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1.
Proc Natl Acad Sci U S A ; 119(1)2022 01 04.
Artigo em Inglês | MEDLINE | ID: mdl-34969849

RESUMO

Infection by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) provokes a potentially fatal pneumonia with multiorgan failure, and high systemic inflammation. To gain mechanistic insight and ferret out the root of this immune dysregulation, we modeled, by in vitro coculture, the interactions between infected epithelial cells and immunocytes. A strong response was induced in monocytes and B cells, with a SARS-CoV-2-specific inflammatory gene cluster distinct from that seen in influenza A or Ebola virus-infected cocultures, and which reproduced deviations reported in blood or lung myeloid cells from COVID-19 patients. A substantial fraction of the effect could be reproduced after individual transfection of several SARS-CoV-2 proteins (Spike and some nonstructural proteins), mediated by soluble factors, but not via transcriptional induction. This response was greatly muted in monocytes from healthy children, perhaps a clue to the age dependency of COVID-19. These results suggest that the inflammatory malfunction in COVID-19 is rooted in the earliest perturbations that SARS-CoV-2 induces in epithelia.


Assuntos
COVID-19/imunologia , Células Epiteliais/imunologia , Monócitos/imunologia , SARS-CoV-2/patogenicidade , Adulto , Linfócitos B/imunologia , COVID-19/patologia , Criança , Técnicas de Cocultura , Ebolavirus/patogenicidade , Células Epiteliais/virologia , Perfilação da Expressão Gênica , Humanos , Inflamação , Vírus da Influenza A/patogenicidade , Pulmão/imunologia , Células Mieloides/imunologia , Especificidade da Espécie , Proteínas Virais/imunologia
2.
Front Immunol ; 12: 729851, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34721393

RESUMO

Multiple agents in the family Filoviridae (filoviruses) are associated with sporadic human outbreaks of highly lethal disease, while others, including several recently identified agents, possess strong zoonotic potential. Although viral glycoprotein (GP)-specific monoclonal antibodies have demonstrated therapeutic utility against filovirus disease, currently FDA-approved molecules lack antiviral breadth. The development of broadly neutralizing antibodies has been challenged by the high sequence divergence among filovirus GPs and the complex GP proteolytic cleavage cascade that accompanies filovirus entry. Despite this variability in the antigenic surface of GP, all filoviruses share a site of vulnerability-the binding site for the universal filovirus entry receptor, Niemann-Pick C1 (NPC1). Unfortunately, this site is shielded in extracellular GP and only uncovered by proteolytic cleavage by host proteases in late endosomes and lysosomes, which are generally inaccessible to antibodies. To overcome this obstacle, we previously developed a 'Trojan horse' therapeutic approach in which engineered bispecific antibodies (bsAbs) coopt viral particles to deliver GP:NPC1 interaction-blocking antibodies to their endo/lysosomal sites of action. This approach afforded broad protection against members of the genus Ebolavirus but could not neutralize more divergent filoviruses. Here, we describe next-generation Trojan horse bsAbs that target the endo/lysosomal GP:NPC1 interface with pan-filovirus breadth by exploiting the conserved and widely expressed host cation-independent mannose-6-phosphate receptor for intracellular delivery. Our work highlights a new avenue for the development of single therapeutics protecting against all known and newly emerging filoviruses.


Assuntos
Anticorpos Biespecíficos/farmacologia , Antivirais/farmacologia , Anticorpos Amplamente Neutralizantes/farmacologia , Ebolavirus/efeitos dos fármacos , Doença pelo Vírus Ebola/tratamento farmacológico , Lisossomos/efeitos dos fármacos , Proteína C1 de Niemann-Pick/antagonistas & inibidores , Proteínas do Envelope Viral/antagonistas & inibidores , Internalização do Vírus/efeitos dos fármacos , Anticorpos Biespecíficos/genética , Anticorpos Amplamente Neutralizantes/genética , Ebolavirus/imunologia , Ebolavirus/patogenicidade , Epitopos , Doença pelo Vírus Ebola/imunologia , Doença pelo Vírus Ebola/metabolismo , Doença pelo Vírus Ebola/virologia , Interações Hospedeiro-Patógeno , Humanos , Ligantes , Lisossomos/imunologia , Lisossomos/metabolismo , Lisossomos/virologia , Proteína C1 de Niemann-Pick/genética , Proteína C1 de Niemann-Pick/imunologia , Proteína C1 de Niemann-Pick/metabolismo , Engenharia de Proteínas , Receptor IGF Tipo 2/genética , Receptor IGF Tipo 2/metabolismo , Células THP-1 , Proteínas de Transporte Vesicular/genética , Proteínas de Transporte Vesicular/metabolismo , Proteínas do Envelope Viral/genética , Proteínas do Envelope Viral/imunologia , Proteínas do Envelope Viral/metabolismo
3.
J Virol ; 95(20): e0116521, 2021 09 27.
Artigo em Inglês | MEDLINE | ID: mdl-34319156

RESUMO

Ebola virus (EBOV) attaches to target cells using two categories of cell surface receptors: C-type lectins and phosphatidylserine (PS) receptors. PS receptors typically bind to apoptotic cell membrane PS and orchestrate the uptake and clearance of apoptotic debris. Many enveloped viruses also contain exposed PS and can therefore exploit these receptors for cell entry. Viral infection can induce PS externalization in host cells, resulting in increased outer PS levels on budding virions. Scramblase enzymes carry out cellular PS externalization; thus, we targeted these proteins in order to manipulate viral envelope PS levels. We investigated two scramblases previously identified to be involved in EBOV PS levels, transmembrane protein 16F and Xk-related protein 8 (XKR8), as possible mediators of cellular and viral envelope surface PS levels during the replication of recombinant vesicular stomatitis virus containing its native glycoprotein (rVSV/G) or the EBOV glycoprotein (rVSV/EBOV-GP). We found that rVSV/G and rVSV/EBOV-GP virions produced in XKR8 knockout cells contain decreased levels of PS on their surfaces, and the PS-deficient rVSV/EBOV-GP virions are 70% less efficient at infecting cells through PS receptors. We also observed reduced rVSV and EBOV virus-like particle (VLP) budding in ΔXKR8 cells. Deletion of XKR8 in HAP1 cells reduced rVSV/G and rVSV/EBOV-GP budding by 60 and 65%, respectively, and reduced Ebola VLP budding more than 60%. We further demonstrated that caspase cleavage of XKR8 is required to promote budding. This suggests that XKR8, in addition to mediating virion PS levels, may also be critical for enveloped virus budding at the plasma membrane. IMPORTANCE Within the last decade, countries in western and central Africa have experienced the most widespread and deadly Ebola outbreaks since Ebola virus was identified in 1976. While outbreaks are primarily attributed to zoonotic transfer events, new evidence is emerging outbreaks may be caused by a combination of spillover events and viral latency or persistence in survivors. The possibility that Ebola virus can remain dormant and then reemerge in survivors highlights the critical need to prevent the virus from entering and establishing infection in human cells. Thus far, host cell scramblases TMEM16F and XKR8 have been implicated in Ebola envelope surface phosphatidylserine (PS) and cell entry using PS receptors. We assessed the contributions of these proteins using CRISPR knockout cells and two EBOV models: rVSV/EBOV-GP and EBOV VLPs. We observed that XKR8 is required for optimal EBOV envelope PS levels and infectivity and particle budding across all viral models.


Assuntos
Ebolavirus/metabolismo , Fosfatidilserinas/metabolismo , Liberação de Vírus/fisiologia , Linhagem Celular , Ebolavirus/patogenicidade , Glicoproteínas/metabolismo , Doença pelo Vírus Ebola/virologia , Humanos , Fosfatidilserinas/fisiologia , Proteínas de Transferência de Fosfolipídeos/metabolismo , Proteínas de Transferência de Fosfolipídeos/fisiologia , Proteínas do Envelope Viral/metabolismo , Vírion/metabolismo , Montagem de Vírus/genética , Montagem de Vírus/fisiologia , Liberação de Vírus/genética
4.
Cell Rep ; 35(2): 108984, 2021 04 13.
Artigo em Inglês | MEDLINE | ID: mdl-33852862

RESUMO

Antibodies that target the glycan cap epitope on the ebolavirus glycoprotein (GP) are common in the adaptive response of survivors. A subset is known to be broadly neutralizing, but the details of their epitopes and basis for neutralization are not well understood. Here, we present cryoelectron microscopy (cryo-EM) structures of diverse glycan cap antibodies that variably synergize with GP base-binding antibodies. These structures describe a conserved site of vulnerability that anchors the mucin-like domains (MLDs) to the glycan cap, which we call the MLD anchor and cradle. Antibodies that bind to the MLD cradle share common features, including use of IGHV1-69 and IGHJ6 germline genes, which exploit hydrophobic residues and form ß-hairpin structures to mimic the MLD anchor, disrupt MLD attachment, destabilize GP quaternary structure, and block cleavage events required for receptor binding. Our results provide a molecular basis for ebolavirus neutralization by broadly reactive glycan cap antibodies.


Assuntos
Anticorpos Monoclonais/farmacologia , Anticorpos Neutralizantes/farmacologia , Anticorpos Antivirais/farmacologia , Ebolavirus/efeitos dos fármacos , Doença pelo Vírus Ebola/tratamento farmacológico , Proteínas do Envelope Viral/química , Sequência de Aminoácidos , Animais , Anticorpos Monoclonais/química , Anticorpos Monoclonais/metabolismo , Anticorpos Neutralizantes/química , Anticorpos Neutralizantes/metabolismo , Anticorpos Antivirais/química , Anticorpos Antivirais/metabolismo , Especificidade de Anticorpos , Sítios de Ligação , Microscopia Crioeletrônica , Ebolavirus/crescimento & desenvolvimento , Ebolavirus/imunologia , Ebolavirus/patogenicidade , Epitopos/química , Epitopos/imunologia , Feminino , Células HEK293 , Células HeLa , Doença pelo Vírus Ebola/imunologia , Doença pelo Vírus Ebola/patologia , Doença pelo Vírus Ebola/virologia , Humanos , Células Jurkat , Camundongos , Modelos Moleculares , Polissacarídeos/química , Polissacarídeos/imunologia , Ligação Proteica , Conformação Proteica em Folha beta , Domínios e Motivos de Interação entre Proteínas , Alinhamento de Sequência , Homologia de Sequência de Aminoácidos , Proteínas do Envelope Viral/antagonistas & inibidores , Proteínas do Envelope Viral/genética , Proteínas do Envelope Viral/metabolismo
5.
Am J Trop Med Hyg ; 104(5): 1751-1754, 2021 03 29.
Artigo em Inglês | MEDLINE | ID: mdl-33782211

RESUMO

Gamma irradiation (GI) is included in the CDC guidance on inactivation procedures to render a group of select agents and toxins nonviable. The Ebola virus falls within this group because it potentially poses a severe threat to public health and safety. To evaluate the impact of GI at a target dose of 50 kGy on neutralizing antibody titers induced by the rVSVΔG-ZEBOV-GP vaccine (V920), we constructed a panel of 48 paired human serum samples (GI-treated versus non-GI-treated) from healthy participants selected from a phase 3 study of V920 (study V920-012; NCT02503202). Neutralizing antibody titers were determined using a validated plaque-reduction neutralization test. GI of sera from V920 recipients was associated with approximately 20% reduction in postvaccination neutralizing antibody titers. GI was not associated with any change in pre-vaccination neutralizing antibody titers.


Assuntos
Anticorpos Neutralizantes/sangue , Anticorpos Antivirais/sangue , Vacinas contra Ebola/administração & dosagem , Ebolavirus/imunologia , Doença pelo Vírus Ebola/prevenção & controle , Soros Imunes/efeitos da radiação , Anticorpos Neutralizantes/análise , Vacinas contra Ebola/síntese química , Ebolavirus/patogenicidade , Voluntários Saudáveis , Doença pelo Vírus Ebola/sangue , Doença pelo Vírus Ebola/imunologia , Doença pelo Vírus Ebola/virologia , Humanos , Soros Imunes/química , Imunogenicidade da Vacina , Testes de Neutralização , Estudos Prospectivos , Vacinação/métodos , Vesiculovirus/química , Vesiculovirus/imunologia , Proteínas do Envelope Viral/imunologia
6.
Lancet Infect Dis ; 21(4): 507-516, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33065039

RESUMO

BACKGROUND: The 2013-16 Ebola virus disease epidemic in west Africa caused international alarm due to its rapid and extensive spread resulting in a significant death toll and social unrest within the affected region. The large number of cases provided an opportunity to study the long-term kinetics of Zaire ebolavirus-specific immune response of survivors in addition to known contacts of those infected with the virus. METHODS: In this observational cohort study, we worked with leaders of Ebola virus disease survivor associations in two regions of Guinea, Guéckédou and Coyah, to recruit survivors of Ebola virus disease, contacts from households of individuals known to have had Ebola virus disease, and individuals who were not knowingly associated with infected individuals or had not had Ebola virus disease symptoms to serve as negative controls. We did Zaire ebolavirus glycoprotein-specific T cell analysis on peripheral blood mononuclear cells (PBMCs) on location in Guinea and transported plasma and PBMCs back to Europe for antibody quantification by ELISA, functional neutralising antibody analysis using live Zaire ebolavirus, and T cell phenotype studies. We report on the longitudinal cellular and humoral response among Ebola virus disease survivors and highlight potentially paucisymptomatic infection. FINDINGS: We recruited 117 survivors of Ebola virus disease, 66 contacts, and 23 negative controls. The mean neutralising antibody titre among the Ebola virus disease survivors 3-14 months after infection was 1/174 (95% CI 1/136-1/223). Individual results varied greatly from 1/10 to more than 1/1000 but were on average ten times greater than that induced after 1 month by single dose Ebola virus vaccines. Following reactivation with glycoprotein peptide, the mean T cell responses among 116 Ebola virus disease survivors as measured by ELISpot was 305 spot-forming units (95% CI 257-353). The dominant CD8+ polyfunctional T cell phenotype, as measured among 53 Ebola virus disease survivors, was interferon γ+, tumour necrosis factor+, interleukin-2-, and the mean response was 0·046% of total CD8+ T cells (95% CI 0·021-0·071). Additionally, both neutralising antibody and T cell responses were detected in six (9%) of 66 Ebola virus disease contacts. We also noted that four (3%) of 117 individuals with Ebola virus disease infections did not have circulating Ebola virus-specific antibodies 3 months after infection. INTERPRETATION: The continuous high titre of neutralising antibodies and increased T cell response might support the concept of long-term protective immunity in survivors. The existence of antibody and T cell responses in contacts of individuals with Ebola virus disease adds further evidence to the existence of sub-clinical Ebola virus infection. FUNDING: US Food & Drug Administration, Horizon 2020 EU EVIDENT, Wellcome, UK Department for International Development. TRANSLATION: For the French translation of the abstract see Supplementary Materials section.


Assuntos
Anticorpos Antivirais/sangue , Ebolavirus/imunologia , Doença pelo Vírus Ebola/imunologia , Sobreviventes/estatística & dados numéricos , Linfócitos T/imunologia , Adolescente , Adulto , Anticorpos Antivirais/imunologia , Anticorpos Antivirais/isolamento & purificação , Criança , Pré-Escolar , Ebolavirus/patogenicidade , Epidemias , Feminino , Guiné/epidemiologia , Doença pelo Vírus Ebola/sangue , Doença pelo Vírus Ebola/transmissão , Doença pelo Vírus Ebola/virologia , Humanos , Imunidade Celular , Imunidade Humoral , Lactente , Recém-Nascido , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Fatores de Tempo , Adulto Jovem
7.
Clin Microbiol Rev ; 34(1)2020 12 16.
Artigo em Inglês | MEDLINE | ID: mdl-33055231

RESUMO

Patients and physicians worldwide are facing tremendous health care hazards that are caused by the ongoing severe acute respiratory distress syndrome coronavirus 2 (SARS-CoV-2) pandemic. Remdesivir (GS-5734) is the first approved treatment for severe coronavirus disease 2019 (COVID-19). It is a novel nucleoside analog with a broad antiviral activity spectrum among RNA viruses, including ebolavirus (EBOV) and the respiratory pathogens Middle East respiratory syndrome coronavirus (MERS-CoV), SARS-CoV, and SARS-CoV-2. First described in 2016, the drug was derived from an antiviral library of small molecules intended to target emerging pathogenic RNA viruses. In vivo, remdesivir showed therapeutic and prophylactic effects in animal models of EBOV, MERS-CoV, SARS-CoV, and SARS-CoV-2 infection. However, the substance failed in a clinical trial on ebolavirus disease (EVD), where it was inferior to investigational monoclonal antibodies in an interim analysis. As there was no placebo control in this study, no conclusions on its efficacy in EVD can be made. In contrast, data from a placebo-controlled trial show beneficial effects for patients with COVID-19. Remdesivir reduces the time to recovery of hospitalized patients who require supplemental oxygen and may have a positive impact on mortality outcomes while having a favorable safety profile. Although this is an important milestone in the fight against COVID-19, approval of this drug will not be sufficient to solve the public health issues caused by the ongoing pandemic. Further scientific efforts are needed to evaluate the full potential of nucleoside analogs as treatment or prophylaxis of viral respiratory infections and to develop effective antivirals that are orally bioavailable.


Assuntos
Monofosfato de Adenosina/análogos & derivados , Alanina/análogos & derivados , Antivirais/farmacologia , Infecções por Coronavirus/tratamento farmacológico , Doença pelo Vírus Ebola/tratamento farmacológico , Pneumonia Viral/tratamento farmacológico , Síndrome Respiratória Aguda Grave/tratamento farmacológico , Monofosfato de Adenosina/farmacocinética , Monofosfato de Adenosina/farmacologia , Alanina/farmacocinética , Alanina/farmacologia , Antivirais/farmacocinética , Betacoronavirus/efeitos dos fármacos , Betacoronavirus/crescimento & desenvolvimento , Betacoronavirus/patogenicidade , COVID-19 , Ensaios Clínicos como Assunto , Ensaios de Uso Compassivo/métodos , Infecções por Coronavirus/mortalidade , Infecções por Coronavirus/patologia , Infecções por Coronavirus/virologia , Esquema de Medicação , Ebolavirus/efeitos dos fármacos , Ebolavirus/crescimento & desenvolvimento , Ebolavirus/patogenicidade , Doença pelo Vírus Ebola/mortalidade , Doença pelo Vírus Ebola/patologia , Doença pelo Vírus Ebola/virologia , Humanos , Coronavírus da Síndrome Respiratória do Oriente Médio/efeitos dos fármacos , Coronavírus da Síndrome Respiratória do Oriente Médio/crescimento & desenvolvimento , Coronavírus da Síndrome Respiratória do Oriente Médio/patogenicidade , Pandemias , Segurança do Paciente , Pneumonia Viral/mortalidade , Pneumonia Viral/patologia , Pneumonia Viral/virologia , Coronavírus Relacionado à Síndrome Respiratória Aguda Grave/efeitos dos fármacos , Coronavírus Relacionado à Síndrome Respiratória Aguda Grave/crescimento & desenvolvimento , Coronavírus Relacionado à Síndrome Respiratória Aguda Grave/patogenicidade , SARS-CoV-2 , Síndrome Respiratória Aguda Grave/mortalidade , Síndrome Respiratória Aguda Grave/patologia , Síndrome Respiratória Aguda Grave/virologia , Análise de Sobrevida , Resultado do Tratamento
8.
PLoS Pathog ; 16(10): e1008900, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-33052961

RESUMO

Multiple cell surface molecules including TAM receptors (TYRO3, AXL, and MERTK), a family of tyrosine kinase receptors, can serve as attachment receptors for Ebola virus (EBOV) entry into cells. The interaction of these receptors with EBOV particles is believed to trigger the initial internalization events that lead to macropinocytosis. However, the details of how these interactions lead to EBOV internalization have yet to be elucidated. Here, we screened receptor tyrosine kinase (RTK) inhibitors for anti-EBOV activity by using our previously established biologically contained Ebola virus that lacks the VP30 gene (EBOVΔVP30) and identified several RTKs, including human epidermal growth factor receptor 2 (HER2), as potential targets of anti-EBOV inhibitors and as novel host factors that have a role in EBOV infection. Of these identified RTKs, it was only HER2 whose knockdown by siRNAs impaired EBOVΔVP30-induced AKT1 phosphorylation, an event that is required for AKT1 activation and subsequent macropinocytosis. Stable expression of HER2 resulted in constitutive activation of AKT1, resulting in the enhancement of EBOVΔVP30 growth, EBOV GP-mediated entry, and macropinocytosis. Moreover, we found that HER2 interacts with the TAM receptors, and in particular forms a complex with TYRO3 and EBOVΔVP30 particles on the cell surface. Interestingly, HER2 was required for EBOVΔVP30-induced TYRO3 and AKT1 activation, but the other TAM receptors (TYRO3 and MERTK) were not essential for EBOVΔVP30-induced HER2 and AKT1 activation. Our findings demonstrate that HER2 plays an important role in EBOV entry and provide novel insights for the development of therapeutics against the virus.


Assuntos
Ebolavirus/patogenicidade , Doença pelo Vírus Ebola/virologia , Receptor ErbB-2/metabolismo , Internalização do Vírus , Animais , Proteínas de Transporte/metabolismo , Chlorocebus aethiops , Ebolavirus/genética , Células HEK293 , Humanos , Glicoproteínas de Membrana/metabolismo , Receptores Proteína Tirosina Quinases/metabolismo , Células Vero/virologia , Internalização do Vírus/efeitos dos fármacos
9.
Biochemistry ; 59(41): 4051-4058, 2020 10 20.
Artigo em Inglês | MEDLINE | ID: mdl-32960042

RESUMO

The fusion of the viral and target cell membranes is a key step in the life cycle of all enveloped viruses. Here, a range of structural data is used to generate an evidence-based model of the active conformation of an archetypical type-I fusion protein, the Ebola glycoprotein 2 (GP2). The stability of the trimeric complex is demonstrated using molecular dynamics and validated by simulating the interaction of the complex with a lipid bilayer. In this model, the fusion peptides project away from the central helix bundle parallel to the target membrane. This maximizes contact with the host membrane, enhances lateral stability, and would explain why, when activated, viral fusion proteins are trimeric.


Assuntos
Ebolavirus/metabolismo , Ebolavirus/patogenicidade , Proteínas do Envelope Viral/metabolismo , Bicamadas Lipídicas/química , Bicamadas Lipídicas/metabolismo , Simulação de Dinâmica Molecular , Conformação Proteica , Estabilidade Proteica , Estrutura Secundária de Proteína , Proteínas do Envelope Viral/química , Proteínas do Envelope Viral/genética , Proteínas Virais de Fusão/química , Proteínas Virais de Fusão/metabolismo , Internalização do Vírus
10.
J Virol ; 94(16)2020 07 30.
Artigo em Inglês | MEDLINE | ID: mdl-32493822

RESUMO

Ebola virus (EBOV) entry requires internalization into host cells and extensive trafficking through the endolysosomal network in order to reach late endosomal/lysosomal compartments that contain triggering factors for viral membrane fusion. These triggering factors include low-pH-activated cellular cathepsin proteases, which cleave the EBOV glycoprotein (GP), exposing a domain which binds to the filoviral receptor, the cholesterol transporter Niemann-Pick C1 (NPC1). Here, we report that trafficking of EBOV to NPC1 requires expression of the homotypic fusion and protein sorting (HOPS) tethering complex as well as its regulator, UV radiation resistance-associated gene (UVRAG). Using an inducible clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 system, we demonstrated that depletion of HOPS subunits as well as UVRAG impairs entry by all pathogenic filoviruses. UVRAG depletion resulted in reduced delivery of EBOV virions to NPC1+ cellular compartments. Furthermore, we show that deletion of a domain on UVRAG known to be required for interaction with the HOPS complex results in impaired EBOV entry. Taken together, our studies demonstrate that EBOV requires both expression of and coordination between the HOPS complex and UVRAG in order to mediate efficient viral entry.IMPORTANCE Ebola viruses (EBOV) and other filoviruses cause sporadic and unpredictable outbreaks of highly lethal diseases. The lack of FDA-approved therapeutics, particularly ones with panfiloviral specificity, highlights the need for continued research efforts to understand aspects of the viral life cycle that are common to all filoviruses. As such, viral entry is of particular interest, as all filoviruses must reach cellular compartments containing the viral receptor Niemann-Pick C1 to enter cells. Here, we present an inducible CRISPR/Cas9 method to rapidly and efficiently generate knockout cells in order to interrogate the roles of a broad range of host factors in viral entry. Using this approach, we showed that EBOV entry depends on both the homotypic fusion and protein sorting (HOPS) tethering complex in coordination with UV radiation resistance-associated gene (UVRAG). Importantly, we demonstrate that the HOPS complex and UVRAG are required by all pathogenic filoviruses, representing potential targets for panfiloviral therapeutics.


Assuntos
Ebolavirus/metabolismo , Proteína C1 de Niemann-Pick/metabolismo , Proteínas Supressoras de Tumor/metabolismo , Transporte Biológico , Proteínas de Transporte/metabolismo , Ebolavirus/genética , Ebolavirus/patogenicidade , Endossomos/metabolismo , Filoviridae/genética , Infecções por Filoviridae/genética , Infecções por Filoviridae/metabolismo , Glicoproteínas/metabolismo , Doença pelo Vírus Ebola/metabolismo , Interações Hospedeiro-Patógeno , Glicoproteínas de Membrana/metabolismo , Transporte Proteico/genética , Transporte Proteico/fisiologia , Receptores Virais/metabolismo , Proteínas Supressoras de Tumor/genética , Proteínas do Envelope Viral/genética , Internalização do Vírus/efeitos dos fármacos
12.
Viruses ; 11(11)2019 11 04.
Artigo em Inglês | MEDLINE | ID: mdl-31689981

RESUMO

Recent studies have shown that transcriptomic analysis of blood samples taken from patients with acute Ebola virus disease (EVD) during the 2013-2016 West African outbreak was suggestive that a severe inflammatory response took place in acutely ill patients. The significant knowledge gained from studying the Makona variant, a cause of the largest known EVD outbreak, may be applicable to other species of ebolavirus, and other variants of the Ebola virus (EBOV) species. To investigate the ability of Makona to initiate an inflammatory response in human macrophages and characterise the host response in a similar manner to previously characterised EBOV variants, the human monocytic cell line THP-1 was differentiated into macrophage-like cells and infected with Makona. RNA-Seq and quantitative proteomics were used to identify and quantify host mRNA and protein abundance during infection. Data from infection with Reston virus (RESTV) were used as comparators to investigate changes that may be specific to, or enhanced in, Makona infection in relation to a less pathogenic species of ebolavirus.. This study found demonstrable induction of the inflammatory response, and increase in the activation state of THP-1 macrophages infected with Makona. NFκB and inflammation-associated transcripts displayed significant changes in abundance, reflective of what was observed in human patients during the 2013-2016 EBOV outbreak in West Africa, and demonstrated that transcriptomic changes found in Makona-infected cells were similar to that observed in Reston virus infection and that have been described in previous studies of other variants of EBOV.


Assuntos
Ebolavirus/isolamento & purificação , Ebolavirus/patogenicidade , Citocinas/genética , Citocinas/metabolismo , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Doença pelo Vírus Ebola/virologia , Humanos , Interferons/genética , Interferons/metabolismo , Macrófagos/imunologia , Macrófagos/virologia , Proteômica , Células THP-1
13.
Viruses ; 11(11)2019 10 31.
Artigo em Inglês | MEDLINE | ID: mdl-31683550

RESUMO

Ebola virus (EBOV) is a highly lethal pathogen that has caused several outbreaks of severe hemorrhagic fever in humans since its emergence in 1976. The EBOV glycoprotein (GP1,2) is the sole viral envelope protein and a major component of immunogenicity; it is encoded by the GP gene along with two truncated versions: soluble GP (sGP) and small soluble GP (ssGP). sGP is, in fact, the primary product of the GP gene, and it is secreted in abundance during EBOV infection. Since sGP shares large portions of its sequence with GP1,2, it has been hypothesized that sGP may subvert the host immune response by inducing antibodies against sGP rather than GP1,2. Several reports have shown that sGP plays multiple roles that contribute to the complex pathogenesis of EBOV. In this review, we focus on sGP and discuss its possible roles with regards to the pathogenesis of EBOV and the development of specific antiviral drugs.


Assuntos
Ebolavirus , Doença pelo Vírus Ebola , Proteínas do Envelope Viral , Animais , Anticorpos Neutralizantes/farmacologia , Anticorpos Antivirais/imunologia , Biomarcadores , Ebolavirus/efeitos dos fármacos , Ebolavirus/genética , Ebolavirus/imunologia , Ebolavirus/patogenicidade , Genes Virais , Glicoproteínas/genética , Glicoproteínas/imunologia , Glicoproteínas/metabolismo , Doença pelo Vírus Ebola/imunologia , Doença pelo Vírus Ebola/virologia , Humanos , Evasão da Resposta Imune , Imunidade Inata , Modificação Traducional de Proteínas , Proteínas do Envelope Viral/genética , Proteínas do Envelope Viral/imunologia , Proteínas do Envelope Viral/metabolismo , Fatores de Virulência/genética , Fatores de Virulência/imunologia , Fatores de Virulência/metabolismo , Replicação Viral
14.
BMC Res Notes ; 12(1): 639, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31570108

RESUMO

OBJECTIVE: Survivors of Ebola virus disease (EVD) are at risk of developing blinding intraocular inflammation-or uveitis-which is associated with retinal pigment epithelial (RPE) scarring and persistence of live Zaire ebolavirus (EBOV) within the eye. As part of a large research project aimed at defining the human RPE cell response to being infected with EBOV, this work focused on the microRNAs (miRNAs) associated with the infection. RESULTS: Using RNA-sequencing, we detected 13 highly induced and 2 highly repressed human miRNAs in human ARPE-19 RPE cells infected with EBOV, including hsa-miR-1307-5p, hsa-miR-29b-3p and hsa-miR-33a-5p (up-regulated), and hsa-miR-3074-3p and hsa-miR-27b-5p (down-regulated). EBOV-miR-1-5p was also found in infected RPE cells. Through computational identification of putative miRNA targets, we predicted a broad range of regulatory activities, including effects on innate and adaptive immune responses, cellular metabolism, cell cycle progression, apoptosis and autophagy. The most highly-connected molecule in the miR-target network was leucine-rich repeat kinase 2, which is involved in neuroinflammation and lysosomal processing. Our findings should stimulate new studies on the impact of miRNA changes in EBOV-infected RPE cells to further understanding of intraocular viral persistence and the pathogenesis of uveitis in EVD survivors.


Assuntos
Ebolavirus/genética , Células Epiteliais/metabolismo , Regulação da Expressão Gênica , Redes Reguladoras de Genes , Interações Hospedeiro-Patógeno/genética , MicroRNAs/genética , Imunidade Adaptativa/genética , Apoptose/genética , Autofagia/genética , Ciclo Celular/genética , Linhagem Celular , Ebolavirus/crescimento & desenvolvimento , Ebolavirus/patogenicidade , Células Epiteliais/imunologia , Células Epiteliais/virologia , Perfilação da Expressão Gênica , Interações Hospedeiro-Patógeno/imunologia , Humanos , Imunidade Inata/genética , MicroRNAs/classificação , MicroRNAs/imunologia , Pigmentos da Retina , Transdução de Sinais
16.
Viruses ; 11(5)2019 05 02.
Artigo em Inglês | MEDLINE | ID: mdl-31052499

RESUMO

Ebola virus (EBOV) disease can result in a range of symptoms anywhere from virtually asymptomatic to severe hemorrhagic fever during acute infection. Additionally, spans of asymptomatic persistence in recovering survivors is possible, during which transmission of the virus may occur. In acute infection, substantial cytokine storm and bystander lymphocyte apoptosis take place, resulting in uncontrolled, systemic inflammation in affected individuals. Recently, studies have demonstrated the presence of EBOV proteins VP40, glycoprotein (GP), and nucleoprotein (NP) packaged into extracellular vesicles (EVs) during infection. EVs containing EBOV proteins have been shown to induce apoptosis in recipient immune cells, as well as contain pro-inflammatory cytokines. In this manuscript, we review the current field of knowledge on EBOV EVs including the mechanisms of their biogenesis, their cargo and their effects in recipient cells. Furthermore, we discuss some of the effects that may be induced by EBOV EVs that have not yet been characterized and highlight the remaining questions and future directions.


Assuntos
Ebolavirus/patogenicidade , Vesículas Extracelulares/metabolismo , Doença pelo Vírus Ebola/metabolismo , Doença pelo Vírus Ebola/virologia , Interações Hospedeiro-Patógeno , Animais , Efeito Espectador , Ciclo Celular , Citocinas/metabolismo , Ebolavirus/imunologia , Exossomos/imunologia , Exossomos/metabolismo , Vesículas Extracelulares/imunologia , Doença pelo Vírus Ebola/imunologia , Interações Hospedeiro-Patógeno/imunologia , Humanos , Evasão da Resposta Imune , Nucleoproteínas/metabolismo , Proteínas do Core Viral/metabolismo , Proteínas da Matriz Viral/metabolismo
17.
Cell ; 177(6): 1566-1582.e17, 2019 05 30.
Artigo em Inglês | MEDLINE | ID: mdl-31104840

RESUMO

Ebola virus (EBOV) remains a public health threat. We performed a longitudinal study of B cell responses to EBOV in four survivors of the 2014 West African outbreak. Infection induced lasting EBOV-specific immunoglobulin G (IgG) antibodies, but their subclass composition changed over time, with IgG1 persisting, IgG3 rapidly declining, and IgG4 appearing late. Striking changes occurred in the immunoglobulin repertoire, with massive recruitment of naive B cells that subsequently underwent hypermutation. We characterized a large panel of EBOV glycoprotein-specific monoclonal antibodies (mAbs). Only a small subset of mAbs that bound glycoprotein by ELISA recognized cell-surface glycoprotein. However, this subset contained all neutralizing mAbs. Several mAbs protected against EBOV disease in animals, including one mAb that targeted an epitope under evolutionary selection during the 2014 outbreak. Convergent antibody evolution was seen across multiple donors, particularly among VH3-13 neutralizing antibodies specific for the GP1 core. Our study provides a benchmark for assessing EBOV vaccine-induced immunity.


Assuntos
Anticorpos Monoclonais/imunologia , Linfócitos B/fisiologia , Doença pelo Vírus Ebola/imunologia , Adulto , Sequência de Aminoácidos/genética , Animais , Anticorpos Monoclonais/isolamento & purificação , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Linfócitos B/metabolismo , Chlorocebus aethiops , Vacinas contra Ebola/imunologia , Ebolavirus/genética , Ebolavirus/metabolismo , Ebolavirus/patogenicidade , Epitopos/sangue , Feminino , Glicoproteínas/genética , Doença pelo Vírus Ebola/metabolismo , Doença pelo Vírus Ebola/virologia , Humanos , Imunoglobulina G/imunologia , Células Jurkat , Estudos Longitudinais , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Sobreviventes , Células Vero , Proteínas do Envelope Viral/genética
18.
PLoS Pathog ; 15(2): e1007564, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30817809

RESUMO

There are a number of vaccine candidates under development against a small number of the most common outbreak filoviruses all employing the virus glycoprotein (GP) as the vaccine immunogen. However, antibodies induced by such GP vaccines are typically autologous and limited to the other members of the same species. In contrast, T-cell vaccines offer a possibility to design a single pan-filovirus vaccine protecting against all known and even likely existing, but as yet unencountered members of the family. Here, we used a cross-filovirus immunogen based on conserved regions of the filovirus nucleoprotein, matrix and polymerase to construct simian adenovirus- and poxvirus MVA-vectored vaccines, and in a proof-of-concept study demonstrated a protection of the BALB/c and C57BL/6J mice against high, lethal challenges with Ebola and Marburg viruses, two distant members of the family, by vaccine-elicited T cells in the absence of GP antibodies.


Assuntos
Filoviridae/imunologia , Linfócitos T/imunologia , Vacinas Virais/farmacologia , Animais , Anticorpos Neutralizantes , Anticorpos Antivirais , Vacinas contra Ebola , Ebolavirus/patogenicidade , Feminino , Filoviridae/metabolismo , Filoviridae/patogenicidade , Doença pelo Vírus Ebola , Imunidade Celular/imunologia , Masculino , Marburgvirus/patogenicidade , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Estudo de Prova de Conceito , Linfócitos T/metabolismo
19.
Rev. cuba. enferm ; 35(1): e1763, ene.-mar. 2019. tab
Artigo em Espanhol | CUMED, LILACS | ID: biblio-1149864

RESUMO

Introducción: El virus del Ébola causa una enfermedad grave sumamente infecciosa, que lleva rápidamente a la muerte, con una tasa de letalidad de hasta 90 por ciento, pero puede prevenirse. Objetivo: Describir relevancia de los procederes de enfermería en la sobrevivencia de los pacientes afectados por el Ébola Métodos: Estudio descriptivo, de corte transversal en Liberia, África Occidental, en el periodo de noviembre 2014 a febrero 2015. El universo estuvo constituido por 203 pacientes a quienes se les aplicó procederes de enfermería por enfermeros que integraron la brigada médica cubana. La información se obtuvo de la observación directa y la revisión de la base de datos estadística de la misión cubana en Liberia, se procesó mediante el Sistema SPSSS versión 11,5 a través de técnicas de estadística descriptiva. Resultados: Predominó el sexo masculino (55,66 por ciento), diciembre fue el mes de mayor ingreso (36,45 por ciento), la mayoría de los pacientes fueron ingresados en la salas de sospechosos (60,09 por ciento), predominó la administración de medicamentos por vía oral, con 820 procederes (52,59 por ciento), se logró que 51,25 por ciento de los pacientes atendidos egresaran vivos, siendo el mes de enero el de mayor letalidad (66,70 por ciento). Conclusiones: La labor realizada por los enfermeros cubanos en la lucha contra el Ébola en Liberia, África Occidental, y el cumplimiento estricto de los protocolos según procederes de enfermería contribuyó al control hemodinámico de los pacientes atendidos y a la disminución paulatina de la epidemia, así como la letalidad por dicho evento(AU)


Introduction: Ebola virus causes a highly infectious and serious disease, which quickly leads to death, with a death rate of up to 90 percent, but it can be prevented. Objective: To describe the relevance of nursing procedures in the survival of patients affected by Ebola. Methods: Descriptive, cross-sectional study carried out in West Africa, Liberia in the period from November 2014 to February 2015. The study population consisted of 203 patients who were applied nursing procedures by personnel who were part of the Cuban medical brigade. The information was obtained by direct observation and review of the statistical database of the Cuban mission in Liberia; and processed through the system SPSSS version 11.5, through descriptive statistics techniques. Results: The male sex predominated (55.66 percent). December was the month with highest admittance (36.45 percent); the majority of patients were admitted to the ward of suspects (60.09 percent). The administration of oral medications predominated, with 820 procedures (52.59 percent). It was achieved for 51.25 percent of the patients attended to be discharged alive, the month of January accounting for the highest mortality (66.70 percent). Conclusions: The work carried out by the Cuban nurses in the fight against Ebola in West Africa, Liberia and the strict compliance with the protocols according to nursing procedures contributed to the hemodynamic control of the patients attended and the gradual reduction of the epidemic, as well as the mortality for the event(AU)


Assuntos
Humanos , Sobrevida , Estudos Transversais , Doença pelo Vírus Ebola/prevenção & controle , Ebolavirus/patogenicidade , Cuidados de Enfermagem/métodos , Epidemiologia Descritiva
20.
Brain Res Bull ; 145: 2-17, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30658129

RESUMO

Viral infections are a major cause of human central nervous system infection, and may be associated with significant mortality, and long-term sequelae. In Africa, the lack of effective therapies, limited diagnostic and human resource facilities are especially in dire need. Most viruses that affect the central nervous system are opportunistic or accidental pathogens. Some of these viruses were initially considered harmless, however they have now evolved to penetrate the nervous system efficiently and exploit neuronal cell biology thus resulting in severe illness. A number of potentially lethal neurotropic viruses have been discovered in Africa and over the course of time shown their ability to spread wider afield involving other continents leaving a devastating impact in their trail. In this review we discuss key viruses involved in central nervous system disease and of major public health concern with respect to Africa. These arise from the families of Flaviviridae, Filoviridae, Retroviridae, Bunyaviridae, Rhabdoviridae and Herpesviridae. In terms of the number of cases affected by these viruses, HIV (Retroviridae) tops the list for morbidity, mortality and long term disability, while the Rift Valley Fever virus (Bunyaviridae) is at the bottom of the list. The most deadly are the Ebola and Marburg viruses (Filoviridae). This review describes their epidemiology and key neurological manifestations as regards the central nervous system such as meningoencephalitis and Guillain-Barré syndrome. The potential pathogenic mechanisms adopted by these viruses are debated and research perspectives suggested.


Assuntos
Viroses do Sistema Nervoso Central/epidemiologia , Sistema Nervoso Central/virologia , África/epidemiologia , Ebolavirus/patogenicidade , HIV/patogenicidade , Humanos , Simplexvirus/patogenicidade , Zika virus/patogenicidade
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