bedjabaga, I; Lansoud-Soukate, J; Mavoungou, E

2002-04-01

297

Ebola Virus VP40Induced Particle Formation and Association with the Lipid Bilayer  

Microsoft Academic Search

Viral protein 40 (VP40) of Ebola virus appears equivalent to matrix proteins of other viruses, yet little is known about its role in the viral life cycle. To elucidate the functions of VP40, we investigated its ability to induce the formation of membrane-bound particles when it was expressed apart from other viral proteins. We found that VP40 is indeed able

LUKE D. JASENOSKY; GABRIELE NEUMANN; IGOR LUKASHEVICH; YOSHIHIRO KAWAOKA

2001-01-01

298

Endosomal Proteolysis of the Ebola Virus Glycoprotein Is Necessary for Infection  

Microsoft Academic Search

Ebola virus (EboV) causes rapidly fatal hemorrhagic fever in humans and there is currently no effective treatment. We found that the infection of African green monkey kidney (Vero) cells by vesicular stomatitis viruses bearing the EboV glycoprotein (GP) requires the activity of endosomal cysteine proteases. Using selective protease inhibitors and protease-deficient cell lines, we identified an essential role for cathepsin

Kartik Chandran; Nancy J. Sullivan; Ute Felbor; Sean P. Whelan; James M. Cunningham

2005-01-01

299

Computational prediction and identification of HLA-A2.1-specific Ebola virus CTL epitopes  

Microsoft Academic Search

Ebola virus (EBOV) is known to cause a severe hemorrhagic fever resulting in high mortality. Although the precise host defense mechanism(s) that afford protection against EBOV is not completely understood, T cell-mediated immune responses is believed to play a pivotal role in controlling virus replication and EBOV infection. There have been no reports on mapping of MHC Class I-binding CTL

Krishnan Sundar; Agnieszka Boesen; Richard Coico

2007-01-01

300

The Organisation of Ebola Virus Reveals a Capacity for Extensive, Modular Polyploidy  

Microsoft Academic Search

BackgroundFiloviruses, including Ebola virus, are unusual in being filamentous animal viruses. Structural data on the arrangement, stoichiometry and organisation of the component molecules of filoviruses has until now been lacking, partially due to the need to work under level 4 biological containment. The present study provides unique insights into the structure of this deadly pathogen.Methodology and Principal FindingsWe have investigated

Daniel R. Beniac; Pasquale L. Melito; Shauna L. deVarennes; Shannon L. Hiebert; Melissa J. Rabb; Lindsey L. Lamboo; Steven M. Jones; Timothy F. Booth

2012-01-01

301

Inhibition of heat-shock protein 90 reduces Ebola virus replication  

Microsoft Academic Search

Ebola virus (EBOV), a negative-sense RNA virus in the family Filoviridae, is known to cause severe hemorrhagic fever in humans and other primates. Infection with EBOV causes a high mortality rate and currently there is no FDA-licensed vaccine or therapeutic treatment available. Recently, heat-shock protein 90 (Hsp90), a molecular chaperone, was shown to be an important host factor for the

Darci R. Smith; Sarah McCarthy; Andrew Chrovian; Gene Olinger; Andrea Stossel; Thomas W. Geisbert; Lisa E. Hensley; John H. Connor

2010-01-01

302

Pathogenesis of Experimental Ebola Zaire Virus Infection in BALB\\/c Mice  

Microsoft Academic Search

Guinea-pigs and non-human primates have traditionally been used as animal models for studying Ebola Zaire virus (EBO-Z) infections. The virus was also recently adapted to the stage of lethal virulence in BALB\\/c mice. This murine model is now in use for testing antiviral medications and vaccines. However, the pathological features of EBO-Z infection in mice have not yet been fully

T. R. Gibb; M. Bray; T. W. Geisbert; K. E. Steele; W. M. Kell; K. J. Davis; N. K. Jaax

2001-01-01

303

Evidence for two subtypes of Ebola virus based on oligonucleotide mapping of RNA.  

PubMed

Ebola viruses isolated during outbreaks of acute hemorrhagic fever in Africa from 1976 to 1979 were examined by T1 oligonucleotide mapping of virion RNA. Two Ebola virus subtypes distinguishable by their oligonucleotide patterns were involved in the outbreaks of the disease during this three-year period. The first type was isolated in Zaire in 1976 and again in 1977; the second type caused outbreaks in Sudan in 1976 and again in 1979. Oligonucleotide patterns of the two groups of Ebola viruses (Zaire and Sudan) were remarkably similar within the group but differed between groups by approximately 60 oligonucleotides. We can conclude from this study (1) that the outbreaks of hemorrhagic fever which occurred concurrently in 1976 in Zaire and Sudan were caused by viruses that are genetically distinct; (2) that compared with other RNA viruses there was an unusually high genetic stability among viruses within Zaire and Sudan over two- and three-year periods, respectively; and (3) that the two genetic subtypes probably evolved from a common ancestor since they share common oligonucleotides. PMID:6827144

Cox, N J; McCormick, J B; Johnson, K M; Kiley, M P

1983-02-01

304

Mapping overlapping functional elements embedded within the protein-coding regions of RNA viruses  

E-print Network

viruses. Such viruses include influenza A virus, Ebola virus, rabies virus, SARS virus, MERS virus, Japanese encephalitis virus, yellow fever virus, dengue virus, eastern equine encephalitis virus, and Lassa virus. Many other human pathogenic viruses...

Firth, Andrew E.

2014-01-01

305

Induction of Immune Responses in Mice and Monkeys to Ebola Virus after Immunization with Liposome-Encapsulated Irradiated Ebola Virus: Protection in Mice Requires CD4+ T Cells  

Microsoft Academic Search

Ebola Zaire virus (EBO-Z) causes severe hemorrhagic fever in humans, with a high mortality rate. It is thought that a vaccine against EBO-Z may have to induce both humoral and cell-mediated immune responses to successfully confer protection. Because it is known that liposome-encapsulated antigens induce both anti- body and cellular responses, we evaluated the protective efficacy of liposome-encapsulated irradiated EBO-Z

Mangala Rao; Mike Bray; Carl R. Alving; Peter Jahrling; Gary R. Matyas

2002-01-01

306

The Virion Glycoproteins of Ebola Viruses are Encoded in Two Reading Frames and are Expressed through Transcriptional Editing  

Microsoft Academic Search

In late 1994 and early 1995, Ebola (EBO) virus dramatically reemerged in Africa, causing human disease in the Ivory Coast and Zaire. Analysis of the entire glycoprotein genes of these viruses and those of other EBO virus subtypes has shown that the virion glycoprotein (130 kDa) is encoded in two reading frames, which are linked by transcriptional editing. This editing

Anthony Sanchez; Sam G. Trappier; Brian W. J. Mahy; Clarence J. Peters; Stuart T. Nichol

1996-01-01

307

Spatial Localization of the Ebola Virus Glycoprotein Mucin-Like Domain Determined by Cryo-Electron Tomography  

PubMed Central

The Ebola virus glycoprotein mucin-like domain (MLD) is implicated in Ebola virus cell entry and immune evasion. Using cryo-electron tomography of Ebola virus-like particles, we determined a three-dimensional structure for the full-length glycoprotein in a near-native state and compared it to that of a glycoprotein lacking the MLD. Our results, which show that the MLD is located at the apex and the sides of each glycoprotein monomer, provide a structural template for analysis of MLD function. PMID:25008940

Tran, Erin E. H.; Simmons, James A.; Bartesaghi, Alberto; Shoemaker, Charles J.; Nelson, Elizabeth; White, Judith M.

2014-01-01

308

The Ebola Virus Genomic Replication Promoter Is Bipartite and Follows the Rule of Six  

Microsoft Academic Search

In this work we investigated the cis-acting signals involved in replication of Ebola virus (EBOV) genomic RNA. A set of mingenomes with mutant 3 ends were generated and used in a reconstituted replication and transcription system. Our results suggest that the EBOV genomic replication promoter is bipartite, consisting of a first element located within the leader region of the genome

Michael Weik; Sven Enterlein; Kathrin Schlenz; Elke Muhlberger

2005-01-01

309

Ebola Virus Glycoproteins Induce Global Surface Protein Down-Modulation and Loss of Cell Adherence  

Microsoft Academic Search

The Ebola virus envelope glycoprotein (GP) derived from the pathogenic Zaire subtype mediates cell rounding and detachment from the extracellular matrix in 293T cells. In this study we provide evidence that GPs from the other pathogenic subtypes, Sudan and Côte d'Ivoire, as well as from Reston, a strain thought to be nonpathogenic in humans, also induced cell rounding, albeit at

Graham Simmons; Rouven J. Wool-Lewis; Frédéric Baribaud; Robert C. Netter; Paul Bates

2002-01-01

310

Analysis of Ebola virus and VLP release using an immunocapture assay.  

PubMed

Ebola virus (EBOV), an emerging pathogen, is the causative agent of a rapidly progressive hemorrhagic fever with high mortality rates. There are currently no approved vaccines or treatments available for Ebola hemorrhagic fever. Standard plaque assays are currently the only reliable techniques for enumerating the virus. Effective drug-discovery screening as well as target identification and validation require simple and more rapid detection methods. This report describes the development of a rapid ELISA that measures virus release with high sensitivity. This assay detects both Ebola virus and EBOV-like particles (VLPs) directly from cell-culture supernatants with the VP40 matrix protein serving as antigen. Using this assay, the contribution of the EBOV nucleocapsid (NC) proteins in VLP release was determined. These findings indicate that a combination of NC proteins together with the envelope components is optimal for VLP formation and release, a finding that is important for vaccination with Ebola VLPs. Furthermore, this assay can be used in surrogate models in non-biocontainment environment, facilitating both basic research on the mechanism of EBOV assembly and budding as well as drug-discovery research. PMID:15893559

Kallstrom, George; Warfield, Kelly L; Swenson, Dana L; Mort, Shannon; Panchal, Rekha G; Ruthel, Gordon; Bavari, Sina; Aman, M Javad

2005-07-01

311

Ebola Virus VP40 Late Domains Are Not Essential for Viral Replication in Cell Culture  

Microsoft Academic Search

Ebola virus particle formation and budding are mediated by the VP40 protein, which possesses overlapping PTAP and PPXY late domain motifs (7-PTAPPXY-13). These late domain motifs have also been found in the Gag proteins of retroviruses and the matrix proteins of rhabdo- and arenaviruses. While in vitro studies suggest a critical role for late domain motifs in the budding of

Gabriele Neumann; Hideki Ebihara; Ayato Takada; Takeshi Noda; Darwyn Kobasa; Luke D. Jasenosky; Shinji Watanabe; Jin H. Kim; Heinz Feldmann; Yoshihiro Kawaoka

2005-01-01

312

Postexposure Protection of Guinea Pigs against a Lethal Ebola Virus Challenge Is Conferred by RNA Interference  

Microsoft Academic Search

Background. Ebola virus (EBOV) infection causes a frequently fatal hemorrhagic fever (HF) that is refractory to treatment with currently available antiviral therapeutics. RNA interference represents a powerful, naturally occurring biological strategy for the inhibition of gene expression and has demonstrated utility in the inhibition of viral replication. Here, we describe the development of a potential therapy for EBOV infection that

Elliott Kagan; Kevin McClintock; Adam Judge; Ian MacLachlan

2006-01-01

313

The ERK Mitogen-Activated Protein Kinase Pathway Contributes to Ebola Virus Glycoprotein-Induced Cytotoxicity  

Microsoft Academic Search

Ebola virus is a highly lethal pathogen that causes hemorrhagic fever in humans and nonhuman primates. Among the seven known viral gene products, the envelope glycoprotein (GP) alone induces cell rounding and detachment that ultimately leads to cell death. Cellular cytoxicity is not seen with comparable levels of expression of a mutant form of GP lacking a mucin-like domain (GPmuc).

Carisa A. Zampieri; Jean-Francois Fortin; Garry P. Nolan; Gary J. Nabel

2007-01-01

314

Development of a preventive vaccine for Ebola virus infection in primates  

Microsoft Academic Search

Outbreaks of haemorrhagic fever caused by the Ebola virus are associated with high mortality rates that are a distinguishing feature of this human pathogen. The highest lethality is associated with the Zaire subtype, one of four strains identified to date. Its rapid progression allows little opportunity to develop natural immunity, and there is currently no effective anti-viral therapy. Therefore, vaccination

Nancy J. Sullivan; Anthony Sanchez; Pierre E. Rollin; Zhi-yong Yang; Gary J. Nabel

2000-01-01

315

SCIENCE sciencemag.org 5 SEPTEMBER 2014 VOL 345 ISSUE 6201 1101 he current crisis with the Ebola virus vividly illus-  

E-print Network

with the Ebola virus vividly illus- trates the priority that must be given to infectious diseases because research on Ebola and the expedited development of a cure; however, recent incidents in biocontain- ment, when it investigated the first outbreaks of Ebola virus in Zaire and Sudan. Nevertheless, its labs

Napp, Nils

316

373. Simian Adenoviral Vector Based-Vaccine Fully Protect Against Ebola Virus Even in the Presence of Pre-Existing Immunity to Human Adenovirus  

Microsoft Academic Search

Ebola virus is one of several pathogens that cause lethal hemorrhagic fever. Most strains of Ebola are highly lethal in humans and extremely infectious. The profile of Ebola virus infections that make it such a dangerous pathogen also contribute to its utility as a potential agent of biological warfare. Adenoviral vector was the only vaccine carrier recently shown to protect

Gary P. Kobinger; Heinz Feldmann; Yan Zhi; Gregory P. Schumer; Guangping Gao; Frederik Feldmann; Steven Jones; James M. Wilson

2004-01-01

317

Successful treatment of advanced Ebola virus infection with T-705 (favipiravir) in a small animal model.  

PubMed

Outbreaks of Ebola hemorrhagic fever in sub-Saharan Africa are associated with case fatality rates of up to 90%. Currently, neither a vaccine nor an effective antiviral treatment is available for use in humans. Here, we evaluated the efficacy of the pyrazinecarboxamide derivative T-705 (favipiravir) against Zaire Ebola virus (EBOV) in vitro and in vivo. T-705 suppressed replication of Zaire EBOV in cell culture by 4log units with an IC90 of 110?M. Mice lacking the type I interferon receptor (IFNAR(-)(/)(-)) were used as in vivo model for Zaire EBOV-induced disease. Initiation of T-705 administration at day 6 post infection induced rapid virus clearance, reduced biochemical parameters of disease severity, and prevented a lethal outcome in 100% of the animals. The findings suggest that T-705 is a candidate for treatment of Ebola hemorrhagic fever. PMID:24583123

Oestereich, Lisa; Lüdtke, Anja; Wurr, Stephanie; Rieger, Toni; Muñoz-Fontela, César; Günther, Stephan

2014-05-01

318

Discovery and early development of AVI-7537 and AVI-7288 for the treatment of Ebola virus and Marburg virus infections.  

PubMed

There are no currently approved treatments for filovirus infections. In this study we report the discovery process which led to the development of antisense Phosphorodiamidate Morpholino Oligomers (PMOs) AVI-6002 (composed of AVI-7357 and AVI-7539) and AVI-6003 (composed of AVI-7287 and AVI-7288) targeting Ebola virus and Marburg virus respectively. The discovery process involved identification of optimal transcript binding sites for PMO based RNA-therapeutics followed by screening for effective viral gene target in mouse and guinea pig models utilizing adapted viral isolates. An evolution of chemical modifications were tested, beginning with simple Phosphorodiamidate Morpholino Oligomers (PMO) transitioning to cell penetrating peptide conjugated PMOs (PPMO) and ending with PMOplus containing a limited number of positively charged linkages in the PMO structure. The initial lead compounds were combinations of two agents targeting separate genes. In the final analysis, a single agent for treatment of each virus was selected, AVI-7537 targeting the VP24 gene of Ebola virus and AVI-7288 targeting NP of Marburg virus, and are now progressing into late stage clinical development as the optimal therapeutic candidates. PMID:23202506

Iversen, Patrick L; Warren, Travis K; Wells, Jay B; Garza, Nicole L; Mourich, Dan V; Welch, Lisa S; Panchal, Rekha G; Bavari, Sina

2012-11-01

319

Discovery and Early Development of AVI-7537 and AVI-7288 for the Treatment of Ebola Virus and Marburg Virus Infections  

PubMed Central

There are no currently approved treatments for filovirus infections. In this study we report the discovery process which led to the development of antisense Phosphorodiamidate Morpholino Oligomers (PMOs) AVI-6002 (composed of AVI-7357 and AVI-7539) and AVI-6003 (composed of AVI-7287 and AVI-7288) targeting Ebola virus and Marburg virus respectively. The discovery process involved identification of optimal transcript binding sites for PMO based RNA-therapeutics followed by screening for effective viral gene target in mouse and guinea pig models utilizing adapted viral isolates. An evolution of chemical modifications were tested, beginning with simple Phosphorodiamidate Morpholino Oligomers (PMO) transitioning to cell penetrating peptide conjugated PMOs (PPMO) and ending with PMOplus containing a limited number of positively charged linkages in the PMO structure. The initial lead compounds were combinations of two agents targeting separate genes. In the final analysis, a single agent for treatment of each virus was selected, AVI-7537 targeting the VP24 gene of Ebola virus and AVI-7288 targeting NP of Marburg virus, and are now progressing into late stage clinical development as the optimal therapeutic candidates. PMID:23202506

Iversen, Patrick L.; Warren, Travis K.; Wells, Jay B.; Garza, Nicole L.; Mourich, Dan V.; Welch, Lisa S.; Panchal, Rekha G.; Bavari, Sina

2012-01-01

320

The rhetorical construction of the predatorial virus: a Burkian analysis of nonfiction accounts of the Ebola virus.  

PubMed

Over the past 5 years, a new subgenre of horror films, referred to as plague films, has turned our focus to the threat of a hemorrhagic viral pandemic, comparable to the Spanish Flu epidemic of 1916. Based on the Ebola viral outbreaks of 1976, various writers have presented their accounts under the guise of increasing interest and prevention strategies. Disregarding inappropriate health care practices as the cause of these epidemics, accountability is refocused onto the rhetorically constructed, predatory nature of the virus. By employing Burke's theory of dramatism and pentadic analysis, the author examines this rhetorical construction of Ebola as a predatorial virus and its implications for public perceptions of public health endeavors. PMID:11147163

Weldon, R A

2001-01-01

321

Recombinant vesicular stomatitis virus vector mediates postexposure protection against Sudan Ebola hemorrhagic fever in nonhuman primates.  

PubMed

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. PMID:18385248

Geisbert, Thomas W; Daddario-DiCaprio, Kathleen M; Williams, Kinola J N; Geisbert, Joan B; Leung, Anders; Feldmann, Friederike; Hensley, Lisa E; Feldmann, Heinz; Jones, Steven M

2008-06-01

322

An "Urban legend" of global proportion: an analysis of nonfiction accounts of the Ebola virus.  

PubMed

Using Brunvald's (1981) six criteria of successful urban legends, this study explores nonfiction accounts of the Ebola virus. Focusing particularly on Richard Preston's book The Hot Zone (1994), this study addresses the social construction of the predatorial virus, demonstrating how events are constructed as social problems via media representations, and reality is transformed into legend. The implications of these depictions of the predatorial virus are discussed, along with exploring the effects of mass media reports on health care beliefs and practices. Likewise, implications regarding these stories, cultural beliefs and values are discussed. PMID:11550594

Weldon, R A

2001-01-01

323

Ebola virus-like particles produced in insect cells exhibit dendritic cell stimulating activity and induce neutralizing antibodies  

SciTech Connect

Recombinant baculoviruses (rBV) expressing Ebola virus VP40 (rBV-VP40) or GP (rBV-GP) proteins were generated. Infection of Sf9 insect cells by rBV-VP40 led to assembly and budding of filamentous particles from the cell surface as shown by electron microscopy. Ebola virus-like particles (VLPs) were produced by coinfection of Sf9 cells with rBV-VP40 and rBV-GP, and incorporation of Ebola GP into VLPs was demonstrated by SDS-PAGE and Western blot analysis. Recombinant baculovirus infection of insect cells yielded high levels of VLPs, which were shown to stimulate cytokine secretion from human dendritic cells similar to VLPs produced in mammalian cells. The immunogenicity of Ebola VLPs produced in insect cells was evaluated by immunization of mice. Analysis of antibody responses showed that most of the GP-specific antibodies were of the IgG2a subtype, while no significant level of IgG1 subtype antibodies specific for GP was induced, indicating the induction of a Th1-biased immune response. Furthermore, sera from Ebola VLP immunized mice were able to block infection by Ebola GP pseudotyped HIV virus in a single round infection assay, indicating that a neutralizing antibody against the Ebola GP protein was induced. These results show that production of Ebola VLPs in insect cells using recombinant baculoviruses represents a promising approach for vaccine development against Ebola virus infection.

Ye Ling [Department of Microbiology and Immunology and Emory Vaccine Center, Emory University School of Medicine, Atlanta, GA 30322 (United States); Lin Jianguo [Department of Microbiology and Immunology and Emory Vaccine Center, Emory University School of Medicine, Atlanta, GA 30322 (United States); Sun Yuliang [Department of Microbiology and Immunology and Emory Vaccine Center, Emory University School of Medicine, Atlanta, GA 30322 (United States); Bennouna, Soumaya [Department of Microbiology and Immunology and Emory Vaccine Center, Emory University School of Medicine, Atlanta, GA 30322 (United States); Department of Pathology, Emory University School of Medicine, Atlanta, GA 30322 (United States); Lo, Michael [Department of Microbiology and Immunology and Emory Vaccine Center, Emory University School of Medicine, Atlanta, GA 30322 (United States); Department of Pathology, Emory University School of Medicine, Atlanta, GA 30322 (United States); Wu Qingyang [Department of Microbiology and Immunology and Emory Vaccine Center, Emory University School of Medicine, Atlanta, GA 30322 (United States); Bu Zhigao [Department of Microbiology and Immunology and Emory Vaccine Center, Emory University School of Medicine, Atlanta, GA 30322 (United States); Pulendran, Bali [Department of Microbiology and Immunology and Emory Vaccine Center, Emory University School of Medicine, Atlanta, GA 30322 (United States); Department of Pathology, Emory University School of Medicine, Atlanta, GA 30322 (United States); Compans, Richard W. [Department of Microbiology and Immunology and Emory Vaccine Center, Emory University School of Medicine, Atlanta, GA 30322 (United States)]. E-mail: compans@microbio.emory.edu; Yang Chinglai [Department of Microbiology and Immunology and Emory Vaccine Center, Emory University School of Medicine, Atlanta, GA 30322 (United States)]. E-mail: chyang@emory.edu

2006-08-01

324

Historical analysis of the Ebola virus: prospective implications for primary care nursing today.  

PubMed

Ebola continues to attract worldwide attention as a highly lethal virus of unknown origin that leaves victims bleeding to death and has no known vaccine or cure. The purpose of this historical research was to review and analyze the primary and secondary sources available on Ebola for use by primary care nurses in the event of future outbreaks. A rich resource of history has been well documented by some of the original physicians, virologists, and members of international teams, but nothing was found to be documented by nurses during these outbreaks. Multiple themes emerged including the origins of the viral strains of Ebola, transmission factors, epidemiology, virology, nonhuman and genetic research, treatment, and clinical implications. This research will provide primary care nurses with historical information about Ebola to help in future treatment options and algorithm development. PMID:12596837

Amundsen, S B

1998-11-01

325

A DNA vaccine for Ebola virus is safe and immunogenic in a phase I clinical trial.  

PubMed

Ebola viruses represent a class of filoviruses that causes severe hemorrhagic fever with high mortality. Recognized first in 1976 in the Democratic Republic of Congo, outbreaks continue to occur in equatorial Africa. A safe and effective Ebola virus vaccine is needed because of its continued emergence and its potential for use for biodefense. We report the safety and immunogenicity of an Ebola virus vaccine in its first phase I human study. A three-plasmid DNA vaccine encoding the envelope glycoproteins (GP) from the Zaire and Sudan/Gulu species as well as the nucleoprotein was evaluated in a randomized, placebo-controlled, double-blinded, dose escalation study. Healthy adults, ages 18 to 44 years, were randomized to receive three injections of vaccine at 2 mg (n = 5), 4 mg (n = 8), or 8 mg (n = 8) or placebo (n = 6). Immunogenicity was assessed by enzyme-linked immunosorbent assay (ELISA), immunoprecipitation-Western blotting, intracellular cytokine staining (ICS), and enzyme-linked immunospot assay. The vaccine was well-tolerated, with no significant adverse events or coagulation abnormalities. Specific antibody responses to at least one of the three antigens encoded by the vaccine as assessed by ELISA and CD4(+) T-cell GP-specific responses as assessed by ICS were detected in 20/20 vaccinees. CD8(+) T-cell GP-specific responses were detected by ICS assay in 6/20 vaccinees. This Ebola virus DNA vaccine was safe and immunogenic in humans. Further assessment of the DNA platform alone and in combination with replication-defective adenoviral vector vaccines, in concert with challenge and immune data from nonhuman primates, will facilitate evaluation and potential licensure of an Ebola virus vaccine under the Animal Rule. PMID:16988008

Martin, Julie E; Sullivan, Nancy J; Enama, Mary E; Gordon, Ingelise J; Roederer, Mario; Koup, Richard A; Bailer, Robert T; Chakrabarti, Bimal K; Bailey, Michael A; Gomez, Phillip L; Andrews, Charla A; Moodie, Zoe; Gu, Lin; Stein, Judith A; Nabel, Gary J; Graham, Barney S

2006-11-01

326

A DNA Vaccine for Ebola Virus Is Safe and Immunogenic in a Phase I Clinical Trial? †  

PubMed Central

Ebola viruses represent a class of filoviruses that causes severe hemorrhagic fever with high mortality. Recognized first in 1976 in the Democratic Republic of Congo, outbreaks continue to occur in equatorial Africa. A safe and effective Ebola virus vaccine is needed because of its continued emergence and its potential for use for biodefense. We report the safety and immunogenicity of an Ebola virus vaccine in its first phase I human study. A three-plasmid DNA vaccine encoding the envelope glycoproteins (GP) from the Zaire and Sudan/Gulu species as well as the nucleoprotein was evaluated in a randomized, placebo-controlled, double-blinded, dose escalation study. Healthy adults, ages 18 to 44 years, were randomized to receive three injections of vaccine at 2 mg (n = 5), 4 mg (n = 8), or 8 mg (n = 8) or placebo (n = 6). Immunogenicity was assessed by enzyme-linked immunosorbent assay (ELISA), immunoprecipitation-Western blotting, intracellular cytokine staining (ICS), and enzyme-linked immunospot assay. The vaccine was well-tolerated, with no significant adverse events or coagulation abnormalities. Specific antibody responses to at least one of the three antigens encoded by the vaccine as assessed by ELISA and CD4+ T-cell GP-specific responses as assessed by ICS were detected in 20/20 vaccinees. CD8+ T-cell GP-specific responses were detected by ICS assay in 6/20 vaccinees. This Ebola virus DNA vaccine was safe and immunogenic in humans. Further assessment of the DNA platform alone and in combination with replication-defective adenoviral vector vaccines, in concert with challenge and immune data from nonhuman primates, will facilitate evaluation and potential licensure of an Ebola virus vaccine under the Animal Rule. PMID:16988008

Martin, Julie E.; Sullivan, Nancy J.; Enama, Mary E.; Gordon, Ingelise J.; Roederer, Mario; Koup, Richard A.; Bailer, Robert T.; Chakrabarti, Bimal K.; Bailey, Michael A.; Gomez, Phillip L.; Andrews, Charla A.; Moodie, Zoe; Gu, Lin; Stein, Judith A.; Nabel, Gary J.; Graham, Barney S.

2006-01-01

327

Ebola virus glycoprotein: proteolytic processing, acylation, cell tropism, and detection of neutralizing antibodies.  

PubMed

Using the vesicular stomatitis virus (VSV) pseudotype system, we studied the functional properties of the Ebola virus glycoprotein (GP). Amino acid substitutions at the GP cleavage site, which reduce glycoprotein cleavability and viral infectivity in some viruses, did not appreciably change the infectivity of VSV pseudotyped with GP. Likewise, removal of two acylated cysteine residues in the transmembrane region of GP showed no discernible effects on infectivity. Although most filoviruses are believed to target endothelial cells and hepatocytes preferentially, the GP-carrying VSV showed greater affinity for epithelial cells than for either of these cell types, indicating that Ebola virus GP does not necessarily have strong tropism toward endothelial cells and hepatocytes. Finally, when it was used to screen for neutralizing antibodies against Ebola virus GP, the VSV pseudotype system allowed us to detect strain-specific neutralizing activity that was inhibited by secretory GP (SGP). This finding provides evidence of shared neutralizing epitopes on GP and SGP molecules and indicates the potential of SGP to serve as a decoy for neutralizing antibodies. PMID:11152533

Ito, H; Watanabe, S; Takada, A; Kawaoka, Y

2001-02-01

328

A current review of Ebola virus: pathogenesis, clinical presentation, and diagnostic assessment.  

PubMed

Ebola hemorrhagic fever (EHF) is an acute viral syndrome that presents with fever and an ensuing bleeding diathesis that is marked by high mortality in human and nonhuman primates. Fatality rates are between 50% and 100%. Due to its lethal nature, this filovirus is classified as a biological class 4 pathogen. The natural reservoir of the virus is unknown. As a result, little is understood about how Ebola virus is transmitted or how it replicates in its host. Although the primary source of infection is unknown, the epidemiologic mode of transmission is well defined. A variety of tests have proven to be specific and useful for Ebola virus identification. There is no FDA-approved antiviral treatment for EHF. Incubation ranges from 2 to 21 days. Patients who are able to mount an immune response to the virus will begin to recover in 7 to 10 days and start a period of prolonged convalescence. Supportive management of infected patients is the primary method of treatment, with particular attention to maintenance of hydration, circulatory volume, blood pressure, and the provision of supplemental oxygen. Since there is no specific treatment outside of supportive management and palliative care, containment of this potentially lethal virus is paramount. In almost all outbreaks of EHF, the fatality rate among health care workers with documented infections was higher than that of non-health care workers. PMID:12698919

Casillas, Adrian M; Nyamathi, Adeline M; Sosa, Anthony; Wilder, Cam L; Sands, Heather

2003-04-01

329

Vaccine to confer to nonhuman primates complete protection against multistrain Ebola and Marburg virus infections.  

PubMed

Filoviruses (Ebola and Marburg viruses) are among the deadliest viruses known to mankind, with mortality rates nearing 90%. These pathogens are highly infectious through contact with infected body fluids and can be easily aerosolized. Additionally, there are currently no licensed vaccines available to prevent filovirus outbreaks. Their high mortality rates and infectious capabilities when aerosolized and the lack of licensed vaccines available to prevent such infectious make Ebola and Marburg viruses serious bioterrorism threats, placing them both on the category A list of bioterrorism agents. Here we describe a panfilovirus vaccine based on a complex adenovirus (CAdVax) technology that expresses multiple antigens from five different filoviruses de novo. Vaccination of nonhuman primates demonstrated 100% protection against infection by two species of Ebola virus and three Marburg virus subtypes, each administered at 1,000 times the lethal dose. This study indicates the feasibility of vaccination against all current filovirus threats in the event of natural hemorrhagic fever outbreak or biological attack. PMID:18216185

Swenson, Dana L; Wang, Danher; Luo, Min; Warfield, Kelly L; Woraratanadharm, Jan; Holman, David H; Dong, John Y; Pratt, William D

2008-03-01

330

Ebola virus glycoprotein Fc fusion protein confers protection against lethal challenge in vaccinated mice  

PubMed Central

Ebola virus is a Filoviridae that causes hemorrhagic fever in humans and induces high morbidity and mortality rates. Filoviruses are classified as "Category A bioterrorism agents", and currently there are no licensed therapeutics or vaccines to treat and prevent infection. The Filovirus glycoprotein (GP) is sufficient to protect individuals against infection, and several vaccines based on GP are under development including recombinant adenovirus, parainfluenza virus, Venezuelan equine encephalitis virus, vesicular stomatitis virus (VSV) and virus-like particles. Here we describe the development of a GP Fc fusion protein as a vaccine candidate. We expressed the extracellular domain of the Zaire Ebola virus (ZEBOV) GP fused to the Fc fragment of human IgG1 (ZEBOVGP-Fc) in mammalian cells and showed that GP undergoes the complex furin cleavage and processing observed in the native membrane-bound GP. Mice immunized with ZEBOVGP-Fc developed T-cell immunity against ZEBOV GP and neutralizing antibodies against replication-competent VSV-G deleted recombinant VSV containing ZEBOV GP. The ZEBOVGP-Fc vaccinated mice were protected against challenge with a lethal dose of ZEBOV. These results show that vaccination with the ZEBOVGP-Fc fusion protein alone without the need of a viral vector or assembly into virus-like particles is sufficient to induce protective immunity against ZEBOV in mice. Our data suggested that Filovirus GP Fc fusion proteins could be developed as a simple, safe, efficacious, and cost effective vaccine against Filovirus infection for human use. PMID:21329775

Konduru, Krishnamurthy; Bradfute, Steven B.; Jacques, Jerome; Manangeeswaran, Mohanraj; Nakamura, Siham; Morshed, Sufi; Wood, Steven C.; Bavari, Sina

2011-01-01

331

Ebola virus glycoprotein Fc fusion protein confers protection against lethal challenge in vaccinated mice.  

PubMed

Ebola virus is a Filoviridae that causes hemorrhagic fever in humans and induces high morbidity and mortality rates. Filoviruses are classified as "Category A bioterrorism agents", and currently there are no licensed therapeutics or vaccines to treat and prevent infection. The Filovirus glycoprotein (GP) is sufficient to protect individuals against infection, and several vaccines based on GP are under development including recombinant adenovirus, parainfluenza virus, Venezuelan equine encephalitis virus, vesicular stomatitis virus (VSV) and virus-like particles. Here we describe the development of a GP Fc fusion protein as a vaccine candidate. We expressed the extracellular domain of the Zaire Ebola virus (ZEBOV) GP fused to the Fc fragment of human IgG1 (ZEBOVGP-Fc) in mammalian cells and showed that GP undergoes the complex furin cleavage and processing observed in the native membrane-bound GP. Mice immunized with ZEBOVGP-Fc developed T-cell immunity against ZEBOV GP and neutralizing antibodies against replication-competent VSV-G deleted recombinant VSV containing ZEBOV GP. The ZEBOVGP-Fc vaccinated mice were protected against challenge with a lethal dose of ZEBOV. These results show that vaccination with the ZEBOVGP-Fc fusion protein alone without the need of a viral vector or assembly into virus-like particles is sufficient to induce protective immunity against ZEBOV in mice. Our data suggested that Filovirus GP Fc fusion proteins could be developed as a simple, safe, efficacious, and cost effective vaccine against Filovirus infection for human use. PMID:21329775

Konduru, Krishnamurthy; Bradfute, Steven B; Jacques, Jerome; Manangeeswaran, Mohanraj; Nakamura, Siham; Morshed, Sufi; Wood, Steven C; Bavari, Sina; Kaplan, Gerardo G

2011-04-01

332

Role of endosomal cathepsins in entry mediated by the Ebola virus glycoprotein.  

PubMed

Using chemical inhibitors and small interfering RNA (siRNA), we have confirmed roles for cathepsin B (CatB) and cathepsin L (CatL) in Ebola virus glycoprotein (GP)-mediated infection. Treatment of Ebola virus GP pseudovirions with CatB and CatL converts GP1 from a 130-kDa to a 19-kDa species. Virus with 19-kDa GP1 displays significantly enhanced infection and is largely resistant to the effects of the CatB inhibitor and siRNA, but it still requires a low-pH-dependent endosomal/lysosomal function. These and other results support a model in which CatB and CatL prime GP by generating a 19-kDa intermediate that can be acted upon by an as yet unidentified endosomal/lysosomal enzyme to trigger fusion. PMID:16571833

Schornberg, Kathryn; Matsuyama, Shutoku; Kabsch, Kirsten; Delos, Sue; Bouton, Amy; White, Judith

2006-04-01

333

Involvement of viral envelope GP2 in Ebola virus entry into cells expressing the macrophage galactose-type C-type lectin  

Microsoft Academic Search

Ebola virus (EBOV) infection is initiated by the interaction of the viral surface envelope glycoprotein (GP) with the binding sites on target cells. Differences in the mortality among different species of the Ebola viruses, i.e., Zaire ebolavirus (ZEBOV) and Reston ebolavirus (REBOV), correspond to the in vitro infectivity of the pseudo-typed virus constructed with the GPs in cells expressing macrophage

Katsuaki Usami; Keita Matsuno; Manabu Igarashi; Kaori Denda-Nagai; Ayato Takada; Tatsuro Irimura

2011-01-01

334

Structure of an antibody in complex with its mucin domain linear epitope that is protective against Ebola virus.  

PubMed

Antibody 14G7 is protective against lethal Ebola virus challenge and recognizes a distinct linear epitope in the prominent mucin-like domain of the Ebola virus glycoprotein GP. The structure of 14G7 in complex with its linear peptide epitope has now been determined to 2.8 Å. The structure shows that this GP sequence forms a tandem ?-hairpin structure that binds deeply into a cleft in the antibody-combining site. A key threonine at the apex of one turn is critical for antibody interaction and is conserved among all Ebola viruses. This work provides further insight into the mechanism of protection by antibodies that target the protruding, highly accessible mucin-like domain of Ebola virus and the structural framework for understanding and characterizing candidate immunotherapeutics. PMID:22171276

Olal, Daniel; Kuehne, Ana I; Bale, Shridhar; Halfmann, Peter; Hashiguchi, Takao; Fusco, Marnie L; Lee, Jeffrey E; King, Liam B; Kawaoka, Yoshihiro; Dye, John M; Saphire, Erica Ollmann

2012-03-01

335

Structure of an Antibody in Complex with Its Mucin Domain Linear Epitope That Is Protective against Ebola Virus  

PubMed Central

Antibody 14G7 is protective against lethal Ebola virus challenge and recognizes a distinct linear epitope in the prominent mucin-like domain of the Ebola virus glycoprotein GP. The structure of 14G7 in complex with its linear peptide epitope has now been determined to 2.8 Å. The structure shows that this GP sequence forms a tandem ?-hairpin structure that binds deeply into a cleft in the antibody-combining site. A key threonine at the apex of one turn is critical for antibody interaction and is conserved among all Ebola viruses. This work provides further insight into the mechanism of protection by antibodies that target the protruding, highly accessible mucin-like domain of Ebola virus and the structural framework for understanding and characterizing candidate immunotherapeutics. PMID:22171276

Olal, Daniel; Kuehne, Ana I.; Bale, Shridhar; Halfmann, Peter; Hashiguchi, Takao; Fusco, Marnie L.; Lee, Jeffrey E.; King, Liam B.; Kawaoka, Yoshihiro; Dye, John M.

2012-01-01

336

Ebola virus disease in southern Sudan: hospital dissemination and intrafamilial spread.  

PubMed

Between 31 July and 6 October 1979, 34 cases of Ebola virus disease (22 of which were fatal) occurred among five families in a rural district of southern Sudan; the disease was introduced into four of the families from a local hospital. Chains of secondary spread within the family units, accounting for 29 cases resulted from direct physical contact with an infected person. Among all persons with such contact in the family setting, those who provided nursing care had a 5.1-fold increased risk of infection, emphasizing the importance of intimate contact in the spread of this disease. The absence of illness among persons who were exposed to cases in confined spaces, but without physical contact, confirmed previous impressions that there is no risk of airborne transmission. While the ecology of Ebola virus is unknown, the presence of anti-Ebola antibodies in the sera of 18% of persons who were unassociated with the outbreak suggests that the region is an endemic focus of Ebola virus activity. PMID:6370486

Baron, R C; McCormick, J B; Zubeir, O A

1983-01-01

337

Passive immunization of Ebola virus-infected cynomolgus monkeys with immunoglobulin from hyperimmune horses.  

PubMed

A commercially available immunoglobulin G (IgG) from horses, hyperimmunized to Ebola virus, was evaluated for its ability to protect cynomolgus monkeys against disease following i.m. inoculation with 1 000 PFU Ebola virus (Zaire '95 strain). Six monkeys were treated immediately after infection by i.m. infection of 6.0 ml IgG; these animals developed passive ELISA titers of 1:160 to 1:320 to Ebola, two days afer inoculation. However, the beneficial effects of IgG treatment were limited to a delay in onset of viremia and clinical signs, in comparison with untreated controls. The six IgG recipients had no detectable viremia day 5, in contrast with three virus infected controls whose viremias exceeded 7.0 log10 PFU/ml that day. The controls died on days 6, 6, and 7, while two IgG recipients died day 7 and the remaining 4 died day 8, all with high viremias. These results document that passively acquired antibody can have a beneficial effect in reducing the viral burden in Ebola-infected primates; however, effective treatment of human patients may require antibodies with higher specific activities and more favorable pharmacokinetic properties than the presently available equine IgG. PMID:8800795

Jahrling, P B; Geisbert, J; Swearengen, J R; Jaax, G P; Lewis, T; Huggins, J W; Schmidt, J J; LeDuc, J W; Peters, C J

1996-01-01

338

Assessment of ebola virus disease, health care infrastructure, and preparedness - four counties, southeastern liberia, august 2014.  

PubMed

Ebola virus disease (Ebola) is a multisystem disease caused by a virus of the genus Ebolavirus. In late March 2014, Ebola cases were described in Liberia, with epicenters in Lofa County and later in Montserrado County. While information about case burden and health care infrastructure was available for the two epicenters, little information was available about remote counties in southeastern Liberia. Over 9 days, August 6-14, 2014, Ebola case burden, health care infrastructure, and emergency preparedness were assessed in collaboration with the Liberian Ministry of Health and Social Welfare in four counties in southeastern Liberia: Grand Gedeh, Grand Kru, River Gee, and Maryland. Data were collected by health care facility visits to three of the four county referral hospitals and by unstructured interviews with county and district health officials, hospital administrators, physicians, nurses, physician assistants, and health educators in all four counties. Local burial practices were discussed with county officials, but no direct observation of burial practices was conducted. Basic information about Ebola surveillance and epidemiology, case investigation, contact tracing, case management, and infection control was provided to local officials. PMID:25299605

Forrester, Joseph D; Pillai, Satish K; Beer, Karlyn D; Neatherlin, John; Massaquoi, Moses; Nyenswah, Tolbert G; Montgomery, Joel M; Cock, Kevin De

2014-10-10

339

Distribution of Hydrophobic Residues Is Crucial for the Fusogenic Properties of the Ebola Virus GP2 Fusion Peptide  

Microsoft Academic Search

The lipid-destabilizing properties of the N-terminal domain of the GP2 of Ebola virus were investigated. Our results suggest that the domain of Ebola virus needed for fusion is shorter than that previously reported. The fusogenic properties of this domain are related to its oblique orientation at the lipid\\/water interface owing to an asymmetric distribution of the hydrophobic residues when helical.

B. Adam; L. Lins; V. Stroobant; A. Thomas; R. Brasseur

2004-01-01

340

Complex of a Protective Antibody with Its Ebola Virus GP Peptide Epitope: Unusual Features of a V? x Light Chain  

Microsoft Academic Search

13F6-1-2 is a murine monoclonal antibody that recognizes the heavily glycosylated mucin-like domain of the Ebola virus virion-attached glycoprotein (GP) and protects animals against lethal viral challenge. Here we present the crystal structure, at 2.0 Å, of 13F6-1-2 in complex with its Ebola virus GP peptide epitope. The GP peptide binds in an extended conformation, anchored primarily by interactions with the

Jeffrey E. Lee; Ana Kuehne; Dafna M. Abelson; Marnie L. Fusco; Mary Kate Hart; Erica Ollmann Saphire

2008-01-01

341

Production of monoclonal antibodies and development of an antigen capture ELISA directed against the envelope glycoprotein GP of Ebola virus  

Microsoft Academic Search

Ebola virus (EBOV) causes severe outbreaks of Ebola hemorrhagic fever in endemic regions of Africa and is considered to be of impact for other parts of the world as an imported viral disease. To develop a new diagnostic test, monoclonal antibodies to EBOV were produced from mice immunized with inactivated EBOV species Zaire. Antibodies directed against the viral glycoprotein GP

Andreas Lucht; Roland Grunow; Christian Otterbein; Peggy Möller; Heinz Feldmann; Stephan Becker

2004-01-01

342

Impact of Ebola mucin-like domain on antiglycoprotein antibody responses induced by Ebola virus-like particles.  

PubMed

Ebola virus (EBOV) glycoprotein (GP), responsible for mediating host-cell attachment and membrane fusion, contains a heavily glycosylated mucin-like domain hypothesized to shield GP from neutralizing antibodies. To test whether the mucin-like domain inhibits the production and function of anti-GP antibodies, we vaccinated mice with Ebola virus-like particles (VLPs) that express vesicular stomatitis virus G, wild-type EBOV GP (EBGP), EBOV GP without its mucin-like domain (?MucGP), or EBOV GP with a Crimean-Congo hemorrhagic fever virus mucin-like domain substituted for the EBOV mucin-like domain (CMsubGP). EBGP-VLP immunized mice elicited significantly higher serum antibody titers toward EBGP or its mutants, as detected by western blot analysis, than did VLP-?MucGP. However, EBGP-, ?MucGP- and CMsubGP-VLP immunized mouse sera contained antibodies that bound to cell surface-expressed GP at similar levels. Furthermore, low but similar neutralizing antibody titers, measured against a vesicular stomatitis virus (VSV) expressing EBGP or ?MucGP, were present in EBGP, ?MucGP, and CMsubGP sera, although a slightly higher neutralizing titer (2- to 2.5-fold) was detected in ?MucGP sera. We conclude that the EBOV GP mucin-like domain can increase relative anti-GP titers, however these titers appear to be directed, at least partly, to denatured GP. Furthermore, removing the mucin-like domain from immunizing VLPs has modest impact on neutralizing antibody titers in serum. PMID:21987758

Martinez, Osvaldo; Tantral, Lee; Mulherkar, Nirupama; Chandran, Kartik; Basler, Christopher F

2011-11-01

343

Impact of Ebola Mucin-Like Domain on Antiglycoprotein Antibody Responses Induced by Ebola Virus-Like Particles  

PubMed Central

Ebola virus (EBOV) glycoprotein (GP), responsible for mediating host-cell attachment and membrane fusion, contains a heavily glycosylated mucin-like domain hypothesized to shield GP from neutralizing antibodies. To test whether the mucin-like domain inhibits the production and function of anti-GP antibodies, we vaccinated mice with Ebola virus-like particles (VLPs) that express vesicular stomatitis virus G, wild-type EBOV GP (EBGP), EBOV GP without its mucin-like domain (?MucGP), or EBOV GP with a Crimean–Congo hemorrhagic fever virus mucin-like domain substituted for the EBOV mucin-like domain (CMsubGP). EBGP-VLP immunized mice elicited significantly higher serum antibody titers toward EBGP or its mutants, as detected by western blot analysis, than did VLP-?MucGP. However, EBGP-, ?MucGP- and CMsubGP-VLP immunized mouse sera contained antibodies that bound to cell surface-expressed GP at similar levels. Furthermore, low but similar neutralizing antibody titers, measured against a vesicular stomatitis virus (VSV) expressing EBGP or ?MucGP, were present in EBGP, ?MucGP, and CMsubGP sera, although a slightly higher neutralizing titer (2- to 2.5-fold) was detected in ?MucGP sera. We conclude that the EBOV GP mucin-like domain can increase relative anti-GP titers, however these titers appear to be directed, at least partly, to denatured GP. Furthermore, removing the mucin-like domain from immunizing VLPs has modest impact on neutralizing antibody titers in serum. PMID:21987758

Martinez, Osvaldo; Tantral, Lee; Mulherkar, Nirupama; Chandran, Kartik

2011-01-01

344

Requirements for cell rounding and surface protein down-regulation by Ebola virus glycoprotein.  

PubMed

Ebola virus causes an acute hemorrhagic fever that is associated with high morbidity and mortality. The viral glycoprotein is thought to contribute to pathogenesis, though precise mechanisms are unknown. Cellular pathogenesis can be modeled in vitro by expression of the Ebola viral glycoprotein (GP) in cells, which causes dramatic morphological changes, including cell rounding and surface protein down-regulation. These effects are known to be dependent on the presence of a highly glycosylated region of the glycoprotein, the mucin domain. Here we show that the mucin domain from the highly pathogenic Zaire subtype of Ebola virus is sufficient to cause characteristic cytopathology when expressed in the context of a foreign glycoprotein. Similarly to full length Ebola GP, expression of the mucin domain causes rounding, detachment from the extracellular matrix, and the down-regulation of cell surface levels of beta1 integrin and major histocompatibility complex class 1. These effects were not seen when the mucin domain was expressed in the context of a glycophosphatidylinositol-anchored isoform of the foreign glycoprotein. In contrast to earlier analysis of full length Ebola glycoproteins, chimeras carrying the mucin domains from the Zaire and Reston strains appear to cause similar levels of down-modulation and cell detachment. Cytopathology associated with Ebola glycoprotein expression does not occur when GP expression is restricted to the endoplasmic reticulum. In contrast to a previously published report, our results demonstrate that GP-induced surface protein down-regulation is not mediated through a dynamin-dependent pathway. Overall, these results support a model in which the mucin domain of Ebola GP acts at the cell surface to induce protein down modulation and cytopathic effects. PMID:19013626

Francica, Joseph R; Matukonis, Meghan K; Bates, Paul

2009-01-20

345

Mapping of conserved and species-specific antibody epitopes on the Ebola virus nucleoprotein  

PubMed Central

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. PMID:23702199

Changula, Katendi; Yoshida, Reiko; Noyori, Osamu; Marzi, Andrea; Miyamoto, Hiroko; Ishijima, Mari; Yokoyama, Ayaka; Kajihara, Masahiro; Feldmann, Heinz; Mweene, Aaron S.; Takada, Ayato

2013-01-01

346

The Ebola Virus Matrix Protein Deeply Penetrates the Plasma Membrane: An Important Step in Viral Egress  

PubMed Central

Ebola virus, from the Filoviridae family has a high fatality rate in humans and nonhuman primates and to date, to the best of our knowledge, has no FDA approved vaccines or therapeutics. Viral protein 40 (VP40) is the major Ebola virus matrix protein that regulates assembly and egress of infectious Ebola virus particles. It is well established that VP40 assembles on the inner leaflet of the plasma membrane; however, the mechanistic details of VP40 membrane binding that are important for viral release remain to be elucidated. In this study, we used fluorescence quenching of a tryptophan on the membrane-binding interface with brominated lipids along with mutagenesis of VP40 to understand the depth of membrane penetration into lipid bilayers. Experimental results indicate that VP40 penetrates 8.1 Å into the hydrocarbon core of the plasma membrane bilayer. VP40 also induces substantial changes to membrane curvature as it tubulates liposomes and induces vesiculation into giant unilamellar vesicles, effects that are abrogated by hydrophobic mutations. This is a critical step in viral egress as cellular assays demonstrate that hydrophobic residues that penetrate deeply into the plasma membrane are essential for plasma membrane localization and virus-like particle formation and release from cells. PMID:23663837

Soni, Smita P.; Adu-Gyamfi, Emmanuel; Yong, Sylvia S.; Jee, Clara S.; Stahelin, Robert V.

2013-01-01

347

FDA-Approved Selective Estrogen Receptor Modulators Inhibit Ebola Virus Infection  

PubMed Central

Ebola viruses remain a substantial threat to both civilian and military populations as bioweapons, during sporadic outbreaks, and from the possibility of accidental importation from endemic regions by infected individuals. Currently, no approved therapeutics exist to treat or prevent infection by Ebola viruses. Therefore, we performed an in vitro screen of Food and Drug Administration (FDA)– and ex–US-approved drugs and selected molecular probes to identify drugs with antiviral activity against the type species Zaire ebolavirus (EBOV). From this screen, we identified a set of selective estrogen receptor modulators (SERMs), including clomiphene and toremifene, which act as potent inhibitors of EBOV infection. Anti-EBOV activity was confirmed for both of these SERMs in an in vivo mouse infection model. This anti-EBOV activity occurred even in the absence of detectable estrogen receptor expression, and both SERMs inhibited virus entry after internalization, suggesting that clomiphene and toremifene are not working through classical pathways associated with the estrogen receptor. Instead, the response appeared to be an off-target effect where the compounds interfere with a step late in viral entry and likely affect the triggering of fusion. These data support the screening of readily available approved drugs to identify therapeutics for the Ebola viruses and other infectious diseases. The SERM compounds described in this report are an immediately actionable class of approved drugs that can be repurposed for treatment of filovirus infections. PMID:23785035

Johansen, Lisa M.; Brannan, Jennifer M.; Delos, Sue E.; Shoemaker, Charles J.; Stossel, Andrea; Lear, Calli; Hoffstrom, Benjamin G.; DeWald, Lisa Evans; Schornberg, Kathryn L.; Scully, Corinne; Lehar, Joseph; Hensley, Lisa E.; White, Judith M.; Olinger, Gene G.

2014-01-01

348

FDA-approved selective estrogen receptor modulators inhibit Ebola virus infection.  

PubMed

Ebola viruses remain a substantial threat to both civilian and military populations as bioweapons, during sporadic outbreaks, and from the possibility of accidental importation from endemic regions by infected individuals. Currently, no approved therapeutics exist to treat or prevent infection by Ebola viruses. Therefore, we performed an in vitro screen of Food and Drug Administration (FDA)- and ex-US-approved drugs and selected molecular probes to identify drugs with antiviral activity against the type species Zaire ebolavirus (EBOV). From this screen, we identified a set of selective estrogen receptor modulators (SERMs), including clomiphene and toremifene, which act as potent inhibitors of EBOV infection. Anti-EBOV activity was confirmed for both of these SERMs in an in vivo mouse infection model. This anti-EBOV activity occurred even in the absence of detectable estrogen receptor expression, and both SERMs inhibited virus entry after internalization, suggesting that clomiphene and toremifene are not working through classical pathways associated with the estrogen receptor. Instead, the response appeared to be an off-target effect where the compounds interfere with a step late in viral entry and likely affect the triggering of fusion. These data support the screening of readily available approved drugs to identify therapeutics for the Ebola viruses and other infectious diseases. The SERM compounds described in this report are an immediately actionable class of approved drugs that can be repurposed for treatment of filovirus infections. PMID:23785035

Johansen, Lisa M; Brannan, Jennifer M; Delos, Sue E; Shoemaker, Charles J; Stossel, Andrea; Lear, Calli; Hoffstrom, Benjamin G; Dewald, Lisa Evans; Schornberg, Kathryn L; Scully, Corinne; Lehár, Joseph; Hensley, Lisa E; White, Judith M; Olinger, Gene G

2013-06-19

349

Biochemical Analysis of the Secreted and Virion Glycoproteins of Ebola Virus  

PubMed Central

The glycoproteins expressed by a Zaire species of Ebola virus were analyzed for cleavage, oligomerization, and other structural properties to better define their functions. The 50- to 70-kDa secreted and 150-kDa virion/structural glycoproteins (SGP and GP, respectively), which share the 295 N-terminal residues, are cleaved near the N terminus by signalase. A second cleavage event, occurring in GP at a multibasic site (RRTRR?) that is likely mediated by furin, results in two glycoproteins (GP1 and GP2) linked by disulfide bonding. This furin cleavage site is present in the same position in the GPs of all Ebola viruses (R[R/K]X[R/K]R?), and one is predicted for Marburg viruses (R[R/K]KR?), although in a different location. Based on the results of cross-linking studies, we were able to determine that Ebola virion peplomers are composed of trimers of GP1-GP2 heterodimers and that aspects of their structure are similar to those of retroviruses, paramyxoviruses, and influenza viruses. We also determined that SGP is secreted from infected cells almost exclusively in the form of a homodimer that is joined by disulfide bonding. PMID:9658086

Sanchez, Anthony; Yang, Zhi-Yong; Xu, Ling; Nabel, Gary J.; Crews, Tamara; Peters, Clarence J.

1998-01-01

350

C-Type Lectins DC-SIGN and L-SIGN Mediate Cellular Entry by Ebola Virus in cis and in trans  

Microsoft Academic Search

Ebola virus is a highly lethal pathogen responsible for several outbreaks of hemorrhagic fever. Here we show that the primate lentiviral binding C-type lectins DC-SIGN and L-SIGN act as cofactors for cellular entry by Ebola virus. Furthermore, DC-SIGN on the surface of dendritic cells is able to function as a trans receptor, binding Ebola virus-pseudotyped lentiviral particles and transmitting infection

Carmen P. Alvarez; Fátima Lasala; Jaime Carrillo; O. Muniz; A. L. Corbi; Rafael Delgado

2002-01-01

351

Ebola virus-like particles produced in insect cells exhibit dendritic cell stimulating activity and induce neutralizing antibodies  

Microsoft Academic Search

Recombinant baculoviruses (rBV) expressing Ebola virus VP40 (rBV-VP40) or GP (rBV-GP) proteins were generated. Infection of Sf9 insect cells by rBV-VP40 led to assembly and budding of filamentous particles from the cell surface as shown by electron microscopy. Ebola virus-like particles (VLPs) were produced by coinfection of Sf9 cells with rBV-VP40 and rBV-GP, and incorporation of Ebola GP into VLPs

Ling Ye; Jianguo Lin; Yuliang Sun; Soumaya Bennouna; Michael Lo; Qingyang Wu; Zhigao Bu; Bali Pulendran; Richard W.. Compans; Chinglai Yang

2006-01-01

352

Physicochemical inactivation of Lassa, Ebola, and Marburg viruses and effect on clinical laboratory analyses  

SciTech Connect

Clinical specimens from patients infected with Lassa, Ebola, or Marburg virus may present a serious biohazard to laboratory workers. The authors have examined the effects of heat, alteration of pH, and gamma radiation on these viruses in human blood and on the electrolytes, enzymes, and coagulation factors measured in laboratory tests that are important in the care of an infected patient. Heating serum at 60 degrees C for 1 h reduced high titers of these viruses to noninfectious levels without altering the serum levels of glucose, blood urea nitrogen, and electrolytes. Dilution of blood in 3% acetic acid, diluent for a leukocyte count, inactivated all of these viruses. All of the methods tested for viral inactivation markedly altered certain serum proteins, making these methods unsuitable for samples that are to be tested for certain enzyme levels and coagulation factors.

Mitchell, S.W.; McCormick, J.B.

1984-09-01

353

Physicochemical inactivation of Lassa, Ebola, and Marburg viruses and effect on clinical laboratory analyses.  

PubMed

Clinical specimens from patients infected with Lassa, Ebola, or Marburg virus may present a serious biohazard to laboratory workers. We have examined the effects of heat, alteration of pH, and gamma radiation on these viruses in human blood and on the electrolytes, enzymes, and coagulation factors measured in laboratory tests that are important in the care of an infected patient. Heating serum at 60 degrees C for 1 h reduced high titers of these viruses to noninfectious levels without altering the serum levels of glucose, blood urea nitrogen, and electrolytes. Dilution of blood in 3% acetic acid, diluent for a leukocyte count, inactivated all of these viruses. All of the methods tested for viral inactivation markedly altered certain serum proteins, making these methods unsuitable for samples that are to be tested for certain enzyme levels and coagulation factors. PMID:6490832

Mitchell, S W; McCormick, J B

1984-09-01

354

Ebola Zaire Virus Blocks Type I Interferon Production by Exploiting the Host SUMO Modification Machinery  

PubMed Central

Ebola Zaire virus is highly pathogenic for humans, with case fatality rates approaching 90% in large outbreaks in Africa. The virus replicates in macrophages and dendritic cells (DCs), suppressing production of type I interferons (IFNs) while inducing the release of large quantities of proinflammatory cytokines. Although the viral VP35 protein has been shown to inhibit IFN responses, the mechanism by which it blocks IFN production has not been fully elucidated. We expressed VP35 from a mouse-adapted variant of Ebola Zaire virus in murine DCs by retroviral gene transfer, and tested for IFN transcription upon Newcastle Disease virus (NDV) infection and toll-like receptor signaling. We found that VP35 inhibited IFN transcription in DCs following these stimuli by disabling the activity of IRF7, a transcription factor required for IFN transcription. By yeast two-hybrid screens and coimmunoprecipitation assays, we found that VP35 interacted with IRF7, Ubc9 and PIAS1. The latter two are the host SUMO E2 enzyme and E3 ligase, respectively. VP35, while not itself a SUMO ligase, increased PIAS1-mediated SUMOylation of IRF7, and repressed Ifn transcription. In contrast, VP35 did not interfere with the activation of NF-?B, which is required for induction of many proinflammatory cytokines. Our findings indicate that Ebola Zaire virus exploits the cellular SUMOylation machinery for its advantage and help to explain how the virus overcomes host innate defenses, causing rapidly overwhelming infection to produce a syndrome resembling fulminant septic shock. PMID:19557165

Jones, Steven; Bradfute, Steven B.; Bray, Mike; Ozato, Keiko

2009-01-01

355

Inactivated or Live-Attenuated Bivalent Vaccines That Confer Protection against Rabies and Ebola Viruses ?  

PubMed Central

The search for a safe and efficacious vaccine for Ebola virus continues, as no current vaccine candidate is nearing licensure. We have developed (i) replication-competent, (ii) replication-deficient, and (iii) chemically inactivated rabies virus (RABV) vaccines expressing Zaire Ebola virus (ZEBOV) glycoprotein (GP) by a reverse genetics system based on the SAD B19 RABV wildlife vaccine. ZEBOV GP is efficiently expressed by these vaccine candidates and is incorporated into virions. The vaccine candidates were avirulent after inoculation of adult mice, and viruses with a deletion in the RABV glycoprotein had greatly reduced neurovirulence after intracerebral inoculation in suckling mice. Immunization with live or inactivated RABV vaccines expressing ZEBOV GP induced humoral immunity against each virus and conferred protection from both lethal RABV and EBOV challenge in mice. The bivalent RABV/ZEBOV vaccines described here have several distinct advantages that may speed the development of inactivated vaccines for use in humans and potentially live or inactivated vaccines for use in nonhuman primates at risk of EBOV infection in endemic areas. PMID:21849459

Blaney, Joseph E.; Wirblich, Christoph; Papaneri, Amy B.; Johnson, Reed F.; Myers, Carey J.; Juelich, Terry L.; Holbrook, Michael R.; Freiberg, Alexander N.; Bernbaum, John G.; Jahrling, Peter B.; Paragas, Jason; Schnell, Matthias J.

2011-01-01

356

Inactivated or live-attenuated bivalent vaccines that confer protection against rabies and Ebola viruses.  

PubMed

The search for a safe and efficacious vaccine for Ebola virus continues, as no current vaccine candidate is nearing licensure. We have developed (i) replication-competent, (ii) replication-deficient, and (iii) chemically inactivated rabies virus (RABV) vaccines expressing Zaire Ebola virus (ZEBOV) glycoprotein (GP) by a reverse genetics system based on the SAD B19 RABV wildlife vaccine. ZEBOV GP is efficiently expressed by these vaccine candidates and is incorporated into virions. The vaccine candidates were avirulent after inoculation of adult mice, and viruses with a deletion in the RABV glycoprotein had greatly reduced neurovirulence after intracerebral inoculation in suckling mice. Immunization with live or inactivated RABV vaccines expressing ZEBOV GP induced humoral immunity against each virus and conferred protection from both lethal RABV and EBOV challenge in mice. The bivalent RABV/ZEBOV vaccines described here have several distinct advantages that may speed the development of inactivated vaccines for use in humans and potentially live or inactivated vaccines for use in nonhuman primates at risk of EBOV infection in endemic areas. PMID:21849459

Blaney, Joseph E; Wirblich, Christoph; Papaneri, Amy B; Johnson, Reed F; Myers, Carey J; Juelich, Terry L; Holbrook, Michael R; Freiberg, Alexander N; Bernbaum, John G; Jahrling, Peter B; Paragas, Jason; Schnell, Matthias J

2011-10-01

357

The envelope glycoprotein of Ebola virus contains an immunosuppressive-like domain similar to oncogenic retroviruses.  

PubMed

Genomic RNA of a Zaire strain of Ebola virus was cloned, and cDNA inserts specific for the glycoprotein gene were isolated and sequenced. The determined sequence has only one open reading frame encoding 318 amino acids and is part of ORF-4 on the plus RNA strand. The putative transcriptional stop site (3' AAUUCUUUUU 5') and the transcriptional start site (3' AACUACUUCUAAUU..5') were identified. Computer-assisted comparison of the amino acid sequence of the C-terminal part of protein encoded by ORF-4 of Ebola virus with sequences of the proteins present in the SWISSPROT and EMBL banks revealed significant homology with the 'immunosuppressive domain' of the p15E envelope proteins of various oncogenic retroviruses. The possible role of such a homology is discussed. PMID:1299611

Volchkov, V E; Blinov, V M; Netesov, S V

1992-07-01

358

Single-particle tracking demonstrates that actin coordinates the movement of the Ebola virus matrix protein.  

PubMed

The Ebola virus causes severe hemorrhagic fever and has a mortality rate that can be as high as 90%, yet no vaccines or approved therapeutics, to our knowledge, are available. To replicate and egress the infected host cell the Ebola virus uses VP40, its major matrix protein to assemble at the inner leaflet of the plasma membrane. The assembly and budding of VP40 from the plasma membrane of host cells seem still poorly understood. We investigated the assembly and egress of VP40 at the plasma membrane of human cells using single-particle tracking. Our results demonstrate that actin coordinates the movement and assembly of VP40, a critical step in viral egress. These findings underscore the ability of single-molecule techniques to investigate the interplay of VP40 and host proteins in viral replication. PMID:23199932

Adu-Gyamfi, Emmanuel; Digman, Michelle A; Gratton, Enrico; Stahelin, Robert V

2012-11-01

359

Single-Particle Tracking Demonstrates that Actin Coordinates the Movement of the Ebola Virus Matrix Protein  

PubMed Central

The Ebola virus causes severe hemorrhagic fever and has a mortality rate that can be as high as 90%, yet no vaccines or approved therapeutics, to our knowledge, are available. To replicate and egress the infected host cell the Ebola virus uses VP40, its major matrix protein to assemble at the inner leaflet of the plasma membrane. The assembly and budding of VP40 from the plasma membrane of host cells seem still poorly understood. We investigated the assembly and egress of VP40 at the plasma membrane of human cells using single-particle tracking. Our results demonstrate that actin coordinates the movement and assembly of VP40, a critical step in viral egress. These findings underscore the ability of single-molecule techniques to investigate the interplay of VP40 and host proteins in viral replication. PMID:23199932

Adu-Gyamfi, Emmanuel; Digman, Michelle A.; Gratton, Enrico; Stahelin, Robert V.

2012-01-01

360

Assessment of the risk of Ebola virus transmission from bodily fluids and fomites.  

PubMed

Although Ebola virus (EBOV) is transmitted by unprotected physical contact with infected persons, few data exist on which specific bodily fluids are infected or on the risk of fomite transmission. Therefore, we tested various clinical specimens from 26 laboratory-confirmed cases of Ebola hemorrhagic fever, as well as environmental specimens collected from an isolation ward, for the presence of EBOV. Virus was detected by culture and/or reverse-transcription polymerase chain reaction in 16 of 54 clinical specimens (including saliva, stool, semen, breast milk, tears, nasal blood, and a skin swab) and in 2 of 33 environmental specimens. We conclude that EBOV is shed in a wide variety of bodily fluids during the acute period of illness but that the risk of transmission from fomites in an isolation ward and from convalescent patients is low when currently recommended infection control guidelines for the viral hemorrhagic fevers are followed. PMID:17940942

Bausch, Daniel G; Towner, Jonathan S; Dowell, Scott F; Kaducu, Felix; Lukwiya, Matthew; Sanchez, Anthony; Nichol, Stuart T; Ksiazek, Thomas G; Rollin, Pierre E

2007-11-15

361

Zaire Ebola virus entry into human dendritic cells is insensitive to cathepsin L inhibition.  

PubMed

Cathepsins B and L contribute to Ebola virus (EBOV) entry into Vero cells and mouse embryonic fibroblasts. However, the role of cathepsins in EBOV-infection of human dendritic cells (DCs), important targets of infection in vivo, remains undefined. Here, EBOV-like particles containing a beta-lactamase-VP40 fusion reporter and Ebola virus were used to demonstrate the cathepsin dependence of EBOV entry into human monocyte-derived DCs. However, while DC infection is blocked by cathepsin B inhibitor, it is insensitive to cathepsin L inhibitor. Furthermore, DCs pre-treated for 48 h with TNFalpha were generally less susceptible to entry and infection by EBOV. This decrease in infection was associated with a decrease in cathepsin B activity. Thus, cathepsin L plays a minimal, if any, role in EBOV infection in human DCs. The inflammatory cytokine TNFalpha modulates cathepsin B activity and affects EBOV entry into and infection of human DCs. PMID:19775255

Martinez, Osvaldo; Johnson, Joshua; Manicassamy, Balaji; Rong, Lijun; Olinger, Gene G; Hensley, Lisa E; Basler, Christopher F

2010-02-01

362

Molecular Determinants of Ebola Virus Virulence in Mice  

Microsoft Academic Search

Zaire ebolavirus (ZEBOV) causes severe hemorrhagic fever in humans and nonhuman primates, with fatality rates in humans of up to 90%. The molecular basis for the extreme virulence of ZEBOV remains elusive. While adult mice resist ZEBOV infection, the Mayinga strain of the virus has been adapted to cause lethal infection in these animals. To understand the pathogenesis underlying the

Hideki Ebihara; Ayato Takada; Darwyn Kobasa; Steven Jones; Gabriele Neumann; Steven Theriault; Mike Bray; Heinz Feldmann; Yoshihiro Kawaoka

2006-01-01

363

Recovery of Infectious Ebola Virus from Complementary DNA: RNA Editing of the GP Gene and Viral Cytotoxicity  

Microsoft Academic Search

To study the mechanisms underlying the high pathogenicity of Ebola virus, we have established a system that allows the recovery of infectious virus from cloned cDNA and thus permits genetic manipulation. We created a mutant in which the editing site of the gene encoding envelope glycoprotein (GP) was eliminated. This mutant no longer expressed the nonstructural glycoprotein sGP. Synthesis of

Viktor E. Volchkov; Valentina A. Volchkova; Elke Mühlberger; Larissa V. Kolesnikova; Michael Weik; Olga Dolnik; Hans-Dieter Klenk

2001-01-01

364

Inhibition of IRF-3 activation by VP35 is critical for the high level of virulence of ebola virus.  

PubMed

Zaire ebolavirus causes a rapidly progressing hemorrhagic disease with high mortality. Identification of the viral virulence factors that contribute to the severity of disease induced by Ebola virus is critical for the design of therapeutics and vaccines against the disease. Given the rapidity of disease progression, virus interaction with the innate immune system early in the course of infection likely plays an important role in determining the outcome of the disease. The Ebola virus VP35 protein inhibits the activation of IRF-3, a critical transcription factor for the induction of early antiviral immunity. Previous studies revealed that a single amino acid change (R312A) in VP35 renders the protein unable to inhibit IRF-3 activation. A reverse-genetics-generated, mouse-adapted, recombinant Ebola virus that encodes the R312A mutation in VP35 was produced. We found that relative to the case for wild-type virus containing the authentic VP35 sequence, this single amino acid change in VP35 renders the virus completely attenuated in mice. Given that these viruses differ by only a single amino acid in the IRF-3 inhibitory domain of VP35, the level of alteration of virulence is remarkable and highlights the importance of VP35 for the pathogenesis of Ebola virus. PMID:18199658

Hartman, Amy L; Bird, Brian H; Towner, Jonathan S; Antoniadou, Zoi-Anna; Zaki, Sherif R; Nichol, Stuart T

2008-03-01

365

Inhibition of IRF-3 Activation by VP35 Is Critical for the High Level of Virulence of Ebola Virus  

Microsoft Academic Search

Zaire ebolavirus causes a rapidly progressing hemorrhagic disease with high mortality. Identification of the viral virulence factors that contribute to the severity of disease induced by Ebola virus is critical for the design of therapeutics and vaccines against the disease. Given the rapidity of disease progression, virus interaction with the innate immune system early in the course of infection likely

Amy L. Hartman; Brian H. Bird; Jonathan S. Towner; Zoi-Anna Antoniadou; Sherif R. Zaki; Stuart T. Nichol

2008-01-01

366

The Ebola virus ribonucleoprotein complex: A novel VP30–L interaction identified  

Microsoft Academic Search

The ribonucleoprotein (RNP) complex of Ebola virus (EBOV) is known to be a multiprotein\\/RNA structure, however, knowledge is rather limited regarding the actual protein–protein interactions involved in its formation. Here we show that singularly expressed VP35 and VP30 are present throughout the cytoplasm, while NP forms prominent cytoplasmic inclusions and L forms smaller perinuclear inclusions. We could demonstrate the existence

A. Groseth; J. E. Charton; M. Sauerborn; F. Feldmann; S. M. Jones; T. Hoenen; H. Feldmann

2009-01-01

367

Differential expression of the Ebola virus GP 1, 2 protein and its fragments in E. coli  

Microsoft Academic Search

Bacterial expression platforms are frequently used for the expression and production of different recombinant proteins. The full length Ebola virus (EBOV) GP1,2 gene and subfragments of the GP1 gene were cloned in a bacterial expression vector as a C-terminal His6 fusion protein. Surprisingly, the full length EBOV GP1,2 gene could not be expressed in Escherichia coli. The subfragments of GP1

Dipankar Das; Fred Jacobs; Heinz Feldmann; Steven M. Jones; Mavanur R. Suresh

2007-01-01

368

Isolation and partial characterisation of a new strain of Ebola virus  

Microsoft Academic Search

We have isolated a new strain of Ebola virus from a non-fatal human case infected during the autopsy of a wild chimpanzee in the Cote-d'Ivoire. The wild troop to which this animal belonged has been decimated by outbreaks of haemorrhagic syndromes. This is the first time that a human infection has been connected to naturally-infected monkeys in Africa. Data from

B. Le Guenno; P Formentry; M. Wyers; P. Gounon; F. Walker; C. Boesch

1995-01-01

369

Crystal Structure of the Ebola Virus Membrane Fusion Subunit, GP2, from the Envelope Glycoprotein Ectodomain  

Microsoft Academic Search

We have determined the structure of GP2 from the Ebola virus membrane fusion glycoprotein by X-ray crystallography. The molecule contains a central triple-stranded coiled coil followed by a disulfide-bonded loop homologous to an immunosuppressive sequence in retroviral glycoproteins, which reverses the chain direction and connects to an ? helix packed antiparallel to the core helices. The structure suggests that fusion

Winfried Weissenhorn; Andrea Carfí; Kon-Ho Lee; John J. Skehel; Don C. Wiley

1998-01-01

370

Biochemical Analysis of the Secreted and Virion Glycoproteins of Ebola Virus  

Microsoft Academic Search

The glycoproteins expressed by a Zaire species of Ebola virus were analyzed for cleavage, oligomerization, and other structural properties to better define their functions. The 50- to 70-kDa secreted and 150-kDa virion\\/structural glycoproteins (SGP and GP, respectively), which share the 295 N-terminal residues, are cleaved near the N terminus by signalase. A second cleavage event, occurring in GP at a

ANTHONY SANCHEZ; ZHI-YONG YANG; LING XU; GARY J. NABEL; TAMARA CREWS

1998-01-01

371

Endoproteolytic Processing of the Ebola Virus Envelope Glycoprotein: Cleavage Is Not Required for Function  

Microsoft Academic Search

Proteolytic processing is required for the activation of numerous viral glycoproteins. Here we show that the envelope glycoprotein from the Zaire strain of Ebola virus (Ebo-GP) is proteolytically processed into two subunits, GP1 and GP2, that are likely covalently associated through a disulfide linkage. Murine leukemia virions pseudotyped with Ebo-GP contain almost exclusively processed glycoprotein, indicating that this is the

ROUVEN J. WOOL-LEWIS; PAUL BATES

1999-01-01

372

The Ebola virus glycoprotein mediates entry via a non-classical dynamin-dependent macropinocytic pathway  

Microsoft Academic Search

Ebola virus (EBOV) has been reported to enter cultured cell lines via a dynamin-2-independent macropinocytic pathway or clathrin-mediated endocytosis. The route(s) of productive EBOV internalization into physiologically relevant cell types remain unexplored, and viral-host requirements for this process are incompletely understood. Here, we use electron microscopy and complementary chemical and genetic approaches to demonstrate that the viral glycoprotein, GP, induces

Nirupama Mulherkar; Matthijs Raaben; Juan Carlos de la Torre; Sean P. Whelan; Kartik Chandran

2011-01-01

373

Effect of Ebola virus proteins GP, NP and VP35 on VP40 VLP morphology  

Microsoft Academic Search

Recently we described a role for Ebola virus proteins, NP, GP, and VP35 in enhancement of VP40 VLP budding. To explore the possibility that VLP structure was altered by co-expression of EBOV proteins leading to the observed enhancement of VP40 VLP budding, we performed density gradient analysis as well as electron microscopy studies. Our data suggest that VP40 is the

Reed F Johnson; Peter Bell; Ronald N Harty

2006-01-01

374

Structure of the Ebola Virus Glycoprotein Bound to An Antibody From a Human Survivor  

Microsoft Academic Search

Ebola virus (EBOV) entry requires the surface glycoprotein (GP) to initiate attachment and fusion of viral and host membranes. Here we report the crystal structure of EBOV GP in its trimeric, pre-fusion conformation (GP1+GP2) bound to a neutralizing antibody, KZ52, derived from a human survivor of the 1995 Kikwit outbreak. Three GP1 viral attachment subunits assemble to form a chalice,

J. E. Lee; M. L. Fusco; A. J. Hessell; W. B. Oswald; D. R. Burton; E. O. Saphire

2009-01-01

375

Mannosyl glycodendritic structure inhibits DC-SIGN-mediated Ebola virus infection in cis and in trans.  

PubMed

We have designed a glycodendritic structure, BH30sucMan, that blocks the interaction between dendritic cell-specific intercellular adhesion molecule 3-grabbing nonintegrin (DC-SIGN) and Ebola virus (EBOV) envelope. BH30sucMan inhibits DC-SIGN-mediated EBOV infection at nanomolar concentrations. BH30sucMan may counteract important steps of the infective process of EBOV and, potentially, of microorganisms shown to exploit DC-SIGN for cell entry and infection. PMID:14638512

Lasala, Fátima; Arce, Eva; Otero, Joaquín R; Rojo, Javier; Delgado, Rafael

2003-12-01

376

Ebola virus uses clathrin-mediated endocytosis as an entry pathway  

Microsoft Academic Search

Ebola virus (EBOV) infects several cell types and while viral entry is known to be pH-dependent, the exact entry pathway(s) remains unknown. To gain insights into EBOV entry, the role of several inhibitors of clathrin-mediated endocytosis in blocking infection mediated by HIV pseudotyped with the EBOV envelope glycoprotein (EbGP) was examined. Wild type HIV and envelope-minus HIV pseudotyped with Vesicular

Suchita Bhattacharyya; Kelly L. Warfield; Gordon Ruthel; Sina Bavari; M. Javad Aman; Thomas J. Hope

2010-01-01

377

Functional Importance of the Coiled-Coil of the Ebola Virus Glycoprotein  

Microsoft Academic Search

Ebola virus contains a single glycoprotein (GP) that is responsible for receptor binding and membrane fusion and is proteolytically cleaved into disulfide-linked GP1 and GP2 subunits. The GP2 subunit possesses a coiled-coil motif, which plays an important role in the oligomerization and fusion activity of other viral GPs. To determine the functional significance of the coiled-coil motif of GP2, we

SHINJI WATANABE; AYATO TAKADA; TOKIKO WATANABE; HIROSHI ITO; HIROSHI KIDA; YOSHIHIRO KAWAOKA

2000-01-01

378

Phosphatidylinositol-Dependent Membrane Fusion Induced by a Putative Fusogenic Sequence of Ebola Virus  

Microsoft Academic Search

The membrane-interacting abilities of three sequences representing the putative fusogenic subdomain of the Ebola virus transmembrane protein have been investigated. In the presence of calcium, the sequence EBOGE (GAAIGLAWIPYFGPAAE) efficiently fused unilamellar vesicles composed of phosphatidylcholine, phosphati- dylethanolamine, cholesterol, and phosphatidylinositol (molar ratio, 2:1:1:0.5), a mixture that roughly resem- bles the lipid composition of the hepatocyte plasma membrane. Analysis of

M. BEGONA RUIZ-ARGUELLO; FELIX M. GONI; FRANCISCA B. PEREIRA; JOSEL. NIEVA

1998-01-01

379

Evidence against an Important Role for Infectivity-Enhancing Antibodies in Ebola Virus Infections  

Microsoft Academic Search

The neutralizing and enhancing activities of Ebola virus (EBOV)-specific antibodies were tested among four murine antibodies specific to the surface glycoprotein (GP), a recombinant human monoclonal antibody specific to GP, a polyclonal equine IgG, and serum obtained from a convalescent monkey. All but one of these antibodies neutralized EBOV infectivity of primary human monocytes\\/macrophages or Vero cells. None of the

Thomas W. Geisbert; Lisa E. Hensley; Joan B. Geisbert; Peter B. Jahrling

2002-01-01

380

Vaccine Potential of Ebola Virus VP24, VP30, VP35, and VP40 Proteins  

Microsoft Academic Search

Previous vaccine efforts with Ebola virus Zaire (EBOV-Z) emphasized the potential protective efficacies of immune responses to the surface glycoprotein and the nucleoprotein. To determine whether the VP24, VP30, VP35, and VP40 proteins are also capable of eliciting protective immune responses, these genes were expressed from alphavirus replicons and used to vaccinate BALB\\/c and C57BL\\/6 mice. Although all of the

Julie A. Wilson; Mike Bray; Russell Bakken; Mary Kate Hart

2001-01-01

381

Effects of Ebola Virus Glycoproteins on Endothelial Cell Activation and Barrier Function  

Microsoft Academic Search

Ebola virus causes severe hemorrhagic fever with high mortality rates in humans and nonhuman primates. Vascular instability and dysregulation are disease-decisive symptoms during severe infection. While the transmembrane glycoprotein GP1,2 has been shown to cause endothelial cell destruction, the role of the soluble glycoproteins in pathogenesis is largely unknown; however, they are hypothesized to be of biological relevance in terms

Victoria M. Wahl-Jensen; Tatiana A. Afanasieva; Jochen Seebach; Ute Stroher; Heinz Feldmann; Hans-Joachim Schnittler

2005-01-01

382

Managing Potential Laboratory Exposure to Ebola Virus by Using a Patient Biocontainment Care Unit1  

PubMed Central

In 2004, a scientist from the US Army Medical Research Institute of Infectious Diseases (USAMRIID) was potentially exposed to a mouse-adapted variant of the Zaire species of Ebola virus. The circumstances surrounding the case are presented, in addition to an update on historical admissions to the medical containment suite at USAMRIID. Research facilities contemplating work with pathogens requiring Biosafety Level 4 laboratory precautions should be mindful of the occupational health issues highlighted in this article. PMID:18507897

Martin, James W.; Rusnak, Janice M.; Cieslak, Theodore J.; Warfield, Kelly L.; Anderson, Edwin L.; Ranadive, Manmohan V.

2008-01-01

383

Managing potential laboratory exposure to ebola virus by using a patient biocontainment care unit.  

PubMed

In 2004, a scientist from the US Army Medical Research Institute of Infectious Diseases (USAMRIID) was potentially exposed to a mouse-adapted variant of the Zaire species of Ebola virus. The circumstances surrounding the case are presented, in addition to an update on historical admissions to the medical containment suite at USAMRIID. Research facilities contemplating work with pathogens requiring Biosafety Level 4 laboratory precautions should be mindful of the occupational health issues highlighted in this article. PMID:18507897

Kortepeter, Mark G; Martin, James W; Rusnak, Janice M; Cieslak, Theodore J; Warfield, Kelly L; Anderson, Edwin L; Ranadive, Manmohan V

2008-06-01

384

Structure of the Ebola virus glycoprotein bound to an antibody from a human survivor  

Microsoft Academic Search

Ebola virus (EBOV) entry requires the surface glycoprotein (GP) to initiate attachment and fusion of viral and host membranes. Here we report the crystal structure of EBOV GP in its trimeric, pre-fusion conformation (GP1+GP2) bound to a neutralizing antibody, KZ52, derived from a human survivor of the 1995 Kikwit outbreak. Three GP1 viral attachment subunits assemble to form a chalice,

Jeffrey E. Lee; Marnie L. Fusco; Ann J. Hessell; Wendelien B. Oswald; Dennis R. Burton; Erica Ollmann Saphire

2008-01-01

385

[Development of the immunoenzyme test-system for detection of Ebola virus antigen].  

PubMed

An enzyme immunoassay system has been developed for the detection of Ebola virus antigen. It permits a highly accurate and sensitive rapid detection of the antigen. Optimal dilutions of specific immunoglobulin (1:500, corresponding to protein concentration of 50 micrograms/ml) and conjugate were found. The resolving capacity of the new test system is 1.9 x 10(-7) g protein. PMID:8967072

Borisevich, I V; Mikha?lov, V V; Potryvaeva, N V; Malinkin, Iu N; Kirillov, A P; Krasnianski?, V P; Markov, V I; Makhla?, A A; Lebedinskaia, E V

1996-01-01

386

Ebola Virus VP24 Binds Karyopherin  1 and Blocks STAT1 Nuclear Accumulation  

Microsoft Academic Search

Ebola virus (EBOV) infection blocks cellular production of alpha\\/beta interferon (IFN-\\/) and the ability of cells to respond to IFN-\\/ or IFN-. The EBOV VP35 protein has previously been identified as an EBOV-encoded inhibitor of IFN-\\/ production. However, the mechanism by which EBOV infection inhibits responses to IFNs has not previously been defined. Here we demonstrate that the EBOV VP24

St. P. Reid; Lawrence W. Leung; Amy L. Hartman; Osvaldo Martinez; Megan L. Shaw; Caroline Carbonnelle; Viktor E. Volchkov; Stuart T. Nichol; Christopher F. Basler

2006-01-01

387

Ebola Virus VP30-Mediated Transcription Is Regulated by RNA Secondary Structure Formation  

Microsoft Academic Search

The nucleocapsid protein VP30 of Ebola virus (EBOV), a member of the Filovirus family, is known to act as a transcription activator. By using a reconstituted minigenome system, the role of VP30 during transcription was investigated. We could show that VP30-mediated transcription activation is dependent on formation of a stem-loop structure at the first gene start site. Destruction of this

Michael Weik; Jens Modrof; Hans-Dieter Klenk; Stephan Becker; Elke Muhlberger

2002-01-01

388

Implication of a retrovirus-like glycoprotein peptide in the immunopathogenesis of Ebola and Marburg viruses.  

PubMed

Ebola and Marburg viruses can cause hemorrhagic fever (HF) outbreaks with high mortality in primates. Whereas Marburg (MARV), Ebola Zaire (ZEBOV), and Ebola Sudan (SEBOV) viruses are pathogenic in humans, apes, and monkeys, Ebola Reston (REBOV) is pathogenic only in monkeys. Early immunosuppression may contribute to pathogenesis by facilitating viral replication. Lymphocyte depletion, intravascular apoptosis, and cytokine dysregulation are prominent in fatal cases. Here we functionally characterize a 17 amino acid domain in filoviral glycoproteins that resembles an immunosuppressive motif in retroviral envelope proteins. Activated human or rhesus peripheral blood mononuclear cells (PBMC) were exposed to inactivated ZEBOV or a panel of 17mer peptides representing all sequenced strains of filoviruses, then analyzed for CD4+ and CD8+ T cell activation, apoptosis, and cytokine expression. Exposure of human and rhesus PBMC to ZEBOV, SEBOV, or MARV peptides or inactivated ZEBOV resulted in decreased expression of activation markers on CD4 and CD8 cells; CD4 and CD8 cell apoptosis as early as 12 h postexposure; inhibition of CD4 and CD8 cell cycle progression; decreased interleukin (IL)-2, IFN-gamma, and IL12-p40 expression; and increased IL-10 expression. In contrast, only rhesus T cells were sensitive to REBOV peptides. These findings are consistent with the observation that REBOV is not pathogenic in humans and have implications for understanding the pathogenesis of filoviral HF. PMID:17023517

Yaddanapudi, Kavitha; Palacios, Gustavo; Towner, Jonathan S; Chen, Ivy; Sariol, Carlos A; Nichol, Stuart T; Lipkin, W Ian

2006-12-01

389

Antigen Capture Enzyme-Linked Immunosorbent Assay for Specific Detection of Reston Ebola Virus Nucleoprotein  

PubMed Central

Antigen capture enzyme-linked immunosorbent assay (ELISA) is one of the most useful methods to detect Ebola virus rapidly. We previously developed an antigen capture ELISA using a monoclonal antibody (MAb), 3-3D, which reacted not only to the nucleoprotein (NP) of Zaire Ebola virus (EBO-Z) but also to the NPs of Sudan (EBO-S) and Reston Ebola (EBO-R) viruses. In this study, we developed antigen capture ELISAs using two novel MAbs, Res2-6C8 and Res2-1D8, specific to the NP of EBO-R. Res2-6C8 and Res2-1D8 recognized epitopes consisting of 4 and 8 amino acid residues, respectively, near the C-terminal region of the EBO-R NP. The antigen capture ELISAs using these two MAbs detected the EBO-R NP in the tissues from EBO-R-infected cynomolgus macaques. The antigen capture ELISAs using Res2-6C8 and Res2-1D8 are useful for the rapid detection of the NP in EBO-R-infected cynomolgus macaques. PMID:12853385

Ikegami, Tetsuro; Niikura, Masahiro; Saijo, Masayuki; Miranda, Mary E.; Calaor, Alan B.; Hernandez, Marvin; Acosta, Luz P.; Manalo, Daria L.; Kurane, Ichiro; Yoshikawa, Yasuhiro; Morikawa, Shigeru

2003-01-01

390

Chemical modifications of antisense morpholino oligomers enhance their efficacy against Ebola virus infection.  

PubMed

Phosphorodiamidate morpholino oligomers (PMOs) are uncharged nucleic acid-like molecules designed to inactivate the expression of specific genes via the antisense-based steric hindrance of mRNA translation. PMOs have been successful at knocking out viral gene expression and replication in the case of acute viral infections in animal models and have been well tolerated in human clinical trials. We propose that antisense PMOs represent a promising class of therapeutic agents that may be useful for combating filoviral infections. We have previously shown that mice treated with a PMO whose sequence is complementary to a region spanning the start codon of VP24 mRNA were protected against lethal Ebola virus challenge. In the present study, we report on the abilities of two additional VP24-specific PMOs to reduce the cell-free translation of a VP24 reporter, to inhibit the in vitro replication of Ebola virus, and to protect mice against lethal challenge when the PMOs are delivered prior to infection. Additionally, structure-activity relationship evaluations were conducted to assess the enhancement of antiviral efficacy associated with PMO chemical modifications that included conjugation with peptides of various lengths and compositions, positioning of conjugated peptides to either the 5' or the 3' terminus, and the conferring of charge modifications by the addition of piperazine moieties. Conjugation with arginine-rich peptides greatly enhanced the antiviral efficacy of VP24-specific PMOs in infected cells and mice during lethal Ebola virus challenge. PMID:19223614

Swenson, Dana L; Warfield, Kelly L; Warren, Travis K; Lovejoy, Candace; Hassinger, Jed N; Ruthel, Gordon; Blouch, Robert E; Moulton, Hong M; Weller, Dwight D; Iversen, Patrick L; Bavari, Sina

2009-05-01

391

Identification of Ebola virus microRNAs and their putative pathological function.  

PubMed

Ebola virus (EBOV), a member of the filovirus family, is an enveloped negative-sense RNA virus that causes lethal infections in humans and primates. Recently, more than 1000 people have been killed by the Ebola virus disease in Africa, yet no specific treatment or diagnostic tests for EBOV are available. In this study, we identified two putative viral microRNA precursors (pre-miRNAs) and three putative mature microRNAs (miRNAs) derived from the EBOV genome. The production of the EBOV miRNAs was further validated in HEK293T cells transfected with a pcDNA6.2-GW/EmGFP-EBOV-pre-miRNA plasmid, indicating that EBOV miRNAs can be produced through the cellular miRNA processing machinery. We also predicted the potential target genes of these EBOV miRNAs and their possible biological functions. Overall, this study reports for the first time that EBOV may produce miRNAs, which could serve as non-invasive biomarkers for the diagnosis and prognosis of EBOV infection and as therapeutic targets for Ebola viral infection treatment. PMID:25266153

Liang, HongWei; Zhou, Zhen; Zhang, SuYang; Zen, Ke; Chen, Xi; Zhang, ChenYu

2014-10-01

392

Evidence for a decrease in transmission of ebola virus - lofa county, liberia, june 8-november 1, 2014.  

PubMed

Lofa County has one of the highest cumulative incidences of Ebola virus disease (Ebola) in Liberia. Recent situation reports from the Liberian Ministry of Health and Social Welfare (MoHSW) have indicated a decrease in new cases of Ebola in Lofa County. In October 2014, the Liberian MoHSW requested the assistance of CDC to further characterize recent trends in Ebola in Lofa County. Data collected during June 8-November 1, 2014 from three sources were analyzed: 1) aggregate data for newly reported cases, 2) case-based data for persons admitted to the dedicated Ebola treatment unit (ETU) for the county, and 3) test results for community decedents evaluated for Ebola. Trends from all three sources suggest that transmission of Ebola virus decreased as early as August 17, 2014, following rapid scale-up of response activities in Lofa County after a resurgence of Ebola in early June 2014. The comprehensive response strategy developed with participation from the local population in Lofa County might serve as a model to implement in other affected areas to accelerate control of Ebola. PMID:25412065

Sharma, Aditya; Heijenberg, Nico; Peter, Clement; Bolongei, Josephus; Reeder, Bruce; Alpha, Tamba; Sterk, Esther; Robert, Hugues; Kurth, Andreas; Cannas, Angela; Bocquin, Anne; Strecker, Thomas; Logue, Christopher; Caro, Antonino Di; Pottage, Thomas; Yue, Constanze; Stoecker, Kilian; Wölfel, Roman; Gabriel, Martin; Günther, Stephan; Damon, Inger

2014-11-21

393

Interaction between Ebola virus glycoprotein and host toll-like receptor 4 leads to induction of proinflammatory cytokines and SOCS1.  

PubMed

Ebola virus initially targets monocytes and macrophages, which can lead to the release of proinflammatory cytokines and chemokines. These inflammatory cytokines are thought to contribute to the development of circulatory shock seen in fatal Ebola virus infections. Here we report that host Toll-like receptor 4 (TLR4) is a sensor for Ebola virus glycoprotein (GP) on virus-like particles (VLPs) and that resultant TLR4 signaling pathways lead to the production of proinflammatory cytokines and suppressor of cytokine signaling 1 (SOCS1) in a human monocytic cell line and in HEK293-TLR4/MD2 cells stably expressing the TLR4/MD2 complex. Ebola virus GP was found to interact with TLR4 by immunoprecipitation/Western blot analyses, and Ebola virus GP on VLPs was able to stimulate expression of NF-kappaB in a TLR4-dependent manner. Interestingly, we found that budding of Ebola virus VLPs was more pronounced in TLR4-stimulated cells than in unstimulated control cells. In sum, these findings identify the host innate immune protein TLR4 as a sensor for Ebola virus GP which may play an important role in the immunopathogenesis of Ebola virus infection. PMID:19846529

Okumura, Atsushi; Pitha, Paula M; Yoshimura, Akihiko; Harty, Ronald N

2010-01-01

394

Importation and containment of ebola virus disease - senegal, august-september 2014.  

PubMed

On August 29, 2014, Senegal confirmed its first case of Ebola virus disease (Ebola) in a Guinean man, aged 21 years, who had traveled from Guinea to Dakar, Senegal, in mid-August to visit family. Senegalese medical and public health personnel were alerted about this patient after public health staff in Guinea contacted his family in Senegal on August 27. The patient had been admitted to a referral hospital in Senegal on August 26. He was promptly isolated, and a blood sample was sent for laboratory confirmation; Ebola was confirmed by reverse transcriptase-polymerase chain reaction at Institut Pasteur Dakar on August 29. The patient's mother and sister had been admitted to an Ebola treatment unit in Guinea on August 26, where they had named the patient as a contact and reported his recent travel to Senegal. Ebola was likely transmitted to the family from the brother of the patient, who had traveled by land from Sierra Leone to Guinea in early August seeking treatment from a traditional healer. The brother died in Guinea on August 10; family members, including the patient, participated in preparing the body for burial. PMID:25275333

Mirkovic, Kelsey; Thwing, Julie; Diack, Papa Amadou

2014-10-01

395

Single-injection vaccine protects nonhuman primates against infection with marburg virus and three species of ebola virus.  

PubMed

The filoviruses Marburg virus and Ebola virus cause severe hemorrhagic fever with high mortality in humans and nonhuman primates. Among the most promising filovirus vaccines under development is a system based on recombinant vesicular stomatitis virus (VSV) that expresses a single filovirus glycoprotein (GP) in place of the VSV glycoprotein (G). Here, we performed a proof-of-concept study in order to determine the potential of having one single-injection vaccine capable of protecting nonhuman primates against Sudan ebolavirus (SEBOV), Zaire ebolavirus (ZEBOV), Cote d'Ivoire ebolavirus (CIEBOV), and Marburgvirus (MARV). In this study, 11 cynomolgus monkeys were vaccinated with a blended vaccine consisting of equal parts of the vaccine vectors VSVDeltaG/SEBOVGP, VSVDeltaG/ZEBOVGP, and VSVDeltaG/MARVGP. Four weeks later, three of these animals were challenged with MARV, three with CIEBOV, three with ZEBOV, and two with SEBOV. Three control animals were vaccinated with VSV vectors encoding a nonfilovirus GP and challenged with SEBOV, ZEBOV, and MARV, respectively, and five unvaccinated control animals were challenged with CIEBOV. Importantly, none of the macaques vaccinated with the blended vaccine succumbed to a filovirus challenge. As expected, an experimental control animal vaccinated with VSVDeltaG/ZEBOVGP and challenged with SEBOV succumbed, as did the positive controls challenged with SEBOV, ZEBOV, and MARV, respectively. All five control animals challenged with CIEBOV became severely ill, and three of the animals succumbed on days 12, 12, and 14, respectively. The two animals that survived CIEBOV infection were protected from subsequent challenge with either SEBOV or ZEBOV, suggesting that immunity to CIEBOV may be protective against other species of Ebola virus. In conclusion, we developed an immunization scheme based on a single-injection vaccine that protects nonhuman primates against lethal challenge with representative strains of all human pathogenic filovirus species. PMID:19386702

Geisbert, Thomas W; Geisbert, Joan B; Leung, Anders; Daddario-DiCaprio, Kathleen M; Hensley, Lisa E; Grolla, Allen; Feldmann, Heinz

2009-07-01

396

Single-Injection Vaccine Protects Nonhuman Primates against Infection with Marburg Virus and Three Species of Ebola Virus?  

PubMed Central

The filoviruses Marburg virus and Ebola virus cause severe hemorrhagic fever with high mortality in humans and nonhuman primates. Among the most promising filovirus vaccines under development is a system based on recombinant vesicular stomatitis virus (VSV) that expresses a single filovirus glycoprotein (GP) in place of the VSV glycoprotein (G). Here, we performed a proof-of-concept study in order to determine the potential of having one single-injection vaccine capable of protecting nonhuman primates against Sudan ebolavirus (SEBOV), Zaire ebolavirus (ZEBOV), Cote d'Ivoire ebolavirus (CIEBOV), and Marburgvirus (MARV). In this study, 11 cynomolgus monkeys were vaccinated with a blended vaccine consisting of equal parts of the vaccine vectors VSV?G/SEBOVGP, VSV?G/ZEBOVGP, and VSV?G/MARVGP. Four weeks later, three of these animals were challenged with MARV, three with CIEBOV, three with ZEBOV, and two with SEBOV. Three control animals were vaccinated with VSV vectors encoding a nonfilovirus GP and challenged with SEBOV, ZEBOV, and MARV, respectively, and five unvaccinated control animals were challenged with CIEBOV. Importantly, none of the macaques vaccinated with the blended vaccine succumbed to a filovirus challenge. As expected, an experimental control animal vaccinated with VSV?G/ZEBOVGP and challenged with SEBOV succumbed, as did the positive controls challenged with SEBOV, ZEBOV, and MARV, respectively. All five control animals challenged with CIEBOV became severely ill, and three of the animals succumbed on days 12, 12, and 14, respectively. The two animals that survived CIEBOV infection were protected from subsequent challenge with either SEBOV or ZEBOV, suggesting that immunity to CIEBOV may be protective against other species of Ebola virus. In conclusion, we developed an immunization scheme based on a single-injection vaccine that protects nonhuman primates against lethal challenge with representative strains of all human pathogenic filovirus species. PMID:19386702

Geisbert, Thomas W.; Geisbert, Joan B.; Leung, Anders; Daddario-DiCaprio, Kathleen M.; Hensley, Lisa E.; Grolla, Allen; Feldmann, Heinz

2009-01-01

397

Epitopes required for antibody-dependent enhancement of Ebola virus infection.  

PubMed

We have shown that antibody-dependent enhancement (ADE) of infection with Zaire Ebola virus (ZEBOV) is mediated by interaction of virus-specific antibodies with Fc receptors or complement component C1q and its receptors in vitro. ADE activities of the antisera to the viral glycoprotein (GP) were virus species specific and were primarily correlated with immunoglobulin (Ig) G2a and IgM levels but not with IgG1 levels. Interestingly, compared with ZEBOV, Reston Ebola virus (REBOV) had substantially weaker potential to induce ADE antibodies. Using monoclonal antibodies, we identified ZEBOV-specific ADE epitopes. To confirm epitope specificity, we constructed a chimeric ZEBOV GP, the ADE epitopes of which were replaced with the corresponding regions of REBOV GP. We found that mouse antisera to the chimeric ZEBOV GP showed less potential to induce ADE activity than did mouse antisera to wild-type ZEBOV GP, although they retained neutralizing activity. These data suggest that GP lacking the ADE-inducing epitopes may increase the potential of GP as a vaccine antigen. PMID:17940970

Takada, Ayato; Ebihara, Hideki; Feldmann, Heinz; Geisbert, Thomas W; Kawaoka, Yoshihiro

2007-11-15

398

A novel mechanism for LSECtin binding to Ebola virus surface glycoprotein through truncated glycans.  

PubMed

LSECtin is a member of the C-type lectin family of glycan-binding receptors that is expressed on sinusoidal endothelial cells of the liver and lymph nodes. To compare the sugar and pathogen binding properties of LSECtin with those of related but more extensively characterized receptors, such as DC-SIGN, a soluble fragment of LSECtin consisting of the C-terminal carbohydrate-recognition domain has been expressed in bacteria. A biotin-tagged version of the protein was also generated and complexed with streptavidin to create tetramers. These forms of the carbohydrate-recognition domain were used to probe a glycan array and to characterize binding to oligosaccharide and glycoprotein ligands. LSECtin binds with high selectivity to glycoproteins terminating in GlcNAcbeta1-2Man. The inhibition constant for this disaccharide is 3.5 microm, making it one of the best low molecular weight ligands known for any C-type lectin. As a result of the selective binding of this disaccharide unit, the receptor recognizes glycoproteins with a truncated complex and hybrid N-linked glycans on glycoproteins. Glycan analysis of the surface glycoprotein of Ebola virus reveals the presence of such truncated glycans, explaining the ability of LSECtin to facilitate infection by Ebola virus. High mannose glycans are also present on the viral glycoprotein, which explains why DC-SIGN also binds to this virus. Thus, multiple receptors interact with surface glycoproteins of enveloped viruses that bear different types of relatively poorly processed glycans. PMID:17984090

Powlesland, Alex S; Fisch, Tanja; Taylor, Maureen E; Smith, David F; Tissot, Bérangère; Dell, Anne; Pöhlmann, Stefan; Drickamer, Kurt

2008-01-01

399

Rapid detection and quantification of RNA of Ebola and Marburg viruses, Lassa virus, Crimean-Congo hemorrhagic fever virus, Rift Valley fever virus, dengue virus, and yellow fever virus by real-time reverse transcription-PCR.  

PubMed

Viral hemorrhagic fevers (VHFs) are acute infections with high case fatality rates. Important VHF agents are Ebola and Marburg viruses (MBGV/EBOV), Lassa virus (LASV), Crimean-Congo hemorrhagic fever virus (CCHFV), Rift Valley fever virus (RVFV), dengue virus (DENV), and yellow fever virus (YFV). VHFs are clinically difficult to diagnose and to distinguish; a rapid and reliable laboratory diagnosis is required in suspected cases. We have established six one-step, real-time reverse transcription-PCR assays for these pathogens based on the Superscript reverse transcriptase-Platinum Taq polymerase enzyme mixture. Novel primers and/or 5'-nuclease detection probes were designed for RVFV, DENV, YFV, and CCHFV by using the latest DNA database entries. PCR products were detected in real time on a LightCycler instrument by using 5'-nuclease technology (RVFV, DENV, and YFV) or SybrGreen dye intercalation (MBGV/EBOV, LASV, and CCHFV). The inhibitory effect of SybrGreen on reverse transcription was overcome by initial immobilization of the dye in the reaction capillaries. Universal cycling conditions for SybrGreen and 5'-nuclease probe detection were established. Thus, up to three assays could be performed in parallel, facilitating rapid testing for several pathogens. All assays were thoroughly optimized and validated in terms of analytical sensitivity by using in vitro-transcribed RNA. The >or=95% detection limits as determined by probit regression analysis ranged from 1,545 to 2,835 viral genome equivalents/ml of serum (8.6 to 16 RNA copies per assay). The suitability of the assays was exemplified by detection and quantification of viral RNA in serum samples of VHF patients. PMID:12089242

Drosten, Christian; Göttig, Stephan; Schilling, Stefan; Asper, Marcel; Panning, Marcus; Schmitz, Herbert; Günther, Stephan

2002-07-01

400

Transmission of Ebola virus from pigs to non-human primates  

PubMed Central

Ebola viruses (EBOV) cause often fatal hemorrhagic fever in several species of simian primates including human. While fruit bats are considered natural reservoir, involvement of other species in EBOV transmission is unclear. In 2009, Reston-EBOV was the first EBOV detected in swine with indicated transmission to humans. In-contact transmission of Zaire-EBOV (ZEBOV) between pigs was demonstrated experimentally. Here we show ZEBOV transmission from pigs to cynomolgus macaques without direct contact. Interestingly, transmission between macaques in similar housing conditions was never observed. Piglets inoculated oro-nasally with ZEBOV were transferred to the room housing macaques in an open inaccessible cage system. All macaques became infected. Infectious virus was detected in oro-nasal swabs of piglets, and in blood, swabs, and tissues of macaques. This is the first report of experimental interspecies virus transmission, with the macaques also used as a human surrogate. Our finding may influence prevention and control measures during EBOV outbreaks. PMID:23155478

Weingartl, Hana M.; Embury-Hyatt, Carissa; Nfon, Charles; Leung, Anders; Smith, Greg; Kobinger, Gary

2012-01-01

401

Transmission of Ebola virus from pigs to non-human primates.  

PubMed

Ebola viruses (EBOV) cause often fatal hemorrhagic fever in several species of simian primates including human. While fruit bats are considered natural reservoir, involvement of other species in EBOV transmission is unclear. In 2009, Reston-EBOV was the first EBOV detected in swine with indicated transmission to humans. In-contact transmission of Zaire-EBOV (ZEBOV) between pigs was demonstrated experimentally. Here we show ZEBOV transmission from pigs to cynomolgus macaques without direct contact. Interestingly, transmission between macaques in similar housing conditions was never observed. Piglets inoculated oro-nasally with ZEBOV were transferred to the room housing macaques in an open inaccessible cage system. All macaques became infected. Infectious virus was detected in oro-nasal swabs of piglets, and in blood, swabs, and tissues of macaques. This is the first report of experimental interspecies virus transmission, with the macaques also used as a human surrogate. Our finding may influence prevention and control measures during EBOV outbreaks. PMID:23155478

Weingartl, Hana M; Embury-Hyatt, Carissa; Nfon, Charles; Leung, Anders; Smith, Greg; Kobinger, Gary

2012-01-01

402

PERSPECTIVES E Evaluation in Nonhuman Primates of Vaccines against Ebola Virus  

E-print Network

Ebola virus (EBOV) causes acute hemorrhagic fever that is fatal in up to 90 % of cases in both humans and nonhuman primates. No vaccines or treatments are available for human use. We evaluated the effects in nonhuman primates of vaccine strategies that had protected mice or guinea pigs from lethal EBOV infection. The following immunogens were used: RNA replicon particles derived from an attenuated strain of Venezuelan equine encephalitis virus (VEEV) expressing EBOV glycoprotein and nucleoprotein; recombinant Vaccinia virus expressing EBOV glycoprotein; liposomes containing lipid A and inactivated EBOV; and a concentrated, inactivated whole-virion preparation. None of these strategies successfully protected nonhuman primates from robust challenge with EBOV. The disease observed in primates differed from that in rodents, suggesting that rodent models of EBOV may not predict the efficacy of candidate vaccines in primates and that protection of primates may require different mechanisms.

Thomas W. Geisbert; Peter Pushko; Kevin Anderson; Jonathan Smith; Kelly J. Davis; Peter B. Jahrling

403

Rapid identification of Ebola virus and related filoviruses in fluid specimens using indirect immunoelectron microscopy.  

PubMed

Recent filoviral outbreaks in animal primates have raised public awareness of the potential for filoviruses to become a public health concern; methods that efficiently identify these viruses are therefore of high priority. An indirect immunoelectron microscopy method, which uses homologous guinea pig polyclonal antiserum, successfully identified Ebola-related (Reston) virus particles in serum and tissue culture fluid specimens with infectivity titres of 300 plaque forming units (pfu) per ml or more. The sensitivity of this procedure is sufficient to show virus in most acute phase sera, and is equal to that of the antigen capture enzyme linked immunosorbent assay (ELISA). The immunoelectron microscopy fluid technique can differentiate among antigenically distinct filoviruses in less than three hours. It should be valuable in the rapid diagnosis of potential filoviral infections. PMID:2066435

Geisbert, T W; Rhoderick, J B; Jahrling, P B

1991-06-01

404

Molecular characterization of an isolate from the 1989\\/90 epizootic of Ebola virus Reston among macaques imported into the United States  

Microsoft Academic Search

We have determined the entire genomic sequence of the Pennsylvania strain, which was isolated along with the Virginia strain during the emergence of Ebola virus Reston in 1989\\/90 in the United States. Thus, either the Pennsylvania or Virginia strain, neither of which had been previously molecularly characterized, can be considered as the prototype for Ebola virus Reston. Comparative analysis showed

Allison Groseth; Ute Ströher; Steven Theriault; Heinz Feldmann

2002-01-01

405

Treatment of lethal Ebola virus infection in mice with a single dose of an S-adenosyl- l-homocysteine hydrolase inhibitor  

Microsoft Academic Search

Ebola Zaire virus causes lethal hemorrhagic fever in humans, for which there is no effective treatment. A variety of adenosine analogues inhibit the replication of Ebola virus in vitro, probably by blocking the cellular enzyme, S-adenosyl-l-homocysteine hydrolase, thereby indirectly limiting methylation of the 5? cap of viral messenger RNA. We previously observed that adult, immunocompetent mice treated thrice daily for

Mike Bray; John Driscoll; John W. Huggins

2000-01-01

406

Ebola Hemorrhagic Fever: Treatment  

MedlinePLUS

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407

Ebola Hemorrhagic Fever: Prevention  

MedlinePLUS

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408

Ebola Hemorrhagic Fever: Transmission  

MedlinePLUS

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409

Ebola Hemorrhagic Fever: Diagnosis  

MedlinePLUS

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410

Identification of novel cellular targets for therapeutic intervention against Ebola virus infection by siRNA screening.  

PubMed

While much progress has been made in developing drugs against a few prominent viruses such as HIV, few examples exist for emerging infectious agents. In some cases broad spectrum anti-viral drugs, such as ribavirin, are effective, but for some groups of viruses, these show little efficacy in animal models. Traditional methods focus on screening small molecule libraries to identify drugs that target virus factors, with the intention that side-effects to the host can be minimized. However, this greatly limits potential drug targets and virus genes can rapidly mutate to avoid drug action. Recent advances in siRNA gene targeting technologies have provided a powerful tool to specifically target and suppress the expression of cell genes. Since viruses are completely dependent upon host cell proteins for propagation, siRNA screening promises to reveal novel cell proteins and signaling pathways that may be viable targets for drug therapy regimens. Here we used an siRNA screening approach to identify gene products that play critical roles in Ebola virus infection. By gene cluster analysis, proteins in phosphatidylinositol-3-kinase and calcium/calmodulin kinase related networks were identified as important for Zaire Ebola virus infection and prioritized for further evaluation. Key roles of each were confirmed by testing available drugs specific for members of each pathway. Interestingly, both sets of proteins are also important in cancer and subject to intense investigation. Thus development of new drugs against these cancer targets may also prove useful in combating Ebola virus. PMID:20930947

Kolokoltsov, Andrey A; Saeed, Mohammad F; Freiberg, Alexander N; Holbrook, Michael R; Davey, Robert A

2009-06-01

411

Identification of novel cellular targets for therapeutic intervention against Ebola virus infection by siRNA screening  

PubMed Central

While much progress has been made in developing drugs against a few prominent viruses such as HIV, few examples exist for emerging infectious agents. In some cases broad spectrum anti-viral drugs, such as ribavirin, are effective, but for some groups of viruses, these show little efficacy in animal models. Traditional methods focus on screening small molecule libraries to identify drugs that target virus factors, with the intention that side-effects to the host can be minimized. However, this greatly limits potential drug targets and virus genes can rapidly mutate to avoid drug action. Recent advances in siRNA gene targeting technologies have provided a powerful tool to specifically target and suppress the expression of cell genes. Since viruses are completely dependent upon host cell proteins for propagation, siRNA screening promises to reveal novel cell proteins and signaling pathways that may be viable targets for drug therapy regimens. Here we used an siRNA screening approach to identify gene products that play critical roles in Ebola virus infection. By gene cluster analysis, proteins in phosphatidylinositol-3-kinase and calcium/calmodulin kinase related networks were identified as important for Zaire Ebola virus infection and prioritized for further evaluation. Key roles of each were confirmed by testing available drugs specific for members of each pathway. Interestingly, both sets of proteins are also important in cancer and subject to intense investigation. Thus development of new drugs against these cancer targets may also prove useful in combating Ebola virus. PMID:20930947

Kolokoltsov, Andrey A.; Saeed, Mohammad F.; Freiberg, Alexander N.; Holbrook, Michael R.; Davey, Robert A.

2010-01-01

412

Response to importation of a case of ebola virus disease - ohio, october 2014.  

PubMed

On September 30, 2014, the Texas Department of State Health Services reported a case of Ebola virus disease (Ebola) diagnosed in Dallas, Texas, and confirmed by CDC, the first case of Ebola diagnosed in the United States. The patient (patient 1) had traveled from Liberia, a country which, along with Sierra Leone and Guinea, is currently experiencing the largest recorded Ebola outbreak. A nurse (patient 2) who provided hospital bedside care to patient 1 in Texas visited an emergency department (ED) with fever and was diagnosed with laboratory-confirmed Ebola on October 11, and a second nurse (patient 3) who also provided hospital bedside care visited an ED with fever and rash on October 14 and was diagnosed with laboratory-confirmed Ebola on October 15. Patient 3 visited Ohio during October 10-13, traveling by commercial airline between Dallas, Texas, and Cleveland, Ohio. Based on the medical history and clinical and laboratory findings on October 14, the date of illness onset was uncertain; therefore, CDC, in collaboration with state and local partners, included the period October 10-13 as being part of the potentially infectious period, out of an abundance of caution to ensure all potential contacts were monitored. On October 15, the Ohio Department of Health requested CDC assistance to identify and monitor contacts of patient 3, assess the risk for disease transmission, provide infection control recommendations, and assess and guide regional health care system preparedness. The description of this contact investigation and hospital assessment is provided to help other states in planning for similar events. PMID:25412070

McCarty, Carolyn L; Basler, Colin; Karwowski, Mateusz; Erme, Marguerite; Nixon, Gene; Kippes, Chris; Allan, Terry; Parrilla, Toinette; DiOrio, Mary; Fijter, Sietske de; Stone, Nimalie D; Yost, David A; Lippold, Susan A; Regan, Joanna J; Honein, Margaret A; Knust, Barbara; Braden, Christopher

2014-11-21

413

Prediction and identification of mouse cytotoxic T lymphocyte epitopes in Ebola virus glycoproteins  

PubMed Central

Background Ebola viruses (EBOVs) cause severe hemorrhagic fever with a high mortality rate. At present, there are no licensed vaccines or efficient therapies to combat EBOV infection. Previous studies have shown that both humoral and cellular immune responses are crucial for controlling Ebola infection. CD8+ T cells play an important role in mediating vaccine-induced protective immunity. The objective of this study was to identify H-2d-specific T cell epitopes in EBOV glycoproteins (GPs). Results Computer-assisted algorithms were used to predict H-2d-specific T cell epitopes in two species of EBOV (Sudan and Zaire) GP. The predicted peptides were synthesized and identified in BALB/c mice immunized with replication-deficient adenovirus vectors expressing the EBOV GP. Enzyme-linked immunospot assays and intracellular cytokine staining showed that the peptides RPHTPQFLF (Sudan EBOV), GPCAGDFAF and LYDRLASTV (Zaire EBOV) could stimulate splenoctyes in immunized mice to produce large amounts of interferon-gamma. Conclusion Three peptides within the GPs of two EBOV strains were identified as T cell epitopes. The identification of these epitopes should facilitate the evaluation of vaccines based on the Ebola virus glycoprotein in a BALB/c mouse model. PMID:22695180

2012-01-01

414

Enhanced Protection against Ebola Virus Mediated by an Improved Adenovirus-Based Vaccine  

PubMed Central

Background The Ebola virus is transmitted by direct contact with bodily fluids of infected individuals, eliciting death rates as high as 90% among infected humans. Currently, replication defective adenovirus-based Ebola vaccine is being studied in a phase I clinical trial. Another Ebola vaccine, based on an attenuated vesicular stomatitis virus has shown efficacy in post-exposure treatment of nonhuman primates to Ebola infection. In this report, we modified the common recombinant adenovirus serotype 5-based Ebola vaccine expressing the wild-type ZEBOV glycoprotein sequence from a CMV promoter (Ad-CMVZGP). The immune response elicited by this improved expression cassette vector (Ad-CAGoptZGP) and its ability to afford protection against lethal ZEBOV challenge in mice was compared to the standard Ad-CMVZGP vector. Methodology/Principal Findings Ad-CMVZGP was previously shown to protect mice, guinea pigs and nonhuman primates from an otherwise lethal challenge of Zaire ebolavirus. The antigenic expression cassette of this vector was improved through codon optimization, inclusion of a consensus Kozak sequence and reconfiguration of a CAG promoter (Ad-CAGoptZGP). Expression of GP from Ad-CAGoptZGP was substantially higher than from Ad-CMVZGP. Ad-CAGoptZGP significantly improved T and B cell responses at doses 10 to 100-fold lower than that needed with Ad-CMVZGP. Additionally, Ad-CAGoptZGP afforded full protections in mice against lethal challenge at a dose 100 times lower than the dose required for Ad-CMVZGP. Finally, Ad-CAGoptZGP induced full protection to mice when given 30 minutes post-challenge. Conclusions/Significance We describe an improved adenovirus-based Ebola vaccine capable of affording post-exposure protection against lethal challenge in mice. The molecular modifications of the new improved vaccine also translated in the induction of significantly enhanced immune responses and complete protection at a dose 100 times lower than with the previous generation adenovirus-based Ebola vaccine. Understanding and improving the molecular components of adenovirus-based vaccines can produce potent, optimized product, useful for vaccination and post-exposure therapy. PMID:19390586

Tran, Kaylie N.; Croyle, Maria A.; Strong, James E.; Feldmann, Heinz; Kobinger, Gary P.

2009-01-01

415

Structural and Functional Characterization of Reston Ebola Virus VP35 Interferon Inhibitory Domain  

SciTech Connect

Ebolaviruses are causative agents of lethal hemorrhagic fever in humans and nonhuman primates. Among the filoviruses characterized thus far, Reston Ebola virus (REBOV) is the only Ebola virus that is nonpathogenic to humans despite the fact that REBOV can cause lethal disease in nonhuman primates. Previous studies also suggest that REBOV is less effective at inhibiting host innate immune responses than Zaire Ebola virus (ZEBOV) or Marburg virus. Virally encoded VP35 protein is critical for immune suppression, but an understanding of the relative contributions of VP35 proteins from REBOV and other filoviruses is currently lacking. In order to address this question, we characterized the REBOV VP35 interferon inhibitory domain (IID) using structural, biochemical, and virological studies. These studies reveal differences in double-stranded RNA binding and interferon inhibition between the two species. These observed differences are likely due to increased stability and loss of flexibility in REBOV VP35 IID, as demonstrated by thermal shift stability assays. Consistent with this finding, the 1.71-{angstrom} crystal structure of REBOV VP35 IID reveals that it is highly similar to that of ZEBOV VP35 IID, with an overall backbone r.m.s.d. of 0.64 {angstrom}, but contains an additional helical element at the linker between the two subdomains of VP35 IID. Mutations near the linker, including swapping sequences between REBOV and ZEBOV, reveal that the linker sequence has limited tolerance for variability. Together with the previously solved ligand-free and double-stranded-RNA-bound forms of ZEBOV VP35 IID structures, our current studies on REBOV VP35 IID reinforce the importance of VP35 in immune suppression. Functional differences observed between REBOV and ZEBOV VP35 proteins may contribute to observed differences in pathogenicity, but these are unlikely to be the major determinant. However, the high level of similarity in structure and the low tolerance for sequence variability, coupled with the multiple critical roles played by Ebola virus VP35 proteins, highlight the viability of VP35 as a potential target for therapeutic development.

Leung, Daisy W.; Shabman, Reed S.; Farahbakhsh, Mina; Prins, Kathleen C.; Borek, Dominika M.; Wang, Tianjiao; Mühlberger, Elke; Basler, Christopher F.; Amarasinghe, Gaya K. (Sinai); (BU-M); (Iowa State); (UTSMC)

2010-09-21

416

Measuring the Strength of Interaction between the Ebola Fusion Peptide and Lipid Rafts: Implications for Membrane Fusion and Virus Infection  

Microsoft Academic Search

The Ebola fusion peptide (EBO16) is a hydrophobic domain that belongs to the GP2 membrane fusion protein of the Ebola virus. It adopts a helical structure in the presence of mimetic membranes that is stabilized by the presence of an aromatic-aromatic interaction established by Trp8 and Phe12. In spite of its infectious cycle becoming better understood recently, several steps still

Mônica S. Freitas; Cristian Follmer; Lilian T. Costa; Cecília Vilani; M. Lucia Bianconi; Carlos Alberto Achete; Jerson L. Silva; Vladimir N. Uversky

2011-01-01

417

Phosphorylation of Ebola Virus VP30 Influences the Composition of the Viral Nucleocapsid Complex  

PubMed Central

Ebola virus is a non-segmented negative-sense RNA virus causing severe hemorrhagic fever with high fatality rates in humans and nonhuman primates. For transcription of the viral genome four viral proteins are essential: the nucleoprotein NP, the polymerase L, the polymerase cofactor VP35, and VP30. VP30 represents an essential Ebola virus-specific transcription factor whose activity is regulated via its phosphorylation state. In contrast to viral transcription, VP30 is not required for viral replication. Using a minigenome assay, we show that phosphorylation of VP30 inhibits viral transcription while viral replication is increased. Concurrently, phosphorylation of VP30 reciprocally regulates a newly described interaction of VP30 with VP35, and strengthens the interaction with NP. Our results indicate a critical role of VP30 phosphorylation for viral transcription and replication, suggesting a mechanism by which VP30 phosphorylation modulates the composition of the viral polymerase complex presumably forming a transcriptase in the presence of non-phosphorylated VP30 or a replicase in the presence of phosphorylated VP30. PMID:23493393

Biedenkopf, Nadine; Hartlieb, Bettina; Hoenen, Thomas; Becker, Stephan

2013-01-01

418

Ebola Hemorrhagic Fever Associated with Novel Virus Strain, Uganda, 2007-2008  

PubMed Central

During August 2007–February 2008, the novel Bundibugyo ebolavirus species was identified during an outbreak of Ebola viral hemorrhagic fever in Bundibugyo district, western Uganda. To characterize the outbreak as a requisite for determining response, we instituted a case-series investigation. We identified 192 suspected cases, of which 42 (22%) were laboratory positive for the novel species; 74 (38%) were probable, and 77 (40%) were negative. Laboratory confirmation lagged behind outbreak verification by 3 months. Bundibugyo ebolavirus was less fatal (case-fatality rate 34%) than Ebola viruses that had caused previous outbreaks in the region, and most transmission was associated with handling of dead persons without appropriate protection (adjusted odds ratio 3.83, 95% confidence interval 1.78–8.23). Our study highlights the need for maintaining a high index of suspicion for viral hemorrhagic fevers among healthcare workers, building local capacity for laboratory confirmation of viral hemorrhagic fevers, and institutionalizing standard precautions. PMID:20587179

Lukwago, Luswa; Malimbo, Mugagga; Nguku, Patrick; Yoti, Zabulon; Musenero, Monica; Amone, Jackson; Mbabazi, William; Nanyunja, Miriam; Zaramba, Sam; Opio, Alex; Lutwama, Julius J.; Talisuna, Ambrose O.; Okware, Sam I.

2010-01-01

419

[Development of SYBR Green I real-time RT-PCR for the detection of Ebola virus].  

PubMed

In order to establish a rapid and accurate method for the detection of Ebola virus (EBOV), the primers used in SYBR Green I real-time RT-PCR were designed based on the EBOV NP gene sequences published in GenBank. The SYBR Green I real-time RT-PCR was established and optimized for the detection of EBOV. The EBOV RNA that was transcribed in vitro was used as a template. The sensitivity of this method was found to reach 1.0 x 10(2) copies/microL and the detection range was 10(2) - 10(10). No cross reaction with RNA samples from Marburg virus, Dengue virus, Xinjiang hemorrhagic fever virus, Japanese encephalitis virus, Influenza virus (H1N1 and H3N2) and Porcine reproductive and respiratory syndrome virus E genomic RNA was found. The method would be useful for the detection and monitoring of EBOV in China. PMID:23233935

Liu, Yang; Shi, Zi-Xue; Ma, Yu-Kun; Wang, Hao-Ting; Wang, Zong-Yao; Shao, Dong-Hua; Wei, Jian-Chao; Wang, Shao-Hui; Li, Bei-Bei; Wang, Shui-Ming; Liu, Xue-Hui; Ma, Zhi-Yong

2012-09-01

420

A replication defective recombinant Ad5 vaccine expressing Ebola virus GP is safe and immunogenic in healthy adults.  

PubMed

Ebola virus causes irregular outbreaks of severe hemorrhagic fever in equatorial Africa. Case mortality remains high; there is no effective treatment and outbreaks are sporadic and unpredictable. Studies of Ebola virus vaccine platforms in non-human primates have established that the induction of protective immunity is possible and safety and human immunogenicity has been demonstrated in a previous Phase I clinical trial of a 1st generation Ebola DNA vaccine. We now report the safety and immunogenicity of a recombinant adenovirus serotype 5 (rAd5) vaccine encoding the envelope glycoprotein (GP) from the Zaire and Sudan Ebola virus species, in a randomized, placebo-controlled, double-blinded, dose escalation, Phase I human study. Thirty-one healthy adults received vaccine at 2×10(9) (n=12), or 2×10(10) (n=11) viral particles or placebo (n=8) as an intramuscular injection. Antibody responses were assessed by ELISA and neutralizing assays; and T cell responses were assessed by ELISpot and intracellular cytokine staining assays. This recombinant Ebola virus vaccine was safe and subjects developed antigen specific humoral and cellular immune responses. PMID:21034824

Ledgerwood, J E; Costner, P; Desai, N; Holman, L; Enama, M E; Yamshchikov, G; Mulangu, S; Hu, Z; Andrews, C A; Sheets, R A; Koup, R A; Roederer, M; Bailer, R; Mascola, J R; Pau, M G; Sullivan, N J; Goudsmit, J; Nabel, G J; Graham, B S

2010-12-16

421

A novel Ebola virus expressing luciferase allows for rapid and quantitative testing of antivirals  

PubMed Central

Ebola virus (EBOV) causes a severe hemorrhagic fever with case fatality rates of up to 90%, for which no antiviral therapies are available. Antiviral screening is hampered by the fact that development of cytopathic effect, the easiest means to detect infection with wild-type EBOV, is relatively slow. To overcome this problem we generated a recombinant EBOV carrying a luciferase reporter. Using this virus we show that EBOV entry is rapid, with viral protein expression detectable within 2 hours after infection. Further, luminescence-based assays were developed to allow highly sensitive titer determination within 48 hours. As a proof-of-concept for its utility in antiviral screening we used this virus to assess neutralizing antibodies and siRNAs, with significantly faster screening times than currently available wild-type or recombinant viruses. The availability of this recombinant virus will allow for more rapid and quantitative evaluation of antivirals against EBOV, as well as the study of details of the EBOV life cycle. PMID:23751367

Hoenen, Thomas; Groseth, Allison; Callison, Julie; Takada, Ayato; Feldmann, Heinz

2013-01-01

422

Functional Genomics Reveals the Induction of Inflammatory Response and Metalloproteinase Gene Expression during Lethal Ebola Virus Infection?†  

PubMed Central

Ebola virus is the etiologic agent of a lethal hemorrhagic fever in humans and nonhuman primates with mortality rates of up to 90%. Previous studies with Zaire Ebola virus (ZEBOV), mouse-adapted virus (MA-ZEBOV), and mutant viruses (ZEBOV-NPma, ZEBOV-VP24ma, and ZEBOV-NP/VP24ma) allowed us to identify the mutations in viral protein 24 (VP24) and nucleoprotein (NP) responsible for acquisition of high virulence in mice. To elucidate specific molecular signatures associated with lethality, we compared global gene expression profiles in spleen samples from mice infected with these viruses and performed an extensive functional analysis. Our analysis showed that the lethal viruses (MA-ZEBOV and ZEBOV-NP/VP24ma) elicited a strong expression of genes 72 h after infection. In addition, we found that although the host transcriptional response to ZEBOV-VP24ma was nearly the same as that to ZEBOV-NP/VP24ma, the contribution of a mutation in the NP gene was required for a lethal phenotype. Further analysis indicated that one of the most relevant biological functions differentially regulated by the lethal viruses was the inflammatory response, as was the induction of specific metalloproteinases, which were present in our newly identify functional network that was associated with Ebola virus lethality. Our results suggest that this dysregulated proinflammatory response increased the severity of disease. Consequently, the newly discovered molecular signature could be used as the starting point for the development of new drugs and therapeutics. To our knowledge, this is the first study that clearly defines unique molecular signatures associated with Ebola virus lethality. PMID:21734050

Cilloniz, Cristian; Ebihara, Hideki; Ni, Chester; Neumann, Gabriele; Korth, Marcus J.; Kelly, Sara M.; Kawaoka, Yoshihiro; Feldmann, Heinz; Katze, Michael G.

2011-01-01

423

Vesicular stomatitis virus-based vaccines protect nonhuman primates against aerosol challenge with Ebola and Marburg viruses.  

PubMed

Considerable progress has been made over the last decade in developing candidate preventive vaccines that can protect nonhuman primates against Ebola and Marburg viruses. A vaccine based on recombinant vesicular stomatitis virus (VSV) seems to be particularly robust as it can also confer protection when administered as a postexposure treatment. While filoviruses are not thought to be transmitted by aerosol in nature the inhalation route is among the most likely portals of entry in the setting of a bioterrorist event. At present, all candidate filoviral vaccines have been evaluated against parenteral challenges but none have been tested against an aerosol exposure. Here, we evaluated our recombinant VSV-based Zaire ebolavirus (ZEBOV) and Marburg virus (MARV) vaccines against aerosol challenge in cynomolgus macaques. All monkeys vaccinated with a VSV vector expressing the glycoprotein of ZEBOV were completely protected against an aerosol exposure of ZEBOV. Likewise, all monkeys vaccinated with a VSV vector expressing the glycoprotein of MARV were completely protected against an aerosol exposure of MARV. All control animals challenged by the aerosol route with either ZEBOV or MARV succumbed. Interestingly, disease in control animals appeared to progress slower than previously seen in macaques exposed to comparable doses by intramuscular injection. PMID:18930776

Geisbert, Thomas W; Daddario-Dicaprio, Kathleen M; Geisbert, Joan B; Reed, Douglas S; Feldmann, Friederike; Grolla, Allen; Ströher, Ute; Fritz, Elizabeth A; Hensley, Lisa E; Jones, Steven M; Feldmann, Heinz

2008-12-01

424

Characterization of host immune responses in Ebola virus infections.  

PubMed

Ebola causes highly lethal hemorrhagic fever in humans with no licensed countermeasures. Its virulence can be attributed to several immunoevasion mechanisms: an early inhibition of innate immunity started by the downregulation of type I interferon, epitope masking and subversion of the adaptive humoural immunity by secreting a truncated form of the viral glycoprotein. Deficiencies in specific and non-specific antiviral responses result in unrestricted viral replication and dissemination in the host, causing death typically within 10 days after the appearance of symptoms. This review summarizes the host immune response to Ebola infection, and highlights the short- and long-term immune responses crucial for protection, which holds implications for the design of future vaccines and therapeutics. PMID:24742338

Wong, Gary; Kobinger, Gary P; Qiu, Xiangguo

2014-06-01

425

Monocyte-Derived Human Macrophages and Peripheral Blood Mononuclear Cells Infected with Ebola Virus Secrete MIP1? and TNF-? and Inhibit Poly-IC-Induced IFN-? in Vitro  

Microsoft Academic Search

Ebola virus infection of humans is associated with high levels of circulating inflammatory chemokines and cytokines. We demonstrate that direct infection of human PBMC results in the induction of MCP-1, MIP-1?, RANTES, and TNF-? as early as 24 h p.i. in response to live virus. Monocyte-derived macrophages infected with live Ebola-virus secreted MIP-1? and TNF-? specifically while RANTES and MCP-1

Manisha Gupta; Siddhartha Mahanty; Rafi Ahmed; Pierre E. Rollin

2001-01-01

426

604. Comparative Analysis of Different Methods for Quantitative Evaluation of Neutralizing Antibody to Ebola Virus in a Biosafety Level 2 or 4 Environment  

Microsoft Academic Search

Ebola hemorrhagic fever virus can be modeled in different animal species such as mice, Guinea pigs and nonhuman primates. Several vaccine strategies were evaluated using DNA-, protein-based and\\/or viral vectors and found to protect mice against challenge with a lethal dose of mouse-adapted Ebola virus. However, only a few strategies involving DNA, Adenovirus or Vesicular Stomatitis virus (VSV), alone or

Hideki Ebihara; Xiangguo Qiu; Steven Theriault; Matthew Klassen; Ute Stroeher; Jim Strong; Steven Jones; James M. Wilson; Heinz Feldmann; Gary Kobinger

2006-01-01

427

A nonreplicating subunit vaccine protects mice against lethal Ebola virus challenge  

PubMed Central

Ebola hemorrhagic fever is an acute and often deadly disease caused by Ebola virus (EBOV). The possible intentional use of this virus against human populations has led to design of vaccines that could be incorporated into a national stockpile for biological threat reduction. We have evaluated the immunogenicity and efficacy of an EBOV vaccine candidate in which the viral surface glycoprotein is biomanufactured as a fusion to a monoclonal antibody that recognizes an epitope in glycoprotein, resulting in the production of Ebola immune complexes (EICs). Although antigen–antibody immune complexes are known to be efficiently processed and presented to immune effector cells, we found that codelivery of the EIC with Toll-like receptor agonists elicited a more robust antibody response in mice than did EIC alone. Among the compounds tested, polyinosinic:polycytidylic acid (PIC, a Toll-like receptor 3 agonist) was highly effective as an adjuvant agent. After vaccinating mice with EIC plus PIC, 80% of the animals were protected against a lethal challenge with live EBOV (30,000 LD50 of mouse adapted virus). Surviving animals showed a mixed Th1/Th2 response to the antigen, suggesting this may be important for protection. Survival after vaccination with EIC plus PIC was statistically equivalent to that achieved with an alternative viral vector vaccine candidate reported in the literature. Because nonreplicating subunit vaccines offer the possibility of formulation for cost-effective, long-term storage in biothreat reduction repositories, EIC is an attractive option for public health defense measures. PMID:22143779

Phoolcharoen, Waranyoo; Dye, John M.; Kilbourne, Jacquelyn; Piensook, Khanrat; Pratt, William D.; Arntzen, Charles J.; Chen, Qiang; Mason, Hugh S.; Herbst-Kralovetz, Melissa M.

2011-01-01

428

Hanta virus (image)  

MedlinePLUS

Hanta virus is a distant cousin of Ebola virus, but is found worldwide. The virus is spread by human contact with rodent waste. Dangerous respiratory illness develops. Effective treatment is not yet available and over 50% of cases end ...

429

The Ebola Virus Glycoprotein Contributes to but Is Not Sufficient for Virulence In Vivo  

PubMed Central

Among the Ebola viruses most species cause severe hemorrhagic fever in humans; however, Reston ebolavirus (REBOV) has not been associated with human disease despite numerous documented infections. While the molecular basis for this difference remains unclear, in vitro evidence has suggested a role for the glycoprotein (GP) as a major filovirus pathogenicity factor, but direct evidence for such a role in the context of virus infection has been notably lacking. In order to assess the role of GP in EBOV virulence, we have developed a novel reverse genetics system for REBOV, which we report here. Together with a previously published full-length clone for Zaire ebolavirus (ZEBOV), this provides a unique possibility to directly investigate the role of an entire filovirus protein in pathogenesis. To this end we have generated recombinant ZEBOV (rZEBOV) and REBOV (rREBOV), as well as chimeric viruses in which the glycoproteins from these two virus species have been exchanged (rZEBOV-RGP and rREBOV-ZGP). All of these viruses could be rescued and the chimeras replicated with kinetics similar to their parent virus in tissue culture, indicating that the exchange of GP in these chimeric viruses is well tolerated. However, in a mouse model of infection rZEBOV-RGP demonstrated markedly decreased lethality and prolonged time to death when compared to rZEBOV, confirming that GP does indeed contribute to the full expression of virulence by ZEBOV. In contrast, rREBOV-ZGP did not show any signs of virulence, and was in fact slightly attenuated compared to rREBOV, demonstrating that GP alone is not sufficient to confer a lethal phenotype or exacerbate disease in this model. Thus, while these findings provide direct evidence that GP contributes to filovirus virulence in vivo, they also clearly indicate that other factors are needed for the acquisition of full virulence. PMID:22876185

Groseth, Allison; Marzi, Andrea; Hoenen, Thomas; Herwig, Astrid; Gardner, Don; Becker, Stephan; Ebihara, Hideki; Feldmann, Heinz

2012-01-01

430

The Ebola virus glycoprotein contributes to but is not sufficient for virulence in vivo.  

PubMed

Among the Ebola viruses most species cause severe hemorrhagic fever in humans; however, Reston ebolavirus (REBOV) has not been associated with human disease despite numerous documented infections. While the molecular basis for this difference remains unclear, in vitro evidence has suggested a role for the glycoprotein (GP) as a major filovirus pathogenicity factor, but direct evidence for such a role in the context of virus infection has been notably lacking. In order to assess the role of GP in EBOV virulence, we have developed a novel reverse genetics system for REBOV, which we report here. Together with a previously published full-length clone for Zaire ebolavirus (ZEBOV), this provides a unique possibility to directly investigate the role of an entire filovirus protein in pathogenesis. To this end we have generated recombinant ZEBOV (rZEBOV) and REBOV (rREBOV), as well as chimeric viruses in which the glycoproteins from these two virus species have been exchanged (rZEBOV-RGP and rREBOV-ZGP). All of these viruses could be rescued and the chimeras replicated with kinetics similar to their parent virus in tissue culture, indicating that the exchange of GP in these chimeric viruses is well tolerated. However, in a mouse model of infection rZEBOV-RGP demonstrated markedly decreased lethality and prolonged time to death when compared to rZEBOV, confirming that GP does indeed contribute to the full expression of virulence by ZEBOV. In contrast, rREBOV-ZGP did not show any signs of virulence, and was in fact slightly attenuated compared to rREBOV, demonstrating that GP alone is not sufficient to confer a lethal phenotype or exacerbate disease in this model. Thus, while these findings provide direct evidence that GP contributes to filovirus virulence in vivo, they also clearly indicate that other factors are needed for the acquisition of full virulence. PMID:22876185

Groseth, Allison; Marzi, Andrea; Hoenen, Thomas; Herwig, Astrid; Gardner, Don; Becker, Stephan; Ebihara, Hideki; Feldmann, Heinz

2012-01-01

431

The Ebola virus glycoprotein mediates entry via a non-classical dynamin-dependent macropinocytic pathway  

SciTech Connect

Ebola virus (EBOV) has been reported to enter cultured cell lines via a dynamin-2-independent macropinocytic pathway or clathrin-mediated endocytosis. The route(s) of productive EBOV internalization into physiologically relevant cell types remain unexplored, and viral-host requirements for this process are incompletely understood. Here, we use electron microscopy and complementary chemical and genetic approaches to demonstrate that the viral glycoprotein, GP, induces macropinocytic uptake of viral particles into cells. GP's highly-glycosylated mucin domain is dispensable for virus-induced macropinocytosis, arguing that interactions between other sequences in GP and the host cell surface are responsible. Unexpectedly, we also found a requirement for the large GTPase dynamin-2, which is proposed to be dispensable for several types of macropinocytosis. Our results provide evidence that EBOV uses an atypical dynamin-dependent macropinocytosis-like entry pathway to enter Vero cells, adherent human peripheral blood-derived monocytes, and a mouse dendritic cell line.

Mulherkar, Nirupama [Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, NY 10461 (United States); Raaben, Matthijs [Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA 02115 (United States); Torre, Juan Carlos de la [Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, CA 92037 (United States); Whelan, Sean P. [Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA 02115 (United States); Chandran, Kartik, E-mail: kartik.chandran@einstein.yu.edu [Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, NY 10461 (United States)

2011-10-25

432

The Baboon (Papio spp.) as a model of human Ebola virus infection.  

PubMed

Baboons are susceptible to natural Ebola virus (EBOV) infection and share 96% genetic homology with humans. Despite these characteristics, baboons have rarely been utilized as experimental models of human EBOV infection to evaluate the efficacy of prophylactics and therapeutics in the United States. This review will summarize what is known about the pathogenesis of EBOV infection in baboons compared to EBOV infection in humans and other Old World nonhuman primates. In addition, we will discuss how closely the baboon model recapitulates human EBOV infection. We will also review some of the housing requirements and behavioral attributes of baboons compared to other Old World nonhuman primates. Due to the lack