scholarly journals Increased Pathogenicity and Virulence of Middle East Respiratory Syndrome Coronavirus Clade B In Vitro and In Vivo

2020 ◽  
Vol 94 (15) ◽  
Author(s):  
Yanqun Wang ◽  
Jing Sun ◽  
Xiaobo Li ◽  
Airu Zhu ◽  
Wenda Guan ◽  
...  
Keyword(s):  
T Cell ◽  
Middle East ◽  
Severe Disease ◽  
Adaptive Immune Response ◽  
Viral Clearance ◽  
Middle East Respiratory Syndrome ◽  
Clade B ◽  
Alignment Analysis

ABSTRACT Middle East respiratory syndrome coronavirus (MERS-CoV) causes severe acute respiratory disease in humans. MERS-CoV strains from early epidemic clade A and contemporary epidemic clade B have not been phenotypically characterized to compare their abilities to infect cells and mice. We isolated the clade B MERS-CoV ChinaGD01 strain from a patient infected during the South Korean MERS outbreak in 2015 and compared the phylogenetics and pathogenicity of MERS-CoV EMC/2012 (clade A) and ChinaGD01 (clade B) in vitro and in vivo. Genome alignment analysis showed that most clade-specific mutations occurred in the orf1ab gene, including mutations that were predicted to be potential glycosylation sites. Minor differences in viral growth but no significant differences in plaque size or sensitivity to beta interferon (IFN-β) were detected between these two viruses in vitro. ChinaGD01 virus infection induced more weight loss and inflammatory cytokine production in human DPP4-transduced mice. Viral titers were higher in the lungs of ChinaGD01-infected mice than with EMC/2012 infection. Decreased virus-specific CD4+ and CD8+ T cell numbers were detected in the lungs of ChinaGD01-infected mice. In conclusion, MERS-CoV evolution induced changes to reshape its pathogenicity and virulence in vitro and in vivo and to evade adaptive immune response to hinder viral clearance. IMPORTANCE MERS-CoV is an important emerging pathogen and causes severe respiratory infection in humans. MERS-CoV strains from early epidemic clade A and contemporary epidemic clade B have not been phenotypically characterized to compare their abilities to infect cells and mice. In this study, we showed that a clade B virus ChinaGD01 strain caused more severe disease in mice, with delayed viral clearance, increased inflammatory cytokines, and decreased antiviral T cell responses, than the early clade A virus EMC/2012. Given the differences in pathogenicity of different clades of MERS-CoV, periodic assessment of currently circulating MERS-CoV is needed to monitor potential severity of zoonotic disease.

scholarly journals Immunotherapeutic Efficacy of IgY Antibodies Targeting the Full-Length Spike Protein in an Animal Model of Middle East Respiratory Syndrome Coronavirus Infection

2021 ◽  
Vol 14 (6) ◽  
pp. 511
Author(s):  
Sherif A. El-Kafrawy ◽  
Aymn T. Abbas ◽  
Sayed S. Sohrab ◽  
Ashraf A. Tabll ◽  
Ahmed M. Hassan ◽  
...  
Keyword(s):  
Middle East ◽  
Specific Binding ◽  
High Titer ◽  
Egg Yolk ◽  
Middle East Respiratory Syndrome ◽  
Therapeutic Interventions ◽  
Dot Blot ◽  
S Protein

Identified in 2012, the Middle East respiratory syndrome coronavirus (MERS-CoV) causes severe and often fatal acute respiratory illness in humans. No approved prophylactic or therapeutic interventions are currently available. In this study, we developed chicken egg yolk antibodies (IgY Abs) specific to the MERS-CoV spike (S) protein and evaluated their neutralizing efficiency against MERS-CoV infection. S-specific IgY Abs were produced by injecting chickens with the purified recombinant S protein of MERS-CoV at a high titer (4.4 mg/mL per egg yolk) at week 7 post immunization. Western blotting and immune-dot blot assays demonstrated specific binding to the MERS-CoV S protein. In vitro neutralization of the generated IgY Abs against MERS-CoV was evaluated and showed a 50% neutralizing concentration of 51.42 μg/mL. In vivo testing using a human-transgenic mouse model showed a reduction of viral antigen positive cells in treated mice, compared to the adjuvant-only controls. Moreover, the lung cells of the treated mice showed significantly reduced inflammation, compared to the controls. Our results show efficient neutralization of MERS-CoV infection both in vitro and in vivo using S-specific IgY Abs. Clinical trials are needed to evaluate the efficiency of the IgY Abs in camels and humans.

scholarly journals In vivo and in vitro Evaluation of Cytokine Expression Profiles During Middle East Respiratory Syndrome Coronavirus (MERS-CoV) Infection

2021 ◽  
Vol Volume 14 ◽  
pp. 2121-2131
Author(s):  
Ayman Mubarak ◽  
Bahauddeen Alrfaei ◽  
Abdullah Aljurayyan ◽  
Mahfoudh M Alqafil ◽  
Mohamed A Farrag ◽  
...  
Keyword(s):  
Middle East ◽  
Expression Profiles ◽  
Cytokine Expression ◽  
Middle East Respiratory Syndrome ◽  
In Vitro Evaluation

scholarly journals ZAP-70 Regulates Autoimmune Arthritis via Alterations in T Cell Activation and Apoptosis

Cells ◽  
2019 ◽  
Vol 8 (5) ◽  
pp. 504 ◽  
Author(s):  
Réka Kugyelka ◽  
Lilla Prenek ◽  
Katalin Olasz ◽  
Zoltán Kohl ◽  
Bálint Botz ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Severe Disease ◽  
Negative Regulator ◽  
Human Rheumatoid Arthritis ◽  
Autoantibody Production

T cells play an essential role in the pathogenesis of both human rheumatoid arthritis (RA) and its murine models. A key molecule in T cell activation is ZAP-70, therefore we aimed to investigate the effects of partial ZAP-70 deficiency on the pathogenesis of recombinant human G1(rhG1)-induced arthritis (GIA), a well-established mouse model of RA. Arthritis was induced in BALB/c and ZAP-70+/− heterozygous mice. Disease progression was monitored using a scoring system and in vivo imaging, antigen-specific proliferation, cytokine and autoantibody production was measured and T cell apoptotic pathways were analyzed. ZAP-70+/− mice developed a less severe arthritis, as shown by both clinical picture and in vitro parameters (decreased T cell proliferation, cytokine and autoantibody production). The amount of cleaved Caspase-3 increased in arthritic ZAP-70+/− T cells, with no significant changes in cleaved Caspase-8 and -9 levels; although expression of Bim, Bcl-2 and Cytochrome C showed alterations. Tyrosine phosphorylation was less pronounced in arthritic ZAP-70+/− T cells and the amount of Cbl-b—a negative regulator of T cell activation—decreased as well. We hypothesize that the less severe disease seen in the partial absence of ZAP-70 might be caused by the decreased T cell activation accompanied by increased apoptosis.

scholarly journals Cyclophilin inhibitors restrict Middle East respiratory syndrome coronavirus via interferon-λ in vitro and in mice

2020 ◽  
Vol 56 (5) ◽  
pp. 1901826 ◽  
Author(s):  
Lucie Sauerhering ◽  
Alexandra Kupke ◽  
Lars Meier ◽  
Erik Dietzel ◽  
Judith Hoppe ◽  
...  
Keyword(s):  
Middle East ◽  
Molecular Mechanisms ◽  
Treatment Strategies ◽  
Middle East Respiratory Syndrome ◽  
Alveolar Epithelial Cells ◽  
Infection Model ◽  
Activated T Cells ◽  
Rna Accumulation

While severe coronavirus infections, including Middle East respiratory syndrome coronavirus (MERS-CoV), cause lung injury with high mortality rates, protective treatment strategies are not approved for clinical use.We elucidated the molecular mechanisms by which the cyclophilin inhibitors cyclosporin A (CsA) and alisporivir (ALV) restrict MERS-CoV to validate their suitability as readily available therapy in MERS-CoV infection.Calu-3 cells and primary human alveolar epithelial cells (hAECs) were infected with MERS-CoV and treated with CsA or ALV or inhibitors targeting cyclophilin inhibitor-regulated molecules including calcineurin, nuclear factor of activated T-cells (NFATs) or mitogen-activated protein kinases. Novel CsA-induced pathways were identified by RNA sequencing and manipulated by gene knockdown or neutralising antibodies. Viral replication was quantified by quantitative real-time PCR and 50% tissue culture infective dose. Data were validated in a murine MERS-CoV infection model.Both CsA and ALV reduced MERS-CoV titres and viral RNA replication in Calu-3 cells and hAECs, improving epithelial integrity. While neither calcineurin nor NFAT inhibition reduced MERS-CoV propagation, blockade of c-Jun N-terminal kinase diminished infectious viral particle release but not RNA accumulation. Importantly, CsA induced interferon regulatory factor 1 (IRF1), a pronounced type III interferon (IFNλ) response and expression of antiviral genes. Downregulation of IRF1 or IFNλ increased MERS-CoV propagation in the presence of CsA. Importantly, oral application of CsA reduced MERS-CoV replication in vivo, correlating with elevated lung IFNλ levels and improved outcome.We provide evidence that cyclophilin inhibitors efficiently decrease MERS-CoV replication in vitro and in vivo via upregulation of inflammatory antiviral cell responses, in particular IFNλ. CsA might therefore represent a promising candidate for treating MERS-CoV infection.

scholarly journals The N-terminal Region of Middle East Respiratory Syndrome Coronavirus Accessory Protein 8b is Essential for Enhanced Virulence of an Attenuated Murine Coronavirus

2021 ◽  
Author(s):  
Yuming Li ◽  
Yingkang Jin ◽  
Lijun Kuang ◽  
Zhenhua Luo ◽  
Fang Li ◽  
...  
Keyword(s):  
Immune Response ◽  
Middle East ◽  
Hepatitis Virus ◽  
Mouse Hepatitis Virus ◽  
Terminal Region ◽  
Middle East Respiratory Syndrome ◽  
Accessory Protein ◽  
Accessory Proteins

Middle East respiratory syndrome coronavirus (MERS-CoV) is a beta coronavirus that emerged in 2012, causing severe pneumonia and renal failure. MERS-CoV encodes five accessory proteins. Some of them have been shown to interfere with host antiviral immune response. However, the roles of protein 8b in innate immunity and viral virulence was rarely studied. Here, we introduced individual MERS-CoV accessory protein genes into the genome of an attenuated murine coronavirus (Mouse hepatitis virus, MHV), respectively and found accessory protein 8b could enhance viral replication in vivo and in vitro , and increase the lethality of infected mice. RNA-seq analysis revealed that protein 8b could significantly inhibit type I interferon production (IFN-I) and innate immune response in mice infected with MHV expressing protein 8b. We also found that MERS-CoV protein 8b could initiate from multiple internal methionine sites and at least three protein variants were identified. Residues 1-23 of protein 8b was demonstrated to be responsible for increased virulence in vivo . In addition, the inhibitory effect on IFN-I of protein 8b might not contribute to its virulence enhancement as aa1-23 deletion did not affect IFN-I production in vitro and in vivo . Next, we also found that protein 8b was localized to the endoplasmic reticulum (ER)/Golgi membrane in infected cells, which was disrupted by C-terminal region aa 88-112 deletion. This study will provide new insight into the pathogenesis of MERS-CoV infection. IMPORTANCE Multiple coronaviruses (CoV) cause severe respiratory infections and become global public health threats such as SARS-CoV, MERS-CoV, and SARS-CoV-2. Each coronavirus contains different numbers of accessory proteins which show high variability among different CoVs. Accessory proteins are demonstrated to play essential roles in pathogenesis of CoVs. MERS-CoV contains 5 accessory proteins (protein 3, 4a, 4b, 5, 8b), and deletion of all four accessory proteins (protein 3, 4a, 4b, 5), significantly affects MERS-CoV replication and pathogenesis. However, whether ORF8b also regulates MERS-CoV infection is unknown. Here, we constructed mouse hepatitis virus (MHV) recombinant virus expressing MERS-CoV protein 8b and demonstrated protein 8b could significantly enhance the virulence of MHV, which is mediated by N-terminal domain of protein 8b. This study will shed light on the understanding of pathogenesis of MERS-CoV infection.

627 The DLL3-targeted half-life extended bispecific T cell engager (HLE BiTE®) immune-oncology therapy AMG 757 has potent antitumor activity in neuroendocrine cancer

2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A663-A663
Author(s):  
Keegan Cooke ◽  
Juan Estrada ◽  
Jinghui Zhan ◽  
Jonathan Werner ◽  
Fei Lee ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Tumor Growth ◽  
Mouse Models ◽  
T Cell Activation ◽  
Phase 1 ◽  
Phase 1 Study ◽  
Human T Cells

BackgroundNeuroendocrine tumors (NET), including small cell lung cancer (SCLC), have poor prognosis and limited therapeutic options. AMG 757 is an HLE BiTE® immune therapy designed to redirect T cell cytotoxicity to NET cells by binding to Delta-like ligand 3 (DLL3) expressed on the tumor cell surface and CD3 on T cells.MethodsWe evaluated activity of AMG 757 in NET cells in vitro and in mouse models of neuroendocrine cancer in vivo. In vitro, co-cultures of NET cells and human T cells were treated with AMG 757 in a concentration range and T cell activation, cytokine production, and tumor cell killing were assessed. In vivo, AMG 757 antitumor efficacy was evaluated in xenograft NET and in orthotopic models designed to mimic primary and metastatic SCLC lesions. NSG mice bearing established NET were administered human T cells and then treated once weekly with AMG 757 or control HLE BiTE molecule; tumor growth inhibition was assessed. Pharmacodynamic effects of AMG 757 in tumors were also evaluated in SCLC models following a single administration of human T cells and AMG 757 or control HLE BiTE molecule.ResultsAMG 757 induced T cell activation, cytokine production, and potent T cell redirected killing of DLL3-expressing SCLC, neuroendocrine prostate cancer, and other DLL3-expressing NET cell lines in vitro. AMG 757-mediated redirected lysis was specific for DLL3-expressing cells. In patient-derived xenograft and orthotopic models of SCLC, single-dose AMG 757 effectively engaged human T cells administered systemically, leading to a significant increase in the number of human CD4+ and CD8+ T cells in primary and metastatic tumor lesions. Weekly administration of AMG 757 induced significant tumor growth inhibition of SCLC (figure 1) and other NET, including complete regression of established tumors and clearance of metastatic lesions. These findings warranted evaluation of AMG 757 (NCT03319940); the phase 1 study includes dose exploration (monotherapy and in combination with pembrolizumab) and dose expansion (monotherapy) in patients with SCLC (figure 2). A study of AMG 757 in patients with neuroendocrine prostate cancer is under development based on emerging data from the ongoing phase 1 study.Abstract 627 Figure 1AMG 757 Significantly reduced tumor growth in orthotopic SCLC mouse modelsAbstract 627 Figure 2AMG 757 Phase 1 study designConclusionsAMG 757 engages and activates T cells to kill DLL3-expressing SCLC and other NET cells in vitro and induces significant antitumor activity against established xenograft tumors in mouse models. These preclinical data support evaluation of AMG 757 in clinical studies of patients with NET.Ethics ApprovalAll in vivo work was conducted under IACUC-approved protocol #2009-00046.

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