Severity of Disease in Humanized Mice Infected With Ebola Virus or Reston Virus Is Associated With Magnitude of Early Viral Replication in Liver

Most filoviruses cause severe disease in humans. For example, Ebola virus (EBOV) is responsible for the two most extensive outbreaks of filovirus disease to date, with case fatality rates of 66% and 40%, respectively. In contrast, Reston virus (RESTV) is apparently apathogenic in humans, and while transmission of RESTV from domestic pigs to people results in seroconversion, no signs of disease have been reported in such cases. The determinants leading to these differences in pathogenicity are not well understood, but such information is needed in order to better evaluate the risks posed by the repeated spillover of RESTV into the human population and to perform risk assessments for newly emerging filoviruses with unknown pathogenic potential. Interestingly, RESTV and EBOV already show marked differences in their growth in vitro, with RESTV growing slower and reaching lower end titers. In order to understand the basis for this in vitro attenuation of RESTV, we used various life cycle modeling systems mimicking different aspects of the virus life cycle. Our results showed that viral RNA synthesis was markedly slower when using the ribonucleoprotein (RNP) components from RESTV, rather than those for EBOV. In contrast, the kinetics of budding and entry were indistinguishable between these two viruses. These data contribute to our understanding of the molecular basis for filovirus pathogenicity by showing that it is primarily differences in the robustness of RNA synthesis by the viral RNP complex that are responsible for the impaired growth of RESTV in tissue culture.

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Facile Discovery of a Diverse Panel of Anti-Ebola Virus Antibodies by Immune Repertoire Mining

Scientific Reports ◽

10.1038/srep13926 ◽

2015 ◽

Vol 5 (1) ◽

Cited By ~ 29

Author(s):

Bo Wang ◽

Christien A. Kluwe ◽

Oana I. Lungu ◽

Brandon J. DeKosky ◽

Scott A. Kerr ◽

...

Keyword(s):

Monoclonal Antibodies ◽

Ebola Virus ◽

Sequence Divergence ◽

West African ◽

Antibody Repertoire ◽

Efficient Technology ◽

Mouse Immunization ◽

Selection For ◽

Reston Virus ◽

Antibody Secreting Cells

Abstract The ongoing evolution of Ebolaviruses poses significant challenges to the development of immunodiagnostics for detecting emergent viral variants. There is a critical need for the discovery of monoclonal antibodies with distinct affinities and specificities for different Ebolaviruses. We developed an efficient technology for the rapid discovery of a plethora of antigen-specific monoclonal antibodies from immunized animals by mining the VH:VL paired antibody repertoire encoded by highly expanded B cells in the draining popliteal lymph node (PLN). This approach requires neither screening nor selection for antigen-binding. Specifically we show that mouse immunization with Ebola VLPs gives rise to a highly polarized antibody repertoire in CD138+ antibody-secreting cells within the PLN. All highly expanded antibody clones (7/7 distinct clones/animal) were expressed recombinantly and shown to recognize the VLPs used for immunization. Using this approach we obtained diverse panels of antibodies including: (i) antibodies with high affinity towards GP; (ii) antibodies which bound Ebola VLP Kissidougou-C15, the strain circulating in the recent West African outbreak; (iii) non-GP binding antibodies that recognize wild type Sudan or Bundibugyo viruses that have 39% and 37% sequence divergence from Ebola virus, respectively and (iv) antibodies to the Reston virus GP for which no antibodies have been reported.

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Functional Interactomes of the Ebola Virus Polymerase Identified by Proximity Proteomics in the Context of Viral Replication

SSRN Electronic Journal ◽

10.2139/ssrn.3895930 ◽

2021 ◽

Author(s):

Jingru Fang ◽

Colette Pietzsch ◽

George Tsaprailis ◽

Gogce Crynen ◽

Kelvin Frank Cho ◽

...

Keyword(s):

Viral Replication ◽

Ebola Virus

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STUDY OF THE INHIBITION POTENTIAL OF REMDESIVIR DERIVATIVES ON MPRO OF SARS-COV-2

International Journal of Research -GRANTHAALAYAH ◽

10.29121/granthaalayah.v8.i11.2020.2342 ◽

2020 ◽

Vol 8 (11) ◽

pp. 164-174

Author(s):

Aluísio Marques da Fonseca ◽

Antonio Luthierre Gama Cavalcante ◽

Rubson Mateus Matos Carvalho ◽

Jeferson Falcão do Amaral ◽

Regilany Paulo Colares ◽

...

Keyword(s):

Viral Replication ◽

Virus Replication ◽

Ebola Virus ◽

Common Diseases ◽

Main Protease ◽

Appropriate Therapy ◽

Potential Inhibitors

The emergence of the new coronavirus (SARS-COV-2) is known to trigger some common diseases in humans such as pneumonia and diarrhea, the search for appropriate therapy combat COVID-19 has been intense and exhaustive. Motivation/Background: Thus, based on the rational study of drugs, a survey of potential ligands that can inhibit the vital protein in virus replication, the main protease (Mpro), has been carried out worldwide. Method: In this battle, the antiviral Remdesivir, which was created to fight the Ebola virus, proved, through the molecular anchorage, to be quite effective against its target because it presented affinity energy far superior to its co-crystallized ligand. Results: In this work, a study was carried out with Remdesivir and its derivatives, obtained in a zinc database15, to present a possible alternative, based on its structure-affinity, as potential Inhibitors of SARS-COV-2 MPro, with affinity energy ranging from -6.3 to -8.2 kcal/mol. Conclusions: It was found that both remdesivir and its diastereoisomeric derivatives have an affinity with the main protease (Mpro), responsible for viral replication, with inhibition capacity and possible alternative in its treatment.

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127 PROLIFERATION OF HEPATITIS B VIRUS INFECTED HUMAN HEPATOCYTES INDUCES SUPPRESSION OF VIRAL REPLICATION AND RAPID cccDNA DECREASE IN HUMANIZED MICE

Journal of Hepatology ◽

10.1016/s0168-8278(13)60129-4 ◽

2013 ◽

Vol 58 ◽

pp. S56-S57 ◽

Cited By ~ 4

Author(s):

L. Allweiss ◽

T. Volz ◽

K. Giersch ◽

A.W. Lohse ◽

J. Petersen ◽

...

Keyword(s):

Hepatitis B Virus ◽

Hepatitis B ◽

Viral Replication ◽

Human Hepatocytes ◽

Humanized Mice ◽

B Virus

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Investigating the Cellular Transcriptomic Response Induced by the Makona Variant of Ebola Virus in Differentiated THP-1 Cells

Viruses ◽

10.3390/v11111023 ◽

2019 ◽

Vol 11 (11) ◽

pp. 1023 ◽

Cited By ~ 1

Author(s):

Andrew Bosworth ◽

Stuart D. Dowall ◽

Stuart Armstrong ◽

Xuan Liu ◽

Xiaofeng Dong ◽

...

Keyword(s):

Inflammatory Response ◽

Ebola Virus ◽

Virus Disease ◽

Monocytic Cell ◽

Monocytic Cell Line ◽

Transcriptomic Response ◽

Human Monocytic Cell Line ◽

Human Monocytic Cell ◽

Transcriptomic Changes ◽

Reston Virus

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.

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Ebolaviruses Associated with Differential Pathogenicity Induce Distinct Host Responses in Human Macrophages

Journal of Virology ◽

10.1128/jvi.00179-17 ◽

2017 ◽

Vol 91 (11) ◽

Cited By ~ 25

Author(s):

Judith Olejnik ◽

Adriana Forero ◽

Laure R. Deflubé ◽

Adam J. Hume ◽

Whitney A. Manhart ◽

...

Keyword(s):

Host Response ◽

Ebola Virus ◽

Severe Disease ◽

Health Concern ◽

Type I ◽

Proinflammatory Response ◽

Tlr4 Signaling ◽

Human Macrophages ◽

Ebov Infection ◽

Reston Virus

ABSTRACT Ebola virus (EBOV) and Reston virus (RESTV) are members of the Ebolavirus genus which greatly differ in their pathogenicity. While EBOV causes a severe disease in humans characterized by a dysregulated inflammatory response and elevated cytokine and chemokine production, there are no reported disease-associated human cases of RESTV infection, suggesting that RESTV is nonpathogenic for humans. The underlying mechanisms determining the pathogenicity of different ebolavirus species are not yet known. In this study, we dissected the host response to EBOV and RESTV infection in primary human monocyte-derived macrophages (MDMs). As expected, EBOV infection led to a profound proinflammatory response, including strong induction of type I and type III interferons (IFNs). In contrast, RESTV-infected macrophages remained surprisingly silent. Early activation of IFN regulatory factor 3 (IRF3) and NF-κB was observed in EBOV-infected, but not in RESTV-infected, MDMs. In concordance with previous results, MDMs treated with inactivated EBOV and Ebola virus-like particles (VLPs) induced NF-κB activation mediated by Toll-like receptor 4 (TLR4) in a glycoprotein (GP)-dependent manner. This was not the case in cells exposed to live RESTV, inactivated RESTV, or VLPs containing RESTV GP, indicating that RESTV GP does not trigger TLR4 signaling. Our results suggest that the lack of immune activation in RESTV-infected MDMs contributes to lower pathogenicity by preventing the cytokine storm observed in EBOV infection. We further demonstrate that inhibition of TLR4 signaling abolishes EBOV GP-mediated NF-κB activation. This finding indicates that limiting the excessive TLR4-mediated proinflammatory response in EBOV infection should be considered as a potential supportive treatment option for EBOV disease. IMPORTANCE Emerging infectious diseases are a major public health concern, as exemplified by the recent devastating Ebola virus (EBOV) outbreak. Different ebolavirus species are associated with widely varying pathogenicity in humans, ranging from asymptomatic infections for Reston virus (RESTV) to severe disease with fatal outcomes for EBOV. In this comparative study of EBOV- and RESTV-infected human macrophages, we identified key differences in host cell responses. Consistent with previous data, EBOV infection is associated with a proinflammatory signature triggered by the surface glycoprotein (GP), which can be inhibited by blocking TLR4 signaling. In contrast, infection with RESTV failed to stimulate a strong host response in infected macrophages due to the inability of RESTV GP to stimulate TLR4. We propose that disparate proinflammatory host signatures contribute to the differences in pathogenicity reported for ebolavirus species and suggest that proinflammatory pathways represent an intriguing target for the development of novel therapeutics.

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Passive Transfer of Antibodies Protects Immunocompetent and Immunodeficient Mice against Lethal Ebola Virus Infection without Complete Inhibition of Viral Replication

Journal of Virology ◽

10.1128/jvi.75.10.4649-4654.2001 ◽

2001 ◽

Vol 75 (10) ◽

pp. 4649-4654 ◽

Cited By ~ 94

Author(s):

Manisha Gupta ◽

Siddhartha Mahanty ◽

Mike Bray ◽

Rafi Ahmed ◽

Pierre E. Rollin

Keyword(s):

Virus Infection ◽

Viral Replication ◽

Ebola Virus ◽

Protective Efficacy ◽

Hemorrhagic Fever ◽

Passive Transfer ◽

Immune Serum ◽

Immunodeficient Mice ◽

Ebola Hemorrhagic Fever ◽

Ebola Virus Infection

ABSTRACT Ebola hemorrhagic fever is a severe, usually fatal illness caused by Ebola virus, a member of the filovirus family. The use of nonhomologous immune serum in animal studies and blood from survivors in two anecdotal reports of Ebola hemorrhagic fever in humans has shown promise, but the efficacy of these treatments has not been demonstrated definitively. We have evaluated the protective efficacy of polyclonal immune serum in a mouse model of Ebola virus infection. Our results demonstrate that mice infected subcutaneously with live Ebola virus survive infection and generate high levels of anti-Ebola virus immunoglobulin G (IgG). Passive transfer of immune serum from these mice before challenge protected upto 100% of naive mice against lethal Ebola virus infection. Protection correlated with the level of anti-Ebola virus IgG titers, and passive treatment with high-titer antiserum was associated with a delay in the peak of viral replication. Transfer of immune serum to SCID mice resulted in 100% survival after lethal challenge with Ebola virus, indicating that antibodies alone can protect from lethal disease. Thus antibodies suppress or delay viral growth, provide protection against lethal Ebola virus infection, and may not require participation of other immune components for protection.

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