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2.
Lancet Infect Dis ; 20(4): 445-454, 2020 04.
Artículo en Inglés | MEDLINE | ID: mdl-32027842

RESUMEN

BACKGROUND: The monoclonal antibody m102.4 is a potent, fully human antibody that neutralises Hendra and Nipah viruses in vitro and in vivo. We aimed to investigate the safety, tolerability, pharmacokinetics, and immunogenicity of m102.4 in healthy adults. METHODS: In this double-blind, placebo-controlled, single-centre, dose-escalation, phase 1 trial of m102.4, we randomly assigned healthy adults aged 18-50 years with a body-mass index of 18·0-35·0 kg/m2 to one of five cohorts. A sentinel pair for each cohort was randomly assigned to either m102.4 or placebo. The remaining participants in each cohort were randomly assigned (5:1) to receive m102.4 or placebo. Cohorts 1-4 received a single intravenous infusion of m102.4 at doses of 1 mg/kg (cohort 1), 3 mg/kg (cohort 2), 10 mg/kg (cohort 3), and 20 mg/kg (cohort 4), and were monitored for 113 days. Cohort 5 received two infusions of 20 mg/kg 72 h apart and were monitored for 123 days. The primary outcomes were safety and tolerability. Secondary outcomes were pharmacokinetics and immunogenicity. Analyses were completed according to protocol. The study was registered on the Australian New Zealand Clinical Trials Registry, ACTRN12615000395538. FINDINGS: Between March 27, 2015, and June 16, 2016, 40 (52%) of 77 healthy screened adults were enrolled in the study. Eight participants were assigned to each cohort (six received m102.4 and two received placebo). 86 treatment-emergent adverse events were reported, with similar rates between placebo and treatment groups. The most common treatment-related event was headache (12 [40%] of 30 participants in the combined m102.4 group, and three [30%] of ten participants in the pooled placebo group). No deaths or severe adverse events leading to study discontinuation occurred. Pharmacokinetics based on those receiving m102.4 (n=30) were linear, with a median half-life of 663·3 h (range 474·3-735·1) for cohort 1, 466·3 h (382·8-522·3) for cohort 2, 397·0 h (333·9-491·8) for cohort 3, and 466·7 h (351·0-889·6) for cohort 4. The elimination kinetics of those receiving repeated dosing (cohort 5) were similar to those of single-dose recipients (median elimination half-time 472·0 [385·6-592·0]). Anti-m102.4 antibodies were not detected at any time-point during the study. INTERPRETATION: Single and repeated dosing of m102.4 were well tolerated and safe, displayed linear pharmacokinetics, and showed no evidence of an immunogenic response. This study will inform future dosing regimens for m102.4 to achieve prolonged exposure for systemic efficacy to prevent and treat henipavirus infections. FUNDING: Queensland Department of Health, the National Health and Medical Research Council, and the National Hendra Virus Research Program.


Asunto(s)
Anticuerpos Monoclonales Humanizados/farmacocinética , Glicoproteínas/inmunología , Voluntarios Sanos , Henipavirus/inmunología , Inmunogenicidad Vacunal , Seguridad , Adulto , Anticuerpos Monoclonales Humanizados/administración & dosificación , Anticuerpos Monoclonales Humanizados/inmunología , Australia , Método Doble Ciego , Femenino , Cefalea/etiología , Humanos , Infusiones Intravenosas , Masculino
3.
Biol Lett ; 15(12): 20190423, 2019 12.
Artículo en Inglés | MEDLINE | ID: mdl-31822244

RESUMEN

Sampling reservoir hosts over time and space is critical to detect epizootics, predict spillover and design interventions. However, because sampling is logistically difficult and expensive, researchers rarely perform spatio-temporal sampling of many reservoir hosts. Bats are reservoirs of many virulent zoonotic pathogens such as filoviruses and henipaviruses, yet the highly mobile nature of these animals has limited optimal sampling of bat populations. To quantify the frequency of temporal sampling and to characterize the geographical scope of bat virus research, we here collated data on filovirus and henipavirus prevalence and seroprevalence in wild bats. We used a phylogenetically controlled meta-analysis to next assess temporal and spatial variation in bat virus detection estimates. Our analysis shows that only one in four bat virus studies report data longitudinally, that sampling efforts cluster geographically (e.g. filovirus data are available across much of Africa and Asia but are absent from Latin America and Oceania), and that sampling designs and reporting practices may affect some viral detection estimates (e.g. filovirus seroprevalence). Within the limited number of longitudinal bat virus studies, we observed high heterogeneity in viral detection estimates that in turn reflected both spatial and temporal variation. This suggests that spatio-temporal sampling designs are important to understand how zoonotic viruses are maintained and spread within and across wild bat populations, which in turn could help predict and preempt risks of zoonotic viral spillover.


Asunto(s)
Quirópteros , Filoviridae , Henipavirus , África , Animales , Asia , Estudios Seroepidemiológicos
4.
Viruses ; 11(9)2019 08 29.
Artículo en Inglés | MEDLINE | ID: mdl-31470664

RESUMEN

The Ghana virus (GhV) is phylogenetically related to the zoonotic henipaviruses Nipah (NiV) and Hendra virus. Although GhV uses the highly conserved receptor ephrin-B2, the fusogenicity is restricted to cell lines of bat origin. Furthermore, the surface expression of the GhV attachment glycoprotein (G) is reduced compared to NiV and most of this protein is retained in the endoplasmic reticulum (ER). Here, we generated truncated as well as chimeric GhV G proteins and investigated the influence of the structural domains (cytoplasmic tail, transmembrane domain, ectodomain) of this protein on the intracellular transport and the fusogenicity following coexpression with the GhV fusion protein (F). We demonstrate that neither the cytoplasmic tail nor the transmembrane domain is responsible for the intracellular retention of GhV G. Furthermore, the cytoplasmic tail of GhV G modulates the fusogenicity of GhV F and therefore controls the species-restricted fusogenicity of the GhV surface glycoproteins.


Asunto(s)
Fusión Celular , Henipavirus/metabolismo , Proteínas del Envoltorio Viral/química , Proteínas del Envoltorio Viral/metabolismo , Proteínas Virales de Fusión/metabolismo , Animales , Línea Celular , Quirópteros , Chlorocebus aethiops , Células HEK293 , Henipavirus/genética , Especificidad del Huésped , Humanos , Dominios Proteicos , Proteínas Recombinantes de Fusión/química , Proteínas Recombinantes de Fusión/genética , Proteínas Recombinantes de Fusión/metabolismo , Eliminación de Secuencia , Células Vero , Proteínas del Envoltorio Viral/genética , Proteínas Virales de Fusión/genética
5.
Proc Natl Acad Sci U S A ; 116(41): 20707-20715, 2019 10 08.
Artículo en Inglés | MEDLINE | ID: mdl-31548390

RESUMEN

Cedar virus (CedV) is a bat-borne henipavirus related to Nipah virus (NiV) and Hendra virus (HeV), zoonotic agents of fatal human disease. CedV receptor-binding protein (G) shares only ∼30% sequence identity with those of NiV and HeV, although they can all use ephrin-B2 as an entry receptor. We demonstrate that CedV also enters cells through additional B- and A-class ephrins (ephrin-B1, ephrin-A2, and ephrin-A5) and report the crystal structure of the CedV G ectodomain alone and in complex with ephrin-B1 or ephrin-B2. The CedV G receptor-binding site is structurally distinct from other henipaviruses, underlying its capability to accommodate additional ephrin receptors. We also show that CedV can enter cells through mouse ephrin-A1 but not human ephrin-A1, which differ by 1 residue in the key contact region. This is evidence of species specific ephrin receptor usage by a henipavirus, and implicates additional ephrin receptors in potential zoonotic transmission.


Asunto(s)
Efrina-B1/metabolismo , Efrina-B2/metabolismo , Efrina-B3/metabolismo , Infecciones por Henipavirus/virología , Henipavirus/fisiología , Receptores Virales/metabolismo , Proteínas del Envoltorio Viral/química , Animales , Fusión Celular , Efrina-B1/genética , Efrina-B2/genética , Efrina-B3/genética , Infecciones por Henipavirus/genética , Infecciones por Henipavirus/metabolismo , Humanos , Ratones , Mutación , Unión Proteica , Conformación Proteica , Receptores Virales/genética , Especificidad de la Especie , Proteínas del Envoltorio Viral/genética , Proteínas del Envoltorio Viral/metabolismo , Internalización del Virus
6.
Vet Microbiol ; 237: 108405, 2019 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-31561922

RESUMEN

Nipah virus (NiV), a BSL-4 pathogen, belongs to the genus Henipavirus within the family Paramyxoviridae. To date, no effective vaccine is available. Although most of the current vaccine studies aim to induce a neutralizing antibody response, it has become evident that a promising vaccine should target both, humoral and cell-mediated immune response. Virus-like particles (VLPs) have been shown to activate both arms of the adaptive immune response. In our study, VLPs composed of the NiV surface glycoproteins G and F and the matrix protein of the closely related Hendra virus (HeV M) induced both, a neutralizing antibody response and an antigen-specific CD8 T cell response with proliferation, IFN-γ expression and Th1 cytokine secretion in C57BL/6 mice. In contrast, in BALB/c mice only a neutralizing antibody response was observed. All three viral proteins included in the VLPs were shown to harbor CD8 T cell epitopes; however, the combination of all three proteins enhanced the magnitude of the CD8 T cell response. To conclude, VLPs represent a promising vaccine candidate, as they induce humoral as well as CD8 T cell-mediated immune responses.


Asunto(s)
Antígenos Virales/inmunología , Linfocitos T CD8-positivos/fisiología , Proliferación Celular/fisiología , Henipavirus/inmunología , Proteínas Virales/inmunología , Animales , Anticuerpos Neutralizantes , Chlorocebus aethiops , Citocinas , Regulación de la Expresión Génica/inmunología , Células HEK293 , Humanos , Interferón gamma/genética , Interferón gamma/metabolismo , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Plásmidos , Bazo/citología , Células TH1 , Células Th2 , Células Vero , Proteínas Virales/genética
7.
Philos Trans R Soc Lond B Biol Sci ; 374(1782): 20190021, 2019 09 30.
Artículo en Inglés | MEDLINE | ID: mdl-31401962

RESUMEN

Pathogen circulation among reservoir hosts is a precondition for zoonotic spillover. Unlike the acute, high morbidity infections typical in spillover hosts, infected reservoir hosts often exhibit low morbidity and mortality. Although it has been proposed that reservoir host infections may be persistent with recurrent episodes of shedding, direct evidence is often lacking. We construct a generalized SEIR (susceptible, exposed, infectious, recovered) framework encompassing 46 sub-models representing the full range of possible transitions among those four states of infection and immunity. We then use likelihood-based methods to fit these models to nine years of longitudinal data on henipavirus serology from a captive colony of Eidolon helvum bats in Ghana. We find that reinfection is necessary to explain observed dynamics; that acute infectious periods may be very short (hours to days); that immunity, if present, lasts about 1-2 years; and that recurring latent infection is likely. Although quantitative inference is sensitive to assumptions about serology, qualitative predictions are robust. Our novel approach helps clarify mechanisms of viral persistence and circulation in wild bats, including estimated ranges for key parameters such as the basic reproduction number and the duration of the infectious period. Our results inform how future field-based and experimental work could differentiate the processes of viral recurrence and reinfection in reservoir hosts. This article is part of the theme issue 'Dynamic and integrative approaches to understanding pathogen spillover'.


Asunto(s)
Quirópteros , Reservorios de Enfermedades/veterinaria , Infecciones por Henipavirus/veterinaria , Henipavirus/fisiología , Animales , Animales de Zoológico , Reservorios de Enfermedades/virología , Ghana/epidemiología , Infecciones por Henipavirus/epidemiología , Infecciones por Henipavirus/transmisión , Infecciones por Henipavirus/virología , Prevalencia , Estudios Seroepidemiológicos
8.
Vector Borne Zoonotic Dis ; 19(7): 455-465, 2019 07.
Artículo en Inglés | MEDLINE | ID: mdl-30985268

RESUMEN

Nipah virus (NiV) and Hendra virus (HeV) are closely related members within the genus Henipavirus, family Paramyxoviridae, for which fruit bats serve as the reservoir. The initial emergence of NiV infections in pigs and humans in Malaysia, and HeV infections in horses and humans in Australia, posed severe impacts on human and animal health, and continues threatening lives of humans and livestock within Southeast Asia and Australia. Recently, henipavirus-specific antibodies have also been detected in fruit bats in a number of sub-Saharan African countries and in Brazil, thereby considerably increasing the known geographic distribution of henipaviruses. Africa is progressively being recognized as a new high prevalence zone for henipaviruses, as deduced from serological and molecular evidence of past infections in Madagascar, Ghana, Republic of Congo, Gulf of Guinea, Zambia, Tanzania, Cameroon, and Nigeria lately. Serological data suggest henipavirus spillover from bats to livestock and human populations in Africa without reported clinical disease in any of these species. All virus isolation attempts have been abortive, highlighting the need for further investigations. The genome of the Ghanaian bat henipavirus designated Ghana virus (GhV), which was detected in a pteropid Eidolon helvum bat, is the only African henipavirus that has been completely sequenced limiting our current knowledge on the genetic diversity and pathogenesis of African henipaviruses. In this review, we summarize the available data on the circulation of henipaviruses in Africa, discuss potential sources for virus spillover, and highlight existing research gaps.


Asunto(s)
Quirópteros/virología , Infecciones por Henipavirus/epidemiología , Henipavirus , África/epidemiología , Animales , Anticuerpos Antivirales , Infecciones por Henipavirus/veterinaria , Infecciones por Henipavirus/virología , Humanos , Ganado/virología , Estudios Seroepidemiológicos , Zoonosis/virología
9.
Pathog Dis ; 77(2)2019 03 01.
Artículo en Inglés | MEDLINE | ID: mdl-30985897

RESUMEN

Nipah virus (NiV) and Hendra virus are highly pathogenic zoonotic viruses of the genus Henipavirus, family Paramyxoviridae. These viruses were first identified as the causative agents of severe respiratory and encephalitic disease in the 1990s across Australia and Southern Asia with mortality rates reaching up to 75%. While outbreaks of Nipah and Hendra virus infections remain rare and sporadic, there is concern that NiV has pandemic potential. Despite increased attention, little is understood about the neuropathogenesis of henipavirus infection. Neuropathogenesis appears to arise from dual mechanisms of vascular disease and direct parenchymal brain infection, but the relative contributions remain unknown while respiratory disease arises from vasculitis and respiratory epithelial cell infection. This review will address NiV basic clinical disease, pathology and pathogenesis with a particular focus on central nervous system (CNS) infection and address the necessity of a model of relapsed CNS infection. Additionally, the innate immune responses to NiV infection in vitro and in the CNS are reviewed as it is likely linked to any persistent CNS infection.


Asunto(s)
Enfermedades Virales del Sistema Nervioso Central/virología , Infecciones por Henipavirus/virología , Henipavirus/fisiología , Enfermedad Aguda , Edad de Inicio , Animales , Enfermedades Virales del Sistema Nervioso Central/diagnóstico , Enfermedades Virales del Sistema Nervioso Central/epidemiología , Enfermedades Virales del Sistema Nervioso Central/transmisión , Modelos Animales de Enfermedad , Susceptibilidad a Enfermedades , Infecciones por Henipavirus/diagnóstico , Infecciones por Henipavirus/epidemiología , Infecciones por Henipavirus/transmisión , Interacciones Huésped-Patógeno/inmunología , Humanos , Inmunidad Innata
10.
Viruses ; 11(3)2019 03 22.
Artículo en Inglés | MEDLINE | ID: mdl-30909389

RESUMEN

Syrian hamsters (Mesocricetus auratus) are a pathogenesis model for the Nipah virus (NiV), and we sought to determine if they are also susceptible to the Cedar virus (CedPV). Following intranasal inoculation with CedPV, virus replication occurred in the lungs and spleens of infected hamsters, a neutralizing antibody was produced in some hamsters within 8 days post-challenge, and no conspicuous signs of disease occurred. CedPV replicated to a similar magnitude as NiV-Bangladesh in type I IFN-deficient BHK-21 Syrian hamster fibroblasts but replicated 4 logs lower in type I IFN-competent primary Syrian hamster and human pulmonary endothelial cells, a principal target of henipaviruses. The coinfection of these cells with CedPV and NiV failed to rescue CedPV titers and did not diminish NiV titers, suggesting the replication machinery is virus-specific. Type I IFN response transcripts Ifna7, Ddx58, Stat1, Stat2, Ccl5, Cxcl10, Isg20, Irf7, and Iigp1 were all significantly elevated in CedPV-infected hamster endothelial cells, whereas Ifna7 and Iigp1 expression were significantly repressed during NiV infection. These results are consistent with the hypothesis that CedPV's inability to counter the host type I IFN response may, in part, contribute to its lack of pathogenicity. Because NiV causes a fatal disease in Syrian hamsters with similarities to human disease, this model will provide valuable information about the pathogenic mechanisms of henipaviruses.


Asunto(s)
Infecciones por Henipavirus/inmunología , Interacciones Huésped-Patógeno/inmunología , Inmunidad Innata , Replicación Viral , Animales , Coinfección/inmunología , Coinfección/virología , Cricetinae , Células Endoteliales/inmunología , Células Endoteliales/virología , Femenino , Henipavirus/patogenicidad , Henipavirus/fisiología , Humanos , Pulmón/virología , Virus Nipah/patogenicidad , Virus Nipah/fisiología , Bazo/virología
11.
Viruses ; 10(11)2018 11 01.
Artículo en Inglés | MEDLINE | ID: mdl-30388838

RESUMEN

Hendra virus (HeV) and Nipah virus (NiV) are among a group of emerging bat-borne paramyxoviruses that have crossed their species-barrier several times by infecting several hosts with a high fatality rate in human beings. Despite the fatal nature of their infection, a comprehensive study to explore their evolution and adaptation in different hosts is lacking. A study of codon usage patterns in henipaviruses may provide some fruitful insight into their evolutionary processes of synonymous codon usage and host-adapted evolution. Here, we performed a systematic evolutionary and codon usage bias analysis of henipaviruses. We found a low codon usage bias in the coding sequences of henipaviruses and that natural selection, mutation pressure, and nucleotide compositions shapes the codon usage patterns of henipaviruses, with natural selection being more important than the others. Also, henipaviruses showed the highest level of adaptation to bats of the genus Pteropus in the codon adaptation index (CAI), relative to the codon de-optimization index (RCDI), and similarity index (SiD) analyses. Furthermore, a comparison to recently identified henipa-like viruses indicated a high tRNA adaptation index of henipaviruses for human beings, mainly due to F, G and L proteins. Consequently, the study concedes the substantial emergence of henipaviruses in human beings, particularly when paired with frequent exposure to direct/indirect bat excretions.


Asunto(s)
Codón , Evolución Molecular , Infecciones por Henipavirus/virología , Henipavirus/genética , Especificidad del Huésped , Interacciones Huésped-Patógeno , Selección Genética , Adaptación Biológica , Animales , Quirópteros/virología , Genoma Viral , Genómica/métodos , Henipavirus/clasificación , Humanos , Filogenia
12.
Nat Commun ; 9(1): 3057, 2018 08 03.
Artículo en Inglés | MEDLINE | ID: mdl-30076298

RESUMEN

Recent studies indicate that nucleoli play critical roles in the DNA-damage response (DDR) via interaction of DDR machinery including NBS1 with nucleolar Treacle protein, a key mediator of ribosomal RNA (rRNA) transcription and processing. Here, using proteomics, confocal and single molecule super-resolution imaging, and infection under biosafety level-4 containment, we show that this nucleolar DDR pathway is targeted by infectious pathogens. We find that the matrix proteins of Hendra virus and Nipah virus, highly pathogenic viruses of the Henipavirus genus in the order Mononegavirales, interact with Treacle and inhibit its function, thereby silencing rRNA biogenesis, consistent with mimicking NBS1-Treacle interaction during a DDR. Furthermore, inhibition of Treacle expression/function enhances henipavirus production. These data identify a mechanism for viral modulation of host cells by appropriating the nucleolar DDR and represent, to our knowledge, the first direct intranucleolar function for proteins of any mononegavirus.


Asunto(s)
Nucléolo Celular/fisiología , Nucléolo Celular/virología , Daño del ADN/fisiología , Virus Hendra/fisiología , Virus Nipah/fisiología , Proteínas de Ciclo Celular/metabolismo , Células HEK293 , Células HeLa , Henipavirus/genética , Infecciones por Henipavirus , Interacciones Huésped-Patógeno/fisiología , Humanos , Mononegavirales/genética , Proteínas Nucleares/metabolismo , Nucleoproteínas/metabolismo , Proteómica , ARN Ribosómico/biosíntesis , Proteínas Virales/metabolismo
13.
Vet Microbiol ; 218: 90-97, 2018 May.
Artículo en Inglés | MEDLINE | ID: mdl-29685227

RESUMEN

Hendra virus (HeV) and Nipah virus (NiV) are highly pathogenic henipaviruses originating from fruit bats in Australia and Asia that can cause severe infections in livestock and humans. In recent years, also African bat henipaviruses were identified at the nucleic acid level. To assess their potential to replicate in non-bat species, several studies were performed to characterize the two surface glycoproteins required for virus entry and spread by cell-cell fusion. It has been shown that surface expression and fusion-helper function of the receptor-binding G protein of Kumasi virus (KV), the prototypic Ghanaian bat henipavirus, is reduced compared to other non-African henipavirus G proteins. Immunostainings and pulse-chase analysis revealed a delayed export of KV G from the ER. As defects in oligomerization of viral glycoproteins can be responsible for limited surface transport thereby restricting the bioactivity, we analyzed the oligomerization pattern of KV G. In contrast to HeV and NiV whose G proteins are known to be expressed at a dimer-tetramer ratio of 1:1, KV G almost exclusively formed stable tetramers or higher oligomers. KV G also showed less stringent requirements for defined stalk cysteines to form dimers and tetramers. Interestingly, any changes in the oligomeric forms negatively affected the fusion-helper activity although surface expression and receptor binding was unchanged. This clearly indicates that the formation of mostly higher oligomeric KV G forms is not a deficiency responsible for ER retention, but is rather a basic structural feature essential for the bioactivity of this African bat henipavirus glycoprotein.


Asunto(s)
Quirópteros/virología , Proteínas de Unión al GTP/química , Henipavirus/metabolismo , Glicoproteínas de Membrana/química , Proteínas del Envoltorio Viral , Animales , Retículo Endoplásmico/virología , Proteínas de Unión al GTP/metabolismo , Ghana/epidemiología , Henipavirus/química , Henipavirus/genética , Infecciones por Henipavirus/epidemiología , Infecciones por Henipavirus/virología , Glicoproteínas de Membrana/genética , Glicoproteínas de Membrana/metabolismo , Proteínas del Envoltorio Viral/química , Proteínas del Envoltorio Viral/metabolismo , Internalización del Virus
14.
Vet J ; 233: 25-34, 2018 03.
Artículo en Inglés | MEDLINE | ID: mdl-29486875

RESUMEN

Bat-borne viruses carry undeniable risks to the health of human beings and animals, and there is growing recognition of the need for a 'One Health' approach to understand their frequently complex spill-over routes. While domesticated animals can play central roles in major spill-over events of zoonotic bat-borne viruses, for example during the pig-amplified Malaysian Nipah virus outbreak of 1998-1999, the extent of their potential to act as bridging or amplifying species for these viruses has not been characterised systematically. This review aims to compile current knowledge on the role of domesticated animals as hosts of two types of bat-borne viruses, henipaviruses and filoviruses. A systematic literature search of these virus-host interactions in domesticated animals identified 72 relevant studies, which were categorised by year, location, design and type of evidence generated. The review then focusses on Africa as a case study, comparing research efforts in domesticated animals and bats with the distributions of documented human cases. Major gaps remain in our knowledge of the potential ability of domesticated animals to contract or spread these zoonoses. Closing these gaps will be necessary to fully evaluate and mitigate spill-over risks of these viruses, especially with global agricultural intensification.


Asunto(s)
Animales Domésticos/virología , Quirópteros/virología , Reservorios de Enfermedades/virología , Filoviridae , Henipavirus , África/epidemiología , Animales , Infecciones por Filoviridae/transmisión , Infecciones por Filoviridae/veterinaria , Infecciones por Henipavirus/transmisión , Infecciones por Henipavirus/veterinaria , Humanos , Zoonosis/transmisión , Zoonosis/virología
15.
PLoS Negl Trop Dis ; 12(3): e0006343, 2018 03.
Artículo en Inglés | MEDLINE | ID: mdl-29538374

RESUMEN

Henipavirus infection causes severe respiratory and neurological disease in humans that can be fatal. To characterize the pathogenic mechanisms of henipavirus infection in vivo, we performed experimental infections in ferrets followed by genome-wide gene expression analysis of lung and brain tissues. The Hendra, Nipah-Bangladesh, and Nipah-Malaysia strains caused severe respiratory and neurological disease with animals succumbing around 7 days post infection. Despite the presence of abundant viral shedding, animal-to-animal transmission did not occur. The host gene expression profiles of the lung tissue showed early activation of interferon responses and subsequent expression of inflammation-related genes that coincided with the clinical deterioration. Additionally, the lung tissue showed unchanged levels of lymphocyte markers and progressive downregulation of cell cycle genes and extracellular matrix components. Infection in the brain resulted in a limited breadth of the host responses, which is in accordance with the immunoprivileged status of this organ. Finally, we propose a model of the pathogenic mechanisms of henipavirus infection that integrates multiple components of the host responses.


Asunto(s)
Infecciones por Henipavirus/genética , Infecciones por Henipavirus/inmunología , Henipavirus/fisiología , Interacciones Huésped-Patógeno , Transcriptoma , Animales , Encéfalo/metabolismo , Encéfalo/virología , Ciclo Celular , Modelos Animales de Enfermedad , Matriz Extracelular/genética , Hurones/virología , Virus Hendra/inmunología , Virus Hendra/patogenicidad , Henipavirus/genética , Infecciones por Henipavirus/virología , Humanos , Inflamación , Interferones/genética , Pulmón/metabolismo , Pulmón/virología , Virus Nipah/inmunología , Virus Nipah/patogenicidad , Esparcimiento de Virus
16.
Antiviral Res ; 153: 101-113, 2018 05.
Artículo en Inglés | MEDLINE | ID: mdl-29601894

RESUMEN

Ebolaviruses, marburgviruses, and henipaviruses are zoonotic pathogens belonging to the Filoviridae and Paramyxoviridae families. They exemplify viruses that continue to spill over into the human population, causing outbreaks characterized by high mortality and significant clinical sequelae in survivors of infection. There are currently no approved small molecule therapeutics for use in humans against these viruses. In this study, we evaluated the antiviral activity of the nucleoside analog 4'-azidocytidine (4'N3-C, R1479) and its 2'-monofluoro- and 2'-difluoro-modified analogs (2'F-4'N3-C and 2'diF-4'N3-C) against representative paramyxoviruses (Nipah virus, Hendra virus, measles virus, and human parainfluenza virus 3) and filoviruses (Ebola virus, Sudan virus, and Ravn virus). We observed enhanced antiviral activity against paramyxoviruses with both 2'diF-4'N3-C and 2'F-4'N3-C compared to R1479. On the other hand, while R1479 and 2'diF-4'N3-C inhibited filoviruses similarly to paramyxoviruses, we observed 10-fold lower filovirus inhibition by 2'F-4'N3-C. To our knowledge, this is the first study to compare the susceptibility of paramyxoviruses and filoviruses to R1479 and its 2'-fluoro-modified analogs. The activity of these compounds against negative-strand RNA viruses endorses the development of 4'-modified nucleoside analogs as broad-spectrum therapeutics against zoonotic viruses of public health importance.


Asunto(s)
Antivirales/farmacología , Citidina/análogos & derivados , Ebolavirus/efectos de los fármacos , Henipavirus/efectos de los fármacos , Marburgvirus/efectos de los fármacos , Citidina/farmacología , Pruebas de Sensibilidad Microbiana
17.
Virol J ; 15(1): 56, 2018 03 27.
Artículo en Inglés | MEDLINE | ID: mdl-29587789

RESUMEN

BACKGROUND: Hendra virus and Nipah virus are zoonotic viruses that have caused severe to fatal disease in livestock and human populations. The isolation of Cedar virus, a non-pathogenic virus species in the genus Henipavirus, closely-related to the highly pathogenic Hendra virus and Nipah virus offers an opportunity to investigate differences in pathogenesis and receptor tropism among these viruses. METHODS: We constructed full-length cDNA clones of Cedar virus from synthetic oligonucleotides and rescued two replication-competent, recombinant Cedar virus variants: a recombinant wild-type Cedar virus and a recombinant Cedar virus that expresses a green fluorescent protein from an open reading frame inserted between the phosphoprotein and matrix genes. Replication kinetics of both viruses and stimulation of the interferon pathway were characterized in vitro. Cellular tropism for ephrin-B type ligands was qualitatively investigated by microscopy and quantitatively by a split-luciferase fusion assay. RESULTS: Successful rescue of recombinant Cedar virus expressing a green fluorescent protein did not significantly affect virus replication compared to the recombinant wild-type Cedar virus. We demonstrated that recombinant Cedar virus stimulated the interferon pathway and utilized the established Hendra virus and Nipah virus receptor, ephrin-B2, but not ephrin-B3 to mediate virus entry. We further characterized virus-mediated membrane fusion kinetics of Cedar virus with the known henipavirus receptors ephrin-B2 and ephrin-B3. CONCLUSIONS: The recombinant Cedar virus platform may be utilized to characterize the determinants of pathogenesis across the henipaviruses, investigate their receptor tropisms, and identify novel pan-henipavirus antivirals. Moreover, these experiments can be conducted safely under BSL-2 conditions.


Asunto(s)
Efrina-B2/metabolismo , Infecciones por Henipavirus/virología , Henipavirus/fisiología , Receptores Virales/metabolismo , Fusión Celular , Línea Celular , Efecto Citopatogénico Viral , Genes Reporteros , Proteínas Fluorescentes Verdes/genética , Henipavirus/genética , Henipavirus/metabolismo , Henipavirus/patogenicidad , Infecciones por Henipavirus/metabolismo , Interferón Tipo I/genética , Pruebas de Neutralización , Unión Proteica , Recombinación Genética , Genética Inversa , Proteínas del Envoltorio Viral/metabolismo , Tropismo Viral , Internalización del Virus , Replicación Viral
18.
PLoS One ; 13(2): e0191933, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29390028

RESUMEN

In 2011, an unusually large number of independent Hendra virus outbreaks were recorded on horse properties in Queensland and New South Wales, Australia. Urine from bat colonies adjacent to the outbreak sites were sampled and screened for Hendra and other viruses. Several novel paramyxoviruses were also isolated at different locations. Here one of the novel viruses, named Hervey virus (HerPV), is fully characterized by genome sequencing, annotation, phylogeny and in vitro host range, and its serological cross-reactivity and neutralization patterns are examined. HerPV may have ecological and spatial and temporal patterns similar to Hendra virus and could serve as a sentinel virus for the surveillance of this highly pathogenic virus. The suitability of HerPV as potential sentinel virus is further assessed by determining the serological prevalence of HerPV antibodies in fruit-eating bats from Australia, Indonesia, Papua New Guinea, Tanzania and the Gulf of Guinea, indicating the presence of similar viruses in regions beyond the Australian border.


Asunto(s)
Quirópteros/virología , Henipavirus/aislamiento & purificación , Paramyxovirinae/aislamiento & purificación , África/epidemiología , Animales , Anticuerpos Antivirales/inmunología , Australia/epidemiología , Línea Celular , Brotes de Enfermedades , Henipavirus/genética , Henipavirus/inmunología , Infecciones por Henipavirus/epidemiología , Infecciones por Henipavirus/virología , Secuenciación de Nucleótidos de Alto Rendimiento , Indonesia/epidemiología , Microscopía Confocal , Pruebas de Neutralización , Papúa Nueva Guinea/epidemiología , Paramyxovirinae/genética , Paramyxovirinae/inmunología
19.
Mol Biosyst ; 13(11): 2254-2267, 2017 Oct 24.
Artículo en Inglés | MEDLINE | ID: mdl-28972216

RESUMEN

Henipaviruses are severe human pathogens within the Paramyxoviridae family. Beyond the P protein, the Henipavirus P gene also encodes the V protein which shares with P its N-terminal, intrinsically disordered region (PNT) and possesses a unique C-terminal domain predicted to be folded and to bind zinc (ZnFD). Henipavirus V proteins antagonize IFN signaling through PNT-mediated binding to STAT1, and several paramyxoviral V proteins promote STAT1 degradation through binding to DDB1. Structural and molecular information on Henipavirus V proteins is lacking, and their ability to interact with DDB1 has not been documented yet. We cloned the V genes from Nipah and Hendra viruses and purified the V proteins from E. coli and DDB1 from insect cells. Using analytical size-exclusion chromatography, CD and SAXS we characterized the V proteins and their domains. Using pull-down and MST we assessed their binding abilities towards DDB1. We show that PNT remains disordered also in the context of the V protein, while the ZnFD adopts a predominant ß conformation. We also show that the V proteins interact with DDB1 predominantly via their ZnFD. This is the first experimental characterization of the Henipavirus V proteins and the first experimental evidence of their interaction with DDB1. The DDB1-ZnFD interaction constitutes a promising target for antiviral strategies. These studies provide a conceptual asset to design new antiviral strategies expected to reduce or abrogate the ability of these viruses to escape the innate immune response. They also contribute to illuminating the conformational behaviour of proteins encompassing large intrinsically disordered domains.


Asunto(s)
Proteínas de Unión al ADN/metabolismo , Henipavirus/metabolismo , Dominios y Motivos de Interacción de Proteínas , Desplegamiento Proteico , Proteínas Virales/química , Proteínas Virales/metabolismo , Dedos de Zinc , Secuencia de Aminoácidos , Dicroismo Circular , Interacciones Hidrofóbicas e Hidrofílicas , Espectrometría de Masas , Unión Proteica , Proteínas Recombinantes , Espectrofotometría Ultravioleta , Proteínas Virales/genética , Proteínas Virales/aislamiento & purificación , Difracción de Rayos X
20.
J Gen Virol ; 98(4): 563-576, 2017 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-28056216

RESUMEN

Viruses of the genus Henipavirus of the family Paramyxoviridae are zoonotic pathogens, which have emerged in Southeast Asia, Australia and Africa. Nipah virus (NiV) and Hendra virus are highly virulent pathogens transmitted from bats to animals and humans, while the henipavirus Cedar virus seems to be non-pathogenic in infection studies. The full replication cycle of the Paramyxoviridae occurs in the host cell's cytoplasm, where viral assembly is orchestrated by the matrix (M) protein. Unexpectedly, the NiV-M protein traffics through the nucleus as an essential step to engage the plasma membrane in preparation for viral budding/release. Comparative studies were performed to assess whether M protein nuclear localization is a common feature of the henipaviruses, including the recently sequenced (although not yet isolated) Ghanaian bat henipavirus (Kumasi virus, GH-M74a virus) and Mojiang virus. Live-cell confocal microscopy revealed that nuclear translocation of GFP-fused M protein is conserved between henipaviruses in both human- and bat-derived cell lines. However, the efficiency of M protein nuclear localization and virus-like particle budding competency varied. Additionally, Cedar virus-, Kumasi virus- and Mojiang virus-M proteins were mutated in a bipartite nuclear localization signal, indicating that a key lysine residue is essential for nuclear import, export and induction of budding events, as previously reported for NiV-M. The results of this study suggest that the M proteins of henipaviruses may utilize a similar nucleocytoplasmic trafficking pathway as an essential step during viral replication in both humans and bats.


Asunto(s)
Transporte Activo de Núcleo Celular , Henipavirus/genética , Henipavirus/fisiología , Proteínas de la Matriz Viral/genética , Proteínas de la Matriz Viral/metabolismo , Animales , Henipavirus/aislamiento & purificación , Humanos , Microscopía Confocal , Microscopía Fluorescente , Señales de Localización Nuclear , Transporte de Proteínas , Virosomas/genética , Virosomas/metabolismo
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