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1.
Sci Rep ; 9(1): 7329, 2019 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-31065012

RESUMO

A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has not been fixed in the paper.

2.
Emerg Infect Dis ; 25(6): 1144-1152, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31107231

RESUMO

Nipah virus (NiV) is a zoonotic pathogen that causes high case-fatality rates (CFRs) in humans. Two NiV strains have caused outbreaks: the Malaysia strain (NiVM), discovered in 1998-1999 in Malaysia and Singapore (≈40% CFR); and the Bangladesh strain (NiVB), discovered in Bangladesh and India in 2001 (≈80% CFR). Recently, NiVB in African green monkeys resulted in a more severe and lethal disease than NiVM. No NiV vaccines or treatments are licensed for human use. We assessed replication-restricted single-injection recombinant vesicular stomatitis vaccine NiV vaccine vectors expressing the NiV glycoproteins against NiVB challenge in African green monkeys. All vaccinated animals survived to the study endpoint without signs of NiV disease; all showed development of NiV F Ig, NiV G IgG, or both, as well as neutralizing antibody titers. These data show protective efficacy against a stringent and relevant NiVB model of human infection.

3.
Cell Host Microbe ; 25(1): 49-58.e5, 2019 01 09.
Artigo em Inglês | MEDLINE | ID: mdl-30629918

RESUMO

Recent and ongoing outbreaks of Ebola virus disease (EVD) underscore the unpredictable nature of ebolavirus reemergence and the urgent need for antiviral treatments. Unfortunately, available experimental vaccines and immunotherapeutics are specific for a single member of the Ebolavirus genus, Ebola virus (EBOV), and ineffective against other ebolaviruses associated with EVD, including Sudan virus (SUDV) and Bundibugyo virus (BDBV). Here we show that MBP134AF, a pan-ebolavirus therapeutic comprising two broadly neutralizing human antibodies (bNAbs), affords unprecedented effectiveness and potency as a therapeutic countermeasure to antigenically diverse ebolaviruses. MBP134AF could fully protect ferrets against lethal EBOV, SUDV, and BDBV infection, and a single 25-mg/kg dose was sufficient to protect NHPs against all three viruses. The development of MBP134AF provides a successful model for the rapid discovery and translational advancement of immunotherapeutics targeting emerging infectious diseases.


Assuntos
Anticorpos Monoclonais/imunologia , Anticorpos Monoclonais/uso terapêutico , Anticorpos Antivirais/imunologia , Anticorpos Antivirais/uso terapêutico , Ebolavirus/patogenicidade , Furões/virologia , Doença pelo Vírus Ebola/imunologia , Doença pelo Vírus Ebola/prevenção & controle , Bem-Estar do Animal , Animais , Anticorpos Monoclonais/administração & dosagem , Anticorpos Monoclonais/isolamento & purificação , Anticorpos Neutralizantes/administração & dosagem , Anticorpos Neutralizantes/imunologia , Anticorpos Neutralizantes/isolamento & purificação , Anticorpos Neutralizantes/uso terapêutico , Anticorpos Antivirais/administração & dosagem , Linhagem Celular , Cercopithecus aethiops , Modelos Animais de Doenças , Feminino , Filoviridae/imunologia , Infecções por Filoviridae/imunologia , Infecções por Filoviridae/prevenção & controle , Infecções por Filoviridae/virologia , Glicoproteínas/imunologia , Cobaias , Células HEK293 , Doença pelo Vírus Ebola/virologia , Humanos , Células Matadoras Naturais , Macaca , Macaca fascicularis , Masculino , Primatas , Análise de Sobrevida , Resultado do Tratamento , Proteínas Virais/imunologia
4.
J Infect Dis ; 218(suppl_5): S565-S573, 2018 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-29982718

RESUMO

Background: The 2013-2016 Ebola virus disease (EVD) epidemics in West Africa highlighted a need for effective therapeutics for treatment of the disease caused by filoviruses. Monoclonal antibodies (mAbs) are promising therapeutic candidates for prophylaxis or treatment of virus infections. Data about efficacy of human mAb monotherapy against filovirus infections in preclinical nonhuman primate models are limited. Methods: Previously, we described a large panel of human mAbs derived from the circulating memory B cells from Bundibugyo virus (BDBV) infection survivors that bind to the surface glycoprotein (GP) of the virus. We tested one of these neutralizing mAbs that recognized the glycan cap of the GP, designated mAb BDBV289, as monotherapy in rhesus macaques. Results: We found that recombinant mAb BDBV289-N could confer up to 100% protection to BDBV-infected rhesus macaques when treatment was initiated as late as 8 days after virus challenge. Protection was associated with survival and decreased viremia levels in the blood of treated animals. Conclusions: These findings define the efficacy of monotherapy of lethal BDBV infection with a glycan cap-specific mAb and identify a candidate mAb therapeutic molecule that could be included in antibody cocktails for prevention or treatment of ebolavirus infections.

6.
J Infect Dis ; 218(suppl_5): S582-S587, 2018 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-29939296

RESUMO

A recombinant vesicular stomatitis virus (rVSV) expressing the Marburg virus (MARV) Musoke variant glycoprotein fully protects macaques against 2 MARV variants and Ravn virus as a preventive vaccine and MARV variant Musoke as a postexposure treatment. To evaluate postexposure efficacy against the most pathogenic MARV variant, Angola, we engineered rVSVs expressing homologous Angola glycoprotein. Macaques were challenged with high or low doses of variant Angola and treated 20-30 minutes after exposure. A total of 25% and 60%-75% of treated macaques survived the high-dose and low-dose challenges, respectively. The more rapid disease progression of variant Angola versus variant Musoke may account for the incomplete protection observed.

7.
J Infect Dis ; 218(suppl_5): S448-S452, 2018 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-29955887

RESUMO

The domestic ferret was recently described as a uniformly lethal model for 3 species of Ebolavirus. More importantly, this new model utilizes nonadapted wild-type Ebolaviruses. Here, in a proof-of-concept study, we infected ferrets with different variants of the closely related Marburg and Ravn viruses using different doses and routes of exposure. Although ferrets produced a neutralizing humoral response to challenge, we did not observe disease or viremia in any animal. The lack of disease in ferrets underscores the notion that differential mechanisms to immunity among filoviruses exist and may provide a model to better understand how differences contribute to disease.

8.
Front Immunol ; 8: 1372, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29123522

RESUMO

Existing models of Ebola virus disease (EVD) suggest antigen-presenting cells are initial targets of Zaire ebolavirus (ZEBOV). In vitro studies have shown that ZEBOV infection of monocytes and macrophages results in the production of inflammatory mediators, which may cause lymphocyte apoptosis. However, these findings have not been corroborated by in vivo studies. In this study, we report the first longitudinal analysis of transcriptional changes in purified monocytes, T-cells, and B-cells isolated from cynomolgus macaques following infection with ZEBOV-Makona. Our data reveal monocytes as one of the major immune cell subsets that supports ZEBOV replication in vivo. In addition, we report a marked increase in the transcription of genes involved in inflammation, coagulation, and vascular disease within monocytes, suggesting that monocytes contribute to EVD manifestations. Further, genes important for antigen presentation and regulation of immunity were downregulated, potentially subverting development of adaptive immunity. In contrast, lymphocytes, which do not support ZEBOV replication, showed transcriptional changes limited to a small number of interferon-stimulated genes (ISGs) and a failure to upregulate genes associated with an antiviral effector immune response. Collectively, these data suggest that ZEBOV-infected monocytes play a significant role in ZEBOV-Makona pathogenesis and strategies to suppress virus replication or modify innate responses to infection in these cells should be a priority for therapeutic intervention.

9.
J Virol ; 2017 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-29142131

RESUMO

Previous studies demonstrated that a single intramuscular (IM) dose of an attenuated vesicular stomatitis virus vector (Vesiculovax™, rVSV-N4CT1) expressing the glycoprotein (GP) from the Mayinga strain of Zaire ebolavirus (EBOV) protected nonhuman primates (NHP) from lethal challenge with EBOV Kikwit and Makona strains. Here we studied the immunogenicity of an expanded range of attenuated rVSV vectors expressing filovirus GP in mice. Based on data from those studies an optimal attenuated tri-valent rVSV vector formulation was identified which included rVSV vectors expressing EBOV, Sudan ebolavirus (SUDV) or Angola strain of Marburg marburgvirus (MARV) GPs. NHPs were then vaccinated with a single dose of the tri-valent formulation, followed by lethal challenge 28 days later with each of the three corresponding filoviruses. At day 14 post vaccination, a serum IgG response specific for all three GPs was detected in all vaccinated macaques. A modest and balanced cell-mediated immune response specific for each GP protein was also detected in a majority of vaccinated macaques. No matter the level of total GP-specific immune response detected post vaccination, all vaccinated macaques were protected from disease and death following lethal challenge with each of the three filoviruses. These findings indicate that vaccination with a single dose of attenuated rVSV-N4CT1 vectors each expressing a single filovirus GP may provide protection against those filoviruses most commonly responsible for outbreaks of hemorrhagic fever in sub-Saharan Africa.IMPORTANCE The West African Ebola Zaire outbreak in 2013 showed that this disease was not only a regional concern, but a worldwide problem and highlighted the need for a safe and efficacious vaccine to be administered to the populace. However, other endemic pathogens like Ebola Sudan and Marburg also pose an important health risk to the public and therefore require development of a vaccine prior to the occurrence of an outbreak. The significance of our research was the development of a blended tri-valent filovirus vaccine that would elicit a balanced immune response when administered as a single dose and provide complete protection against a lethal challenge of all three filovirus pathogens.

10.
J Clin Invest ; 127(12): 4437-4448, 2017 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-29106386

RESUMO

Ebolaviruses and marburgviruses belong to the family Filoviridae and cause high lethality in infected patients. There are currently no licensed filovirus vaccines or antiviral therapies. The development of broad-spectrum therapies against members of the Marburgvirus genus, including Marburg virus (MARV) and Ravn virus (RAVV), is difficult because of substantial sequence variability. RNAi therapeutics offer a potential solution, as identification of conserved target nucleotide sequences may confer activity across marburgvirus variants. Here, we assessed the therapeutic efficacy of lipid nanoparticle (LNP) delivery of a single nucleoprotein-targeting (NP-targeting) siRNA in nonhuman primates at advanced stages of MARV or RAVV disease to mimic cases in which patients begin treatment for fulminant disease. Sixteen rhesus monkeys were lethally infected with MARV or RAVV and treated with NP siRNA-LNP, with MARV-infected animals beginning treatment four or five days after infection and RAVV-infected animals starting treatment three or six days after infection. While all untreated animals succumbed to disease, NP siRNA-LNP treatment conferred 100% survival of RAVV-infected macaques, even when treatment began just 1 day prior to the death of the control animals. In MARV-infected animals, day-4 treatment initiation resulted in 100% survival, and day-5 treatment resulted in 50% survival. These results identify a single siRNA therapeutic that provides broad-spectrum protection against both MARV and RAVV.

11.
Nat Med ; 23(10): 1146-1149, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28869611

RESUMO

There are no approved treatments for Lassa fever, which is endemic to the same regions of West Africa that were recently devastated by Ebola. Here we show that a combination of human monoclonal antibodies that cross-react with the glycoproteins of all four clades of Lassa virus is able to rescue 100% of cynomolgus macaques when treatment is initiated at advanced stages of disease, including up to 8 d after challenge.


Assuntos
Anticorpos Monoclonais/uso terapêutico , Anticorpos Neutralizantes/uso terapêutico , Anticorpos Antivirais/uso terapêutico , Febre Lassa/prevenção & controle , Animais , Reações Cruzadas , Ensaio de Imunoadsorção Enzimática , Humanos , Evasão da Resposta Imune/genética , Imuno-Histoquímica , Vírus Lassa/genética , Macaca fascicularis , RNA Viral/sangue , Distribuição Aleatória , Taxa de Sobrevida , Carga Viral
12.
Sci Rep ; 7(1): 9730, 2017 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-28852031

RESUMO

Zaire Ebolavirus (ZEBOV) continues to pose a significant threat to human health as highlighted by the recent epidemic that originated in West Africa and the ongoing outbreak in the Democratic Republic of the Congo. Although the ZEBOV variant responsible for this epidemic (Makona) shares significant genetic similarity with previously identified variants (Kikwit and Mayinga), recent reports suggest slower disease progression in nonhuman primates. However, the pathogenesis caused by the new variant is not fully understood. We present the first comprehensive approach in understanding ZEBOV-Makona pathogenesis in cynomolgus macaques by measuring changes in immune cell frequencies, plasma levels of immune mediators, and differentially expressed genes (DEGs) within whole blood (WB) and peripheral blood mononuclear cells (PBMC). Our combined approach revealed a link between: 1) increased interferon-stimulated gene expression, IFNα levels, and activated plasmacytoid dendritic cells; 2) higher proinflammatory gene expression, cytokine and chemokine levels, and non-classical monocytes; 3) gene signature of leukocyte activation and increased granulocytes; and 4) decreased expression of lymphocyte related genes and lymphopenia. In addition, our data strongly indicate delayed disease progression as well as limited overlap (~30%) in host transcriptome changes following ZEBOV-Makona infection compared to ZEBOV-Kikwit. These observations provide novel insight into the molecular mechanisms of ZEBOV-Makona pathogenesis.

13.
PLoS One ; 12(6): e0179728, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28651016

RESUMO

Light microscopy is a powerful tool in the detection and analysis of parasites, fungi, and prokaryotes, but has been challenging to use for the detection of individual virus particles. Unlabeled virus particles are too small to be visualized using standard visible light microscopy. Characterization of virus particles is typically performed using higher resolution approaches such as electron microscopy or atomic force microscopy. These approaches require purification of virions away from their normal millieu, requiring significant levels of expertise, and can only enumerate small numbers of particles per field of view. Here, we utilize a visible light imaging approach called Single Particle Interferometric Reflectance Imaging Sensor (SP-IRIS) that allows automated counting and sizing of thousands of individual virions. Virions are captured directly from complex solutions onto a silicon chip and then detected using a reflectance interference imaging modality. We show that the use of different imaging wavelengths allows the visualization of a multitude of virus particles. Using Violet/UV illumination, the SP-IRIS technique is able to detect individual flavivirus particles (~40 nm), while green light illumination is capable of identifying and discriminating between vesicular stomatitis virus and vaccinia virus (~360 nm). Strikingly, the technology allows the clear identification of filamentous infectious ebolavirus particles and virus-like particles. The ability to differentiate and quantify unlabeled virus particles extends the usefulness of traditional light microscopy and can be embodied in a straightforward benchtop approach allowing widespread applications ranging from rapid detection in biological fluids to analysis of virus-like particles for vaccine development and production.


Assuntos
Ebolavirus/ultraestrutura , Microscopia de Interferência/métodos , Microscopia Ultravioleta/métodos , Vírion/ultraestrutura , Zika virus/ultraestrutura , Animais , Desenho de Equipamento , Humanos , Microscopia Eletrônica de Varredura , Microscopia de Interferência/instrumentação , Microscopia Ultravioleta/instrumentação , Vírus Vaccinia/ultraestrutura , Vesiculovirus/ultraestrutura
14.
Sci Transl Med ; 9(384)2017 04 05.
Artigo em Inglês | MEDLINE | ID: mdl-28381540

RESUMO

As observed during the 2013-2016 Ebola virus disease epidemic, containment of filovirus outbreaks is challenging and made more difficult by the lack of approved vaccine or therapeutic options. Marburg and Ravn viruses are highly virulent and cause severe and frequently lethal disease in humans. Monoclonal antibodies (mAbs) are a platform technology in wide use for autoimmune and oncology indications. Previously, we described human mAbs that can protect mice from lethal challenge with Marburg virus. We demonstrate that one of these mAbs, MR191-N, can confer a survival benefit of up to 100% to Marburg or Ravn virus-infected rhesus macaques when treatment is initiated up to 5 days post-inoculation. These findings extend the small but growing body of evidence that mAbs can impart therapeutic benefit during advanced stages of disease with highly virulent viruses and could be useful in epidemic settings.


Assuntos
Anticorpos Monoclonais/uso terapêutico , Infecções por Filoviridae/tratamento farmacológico , Filoviridae/fisiologia , Doença do Vírus de Marburg/tratamento farmacológico , Marburgvirus/fisiologia , Animais , Proteção Cruzada , Infecções por Filoviridae/virologia , Cobaias , Humanos , Macaca fascicularis , Macaca mulatta , Doença do Vírus de Marburg/virologia , Projetos Piloto
15.
Lab Chip ; 17(5): 917-925, 2017 02 28.
Artigo em Inglês | MEDLINE | ID: mdl-28194457

RESUMO

Light microscopy is a straightforward and highly portable imaging approach that is used for the detection of parasites, fungi, and bacteria. The detection of individual virus particles has historically not been possible through this approach. Thus, characterization of virus particles is typically performed using high-energy approaches such as electron microscopy. These approaches require purification of virions away from its normal milieu, significant levels of expertise, and only count a small number of particles at a time. To correct these deficiencies we created a platform that allows label-free, point-of-need virus imaging and counting. We adapted a multiplex-capable, interferometric imaging technique to a closed-system that allows real-time particle detection in complex mixtures. To maximize virus particle binding we constructed a disposable device with a constant flow rate of ∼3 µl min-1. Biosafety was achieved by having a sealable sample addition port. Using this platform we were able to readily identify virus binding in a 20 minute experiment. Sensitivity was comparable to laboratory-based assays such as ELISA and plaque assay, and showed equal or better sensitivity against paper-based assays designed for point-of-need use. Our results demonstrate a platform that can be used for rapid multiplexed detection and visualization of whole virus particles. We envision this technology as a sample-to-answer platform for detection and visualization of viruses without the need for prior labeling. This would enable both research investigation of virus particle behavior and morphology and have the potential to be used in a diagnostic context, where direct imaging from samples such as blood and urine would be valuable.


Assuntos
Ebolavirus/isolamento & purificação , Interferometria/instrumentação , Dispositivos Lab-On-A-Chip , Virologia/instrumentação , Desenho de Equipamento , Processamento de Imagem Assistida por Computador , Limite de Detecção , Microscopia , Papel , Reprodutibilidade dos Testes , Vírion/isolamento & purificação
16.
Antiviral Res ; 138: 22-31, 2017 02.
Artigo em Inglês | MEDLINE | ID: mdl-27908828

RESUMO

Iminosugars are host-directed antivirals with broad-spectrum activity. The iminosugar, N-butyl-deoxynojirimycin (NB-DNJ or Miglustat®), is used in humans for treatment of Gaucher's disease and has mild antiviral properties. More potent analogs of NB-DNJ have been generated and have demonstrated activity against a variety of viruses including flaviviruses, influenza, herpesviruses and filoviruses. In the current study, a panel of analogs based on NB-DNJ was analyzed for activity against Ebola (EBOV) and Marburg viruses (MARV). The antiviral activity of NB-DNJ (UV-1), UV-2, UV-3, UV-4 and UV-5 against both EBOV and MARV was demonstrated in Vero cells. Subsequent studies to examine the activity of UV-4 and UV-5 using rodent models of EBOV and MARV were performed. In vivo efficacy studies provided inconsistent data following treatment with iminosugars using filovirus mouse models. A tolerability study in nonhuman primates demonstrated that UV-4 could be administered at much higher dose levels than rodents. Since UV-4 was active in vitro, had been demonstrated to be active against influenza and dengue in vivo, and was being tested in a Phase 1 clinical trial, a small proof-of-concept nonhuman primate trial was performed to determine whether this antiviral candidate could provide clinical benefit to EBOV-infected individuals. Administration of UV-4B did not provide a clinical or survival benefit to macaques infected with EBOV-Makona; however, dosing of animals was not optimal in this study. Efficacy may be improved by thrice daily dosing (e.g. by nasogastric tube feeding) to match the efficacious dosing regimens demonstrated against dengue and influenza viruses.


Assuntos
Antivirais/farmacologia , Antivirais/uso terapêutico , Ebolavirus/efeitos dos fármacos , Imino Açúcares/farmacologia , Imino Açúcares/uso terapêutico , Marburgvirus/efeitos dos fármacos , 1-Desoxinojirimicina/administração & dosagem , 1-Desoxinojirimicina/agonistas , 1-Desoxinojirimicina/análogos & derivados , 1-Desoxinojirimicina/farmacologia , 1-Desoxinojirimicina/uso terapêutico , Animais , Antivirais/administração & dosagem , Antivirais/química , Cercopithecus aethiops , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Imino Açúcares/administração & dosagem , Imino Açúcares/química , Macaca , Camundongos , Modelos Animais , Células Vero
17.
Nat Microbiol ; 1(10): 16142, 2016 08 22.
Artigo em Inglês | MEDLINE | ID: mdl-27670117

RESUMO

Although significant progress has been made in developing therapeutics against Zaire ebolavirus, these therapies do not protect against other Ebola species such as Sudan ebolavirus (SUDV). Here, we describe an RNA interference therapeutic comprising siRNA targeting the SUDV VP35 gene encapsulated in lipid nanoparticle (LNP) technology with increased potency beyond formulations used in TKM-Ebola clinical trials. Twenty-five rhesus monkeys were challenged with a lethal dose of SUDV. Twenty animals received siRNA-LNP beginning at 1, 2, 3, 4 or 5 days post-challenge. VP35-targeting siRNA-LNP treatment resulted in up to 100% survival, even when initiated when fever, viraemia and disease signs were evident. Treatment effectively controlled viral replication, mediating up to 4 log10 reductions after dosing. Mirroring clinical findings, a correlation between high viral loads and fatal outcome was observed, emphasizing the importance of stratifying efficacy according to viral load. In summary, strong survival benefit and rapid control of SUDV replication by VP35-targeting LNP confirm its therapeutic potential in combatting this lethal disease.


Assuntos
Doença pelo Vírus Ebola/terapia , Lipídeos , Interferência de RNA , RNA Interferente Pequeno/uso terapêutico , Animais , Anticorpos Antivirais , Modelos Animais de Doenças , Composição de Medicamentos , Ebolavirus/isolamento & purificação , Ebolavirus/patogenicidade , Doença pelo Vírus Ebola/virologia , Células Hep G2 , Humanos , Macaca mulatta , Nanopartículas/administração & dosagem , Nanopartículas/química , RNA Interferente Pequeno/genética , Sudão , Carga Viral/efeitos dos fármacos , Proteínas Virais Reguladoras e Acessórias/genética , Proteínas Virais Reguladoras e Acessórias/metabolismo , Viremia/terapia , Replicação Viral
18.
J Infect Dis ; 214(suppl 3): S234-S242, 2016 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-27638947

RESUMO

A molecular diagnostic method for robust detection of Ebola virus (EBOV) at the point of care (POC) directly from blood samples is described. This assay is based on reverse transcriptase loop-mediated isothermal amplification (RT-LAMP) of the glycoprotein gene of EBOV. Complete reaction formulations were lyophilized in 0.2-mL polymerase chain reaction tubes. RT-LAMP reactions were performed on a battery-operated isothermal instrument. Limit of detection of this RT-LAMP assay was 2.8 × 102 plaque-forming units (PFU)/test and 1 × 103 PFU/test within 40 minutes for EBOV-Kikwit and EBOV-Makona, respectively. This assay was found to be specific for the detection of EBOV, as no nonspecific amplification was detected in blood samples spiked with closely related viruses and other pathogens. These results showed that this diagnostic test can be used at the point of care for rapid and specific detection of EBOV directly from blood with high sensitivity within 40 minutes.


Assuntos
Ebolavirus/isolamento & purificação , Doença pelo Vírus Ebola/diagnóstico , Técnicas de Amplificação de Ácido Nucleico/métodos , Sistemas Automatizados de Assistência Junto ao Leito , RNA Viral/sangue , Ebolavirus/genética , Doença pelo Vírus Ebola/virologia , Humanos , Técnicas de Diagnóstico Molecular , RNA Viral/genética , Sensibilidade e Especificidade
19.
J Infect Dis ; 214(suppl 3): S210-S217, 2016 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-27587634

RESUMO

BACKGROUND: Ebola virus disease (EVD) is a severe viral illness caused by Ebola virus (EBOV). The 2013-2016 EVD outbreak in West Africa is the largest recorded, with >11 000 deaths. Development of the ReEBOV Antigen Rapid Test (ReEBOV RDT) was expedited to provide a point-of-care test for suspected EVD cases. METHODS: Recombinant EBOV viral protein 40 antigen was used to derive polyclonal antibodies for RDT and enzyme-linked immunosorbent assay development. ReEBOV RDT limits of detection (LOD), specificity, and interference were analytically validated on the basis of Food and Drug Administration (FDA) guidance. RESULTS: The ReEBOV RDT specificity estimate was 95% for donor serum panels and 97% for donor whole-blood specimens. The RDT demonstrated sensitivity to 3 species of Ebolavirus (Zaire ebolavirus, Sudan ebolavirus, and Bundibugyo ebolavirus) associated with human disease, with no cross-reactivity by pathogens associated with non-EBOV febrile illness, including malaria parasites. Interference testing exhibited no reactivity by medications in common use. The LOD for antigen was 4.7 ng/test in serum and 9.4 ng/test in whole blood. Quantitative reverse transcription-polymerase chain reaction testing of nonhuman primate samples determined the range to be equivalent to 3.0 × 105-9.0 × 108 genomes/mL. CONCLUSIONS: The analytical validation presented here contributed to the ReEBOV RDT being the first antigen-based assay to receive FDA and World Health Organization emergency use authorization for this EVD outbreak, in February 2015.


Assuntos
Antígenos Virais/sangue , Surtos de Doenças , Ebolavirus/imunologia , Doença pelo Vírus Ebola/diagnóstico , Sistemas Automatizados de Assistência Junto ao Leito , Proteínas da Matriz Viral/sangue , África Ocidental/epidemiologia , Animais , Ebolavirus/isolamento & purificação , Ensaio de Imunoadsorção Enzimática , Doença pelo Vírus Ebola/virologia , Humanos , Imunoensaio , Limite de Detecção , Kit de Reagentes para Diagnóstico , Sensibilidade e Especificidade
20.
J Infect Dis ; 214(suppl 3): S367-S374, 2016 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-27571900

RESUMO

BACKGROUND: Convalescent serum and blood were used to treat patients during outbreaks of Zaire ebolavirus (ZEBOV) infection in 1976 and 1995, with inconclusive results. During the recent 2013-2016 West African epidemic, serum/plasma from survivors of ZEBOV infection was used to treat patients in the affected countries and several repatriated patients. The effectiveness of this strategy remains unknown. METHODS: Nine rhesus monkeys were experimentally infected with ZEBOV-Makona. Beginning on day 3 after exposure (at the onset of viremia), 4 animals were treated with homologous ZEBOV-Makona convalescent macaque sera, 3 animals were treated in parallel with heterologous Sudan ebolavirus (SEBOV) convalescent macaque sera, and 2 animals served as positive controls and were not treated. Surviving animals received additional treatments on days 6 and 9. RESULTS: Both untreated control animals died on postinfection day 9. All 4 ZEBOV-Makona-infected macaques treated with homologous ZEBOV-Makona convalescent sera died on days 8-9. One macaque treated with heterologous SEBOV convalescent sera survived, while the other animals treated with the heterologous SEBOV sera died on days 7 and 9. CONCLUSIONS: The findings suggest that convalescent sera alone is not sufficient for providing 100% protection against lethal ZEBOV infection when administered at the onset of viremia.


Assuntos
Ebolavirus/imunologia , Doença pelo Vírus Ebola/prevenção & controle , Imunização Passiva , Animais , Convalescença , Feminino , Doença pelo Vírus Ebola/virologia , Humanos , Macaca mulatta , Masculino , Soro/imunologia , Viremia
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