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late assembly domain function can exhibit context dependence and involves ubiquitin residues implicated in endocytosis.retroviral gag polyproteins contain regions that promote the separation of virus particles from the plasma membrane and from each other. these gag regions are often referred to as late assembly (l) domains. the l domain of human immunodeficiency virus type 1 (hiv-1) is in the c-terminal p6(gag) domain and harbors an essential p(t/s)app motif, whereas the l domains of oncoretroviruses are in the n-terminal half of the gag precursor and have a ppxy core motif. we recently observed that l domains i ...200211991975
representations of far-flung illnesses: the case of ebola in britain.in western cultures lay people are faced with a plethora of far-flung illnesses, relayed to them by the mass media. a number of social scientists have called for scrutiny of the link between people's patterns of thinking concerning such events, and the messages to which they are exposed. using the outbreaks of ebola in africa in the mid-1990s as a vehicle, the study examines how british broadsheets and their readers, and british tabloids and their readers, make sense of this far-flung illness. e ...200211996028
evaluation in nonhuman primates of vaccines against ebola virus.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 ...200211996686
chronological and spatial analysis of the 1996 ebola reston virus outbreak in a monkey breeding facility in the philippines.to describe the transmission pattern of natural infection with ebola reston (ebo-r) virus in a breeding colony, the chronological and spatial analysis of mortality during the 1996 ebo-r virus outbreak was done in this study. the ebo-r virus infection among monkeys in the facility was widespread. over a period of 3 months, 14 out of 21 occupied units were contaminated with antigen positive animals. a large number of wild-caught monkeys were involved in this outbreak suggesting that wild-caught mo ...200212012728
pre- and postexposure prophylaxis of ebola virus infection in an animal model by passive transfer of a neutralizing human antibody.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 infectio ...200212021376
[sensitizing and virus-neutralizing characteristics of goat immunoglobulins to ebola virus].sensitizing and virus-neutralizing properties of igg isolated from the sera of goats immunized with ebola virus and a relevant gammaglobulin prepared by ethanol fractionation were compared. the ratio of the virus-neutralizing activities of subclasses igg2, igg1a, and igg1b was 100:10:1. anaphylactogenic activity of igg2 in the immediate type hypersensitivity test in guinea pigs was 2-fold lower than that of igg1a and igg1b. goat gammaglobulin to ebola virus, consisting from igg2 antibodies by mo ...200212046470
c-type lectins dc-sign and l-sign mediate cellular entry by ebola virus in cis and in trans.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 to susceptible cells. our data underscore a role for dc-sign and l-sign in the infective proc ...200212050398
phosphorylation of vp30 impairs ebola virus transcription.transcription of the highly pathogenic ebola virus (ebov) is dependent on vp30, a constituent of the viral nucleocapsid complex. here we present evidence that phosphorylation of vp30, which takes place at six n-terminal serine residues and one threonine residue, is of functional significance. replacement of the phosphoserines by alanines resulted in an only slightly phosphorylated vp30 (vp30(6a)) that is still able to activate ebov-specific transcription in a plasmid-based minigenome system. vp3 ...200212052831
viral rna-polymerases -- a predicted 2'-o-ribose methyltransferase domain shared by all mononegavirales.the mononegavirales virus group comprises several major human pathogens, including measles, rabies and ebola viruses. this article reports a computational analysis of the c-terminal region of rna-dependent rna-polymerases from mononegavirales. using a combination of sequence similarity and threading analysis, a 2'-o-ribose methyltransferase domain was identified that is involved in the capping of viral mrnas.200212076527
3-deazaneplanocin a induces massively increased interferon-alpha production in ebola virus-infected mice.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 ...200212076759
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.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- ...200212089242
ebola vaccine gets corporate backer. 200212091886
dendritic cell (dc)-specific intercellular adhesion molecule 3 (icam-3)-grabbing nonintegrin (dc-sign, cd209), a c-type surface lectin in human dcs, is a receptor for leishmania amastigotes.dendritic cells (dcs) play a critical role in the initiation of the immunological response against leishmania parasites. however, the receptors involved in amastigote-dendritic cell interaction are unknown, especially in absence of opsonizing antibodies. we have studied the interaction of leishmania pifanoi axenic amastigotes with the c-type lectin dc-specific intercellular adhesion molecule (icam)-3-grabbing nonintegrin (dc-sign, cd209), a receptor for icam-2, icam-3, human immunodeficiency vir ...200212122001
lentiviral vectors pseudotyped with a modified rd114 envelope glycoprotein show increased stability in sera and augmented transduction of primary lymphocytes and cd34+ cells derived from human and nonhuman primates.generating lentiviral vectors pseudotyped with different viral glycoproteins (gps) may modulate the physicochemical properties of the vectors, their interaction with the host immune system, and their host range. we have investigated the capacity of a panel of gps of both retroviral (amphotropic murine leukemia virus [mlv-a]; gibbon ape leukemia virus [galv]; rd114, feline endogenous virus) and nonretroviral (fowl plague virus [fpv]; ebola virus [ebov]; vesicular stomatitis virus [vsv]; lymphocyt ...200212130492
defend the human rights of the ebola victims! 200212139173
proinflammatory response during ebola virus infection of primate models: possible involvement of the tumor necrosis factor receptor superfamily.ebola virus (ebov) infections are characterized by dysregulation of normal host immune responses. insight into the mechanism came from recent studies in nonhuman primates, which showed that ebov infects cells of the mononuclear phagocyte system (mps), resulting in apoptosis of bystander lymphocytes. in this study, we evaluated serum levels of cytokines/chemokines in ebov-infected nonhuman primates, as possible correlates of this bystander apoptosis. increased levels of interferon (ifn)-alpha, if ...200211803049
viral replication and host gene expression in alveolar macrophages infected with ebola virus (zaire strain).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, immunohistochemical analysis, and in situ hybridization. fluorogenic 5'-nuclease assays specific for nonhuman primate proinflammatory cytokines and chemokines were designed and used to evalua ...200211777824
[effect of ebola virus antigen on proliferative response of human lymphocytes in vitro: imbalance in production of tumor necrosis factor alpha and interleukin-1].an in vitro model infection caused by ebola virus (ev) showed a high production of tumor necrosis factor-alpha by human peripheral lymphocytes concurrently with a simultaneous reduction in the synthesis of interleukin-1 in response ev antigen stimulation. this may be an important factor in that ve suppresses the body's immunological resistance, which in turn causes unterferon deficiency and suppresses the formation of t helper cells.200212522966
[sanitary control of the territory: data bases on the spread of some quarantine infections].the data bases (db) on the spread of plague, yellow fever and contagious virus hemorrhagic fevers (cvhf) in foreign countries have been created. these db contain information on the main international air and sea ports and their relationships with natural focal territories. the data base "sanitary control. yellow fever" contains information on different species serving as vectors for yellow fever virus. information on the circulation of the causative agents of ebola fever, lassa fever and marburg ...200212524996
[filovirus haemorrhagic fevers: ebola fever].epidemiological issues, clinical course and laboratory diagnostics of ebola haemorrhagic fever are reviewed. the structural features of virions and genetic variants of the virus are described along with ecology of ebola virus. the data on ebola fever global morbidity are also presented.200212525016
imported viral haemorrhagic fever with a potential for person-to-person transmission: review and recommendations for initial management of a suspected case in belgium.viral haemorrhagic fevers are caused by a wide range of viruses. there are 4 types of viruses well known to spread from person to person and able to cause nosocomial outbreaks with a high case fatality rate: an arenavirus (lassa fever and more exceptionally the junin and machupo virus), a bunyavirus (crimean-congo haemorrhagic fever) and the filoviridae (ebola and marburg viruses). so far there have been only a limited number of imported cases of viral haemorrhagic fever in industrialized countr ...200212534129
[the restructuring of national sanitary inspectorate with regard to environmental hazards and health needs of the population].the article presents the history of polish sanitary and epidemiological services from 1918 until contemporary times. emphasizing many achievements of national sanitary inspectorate, which are responsible for the low sick-rate of infectious diseases in poland, the article also points to the increasing number and growing severity of environmental hazards in recent years. the article discusses problems caused by the "old" infectious diseases, which, though until recently regarded as passed, are pos ...200217474584
covalent modifications of the ebola virus glycoprotein.the role of covalent modifications of the ebola virus glycoprotein (gp) and the significance of the sequence identity between filovirus and avian retrovirus gps were investigated through biochemical and functional analyses of mutant gps. the expression and processing of mutant gps with altered n-linked glycosylation, substitutions for conserved cysteine residues, or a deletion in the region of o-linked glycosylation were analyzed, and virus entry capacities were assayed through the use of pseudo ...200212438572
examining unmet needs in infectious disease.in the past 30 years, more than 30 new aetiological agents of infectious disease have been identified. some of these are responsible for entirely novel and life-threatening disorders, such as aids, ebola fever, hantavirus pulmonary syndrome and nipah virus encephalitis. during the same period, some longstanding infectious diseases (such as tuberculosis) have became resurgent, as a result of a combination of complacency, increased travel and social dislocation, and also increasing drug resistance ...200312546988
ebola virus matrix protein vp40 interaction with human cellular factors tsg101 and nedd4.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, we report that ebola vp40 can interact with cellular factors human nedd4 and tsg101 in vitro. we show that ww domain 3 of human nedd4 is necessary a ...200312559917
calcium-dependent conformational changes of membrane-bound ebola fusion peptide drive vesicle fusion.the fusogenic subdomain of the ebola virus envelope glycoprotein is an internal sequence located ca. 20 residues downstream the n-terminus of the glycoprotein transmembrane subunit. partitioning of the ebola fusion peptide into membranes containing phosphatidylinositol in the absence of ca2+ stabilizes an alpha-helical conformation, and gives rise to vesicle efflux but not vesicle fusion. in the presence of millimolar ca2+ the membrane-bound peptide adopts an extended beta-structure, and induces ...200312560072
ebola virus transcription activator vp30 is a zinc-binding protein.ebola virus vp30 is an essential activator of viral transcription. in viral particles, vp30 is closely associated with the nucleocapsid complex. a conspicuous structural feature of vp30 is an unconventional zinc-binding cys(3)-his motif comprising amino acids 68 to 95. by using a colorimetric zinc-binding assay we found that the vp30-specific cys(3)-his motif stoichiometrically binds zinc ions in a one-to-one relationship. substitution of the conserved cysteines and the histidine within the moti ...200312584359
biochemical and functional characterization of the ebola virus vp24 protein: implications for a role in virus assembly and budding.the vp24 protein of ebola virus is believed to be a secondary matrix protein and minor component of virions. in contrast, the vp40 protein of ebola virus is the primary matrix protein and the most abundant virion component. the structure and function of vp40 have been well characterized; however, virtually nothing is known regarding the structure and function of vp24. wild-type and mutant forms of vp24 were expressed in mammalian cells to gain a better understanding of the biochemical and functi ...200312525613
overlapping motifs (ptap and ppey) within the ebola virus vp40 protein function independently as late budding domains: involvement of host proteins tsg101 and vps-4.the vp40 protein of ebola virus can bud from mammalian cells in the form of lipid-bound, virus-like particles (vlps), and late budding domains (l-domains) are conserved motifs (ptap, ppxy, or yxxl; where "x" is any amino acid) that facilitate the budding of vp40-containing vlps. vp40 is unique in that potential overlapping l-domains with the sequences ptap and ppey are present at amino acids 7 to 13 of vp40 (ptappey). l-domains are thought to function by interacting with specific cellular protei ...200312525615
towards a vaccine against ebola virus.ebola virus infection causes hemorrhagic fever with high mortality rates in humans and nonhuman primates. currently, there are no vaccines or therapies approved for human use. outbreaks of ebola virus have been infrequent, largely confined to remote locations in africa and quarantine of sick patients has been effective in controlling epidemics. in the past, this small global market has generated little commercial interest for developing an ebola virus vaccine. however, heightened awareness of bi ...200314711361
risk factors for marburg hemorrhagic fever, democratic republic of the congo.we conducted two antibody surveys to assess risk factors for marburg hemorrhagic fever in an area of confirmed marburg virus transmission in the democratic republic of the congo. questionnaires were administered and serum samples tested for marburg-specific antibodies by enzyme-linked immunosorbent assay. fifteen (2%) of 912 participants in a general village cross-sectional antibody survey were positive for marburg immunoglobulin g antibody. thirteen (87%) of these 15 were men who worked in the ...200314720391
polystyrene derivatives substituted with arginine interact with babanki (togaviridae) and kedougou (flaviviridae) viruses.outbreaks of new or old diseases appear primarily in tropical zones such as africa, south and central america, or asia. among these diseases, those induced by arboviruses (the best known of which are being yellow fever, dengue, ebola, and sindbis) are under intensive observation by the world health organization. rapid isolation and identification of the viral species is the first step in the diagnosis, study, and control of epidemics. one major problem with the isolation of viruses is capturing ...200312601758
[in vitro synthesis of immunoglobulins caused by an inactivated ebola virus].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 ...200312608056
[titration of ebola and marburg viruses by plaque formation under semi liquid agar].the method of titration of ebola and marburg viruses using plaque formation under semifluid agar cover is considered. advantages of this method over conventional method of titration of these viruses with the use of hard agar cover are discussed.200312608062
defense against filoviruses used as biological weapons.the filoviruses, marburg and ebola, are classified as category a biowarfare agents by the centers for disease control. most known human infections with these viruses have been fatal, and no vaccines or effective therapies are currently available. filoviruses are highly infectious by the airborne route in the laboratory, but investigations of african outbreaks have shown that person-to-person spread requires direct contact with virus-containing material. in consequence, filovirus epidemics can be ...200312615303
cutting edge: impairment of dendritic cells and adaptive immunity by ebola and lassa viruses.acute infection of humans with ebola and lassa viruses, two principal etiologic agents of hemorrhagic fevers, often results in a paradoxical pattern of immune responses: early infection, characterized by an outpouring of inflammatory mediators such as tnf-alpha, il-1 beta, and il-6, vs late stage infections, which are associated with poor immune responses. the mechanisms underlying these diverse outcomes are poorly understood. in particular, the role played by cells of the innate immune system, ...200312626527
analysis of the role of predicted rna secondary structures in ebola virus replication.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 within a second region (internal by approximately 20 nucleotides). while base pairing of the two conserved regions could l ...200312642094
role of escrt-i in retroviral budding.retroviral late-budding (l) domains are required for the efficient release of nascent virions. the three known types of l domain, designated according to essential tetrapeptide motifs (ptap, ppxy, or ypdl), each bind distinct cellular cofactors. we and others have demonstrated that recruitment of an escrt-i subunit, tsg101, a component of the class e vacuolar protein sorting (vps) machinery, is required for the budding of viruses, such as human immunodeficiency virus type 1 (hiv-1) and ebola vir ...200312663786
therapeutic options for diseases due to potential viral agents of bioterrorism.the etiologic agents of smallpox and viral hemorrhagic fever have emerged as potential agents of bioterrorism due to their virulence, potential for human to human dissemination and limited strategies for treatment and prevention. cidofovir has shown significant promise in animal models, and limited case reports in humans are encouraging. ribavirin is the treatment of choice for certain hemorrhagic fever viral infections, but has no current application to ebola and marburg infections. current vac ...200312669378
catastrophic ape decline in western equatorial africa.because rapidly expanding human populations have devastated gorilla (gorilla gorilla) and common chimpanzee (pan troglodytes) habitats in east and west africa, the relatively intact forests of western equatorial africa have been viewed as the last stronghold of african apes. gabon and the republic of congo alone are thought to hold roughly 80% of the world's gorillas and most of the common chimpanzees. here we present survey results conservatively indicating that ape populations in gabon decline ...200312679788
comparison of the protective efficacy of dna and baculovirus-derived protein vaccines for ebola virus in guinea pigs.the filoviruses ebola virus (ebov) and marburg virus (marv) cause severe hemorrhagic fever in humans for which no vaccines are available. previously, a priming dose of a dna vaccine expressing the glycoprotein (gp) gene of marv followed by boosting with recombinant baculovirus-derived gp protein was found to confer protective immunity to guinea pigs (hevey et al., 2001. vaccine 20, 568-593). to determine whether a similar prime-boost vaccine approach would be effective for ebov, we generated and ...200312686428
vaccine for aids and ebola virus infection.ebola virus and hiv present challenges for vaccine development because natural immunity to these viruses is difficult to find, and there are no immune correlates of protection in humans. modern molecular genetic, virologic and immune analyses have been used to rationally identify promising approaches based on animal model and human clinical studies. improved vaccine candidates have been defined for hiv, and a promising ebola vaccine have conferred protection in non-human primates. further evalua ...200312686432
ape populations decimated by hunting and ebola virus. 200312686965
conservation biology. ebola, hunting push ape populations to the brink. 200312690159
ebola virus infection inversely correlates with the overall expression levels of promyelocytic leukaemia (pml) protein in cultured cells.ebola virus causes severe, often fatal hemorrhagic fever in humans. the mechanism of escape from cellular anti-viral mechanisms is not yet fully understood. the promyelocytic leukaemia (pml) associated nuclear body is part of the interferon inducible cellular defense system. several rna viruses have been found to interfere with the anti-viral function of the pml body. the possible interaction between ebola virus and the pml bodies has not yet been explored.200312697055
a current review of ebola virus: pathogenesis, clinical presentation, and diagnostic assessment.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 infect ...200312698919
ebola virus: immune mechanisms of protection and vaccine development.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 ...200312698920
[ebola virus and marburg virus]. 200312718026
cyanovirin-n binds to the viral surface glycoprotein, gp1,2 and inhibits infectivity of ebola virus.ebola virus (ebo) causes severe hemorrhagic fever and high mortality in humans. there are currently no effective therapies. here, we have explored potential anti-ebo activity of the human immunodeficiency virus (hiv)-inactivating protein cyanovirin-n (cv-n). cv-n is known to potently inhibit the infectivity of a broad spectrum of hiv strains at the level of viral entry. this involves cv-n binding to n-linked high-mannose oligossacharides on the viral glycoprotein gp120. the ebola envelope contai ...200312719006
lentivirus vectors pseudotyped with filoviral envelope glycoproteins transduce airway epithelia from the apical surface independently of folate receptor alpha.the practical application of gene therapy as a treatment for cystic fibrosis is limited by poor gene transfer efficiency with vectors applied to the apical surface of airway epithelia. recently, folate receptor alpha (fr alpha), a glycosylphosphatidylinositol-linked surface protein, was reported to be a cellular receptor for the filoviruses. we found that polarized human airway epithelia expressed abundant fr alpha on their apical surface. in an attempt to target these apical receptors, we pseud ...200312719583
a fatal attraction: mycobacterium tuberculosis and hiv-1 target dc-sign to escape immune surveillance.dendritic cells (dcs) are vital in the defense against pathogens. however, it is becoming increasingly clear that some pathogens subvert dc functions to escape immune surveillance. for example, hiv-1 targets the dc-specific c-type lectin dc-sign (dc-specific intercellular-adhesion-molecule-3-grabbing nonintegrin) to hijack dcs for viral dissemination. binding to dc-sign protects hiv-1 from antigen processing and facilitates its transport to lymphoid tissues, where dc-sign promotes hiv-1 infectio ...200312727141
serological reactivity of baculovirus-expressed ebola virus vp35 and nucleoproteins.ebola virus (ebov) is a member of the family filoviridae and is classified as a biosafety level 4 virus. this classification makes the preparation of antigen and performance of diagnostic assays time-consuming and complicated. the objective of this study was to evaluate the value of ebov immunoassays based on recombinant nucleoprotein (r-np) and recombinant vp35 (r-vp35) using large serum panels of african origin and from primates. furthermore, we investigated whether the results obtained with e ...200312737993
u.s. military officer participation in the centers for disease control and prevention's epidemic intelligence service (1951-2001).the epidemic intelligence service (eis) was created in 1951 to provide epidemiologists to investigate natural and intentional disease epidemics. from an initial class of 23 u.s. citizens, the program has evolved into a globally recognized, hands-on learning experience, accepting approximately 65 to 75 new officers each year. the first u.s. military epidemic intelligence service officer (eiso) was accepted into the program in 1994. since that time, 12 such officers have completed, or have begun, ...200312775171
vaccine research efforts for filoviruses.ebola and marburg viruses belong to the family filoviridae, and cause acute, frequently fatal, haemorrhagic fever in humans and non-human primates. no vaccines are available for human use. this review describes the status of research efforts to develop vaccines for these viruses and to identify the immune mechanisms of protection. the vaccine approaches discussed include dna-based vaccines, and subunit vaccines vectored by adenovirus, alphavirus replicons, and vaccinia virus.200312782057
viral hemorrhagic fever--a vascular disease?the syndrome of "viral hemorrhagic fever" in man caused by certain viruses, such as ebola, lassa, dengue, and crimean-congo hemorrhagic fever viruses, is often associated with a shock syndrome of undetermined pathogenesis. however, the vascular system, particularly the vascular endothelium, seems to be directly and indirectly targeted by all these viruses. here we briefly summarize the current knowledge on marburg and ebola virus infections, the prototype viral hemorrhagic fever agents, and form ...200312783108
changing world, changing doctors, changing education!future developments in the community will underline the need to provide a community-oriented health care system in which public health doctors collaborate with general practitioners, as the hospital-based health care system that currently exists in many countries will not be able to solve the problems of health care in the future. increasing populations, increasing mobility all over the world, spread of new diseases (aids/hiv and ebola virus for example) will have great impact on our societies a ...200312784489
lentiviral vectors pseudotyped with minimal filovirus envelopes increased gene transfer in murine lung.a human immunodeficiency virus (hiv)-based vector pseudotyped with the ebola zaire (eboz) viral envelope glycoprotein (gp) was recently shown to transduce murine airway epithelia cells in vivo. in this study, the vector was further redesigned to improve gene transfer and also to increase safety. we used mutant eboz envelopes for pseudotyping, which resulted in higher titers and increased transduction of airway cells in vivo compared to vectors pseudotyped with wild-type eboz gp. as these envelop ...200314599811
virology. new vaccine and treatment excite ebola researchers. 200314615510
antibody-dependent enhancement of viral infection: molecular mechanisms and in vivo implications.besides the common receptor/coreceptor-dependent mechanism of cellular attachment, some viruses rely on antiviral antibodies for their efficient entry into target cells. this mechanism, known as antibody-dependent enhancement (ade) of viral infection, depends on the cross-linking of complexes of virus-antibody or virus-activated complement components through interaction with cellular molecules such as fc receptors or complement receptors, leading to enhanced infection of susceptible cells. recen ...200314625886
pathogenesis of ebola hemorrhagic fever in cynomolgus macaques: evidence that dendritic cells are early and sustained targets of infection.ebola virus (ebov) infection causes a severe and fatal hemorrhagic disease that in many ways appears to be similar in humans and nonhuman primates; however, little is known about the development of ebov hemorrhagic fever. in the present study, 21 cynomolgus monkeys were experimentally infected with ebov and examined sequentially over a 6-day period to investigate the pathological events of ebov infection that lead to death. importantly, dendritic cells in lymphoid tissues were identified as earl ...200314633608
pathogenesis of ebola hemorrhagic fever in primate models: evidence that hemorrhage is not a direct effect of virus-induced cytolysis of endothelial cells.ebola virus (ebov) infection causes a severe and often fatal hemorrhagic disease in humans and nonhuman primates. whether infection of endothelial cells is central to the pathogenesis of ebov hemorrhagic fever (hf) remains unknown. to clarify the role of endothelial cells in ebov hf, we examined tissues of 21 ebov-infected cynomolgus monkeys throughout time, and also evaluated ebov infection of primary human umbilical vein endothelial cells and primary human lung-derived microvascular endothelia ...200314633609
mannosyl glycodendritic structure inhibits dc-sign-mediated ebola virus infection in cis and in trans.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.200314638512
mechanisms underlying coagulation abnormalities in ebola hemorrhagic fever: overexpression of tissue factor in primate monocytes/macrophages is a key event.disseminated intravascular coagulation is a prominent manifestation of ebola virus (ebov) infection. here, we report that tissue factor (tf) plays an important role in triggering the hemorrhagic complications that characterize ebov infections. analysis of samples obtained from 25 macaques showed increased levels of tf associated with lymphoid macrophages, whereas analysis of peripheral blood-cell rna showed increased levels of tf transcripts by day 3. plasma from macaques contained increased num ...200314639531
ebola and marburg viruses replicate in monocyte-derived dendritic cells without inducing the production of cytokines and full maturation.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 to interfere with dendritic cells (dcs), which link innate and adaptive immune responses. we demonstrate that ebov and marv infected and replicated in primary human dcs without inducing cytokine secretion. infected dc cultures supported exponent ...200314639532
folate receptor alpha and caveolae are not required for ebola virus glycoprotein-mediated viral infection.folate receptor alpha (fralpha) has been described as a factor involved in mediating ebola virus entry into cells (6). furthermore, it was suggested that interaction with fralpha results in internalization and subsequent viral ingress into the cytoplasm via caveolae (9). descriptions of cellular receptors for ebola virus and its entry mechanisms are of fundamental importance, particularly with the advent of vectors bearing ebola virus glycoprotein (gp) being utilized for gene transfer into cell ...200314645601
emerging viral infections in a rapidly changing world.emerging viral infections in both humans and animals have been reported with increased frequency in recent years. recent advances have been made in our knowledge of some of these, including severe acute respiratory syndrome-associated coronavirus, influenza a virus, human metapneumovirus, west nile virus and ebola virus. research efforts to mitigate their effects have concentrated on improved surveillance and diagnostic capabilities, as well as on the development of vaccines and antiviral agents ...200314662395
ebola virus-like particles protect from lethal ebola virus infection.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 ce ...200314673108
in vivo oligomerization and raft localization of ebola virus protein vp40 during vesicular budding.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 membra ...200314673115
5'-nor carbocyclic ribavirin.an efficient synthesis of 5'-nor carbocyclic ribavirin (4) is described in 13 steps from conveniently available (+)-(ir,4s)-4-hydroxy-2-cyclopenten-1-yl acetate (6). compound 4 was evaluated against the following viruses: herpes simplex type 1 and 2, vaccinia, cowpox, smallpox, ebola, hepatitis b, hepatitis c, adenovirus type 1, influenza a (h1n1 and h3n2), influenza b, parainfluenza type 3, pichinde, punta toro a, respiratory syncytial, rhinovirus type 2, venezuelan equine encephalitis, yellow ...200314680022
treatment of ebola virus infection with a recombinant inhibitor of factor viia/tissue factor: a study in rhesus monkeys.infection with the ebola virus induces overexpression of the procoagulant tissue factor in primate monocytes and macrophages, suggesting that inhibition of the tissue-factor pathway could ameliorate the effects of ebola haemorrhagic fever. here, we tested the notion that blockade of fviia/tissue factor is beneficial after infection with ebola virus.200314683653
conference report - i. investigating new vaccines: ebola and hiv: highlights from the viral vaccine meeting; october 25-28, 2003; barcelona, spain. 200314745371
experimental vaccine protects monkeys against ebola virus. 200311217674
overcoming immunity to a viral vaccine by dna priming before vector boosting.replication-defective adenovirus (adv) and poxvirus vectors have shown potential as vaccines for pathogens such as ebola or human immunodeficiency virus in nonhuman primates, but prior immunity to the viral vector in humans may limit their clinical efficacy. to overcome this limitation, the effect of prior viral exposure on immune responses to ebola virus glycoprotein (gp), shown previously to protect against lethal hemorrhagic fever in animals, was studied. prior exposure to adv substantially r ...200312477888
identification of protective epitopes on ebola virus glycoprotein at the single amino acid level by using recombinant vesicular stomatitis viruses.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 recogni ...200312502822
differential n-linked glycosylation of human immunodeficiency virus and ebola virus envelope glycoproteins modulates interactions with dc-sign and dc-signr.the c-type lectins dc-sign and dc-signr [collectively referred to as dc-sign(r)] bind and transmit human immunodeficiency virus (hiv) and simian immunodeficiency virus to t cells via the viral envelope glycoprotein (env). other viruses containing heavily glycosylated glycoproteins (gps) fail to interact with dc-sign(r), suggesting some degree of specificity in this interaction. we show here that dc-sign(r) selectively interact with hiv env and ebola virus gps containing more high-mannose than co ...200312502850
newcastle disease virus (ndv)-based assay demonstrates interferon-antagonist activity for the ndv v protein and the nipah virus v, w, and c proteins.we have generated a recombinant newcastle disease virus (ndv) that expresses the green fluorescence protein (gfp) in infected chicken embryo fibroblasts (cefs). this virus is interferon (ifn) sensitive, and pretreatment of cells with chicken alpha/beta ifn (ifn-alpha/beta) completely blocks viral gfp expression. prior transfection of plasmid dna induces an ifn response in cefs and blocks ndv-gfp replication. however, transfection of known inhibitors of the ifn-alpha/beta system, including the in ...200312502864
dc-sign and dc-signr bind ebola glycoproteins and enhance infection of macrophages and endothelial cells.ebola virus exhibits a broad cellular tropism in vitro. in humans and animal models, virus is found in most tissues and organs during the latter stages of infection. in contrast, a more restricted cell and tissue tropism is exhibited early in infection where macrophages, liver, lymph node, and spleen are major initial targets. this indicates that cellular factors other than the broadly expressed virus receptor(s) modulate ebola virus tropism. here we demonstrate that the c-type lectins dc-sign a ...200312504546
pre-transmembrane sequence of ebola glycoprotein. interfacial hydrophobicity distribution and interaction with membranes.the membrane-interacting domain that precedes the transmembrane anchor of ebola glycoprotein has been characterized. this aromatic-rich region is predicted to bind the membrane interface adopting an alpha-helical structure. peptides representing either the ebola glycoprotein pre-transmembrane sequence, or a 'scrambled' control with a different hydrophobic-at-interface moment, have been studied. insertion into lipid monolayers, changes in intrinsic fluorescence and in infrared spectra demonstrate ...200312505157
analysis of linear b-cell epitopes of the nucleoprotein of ebola virus that distinguish ebola virus subtypes.ebola virus consists of four genetically distinguishable subtypes. we developed monoclonal antibodies (mabs) to the nucleoprotein (np) of ebola virus zaire subtype and analyzed their cross-reactivities to the reston and sudan subtypes. we further determined the epitopes recognized by these mabs. three mabs reacted with the three major subtypes and recognized a fragment containing 110 amino acids (aa) at the c-terminal extremity. they did not show specific reactivities to any 10-aa short peptides ...200312522044
the crystal structure of the proprotein processing proteinase furin explains its stringent specificity.in eukaryotes, many essential secreted proteins and peptide hormones are excised from larger precursors by members of a class of calcium-dependent endoproteinases, the prohormone-proprotein convertases (pcs). furin, the best-characterized member of the mammalian pc family, has essential functions in embryogenesis and homeostasis but is also implicated in various pathologies such as tumor metastasis, neurodegeneration and various bacterial and viral diseases caused by such pathogens as anthrax an ...200312794637
[analysis of antigenic determinant profiles of the ebola virus vp35 protein n-terminal region using its short recombinant fragments].cdna of fragments of gene vp35 of the ebola virus (ev) were expressed in vector pqe30 for the purpose of isolation of recombinant fragments of protein vp35. five short affinity-purified fragments of the ev vp35 protein were analyzed, by using the methods of iea and immunoblotting, with polyclonal antiviral sera (pas) against ev and with hybrid monoclonal antibodies (mabs) ic6 and 6f7 specific to ev vp35 protein. all fragments of protein vp35 with an intact n-terminal region and removed c-termina ...200312800775
antibody-dependent enhancement of ebola virus infection.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 by the zaire virus, and this enhancement was mediated by antibodies to the viral glycoprotein and ...200312805454
conservation biology. can great apes be saved from ebola? 200312805515
development, characterization and use of monoclonal vp40-antibodies for the detection of ebola virus.ebola virus (ebov) causes uncommon but dramatic outbreaks in remote regions of africa, where diagnostic facilities are limited. in order to develop diagnostic tests, which can be handled and distributed easily, monoclonal antibodies (mabs) to ebov, species zaire, were produced from mice immunized with inactivated viral particles. nine stable hybridoma cell lines were obtained producing specific mabs directed against the viral structural protein vp40. these mabs were characterized by enzyme-linke ...200312821193
immunoglobulin g enzyme-linked immunosorbent assay using truncated nucleoproteins of reston ebola virus.we developed an immunoglobulin g (igg) enzyme-linked immunosorbent assay (elisa), using partial recombinant nucleoproteins (rnp) of reston ebola virus (ebo-r) and zaire ebola virus (ebo-z). we examined the reaction of 10 sera from cynomolgus macaques naturally infected with ebo-r to each of the partial rnp in the igg elisa. all the sera reacted to the c-terminal halves of the rnp of both ebo-r and ebo-z. most of the sera reacted to the rdeltac (amino acid (aa) 360-739), and rdelta6 (aa 451-551) ...200312825739
the ebola virus vp35 protein inhibits activation of interferon regulatory factor 3.the ebola virus vp35 protein was previously found to act as an interferon (ifn) antagonist which could complement growth of influenza delns1 virus, a mutant influenza virus lacking the influenza virus ifn antagonist protein, ns1. the ebola virus vp35 could also prevent the virus- or double-stranded rna-mediated transcriptional activation of both the beta ifn (ifn-beta) promoter and the ifn-stimulated isg54 promoter (c. basler et al., proc. natl. acad. sci. usa 97:12289-12294, 2000). we now show ...200312829834
antigen capture enzyme-linked immunosorbent assay for specific detection of reston ebola virus nucleoprotein.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 ...200312853385
an ebola epidemic simmers in africa: in remote region, outbreak shows staying power. 200312865357
ebola glycoprotein: the key to successful gene therapy? 200312867139
inactivation of ebola virus with a surfactant nanoemulsion.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 of ebo (strain zaire) obtained from vero cell culture fluid (ebo-zc ...200312875924
elaboration of laboratory strains of ebola virus and study of pathophysiological reactions of animals inoculated with these strains.selective passages in animals and cell cultures were used to produce a set of ebola virus (ebo) laboratory strains with changed virulence for some animal genera. comparative study of the genomes of wild-type ebo and selected variants formed the basis for studying the molecular causes of ebo virulence. investigation of pathophysiological reactions of the animals inoculated with these strains allowed some key factors in ebola fever pathogenesis to be determined.200312875925
pathogens: raft hijackers.throughout evolution, organisms have developed immune-surveillance networks to protect themselves from potential pathogens. at the cellular level, the signalling events that regulate these defensive responses take place in membrane rafts--dynamic microdomains that are enriched in cholesterol and glycosphingolipids--that facilitate many protein-protein and lipid-protein interactions at the cell surface. pathogens have evolved many strategies to ensure their own survival and to evade the host immu ...200312876558
fast vaccine offers hope in battle with ebola. 200312904747
accelerated vaccination for ebola virus haemorrhagic fever in non-human primates.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 immunization with an adenoviral (adv) vector encoding the ebola glycop ...200312904795
oligomerization of ebola virus vp30 is essential for viral transcription and can be inhibited by a synthetic peptide.transcription of ebola virus (ebov)-specific mrna is driven by the nucleocapsid proteins np, vp35, and l. this process is further dependent on vp30, an essential ebov-specific transcription factor. the present study addresses the self-assembly of vp30 and the functional significance of this process for viral transcription and propagation. essential for oligomerization of vp30 is a region spanning amino acids 94-112. within this region a cluster of four leucine residues is of critical importance. ...200312912982
specific association of glycoprotein b with lipid rafts during herpes simplex virus entry.herpes simplex virus (hsv) entry requires the interaction of glycoprotein d (gd) with a cellular receptor such as herpesvirus entry mediator (hvem or hvea) or nectin-1 (hvec). however, the fusion mechanism is still not understood. since cholesterol-enriched cell membrane lipid rafts are involved in the entry of other enveloped viruses such as human immunodeficiency virus and ebola virus, we tested whether hsv entry proceeds similarly. vero cells and cells expressing either hvem or nectin-1 were ...200312915568
oligomerization and polymerization of the filovirus matrix protein vp40.the matrix protein vp40 from ebola virus plays an important role in the assembly process of virus particles by interacting with cellular factors, cellular membranes, and the ribonuclearprotein particle complex. here we show that the n-terminal domain of vp40 folds into a mixture of two different oligomeric states in vitro, namely hexameric and octameric ringlike structures, as detected by gel filtration chromatography, chemical cross-linking, and electron microscopy. octamer formation depends la ...200312919741
protection from lethal infection is determined by innate immune responses in a mouse model of ebola virus infection.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 ip (10 pfu/mouse), or sc (100 pfu/mouse) and sc "immune" mice rechallenged ip (10(6 ...200312919746
comparison of individual and combination dna vaccines for b. anthracis, ebola virus, marburg virus and venezuelan equine encephalitis virus.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 protective immunity in relevant animal model ...200312922144
ebola virus pathogenesis: implications for vaccines and therapies. 200312941881
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