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1.
Nat Commun ; 12(1): 1153, 2021 02 19.
Artigo em Inglês | MEDLINE | ID: mdl-33608536

RESUMO

Zaire ebolavirus (EBOV) is a highly pathogenic filovirus which can result in Ebola virus disease (EVD); a serious medical condition that presents as flu like symptoms but then often leads to more serious or fatal outcomes. The 2013-16 West Africa epidemic saw an unparalleled number of cases. Here we show characterisation and identification of T cell epitopes in surviving patients from Guinea to the EBOV glycoprotein. We perform interferon gamma (IFNγ) ELISpot using a glycoprotein peptide library to identify T cell epitopes and determine the CD4+ or CD8+ T cell component response. Additionally, we generate data on the T cell phenotype and measure polyfunctional cytokine secretion by these antigen specific cells. We show candidate peptides able to elicit a T cell response in EBOV survivors and provide inferred human leukocyte antigen (HLA) allele restriction. This data informs on the long-term T cell response to Ebola virus disease and highlights potentially important immunodominant peptides.


Assuntos
Ebolavirus/imunologia , Epitopos de Linfócito T/imunologia , Glicoproteínas/imunologia , Doença pelo Vírus Ebola/imunologia , Linfócitos T/imunologia , África Ocidental/epidemiologia , Linfócitos T CD4-Positivos , Linfócitos T CD8-Positivos , Ebolavirus/genética , ELISPOT , Epidemias , Glicoproteínas/genética , Doença pelo Vírus Ebola/epidemiologia , Humanos , Imunidade Celular , Interferon gama , Sobreviventes
2.
Nature ; 590(7846): 468-472, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33505020

RESUMO

Neutralizing antibody function provides a foundation for the efficacy of vaccines and therapies1-3. Here, using a robust in vitro Ebola virus (EBOV) pseudo-particle infection assay and a well-defined set of solid-phase assays, we describe a wide spectrum of antibody responses in a cohort of healthy survivors of the Sierra Leone EBOV outbreak of 2013-2016. Pseudo-particle virus-neutralizing antibodies correlated with total anti-EBOV reactivity and neutralizing antibodies against live EBOV. Variant EBOV glycoproteins (1995 and 2014 strains) were similarly neutralized. During longitudinal follow-up, antibody responses fluctuated in a 'decay-stimulation-decay' pattern that suggests de novo restimulation by EBOV antigens after recovery. A pharmacodynamic model of antibody reactivity identified a decay half-life of 77-100 days and a doubling time of 46-86 days in a high proportion of survivors. The highest antibody reactivity was observed around 200 days after an individual had recovered. The model suggests that EBOV antibody reactivity declines over 0.5-2 years after recovery. In a high proportion of healthy survivors, antibody responses undergo rapid restimulation. Vigilant follow-up of survivors and possible elective de novo antigenic stimulation by vaccine immunization should be considered in order to prevent EBOV viral recrudescence in recovering individuals and thereby to mitigate the potential risk of reseeding an outbreak.


Assuntos
Anticorpos Antivirais/sangue , Anticorpos Antivirais/imunologia , Convalescença , Ebolavirus/imunologia , Doença pelo Vírus Ebola/imunologia , Sobreviventes , Adolescente , Adulto , África Ocidental/epidemiologia , Anticorpos Neutralizantes/sangue , Anticorpos Neutralizantes/imunologia , Estudos de Coortes , Feminino , Meia-Vida , Doença pelo Vírus Ebola/sangue , Doença pelo Vírus Ebola/epidemiologia , Doença pelo Vírus Ebola/prevenção & controle , Humanos , Masculino , Pessoa de Meia-Idade , Testes de Neutralização , Fatores de Tempo , Viremia/sangue , Viremia/imunologia , Adulto Jovem
4.
Front Immunol ; 11: 572567, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33101294

RESUMO

Immunological adaptations in pregnancy allow maternal tolerance of the semi-allogeneic fetus but also increase maternal susceptibility to infection. At implantation, the endometrial stroma, glands, arteries and immune cells undergo anatomical and functional transformation to create the decidua, the specialized secretory endometrium of pregnancy. The maternal decidua and the invading fetal trophoblast constitute a dynamic junction that facilitates a complex immunological dialogue between the two. The decidual and peripheral immune systems together assume a pivotal role in regulating the critical balance between tolerance and defense against infection. Throughout pregnancy, this equilibrium is repeatedly subjected to microbial challenge. Acute viral infection in pregnancy is associated with a wide spectrum of adverse consequences for both mother and fetus. Vertical transmission from mother to fetus can cause developmental anomalies, growth restriction, preterm birth and stillbirth, while the mother is predisposed to heightened morbidity and maternal death. A rapid, effective response to invasive pathogens is therefore essential in order to avoid overwhelming maternal infection and consequent fetal compromise. This sentinel response is mediated by the innate immune system: a heritable, highly evolutionarily conserved system comprising physical barriers, antimicrobial peptides (AMP) and a variety of immune cells-principally neutrophils, macrophages, dendritic cells, and natural killer cells-which express pattern-receptors that detect invariant molecular signatures unique to pathogenic micro-organisms. Recognition of these signatures during acute infection triggers signaling cascades that enhance antimicrobial properties such as phagocytosis, secretion of pro-inflammatory cytokines and activation of the complement system. As well as coordinating the initial immune response, macrophages and dendritic cells present microbial antigens to lymphocytes, initiating and influencing the development of specific, long-lasting adaptive immunity. Despite extensive progress in unraveling the immunological adaptations of pregnancy, pregnant women remain particularly susceptible to certain acute viral infections and continue to experience mortality rates equivalent to those observed in pandemics several decades ago. Here, we focus specifically on the pregnancy-induced vulnerabilities in innate immunity that contribute to the disproportionately high maternal mortality observed in the following acute viral infections: Lassa fever, Ebola virus disease (EVD), dengue fever, hepatitis E, influenza, and novel coronavirus infections.


Assuntos
Decídua/imunologia , Placenta/imunologia , Viroses/imunologia , Imunidade Adaptativa/imunologia , Infecções por Coronavirus/imunologia , Infecções por Coronavirus/patologia , Dengue/imunologia , Dengue/patologia , Feminino , Doença pelo Vírus Ebola/imunologia , Doença pelo Vírus Ebola/patologia , Hepatite E/imunologia , Hepatite E/patologia , Humanos , Tolerância Imunológica/imunologia , Imunidade Inata/imunologia , Influenza Humana/imunologia , Influenza Humana/patologia , Febre Lassa/imunologia , Febre Lassa/patologia , Pandemias , Pneumonia Viral/imunologia , Pneumonia Viral/patologia , Gravidez
5.
PLoS Negl Trop Dis ; 14(9): e0008602, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32886656

RESUMO

Besides the common Fc receptor (FcR)-mediated mechanism of antibody-dependent enhancement (ADE), Ebola virus (EBOV) is known to utilize the complement component C1q for ADE of infection. This mechanism is FcR-independent and mediated by cross-linking of virus-antibody-C1q complexes to cell surface C1q receptors, leading to enhanced viral entry into cells. Using confocal microscopy, we found that virus-like particles (VLPs) consisting of EBOV glycoprotein, nucleoprotein, and matrix protein attached to the surface of human kidney 293 cells more efficiently in the presence of an ADE monoclonal antibody and C1q than with the antibody or C1q alone, and that there was no significant difference in the efficiency of VLP uptake into endosomes between the C1q-mediated ADE and non-ADE entry. Accordingly, both ADE and non-ADE infection were similarly decreased by inhibitors of the signaling pathways known to be required for endocytosis. These results suggest that C1q-mediated ADE of EBOV infection is simply caused by increased attachment of virus particles to the cell surface, which is distinct from the mechanism of FcR-mediated ADE requiring intracellular signaling to promote phagocytosis/macropinocytosis.


Assuntos
Anticorpos Facilitadores/imunologia , Complemento C1q/metabolismo , Ebolavirus/imunologia , Doença pelo Vírus Ebola/imunologia , Glicoproteínas de Membrana/metabolismo , Receptores de Complemento/metabolismo , Animais , Anticorpos Monoclonais/imunologia , Anticorpos Antivirais/imunologia , Linhagem Celular , Chlorocebus aethiops , Ebolavirus/patogenicidade , Endocitose/imunologia , Células HEK293 , Doença pelo Vírus Ebola/patologia , Humanos , Células Vero , Proteínas Virais/imunologia , Proteínas Virais/metabolismo , Ligação Viral
7.
Science ; 370(6513): 241-247, 2020 10 09.
Artigo em Inglês | MEDLINE | ID: mdl-32855215

RESUMO

Recent outbreaks of Ebola virus (EBOV) and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have exposed our limited therapeutic options for such diseases and our poor understanding of the cellular mechanisms that block viral infections. Using a transposon-mediated gene-activation screen in human cells, we identify that the major histocompatibility complex (MHC) class II transactivator (CIITA) has antiviral activity against EBOV. CIITA induces resistance by activating expression of the p41 isoform of invariant chain CD74, which inhibits viral entry by blocking cathepsin-mediated processing of the Ebola glycoprotein. We further show that CD74 p41 can block the endosomal entry pathway of coronaviruses, including SARS-CoV-2. These data therefore implicate CIITA and CD74 in host defense against a range of viruses, and they identify an additional function of these proteins beyond their canonical roles in antigen presentation.


Assuntos
Antígenos de Diferenciação de Linfócitos B/fisiologia , Betacoronavirus/fisiologia , Infecções por Coronavirus/imunologia , Ebolavirus/fisiologia , Doença pelo Vírus Ebola/imunologia , Antígenos de Histocompatibilidade Classe II/fisiologia , Interações Hospedeiro-Patógeno/imunologia , Proteínas Nucleares/fisiologia , Pneumonia Viral/imunologia , Transativadores/fisiologia , Internalização do Vírus , Antígenos de Diferenciação de Linfócitos B/genética , Linhagem Celular Tumoral , Infecções por Coronavirus/virologia , Elementos de DNA Transponíveis , Endossomos/virologia , Testes Genéticos , Doença pelo Vírus Ebola/virologia , Antígenos de Histocompatibilidade Classe II/genética , Interações Hospedeiro-Patógeno/genética , Humanos , Proteínas Nucleares/genética , Pandemias , Pneumonia Viral/virologia , Transativadores/genética , Transcrição Genética
8.
PLoS One ; 15(8): e0238196, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32841291

RESUMO

The need for an efficacious vaccine against highly pathogenic filoviruses was reinforced by the devastating 2014-2016 outbreak of Ebola virus (EBOV) disease (EVD) in Guinea, Sierra Leone, and Liberia that resulted in over 28,000 cases and over 11,300 deaths. In addition, the 2018-2020 outbreak in the Democratic Republic of the Congo currently has over 3,400 cases and over 2,200 deaths. A fully licensed vaccine and at least one other investigational vaccine are being deployed to combat this EVD outbreak. To support vaccine development and pre-clinical/clinical testing a Filovirus Animal Nonclinical Group (FANG) human anti-EBOV GP IgG ELISA was developed to measure anti-EBOV GP IgG antibodies. This ELISA is currently being used in multiple laboratories. Reported here is a characterization of an interlaboratory statistical analysis of the human anti-EBOV GP IgG ELISA as part of a collaborative study between five participating laboratories. Each laboratory used similar method protocols and reagents to measure anti-EBOV GP IgG levels in human serum samples from a proficiency panel consisting of ten serum samples created by the differential dilution of a serum sample positive for anti-GP IgG antibodies (BMIZAIRE105) with negative serum (BMI529). The total assay variability (inter- and intra-assay variability) %CVs observed at each laboratory ranged from 12.2 to 30.6. Intermediate precision (inter-assay variability) for the laboratory runs ranged from 8.9 to 21.7%CV and repeatability (intra-assay variability) %CVs ranged from 7.2 to 23.7. The estimated slope for the relationship between log10(Target Concentration) and the log10(Observed Concentration) across all five laboratories was 0.95 with a 90% confidence interval of (0.93, 0.97). Equivalence test results showed that the 90% confidence interval for the ratios for the sample-specific mean concentrations at the five individual labs to the overall laboratory consensus value were within the equivalence bounds of 0.80 to 1.25 for each laboratory and test sample, except for six test samples from Lab D, two samples from Lab B1, and one sample from Lab B2. The mean laboratory concentrations for Lab D were less than those from the other laboratories by 20% on average across the serum samples. The evaluation of the proficiency panel at these laboratories provides a limited assessment of assay precision (intermediate precision, repeatability, and total assay variability), dilutional linearity, and accuracy. This evaluation suggests that the within-laboratory performance of the anti-EBOV GP IgG ELISA as implemented at the five laboratories is consistent with the intended use of the assay based on the acceptance criteria used by laboratories that have validated the assay. However, the assessment of between-laboratory performance revealed lower observed concentrations at Lab D and greater variability in assay results at Lab B1 relative to other laboratories.


Assuntos
Anticorpos Antivirais/sangue , Ebolavirus/imunologia , Ensaio de Imunoadsorção Enzimática/normas , Doença pelo Vírus Ebola/imunologia , Proteínas Virais/imunologia , África Ocidental/epidemiologia , Animais , República Democrática do Congo/epidemiologia , Surtos de Doenças , Vacinas contra Ebola/imunologia , Vacinas contra Ebola/isolamento & purificação , Ensaio de Imunoadsorção Enzimática/estatística & dados numéricos , Doença pelo Vírus Ebola/epidemiologia , Doença pelo Vírus Ebola/prevenção & controle , Humanos , Imunoglobulina G/sangue , Laboratórios , Variações Dependentes do Observador
9.
Nat Commun ; 11(1): 3736, 2020 07 27.
Artigo em Inglês | MEDLINE | ID: mdl-32719371

RESUMO

A replication-competent vesicular stomatitis virus vaccine expressing the Ebola virus (EBOV) glycoprotein (GP) (rVSV-ZEBOV) was successfully used during the 2013-16 EBOV epidemic. Additionally, chimeric and human monoclonal antibodies (mAb) against the EBOV GP have shown promise in animals and humans when administered therapeutically. Uncertainty exists regarding the efficacy of postexposure antibody treatments in the event of a known exposure of a recent rVSV-ZEBOV vaccinee. Here, we model a worst-case scenario using rhesus monkeys vaccinated or unvaccinated with the rVSV-ZEBOV vaccine. We demonstrate that animals challenged with a uniformly lethal dose of EBOV one day following vaccination, and then treated with the anti-EBOV GP mAb MIL77 starting 3 days postexposure show no evidence of clinical illness and survive challenge. In contrast, animals receiving only vaccination or only mAb-based therapy become ill, with decreased survival compared to animals vaccinated and subsequently treated with MIL77. These results suggest that rVSV-ZEBOV augments immunotherapy.


Assuntos
Anticorpos Monoclonais/uso terapêutico , Anticorpos Antivirais/uso terapêutico , Vacinas contra Ebola/imunologia , Doença pelo Vírus Ebola/imunologia , Doença pelo Vírus Ebola/prevenção & controle , Profilaxia Pós-Exposição , Vacinação , Vírus da Estomatite Vesicular Indiana/imunologia , Animais , Anticorpos Monoclonais/administração & dosagem , Anticorpos Monoclonais/imunologia , Anticorpos Antivirais/administração & dosagem , Anticorpos Antivirais/imunologia , Doença pelo Vírus Ebola/patologia , Doença pelo Vírus Ebola/virologia , Humanos , Imunoglobulina G/sangue , Imunoglobulina M/sangue , Estimativa de Kaplan-Meier , Macaca mulatta , Resultado do Tratamento , Carga Viral/imunologia
10.
Trends Biotechnol ; 38(9): 943-947, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32600777

RESUMO

Vaccine solutions rarely reach the public until after an outbreak abates; an Ebola vaccine was approved 5 years after peak outbreak and SARS, MERS, and Zika vaccines are still in clinical development. Despite massive leaps forward in rapid science, other regulatory bottlenecks are hamstringing the global effort for pandemic vaccines.


Assuntos
Infecções por Coronavirus/prevenção & controle , Aprovação de Drogas/organização & administração , Doença pelo Vírus Ebola/prevenção & controle , Influenza Humana/prevenção & controle , Pandemias/prevenção & controle , Pneumonia Viral/prevenção & controle , Vacinas Virais/biossíntese , Betacoronavirus/efeitos dos fármacos , Betacoronavirus/imunologia , Betacoronavirus/patogenicidade , Infecções por Coronavirus/epidemiologia , Infecções por Coronavirus/imunologia , Infecções por Coronavirus/virologia , Vacinas contra Ebola/administração & dosagem , Vacinas contra Ebola/biossíntese , Ebolavirus/efeitos dos fármacos , Ebolavirus/imunologia , Ebolavirus/patogenicidade , Europa (Continente)/epidemiologia , Saúde Global/tendências , Regulamentação Governamental , Doença pelo Vírus Ebola/epidemiologia , Doença pelo Vírus Ebola/imunologia , Doença pelo Vírus Ebola/virologia , Humanos , Vírus da Influenza A Subtipo H1N1/genética , Vírus da Influenza A Subtipo H1N1/imunologia , Vacinas contra Influenza/administração & dosagem , Vacinas contra Influenza/biossíntese , Influenza Humana/epidemiologia , Influenza Humana/imunologia , Influenza Humana/virologia , Coronavírus da Síndrome Respiratória do Oriente Médio/efeitos dos fármacos , Coronavírus da Síndrome Respiratória do Oriente Médio/imunologia , Coronavírus da Síndrome Respiratória do Oriente Médio/patogenicidade , Pneumonia Viral/epidemiologia , Pneumonia Viral/imunologia , Pneumonia Viral/virologia , Vírus da SARS/efeitos dos fármacos , Vírus da SARS/imunologia , Vírus da SARS/patogenicidade , Síndrome Respiratória Aguda Grave/epidemiologia , Síndrome Respiratória Aguda Grave/imunologia , Síndrome Respiratória Aguda Grave/prevenção & controle , Síndrome Respiratória Aguda Grave/virologia , Estados Unidos/epidemiologia , Vacinas Virais/administração & dosagem , Zika virus/efeitos dos fármacos , Zika virus/imunologia , Zika virus/patogenicidade , Infecção por Zika virus/epidemiologia , Infecção por Zika virus/imunologia , Infecção por Zika virus/prevenção & controle , Infecção por Zika virus/virologia
11.
Nat Commun ; 11(1): 3730, 2020 07 24.
Artigo em Inglês | MEDLINE | ID: mdl-32709840

RESUMO

Long-term follow up studies from Ebola virus disease (EVD) survivors (EBOV_S) are lacking. Here, we evaluate immune and gene expression profiles in 35 Guinean EBOV_S from the last West African outbreak, a median of 23 months (IQR [18-25]) after discharge from treatment center. Compared with healthy donors, EBOV_S exhibit increases of blood markers of inflammation, intestinal tissue damage, T cell and B cell activation and a depletion of circulating dendritic cells. All survivors have EBOV-specific IgG antibodies and robust and polyfunctional EBOV-specific memory T-cell responses. Deep sequencing of the genes expressed in blood reveals an enrichment in 'inflammation' and 'antiviral' pathways. Integrated analyses identify specific immune markers associated with the persistence of clinical symptoms. This study identifies a set of biological and genetic markers that could be used to define a signature of "chronic Ebola virus disease (CEVD)".


Assuntos
Ebolavirus/imunologia , Doença pelo Vírus Ebola/complicações , Doença pelo Vírus Ebola/imunologia , Doenças do Sistema Imunitário/complicações , Doenças do Sistema Imunitário/imunologia , Adulto , Anticorpos Antivirais/sangue , Anticorpos Antivirais/imunologia , Antivirais/farmacologia , Linfócitos B/imunologia , Citocinas/sangue , Ebolavirus/efeitos dos fármacos , Ebolavirus/genética , Feminino , Marcadores Genéticos , Doença pelo Vírus Ebola/tratamento farmacológico , Doença pelo Vírus Ebola/virologia , Humanos , Doenças do Sistema Imunitário/genética , Imunoglobulina G/sangue , Imunoglobulina G/imunologia , Inflamação/genética , Ativação Linfocitária , Masculino , Sobreviventes , Linfócitos T/imunologia , Transcriptoma , Adulto Jovem
12.
BMJ Glob Health ; 5(6)2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32565430

RESUMO

The evidence produced in mathematical models plays a key role in shaping policy decisions in pandemics. A key question is therefore how well pandemic models relate to their implementation contexts. Drawing on the cases of Ebola and influenza, we map how sociological and anthropological research contributes in the modelling of pandemics to consider lessons for COVID-19. We show how models detach from their implementation contexts through their connections with global narratives of pandemic response, and how sociological and anthropological research can help to locate models differently. This potentiates multiple models of pandemic response attuned to their emerging situations in an iterative and adaptive science. We propose a more open approach to the modelling of pandemics which envisages the model as an intervention of deliberation in situations of evolving uncertainty. This challenges the 'business-as-usual' of evidence-based approaches in global health by accentuating all science, within and beyond pandemics, as 'emergent' and 'adaptive'.


Assuntos
Controle de Doenças Transmissíveis , Infecções por Coronavirus/epidemiologia , Política de Saúde , Modelos Biológicos , Pneumonia Viral/epidemiologia , Viroses/epidemiologia , Infecções por Coronavirus/imunologia , Doença pelo Vírus Ebola/epidemiologia , Doença pelo Vírus Ebola/imunologia , Humanos , Imunidade Coletiva , Vírus da Influenza A Subtipo H1N1/fisiologia , Virus da Influenza A Subtipo H5N1/fisiologia , Influenza Humana/epidemiologia , Influenza Humana/imunologia , Pandemias , Pneumonia Viral/imunologia , Incerteza
13.
Vaccine ; 38(28): 4464-4475, 2020 06 09.
Artigo em Inglês | MEDLINE | ID: mdl-32418793

RESUMO

The 2013-2016 West Africa EBOV epidemic was the biggest EBOV outbreak to date. An analysis of virus-specific CD8+ T-cell immunity in 30 survivors showed that 26 of those individuals had a CD8+ response to at least one EBOV protein. The dominant response (25/26 subjects) was specific to the EBOV nucleocapsid protein (NP). It has been suggested that epitopes on the EBOV NP could form an important part of an effective T-cell vaccine for Ebola Zaire. We show that a 9-amino-acid peptide NP44-52 (YQVNNLEEI) located in a conserved region of EBOV NP provides protection against morbidity and mortality after mouse adapted EBOV challenge. A single vaccination in a C57BL/6 mouse using an adjuvanted microsphere peptide vaccine formulation containing NP44-52 is enough to confer immunity in mice. Our work suggests that a peptide vaccine based on CD8+ T-cell immunity in EBOV survivors is conceptually sound and feasible. Nucleocapsid proteins within SARS-CoV-2 contain multiple Class I epitopes with predicted HLA restrictions consistent with broad population coverage. A similar approach to a CTL vaccine design may be possible for that virus.


Assuntos
Desenho de Fármacos , Vacinas contra Ebola/imunologia , Epitopos de Linfócito T/imunologia , Proteínas do Nucleocapsídeo/imunologia , Linfócitos T Citotóxicos/imunologia , Vacinas de Subunidades/imunologia , Vacinas Virais , Sequência de Aminoácidos , Animais , Infecções por Coronavirus/imunologia , Infecções por Coronavirus/prevenção & controle , Modelos Animais de Doenças , Vacinas contra Ebola/química , Epitopos de Linfócito T/química , Doença pelo Vírus Ebola/imunologia , Doença pelo Vírus Ebola/prevenção & controle , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Proteínas do Nucleocapsídeo/química , Pandemias/prevenção & controle , Pneumonia Viral/imunologia , Pneumonia Viral/prevenção & controle , Vacinas de Subunidades/química , Vacinas Virais/química , Vacinas Virais/imunologia
14.
Am J Pathol ; 190(7): 1449-1460, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32275904

RESUMO

Zaire ebolavirus (EBOV) causes Ebola virus disease (EVD), which carries a fatality rate between 25% and 90% in humans. Liver pathology is a hallmark of terminal EVD; however, little is known about temporal disease progression. We used multiplexed fluorescent immunohistochemistry and in situ hybridization in combination with whole slide imaging and image analysis (IA) to quantitatively characterize temporospatial signatures of viral and host factors as related to EBOV pathogenesis. Eighteen rhesus monkeys euthanized between 3 and 8 days post-infection, and 3 uninfected controls were enrolled in this study. Compared with semiquantitative histomorphologic ordinal scoring, quantitative IA detected subtle and progressive features of early and terminal EVD that was not feasible with routine approaches. Sinusoidal macrophages were the earliest cells to respond to infection, expressing proinflammatory cytokine interleukin 6 (IL6) mRNA, which was subsequently also observed in fibrovascular compartments. The mRNA of interferon-stimulated gene-15 (ISG-15), also known as ISG15 ubiquitin like modifier (ISG15), was observed early, with a progressive and ubiquitous hybridization signature involving mesenchymal and epithelial compartments. ISG-15 mRNA was prominent near infected cells, but not in infected cells, supporting the hypothesis that bystander cells produce a robust interferon gene response. This study contributes to our current understanding of early EVD progression and illustrates the value that digital pathology and quantitative IA serve in infectious disease research.


Assuntos
Biomarcadores/análise , Doença pelo Vírus Ebola/patologia , Doença pelo Vírus Ebola/virologia , Interações Hospedeiro-Patógeno/fisiologia , Fígado/virologia , Animais , Ebolavirus , Feminino , Doença pelo Vírus Ebola/imunologia , Fígado/imunologia , Fígado/patologia , Estudos Longitudinais , Macaca mulatta , Masculino
15.
Transfusion ; 60(5): 1024-1031, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32129478

RESUMO

BACKGROUND: In 2014, passive immunization by transfusion of Ebola convalescent plasma (ECP) was considered for treating patients with acute Ebola virus disease (EVD). Early Ebola virus (EBOV) seroconversion confers a survival advantage in natural infection, hence transfusion of ECP plasma with high levels of neutralizing EBOV antibodies is a potential passive immune therapy. Techniques to reduce the risk of other transfusion-transmitted infections (TTIs) are warranted as recent ECP survivors are ineligible as routine blood donors. As part of an ongoing clinical trial to evaluate the safety and effectiveness of ECP, the impact of amotosalen/UVA pathogen reduction technology (PRT) on EBOV antibody characteristics was examined. STUDY DESIGN AND METHODS: Serum and plasma samples were collected from EVD-recovered subjects at multiple timepoints and evaluated by ELISA for antibodies to recombinant EBOV glycoprotein (GP) and irradiated whole EBOV antigen, as well as for EBOV microneutralization, classic plaque reduction neutralization test (PRNT) and EBOV pseudovirion neutralization assay (PsVNA) activity. RESULTS: Six subjects donated 40 individual ECP units. Substantial antibody titers and neutralizing activity results were demonstrated but were generally lower for the ACD plasma samples compared to the serum samples. Anti-EBOV titers by all assays remained essentially unchanged after PRT. CONCLUSION: Treatment of ECP with PRT to reduce the risk of TTI did not significantly reduce EBOV IgG antibody titers or neutralizing activity. Although ECP was used in the treatment of repatriated patients, no PRT units from this study were transfused to EVD patients. This inventory of PRT-treated ECP is currently available for future clinical evaluation.


Assuntos
Anticorpos Neutralizantes/análise , Doadores de Sangue , Ebolavirus/imunologia , Doença pelo Vírus Ebola/sangue , Imunidade Ativa , Plasma/imunologia , Animais , Anticorpos Neutralizantes/sangue , Anticorpos Neutralizantes/uso terapêutico , Anticorpos Antivirais/análise , Anticorpos Antivirais/sangue , Anticorpos Antivirais/uso terapêutico , Chlorocebus aethiops , Convalescença , Ficusina/farmacologia , Doença pelo Vírus Ebola/imunologia , Doença pelo Vírus Ebola/prevenção & controle , Humanos , Imunidade Ativa/fisiologia , Imunização Passiva/métodos , Testes de Neutralização , Plasma/efeitos dos fármacos , Soroconversão/fisiologia , Estados Unidos , Células Vero , Carga Viral/efeitos dos fármacos , Carga Viral/imunologia
16.
Annu Rev Virol ; 7(1): 475-494, 2020 09 29.
Artigo em Inglês | MEDLINE | ID: mdl-32212920

RESUMO

The conduct of clinical trials during the West Africa Ebola outbreak in 2014 highlighted many ethical challenges. How these challenges were addressed, what clinical studies were conducted during that outbreak, and the lessons learned for dealing with future outbreaks were the subject of a National Academy of Medicine committee report titled Integrating Clinical Research into Epidemic Response: The Ebola Experience. This report suggested improvements for research during subsequent emerging or re-emerging outbreaks and is summarized in this review. We also discuss the current Ebola outbreak in the Democratic Republic of the Congo and highlight how the dialogue has changed and how successful clinical trials have been implemented. We conclude with a description of productive efforts to include pregnant women and children in therapeutic and vaccine trials during outbreaks that are currently ongoing.


Assuntos
Pesquisa Biomédica/ética , Ensaios Clínicos como Assunto/ética , Surtos de Doenças , Ebolavirus/patogenicidade , Doença pelo Vírus Ebola/epidemiologia , Seleção de Pacientes/ética , Adulto , África Ocidental/epidemiologia , Antivirais/uso terapêutico , Pesquisa Biomédica/organização & administração , Criança , Ensaios Clínicos como Assunto/organização & administração , Vacinas contra Ebola/administração & dosagem , Feminino , Doença pelo Vírus Ebola/imunologia , Doença pelo Vírus Ebola/mortalidade , Doença pelo Vírus Ebola/prevenção & controle , Humanos , Cooperação Internacional , Masculino , Gravidez , Análise de Sobrevida
17.
J Virol ; 94(11)2020 05 18.
Artigo em Inglês | MEDLINE | ID: mdl-32213610

RESUMO

Ebola virus (EBOV) continues to pose a significant threat to human health, as evidenced by the 2013-2016 epidemic in West Africa and the ongoing outbreak in the Democratic Republic of the Congo. EBOV causes hemorrhagic fever, organ damage, and shock culminating in death, with case fatality rates as high as 90%. This high lethality combined with the paucity of licensed medical countermeasures makes EBOV a critical human pathogen. Although EBOV infection results in significant damage to the liver and the adrenal glands, little is known about the molecular signatures of injury in these organs. Moreover, while changes in peripheral blood cells are becoming increasingly understood, the host responses within organs and lymphoid tissues remain poorly characterized. To address this knowledge gap, we tracked longitudinal transcriptional changes in tissues collected from EBOV-Makona-infected cynomolgus macaques. Following infection, both liver and adrenal glands exhibited significant and early downregulation of genes involved in metabolism, coagulation, hormone synthesis, and angiogenesis; upregulated genes were associated with inflammation. Analysis of lymphoid tissues showed early upregulation of genes that play a role in innate immunity and inflammation and downregulation of genes associated with cell cycle and adaptive immunity. Moreover, transient activation of innate immune responses and downregulation of humoral immune responses in lymphoid tissues were confirmed with flow cytometry. Together, these data suggest that the liver, adrenal gland, and lymphatic organs are important sites of EBOV infection and that dysregulating the function of these vital organs contributes to the development of Ebola virus disease.IMPORTANCE Ebola virus (EBOV) remains a high-priority pathogen since it continues to cause outbreaks with high case fatality rates. Although it is well established that EBOV results in severe organ damage, our understanding of tissue injury in the liver, adrenal glands, and lymphoid tissues remains limited. We begin to address this knowledge gap by conducting longitudinal gene expression studies in these tissues, which were collected from EBOV-infected cynomolgus macaques. We report robust and early gene expression changes within these tissues, indicating they are primary sites of EBOV infection. Furthermore, genes involved in metabolism, coagulation, and adaptive immunity were downregulated, while inflammation-related genes were upregulated. These results indicate significant tissue damage consistent with the development of hemorrhagic fever and lymphopenia. Our study provides novel insight into EBOV-host interactions and elucidates how host responses within the liver, adrenal glands, and lymphoid tissues contribute to EBOV pathogenesis.


Assuntos
Glândulas Suprarrenais , Ebolavirus , Regulação Viral da Expressão Gênica/imunologia , Doença pelo Vírus Ebola , Fígado , Tecido Linfoide , Doenças dos Macacos , Transcrição Genética/imunologia , Glândulas Suprarrenais/imunologia , Glândulas Suprarrenais/metabolismo , Glândulas Suprarrenais/patologia , Glândulas Suprarrenais/virologia , Animais , Ebolavirus/imunologia , Ebolavirus/metabolismo , Feminino , Doença pelo Vírus Ebola/imunologia , Doença pelo Vírus Ebola/metabolismo , Doença pelo Vírus Ebola/patologia , Doença pelo Vírus Ebola/veterinária , Fígado/imunologia , Fígado/metabolismo , Fígado/patologia , Fígado/virologia , Tecido Linfoide/imunologia , Tecido Linfoide/metabolismo , Tecido Linfoide/patologia , Tecido Linfoide/virologia , Macaca fascicularis , Masculino , Doenças dos Macacos/imunologia , Doenças dos Macacos/metabolismo , Doenças dos Macacos/patologia , Doenças dos Macacos/virologia
18.
J Virol ; 94(9)2020 04 16.
Artigo em Inglês | MEDLINE | ID: mdl-32075939

RESUMO

The 2013-2016 Ebola outbreak in West Africa led to accelerated efforts to develop vaccines against these highly virulent viruses. A live, recombinant vesicular stomatitis virus-based vaccine has been deployed in outbreak settings and appears highly effective. Vaccines based on replication-deficient adenovirus vectors either alone or in combination with a multivalent modified vaccinia Ankara (MVA) Ebola vaccine also appear promising and are progressing in clinical evaluation. However, the ability of current live vector-based approaches to protect against multiple pathogenic species of Ebola is not yet established, and eliciting durable responses may require additional booster vaccinations. Here, we report the development of a bivalent, spherical Ebola virus-like particle (VLP) vaccine that incorporates glycoproteins (GPs) from Zaire Ebola virus (EBOV) and Sudan Ebola virus (SUDV) and is designed to extend the breadth of immunity beyond EBOV. Immunization of rabbits with bivalent Ebola VLPs produced antibodies that neutralized all four pathogenic species of Ebola viruses and elicited antibody-dependent cell-mediated cytotoxicity (ADCC) responses against EBOV and SUDV. Vaccination of rhesus macaques with bivalent VLPs generated strong humoral immune responses, including high titers of binding, as well as neutralizing antibodies and ADCC responses. VLP vaccination led to a significant increase in the frequency of Ebola GP-specific CD4 and CD8 T cell responses. These results demonstrate that a novel bivalent Ebola VLP vaccine elicits strong humoral and cellular immune responses against pathogenic Ebola viruses and support further evaluation of this approach as a potential addition to Ebola vaccine development efforts.IMPORTANCE Ebola outbreaks result in significant morbidity and mortality in affected countries. Although several leading candidate Ebola vaccines have been developed and advanced in clinical testing, additional vaccine candidates may be needed to provide protection against different Ebola species and to extend the durability of protection. A novel approach demonstrated here is to express two genetically diverse glycoproteins on a spherical core, generating a vaccine that can broaden immune responses against known pathogenic Ebola viruses. This approach provides a new method to broaden and potentially extend protective immune responses against Ebola viruses.


Assuntos
Vacinas contra Ebola/imunologia , Ebolavirus/imunologia , Doença pelo Vírus Ebola/imunologia , África Ocidental , Animais , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Modelos Animais de Doenças , Feminino , Glicoproteínas/imunologia , Imunização , Macaca mulatta , Masculino , Vacinação , Vacinas Atenuadas , Vacinas de Partículas Semelhantes a Vírus/imunologia , Proteínas do Envelope Viral/imunologia , Vacinas Virais/imunologia
19.
Cell Host Microbe ; 27(2): 262-276.e4, 2020 02 12.
Artigo em Inglês | MEDLINE | ID: mdl-32053790

RESUMO

Evolution of antibody repertoire against the Ebola virus (EBOV) proteome was characterized in an acutely infected patient receiving supportive care alone to elucidate virus-host interactions over time. Differential kinetics are observed for IgM-IgG-IgA epitope diversity, antibody binding, and affinity maturation to EBOV proteins. During acute illness, antibodies predominate to VP40 and glycoprotein (GP). At day 13 of clinical illness, a marked increase in antibody titers to most EBOV proteins and affinity maturation to GP is associated with rapid decline in viral replication and illness severity. At one year, despite undetectable virus, a diverse IgM repertoire against VP40 and GP epitopes is observed suggesting occult viral persistence. Rabbit immunization experiments identify key immunodominant sites of GP, while challenge studies in mice found these epitopes induce EBOV-neutralizing antibodies and protect against lethal EBOV challenge. This study reveals markers of viral persistence and provides promising approaches for development and evaluation of vaccines and therapeutics.


Assuntos
Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Ebolavirus/imunologia , Doença pelo Vírus Ebola/imunologia , Animais , Anticorpos Neutralizantes/biossíntese , Anticorpos Antivirais/biossíntese , Epitopos/imunologia , Doença pelo Vírus Ebola/prevenção & controle , Doença pelo Vírus Ebola/terapia , Humanos , Imunoglobulina A/isolamento & purificação , Imunoglobulina G/isolamento & purificação , Imunoglobulina M/isolamento & purificação , Camundongos , Proteoma/imunologia , Coelhos , Sobreviventes , Proteínas do Envelope Viral/imunologia , Proteínas da Matriz Viral/imunologia , Proteínas Virais/imunologia , Vacinas Virais
20.
Immunity ; 52(2): 388-403.e12, 2020 02 18.
Artigo em Inglês | MEDLINE | ID: mdl-32023489

RESUMO

Structural principles underlying the composition of protective antiviral monoclonal antibody (mAb) cocktails are poorly defined. Here, we exploited antibody cooperativity to develop a therapeutic mAb cocktail against Ebola virus. We systematically analyzed the antibody repertoire in human survivors and identified a pair of potently neutralizing mAbs that cooperatively bound to the ebolavirus glycoprotein (GP). High-resolution structures revealed that in a two-antibody cocktail, molecular mimicry was a major feature of mAb-GP interactions. Broadly neutralizing mAb rEBOV-520 targeted a conserved epitope on the GP base region. mAb rEBOV-548 bound to a glycan cap epitope, possessed neutralizing and Fc-mediated effector function activities, and potentiated neutralization by rEBOV-520. Remodeling of the glycan cap structures by the cocktail enabled enhanced GP binding and virus neutralization. The cocktail demonstrated resistance to virus escape and protected non-human primates (NHPs) against Ebola virus disease. These data illuminate structural principles of antibody cooperativity with implications for development of antiviral immunotherapeutics.


Assuntos
Anticorpos Monoclonais/imunologia , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Ebolavirus/imunologia , Glicoproteínas/imunologia , Doença pelo Vírus Ebola/imunologia , Animais , Anticorpos Monoclonais/uso terapêutico , Anticorpos Neutralizantes/uso terapêutico , Anticorpos Antivirais/uso terapêutico , Linhagem Celular , Modelos Animais de Doenças , Quimioterapia Combinada , Epitopos , Feminino , Glicoproteínas/química , Doença pelo Vírus Ebola/prevenção & controle , Humanos , Fragmentos Fab das Imunoglobulinas/imunologia , Macaca mulatta , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Mimetismo Molecular , Conformação Proteica
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