scholarly journals One mucosal administration of a live attenuated recombinant COVID-19 vaccine protects non-human primates from SARS-CoV-2

2021 ◽  
Author(s):  
Mariana F. Tioni ◽  
Robert Jordan ◽  
Angie Silva Pena ◽  
Aditya Garg ◽  
Danlu Wu ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Rna Virus ◽  
Low Cost ◽  
Viral Envelope ◽  
Host Cells ◽  
Surface Glycoprotein ◽  
Viral Envelope Protein ◽  
Phase I Clinical Trials ◽  
Global Pandemic ◽  
Syncytial Virus

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) is the causative agent of the COVID-19 global pandemic. Vaccines are needed to control the disease and bring an end to the pandemic. SARS-CoV-2 is an enveloped RNA virus that relies on its trimeric surface glycoprotein, spike, for entry into host cells. Here we describe the COVID-19 vaccine candidate MV-014-212, a live attenuated, recombinant human respiratory syncytial virus (RSV) expressing a chimeric SARS-CoV-2 spike as the only viral envelope protein. MV-014-212 was attenuated and immunogenic in African green monkeys (AGMs). One mucosal administration of MV-014-212 in AGMs protected against SARS-CoV-2 challenge, reducing the peak shedding of SARS-CoV-2 in the nose by more than 200-fold. MV-014-212 elicited mucosal immunity in the nose and neutralizing antibodies in serum that exhibited cross neutralization against two virus variants of concern. Intranasally delivered, live attenuated vaccines such as MV-014-212 entail low-cost manufacturing suitable for global deployment. MV-014-212 is currently in phase I clinical trials as a single-dose intranasal COVID-19 vaccine.

scholarly journals Generation of a Candidate Live Marker Vaccine for Equine Arteritis Virus by Deletion of the Major Virus Neutralization Domain

2003 ◽  
Vol 77 (15) ◽  
pp. 8470-8480 ◽  
Author(s):  
Javier Castillo-Olivares ◽  
Roeland Wieringa ◽  
Tamás Bakonyi ◽  
Antoine A. F. de Vries ◽  
Nick J. Davis-Poynter ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Rna Virus ◽  
Viral Envelope ◽  
Equine Arteritis Virus ◽  
Wild Type Virus ◽  
Enzyme Linked Immunosorbent Assay ◽  
Wild Type ◽  
Challenge Virus ◽  
Marker Vaccine

ABSTRACT Equine arteritis virus (EAV) is an enveloped plus-strand RNA virus of the family Arteriviridae (order Nidovirales) that causes respiratory and reproductive disease in equids. Protective, virus-neutralizing antibodies (VNAb) elicited by infection are directed predominantly against an immunodominant region in the membrane-proximal domain of the viral envelope glycoprotein GL, allowing recently the establishment of a sensitive peptide enzyme-linked immunosorbent assay (ELISA) based on this particular domain (J. Nugent et al., J. Virol. Methods 90:167-183, 2000). By using an infectious cDNA we have now generated, in the controlled background of a nonvirulent virus, a mutant EAV from which this immunodominant domain was deleted. This virus, EAV-GLΔ, replicated to normal titers in culture cells, although at a slower rate than wild-type EAV, and caused an asymptomatic infection in ponies. The antibodies induced neutralized the mutant virus efficiently in vitro but reacted poorly to wild-type EAV strains. Nevertheless, when inoculated subsequently with virulent EAV, the immunized animals, in contrast to nonvaccinated controls, were fully protected against disease; replication of the challenge virus occurred briefly at low though detectable levels. The levels of protection achieved suggest that an immune effector mechanism other than VNAb plays an important role in protection against infection. As expected, infection with EAV-GLΔ did not induce a measurable response in our GL-peptide ELISA while the challenge infection of the animals clearly did. EAV-GLΔ or similar mutants are therefore attractive marker vaccine candidates, enabling serological discrimination between vaccinated and wild-type virus-infected animals.

scholarly journals Seneca Valley virus intercellular transmission mediated by exosomes

2020 ◽  
Author(s):  
Keshan Zhang ◽  
Guowei Xu ◽  
Shouxing Xu ◽  
Xijuan Shi ◽  
Chaochao Shen ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Clinical Symptoms ◽  
Rna Virus ◽  
Virus Transmission ◽  
Foot And Mouth Disease ◽  
Host Cells ◽  
Productive Infection ◽  
Infected Cells ◽  
Seneca Valley Virus ◽  
Positive Strand Rna

ABSTRACTExosomes are cup-shaped vesicles that are secreted by cells and are involved in the intercellular transport of a variety of substances, including proteins, RNA, and liposomes. Studies have shown that pathogenic microorganisms are contained in exosomes extracted from pathogenic micro-infected cells. The Seneca Valley virus (SVV) is a non-encapsulated single-stranded positive-strand RNA virus that causes ulceration in the pig’s nose, the appearance of blisters, and other clinical symptoms similar to foot-and-mouth disease (FMD). Whether exosomes from SVV-infected cells can mediate SVV intercellular transmission is of great significance. There have been no studies showing whether exosomes can carry SVV in susceptible and non-susceptible cells. Here, we first extracted and identified exosomes from SVV-infected IBRS-2 cells. It was confirmed that replication of SVV can be inhibited when IBRS-2 cells treated with exosomes inbihitor GW4869. Furthermore, laser confocal microscopy and qRT-PCR experiments were performed to investigate whether exosomes can carry SVV and enable the virus to proliferate in susceptible and non-susceptible cells. Finally, exosome-mediated intercellular transmission can not be completely blocked by SVV-specific neutralizing antibodies. Taken together, this study showed that exosomes extracted from the SVV-infected IBRS-2 cells can carry SVV and transmit productive SVV infection between SVV susceptible and non-susceptible cells, this transmit infection is resistant to SVV specific neutralization antibody.IMPORTANCEExosomes participate in intercellular communnication between cells. Exosomes derived from virus-infected cells can mediate virus transmission or/and regulate immune response. However, the function of exosomes that from SVV-infected host cells during SVV transmission is unclear. Here, we demonstrate SVV can utilize host exosomes to establish productive infection in intercellular transmission. Furthermore, exosome-mediated SVV transmission is resistant to SVVV-specific neutralizing antibodies. This discovery sheds light on neutralizing antibodies resistant to SVVV transmission by exosomes as a potential immune evasion mechanism.

scholarly journals SARS-CoV-2 envelope-protein corruption of homeostatic signaling mechanisms in mammalian cells

2021 ◽  
Author(s):  
Tobias Schulze ◽  
Andreas Hartel ◽  
Sebastian Hoeler ◽  
Clara Hemming ◽  
Robert Lehn ◽  
...  
Keyword(s):  
Envelope Protein ◽  
Viral Protein ◽  
Mammalian Cells ◽  
Fluorescent Protein ◽  
Ion Selectivity ◽  
Cellular Protein ◽  
Viral Envelope ◽  
Host Cells ◽  
Viral Envelope Protein ◽  
Cell Protection

During a SARS-CoV2 infection, host cells produce large amounts of the viral envelope protein (Ep-CoV2). Ep-CoV2 is partially inserted into the membrane of nascent viral particles and into cellular membranes. To mimic the pathophysiological impact of the cellular protein fraction, Ep-CoV2 was overexpressed in mammalian cells and effects on key signaling parameters were monitored. By tagging with green fluorescent protein (GFP), we found that Ep-CoV2 protein is mostly present in the endoplasmic reticulum with additional trace amounts in the plasma membrane. We observed that wild-type Ep-CoV2 and, to a lesser extent, its mutants (N15A, V25F) corrupted some of the most important homeostatic mechanisms in cells. The same was observed with isolated transmembrane domains of the protein. The Ep-CoV2-evoked elevation of intracellular Ca2+ and pH as well as the induced membrane depolarization produced by the presence of the protein interfere with major signal transduction cascades in host cells. These functions of Ep-CoV2, which likely contribute to the pathogenesis of the viral protein, result from the ion-channel activity of the viral protein. Two independent assays, a functional reconstitution of Ep-CoV2 protein in artificial membranes and a rescue of K+-deficient yeast mutants, confirm that Ep-CoV2 generates a cation-conducting channel with a low unitary conductance and a complex ion selectivity. The data presented here suggest that specific channel function inhibitors of Ep-CoV2 can provide cell protection and virostatic effects.

scholarly journals COVID-19: Attacks the 1-Beta Chain of Hemoglobin and Captures the Porphyrin to Inhibit Human Heme Metabolism

2020 ◽  
Author(s):  
liu wenzhong ◽  
Li hualan
Keyword(s):  
Carbon Dioxide ◽  
Rna Virus ◽  
Host Cells ◽  
Surface Glycoprotein ◽  
The Novel ◽  
Beta Chain ◽  
Positive Strand Rna Virus ◽  
Novel Coronavirus ◽  
Positive Strand Rna ◽  
Bat Coronavirus

<p>The novel coronavirus pneumonia (COVID-19) is an infectious acute respiratory infection caused by the novel coronavirus. The virus is a positive-strand RNA virus with high homology to bat coronavirus. In this study, conserved domain analysis, homology modeling, and molecular docking were used to compare the biological roles of certain proteins of the novel coronavirus. The results showed the ORF8 and surface glycoprotein could bind to the porphyrin, respectively. At the same time, orf1ab, ORF10, and ORF3a proteins could coordinate attack the heme on the 1-beta chain of hemoglobin to dissociate the iron to form the porphyrin. The attack will cause less and less hemoglobin that can carry oxygen and carbon dioxide. The lung cells have extremely intense poisoning and inflammatory due to the inability to exchange carbon dioxide and oxygen frequently, which eventually results in ground-glass-like lung images. The mechanism also interfered with the normal heme anabolic pathway of the human body, is expected to result in human disease. According to the validation analysis of these finds, chloroquine could prevent orf1ab, ORF3a, and ORF10 to attack the heme to form the porphyrin, and inhibit the binding of ORF8 and surface glycoproteins to porphyrins to a certain extent, effectively relieve the symptoms of respiratory distress. Favipiravir could inhibit the envelope protein and ORF7a protein bind to porphyrin, prevent the virus from entering host cells, and catching free porphyrins. Because the novel coronavirus is dependent on porphyrins, it may originate from an ancient virus. Therefore, this research is of high value to contemporary biological experiments, disease prevention, and clinical treatment.<br></p>

scholarly journals COVID-19: Attacks the 1-Beta Chain of Hemoglobin and Captures the Porphyrin to Inhibit Human Heme Metabolism

2020 ◽  
Author(s):  
liu wenzhong ◽  
Li hualan
Keyword(s):  
Carbon Dioxide ◽  
Rna Virus ◽  
Host Cells ◽  
Surface Glycoprotein ◽  
The Novel ◽  
Beta Chain ◽  
Positive Strand Rna Virus ◽  
Novel Coronavirus ◽  
Positive Strand Rna ◽  
Bat Coronavirus

<p>The novel coronavirus pneumonia (COVID-19) is an infectious acute respiratory infection caused by the novel coronavirus. The virus is a positive-strand RNA virus with high homology to bat coronavirus. In this study, conserved domain analysis, homology modeling, and molecular docking were used to compare the biological roles of certain proteins of the novel coronavirus. The results showed the ORF8 and surface glycoprotein could bind to the porphyrin, respectively. At the same time, orf1ab, ORF10, and ORF3a proteins could coordinate attack the heme on the 1-beta chain of hemoglobin to dissociate the iron to form the porphyrin. The attack will cause less and less hemoglobin that can carry oxygen and carbon dioxide. The lung cells have extremely intense poisoning and inflammatory due to the inability to exchange carbon dioxide and oxygen frequently, which eventually results in ground-glass-like lung images. The mechanism also interfered with the normal heme anabolic pathway of the human body, is expected to result in human disease. According to the validation analysis of these finds, chloroquine could prevent orf1ab, ORF3a, and ORF10 to attack the heme to form the porphyrin, and inhibit the binding of ORF8 and surface glycoproteins to porphyrins to a certain extent, effectively relieve the symptoms of respiratory distress. Favipiravir could inhibit the envelope protein and ORF7a protein bind to porphyrin, prevent the virus from entering host cells, and catching free porphyrins. Because the novel coronavirus is dependent on porphyrins, it may originate from an ancient virus. Therefore, this research is of high value to contemporary biological experiments, disease prevention, and clinical treatment.<br></p>

scholarly journals Emerging antibody-based therapeutics against SARS-CoV-2 during the global pandemic

2020 ◽  
Vol 3 (4) ◽  
pp. 246-256
Author(s):  
Yaping Sun ◽  
Mitchell Ho
Keyword(s):  
Receptor Binding ◽  
Neutralizing Antibodies ◽  
Neutralizing Antibody ◽  
Host Cells ◽  
Spike Protein ◽  
Inhaled Drugs ◽  
Viral Attachment ◽  
Global Pandemic ◽  
Attachment Sites ◽  
Antibody Discovery

Abstract SARS-CoV-2 antibody therapeutics are being evaluated in clinical and preclinical stages. As of 11 October 2020, 13 human monoclonal antibodies targeting the SARS-CoV-2 spike protein have entered clinical trials with three (REGN-COV2, LY3819253/LY-CoV555, and VIR-7831/VIR-7832) in phase 3. On 9 November 2020, the US Food and Drug Administration issued an emergency use authorization for bamlanivimab (LY3819253/LY-CoV555) for the treatment of mild-to-moderate COVID-19. This review outlines the development of neutralizing antibodies against SARS-CoV-2, with a focus on discussing various antibody discovery strategies (animal immunization, phage display and B cell cloning), describing binding epitopes and comparing neutralizing activities. Broad-neutralizing antibodies targeting the spike proteins of SARS-CoV-2 and SARS-CoV might be helpful for treating COVID-19 and future infections. VIR-7831/7832 based on S309 is the only antibody in late clinical development, which can neutralize both SARS-CoV-2 and SARS-CoV although it does not directly block virus receptor binding. Thus far, the only cross-neutralizing antibody that is also a receptor binding blocker is nanobody VHH-72. The feasibility of developing nanobodies as inhaled drugs for treating COVID-19 and other respiratory diseases is an attractive idea that is worth exploring and testing. A cocktail strategy such as REGN-COV2, or engineered multivalent and multispecific molecules, combining two or more antibodies might improve the efficacy and protect against resistance due to virus escape mutants. Besides the receptor-binding domain, other viral antigens such as the S2 subunit of the spike protein and the viral attachment sites such as heparan sulfate proteoglycans that are on the host cells are worth investigating.

scholarly journals More Is Always Better Than One: The N-Terminal Domain of the Spike Protein as Another Emerging Target for Hampering the SARS-CoV-2 Attachment to Host Cells

2021 ◽  
Vol 22 (12) ◽  
pp. 6462
Author(s):  
Sonia Di Gaetano ◽  
Domenica Capasso ◽  
Pietro Delre ◽  
Luciano Pirone ◽  
Michele Saviano ◽  
...  
Keyword(s):  
Small Molecules ◽  
Neutralizing Antibodies ◽  
Recent Literature ◽  
Rna Virus ◽  
Binding Domain ◽  
Host Cells ◽  
Virus Attachment ◽  
Terminal Domain ◽  
Putative Target ◽  
Better Than

Although the approved vaccines are proving to be of utmost importance in containing the Coronavirus disease 2019 (COVID-19) threat, they will hardly be resolutive as new severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, a single-stranded RNA virus) variants might be insensitive to the immune response they induce. In this scenario, developing an effective therapy is still a dire need. Different targets for therapeutic antibodies and diagnostics have been identified, among which the SARS-CoV-2 spike (S) glycoprotein, particularly its receptor-binding domain, has been defined as crucial. In this context, we aim to focus attention also on the role played by the S N-terminal domain (S1-NTD) in the virus attachment, already recognized as a valuable target for neutralizing antibodies, in particular, building on a cavity mapping indicating the presence of two druggable pockets and on the recent literature hypothesizing the presence of a ganglioside-binding domain. In this perspective, we aim at proposing S1-NTD as a putative target for designing small molecules hopefully able to hamper the SARS-CoV-2 attachment to host cells.

scholarly journals The Fight against COVID-19 on the Multi-Protease Front and Surroundings: Could an Early Therapeutic Approach with Repositioning Drugs Prevent the Disease Severity?

Biomedicines ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 710
Author(s):  
Annamaria Vianello ◽  
Serena Del Turco ◽  
Serena Babboni ◽  
Beatrice Silvestrini ◽  
Rosetta Ragusa ◽  
...  
Keyword(s):  
Host Cell ◽  
Serine Proteases ◽  
Time Window ◽  
Low Cost ◽  
Critical Role ◽  
Severe Infection ◽  
Viral Envelope ◽  
Host Cells ◽  
Host Cell Membrane ◽  
Inflammatory Conditions

The interaction between the membrane spike (S) protein of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and the transmembrane angiotensin-converting enzyme 2 (ACE2) receptor of the human epithelial host cell is the first step of infection, which has a critical role for viral pathogenesis of the current coronavirus disease-2019 (COVID-19) pandemic. Following the binding between S1 subunit and ACE2 receptor, different serine proteases, including TMPRSS2 and furin, trigger and participate in the fusion of the viral envelope with the host cell membrane. On the basis of the high virulence and pathogenicity of SARS-CoV-2, other receptors have been found involved for viral binding and invasiveness of host cells. This review comprehensively discusses the mechanisms underlying the binding of SARS-CoV2 to ACE2 and putative alternative receptors, and the role of potential co-receptors and proteases in the early stages of SARS-CoV-2 infection. Given the short therapeutic time window within which to act to avoid the devastating evolution of the disease, we focused on potential therapeutic treatments—selected mainly among repurposing drugs—able to counteract the invasive front of proteases and mild inflammatory conditions, in order to prevent severe infection. Using existing approved drugs has the advantage of rapidly proceeding to clinical trials, low cost and, consequently, immediate and worldwide availability.

scholarly journals How Do Enveloped Viruses Exploit the Secretory Proprotein Convertases to Regulate Infectivity and Spread?

2021 ◽  
Author(s):  
Nabil G Seidah ◽  
Antonella Pasquato ◽  
Ursula Andreo
Keyword(s):  
Plasma Membranes ◽  
Viral Infections ◽  
Limited Proteolysis ◽  
Viral Envelope ◽  
Host Cells ◽  
Surface Glycoprotein ◽  
Type I ◽  
Proprotein Convertases ◽  
Enveloped Viruses ◽  
Surface Glycoproteins

Inhibition of the binding of enveloped viruses surface glycoproteins to host cell receptor(s) is a major target of vaccines and constitutes an efficient strategy to block viral entry and infection of various host cells and tissues. Cellular entry usually requires fusion of the viral envelope with host plasma membranes. Such entry mechanism is often preceded by &ldquo;priming&rdquo; and/or &ldquo;activation&rdquo; steps requiring limited proteolysis of the viral surface glycoprotein to expose a fusiogenic domain for efficient membrane juxtapositions. The 9-membered family of Proprotein Convertases related to Subtilisin/Kexin (PCSK) serine proteases (PC1, PC2, Furin, PC4, PC5, PACE4, PC7, SKI-1/S1P and PCSK9) participate in post-translational cleavages and/or regulation of multiple secretory proteins. The type-I membrane-bound Furin and SKI-1/S1P are the major convertases responsible for the processing of surface glycoproteins of enveloped viruses. Stefan Kunz has considerably contributed to define the role of SKI-1/S1P in the activation of arenaviruses causing hemorrhagic fever. Furin was recently implicated in the activation of the spike S-protein of SARS-CoV-2 and Furin-inhibitors are being tested as antivirals in COVID-19. Other members of the PCSK-family are also implicated in some viral infections such as PCSK9 in Dengue. Herein, we summarize the various functions of the PCSKs and present arguments whereby their inhibition could represent a powerful arsenal to limit viral infections causing the present and future pandemics.

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