scholarly journals Towards the design of multiepitope-based peptide vaccine candidate against SARS-CoV-2

2020 ◽  
Author(s):  
Hasanain Abdulhameed Odhar ◽  
Salam Waheed Ahjel ◽  
Suhad Sami Humadi
Keyword(s):  
Viral Entry ◽  
Simulation Analysis ◽  
Peptide Vaccine ◽  
Spike Protein ◽  
Good Stability ◽  
Target Cells ◽  
Potential Candidate ◽  
Angiotensin Converting Enzyme 2

AbstractCoronavirus disease 2019 is a current pandemic health threat especially for elderly patients with comorbidities. This respiratory disease is caused by a beta coronavirus known as severe acute respiratory syndrome coronavirus 2. The disease can progress into acute respiratory distress syndrome that can be fatal. Currently, no specific drug or vaccine are available to combat this pandemic outbreak. Social distancing and lockdown have been enforced in many places worldwide. The spike protein of coronavirus 2 is essential for viral entry into host target cells via interaction with angiotensin converting enzyme 2. This viral protein is considered a potential target for design and development of a drug or vaccine. Previously, we have reported several potential epitopes on coronavirus 2 spike protein with high antigenicity, low allergenicity and good stability against specified proteases. In the current study, we have constructed and evaluated a peptide vaccine from these potential epitopes by using in silico approach. This construct is predicted to have a protective immunogenicity, low allergenicity and good stability with minor structural flaws in model build. The population coverage of the used T-cells epitopes is believed to be high according to the employed restricted alleles. The vaccine construct can elicit efficient and long-lasting immune response as appeared through simulation analysis. This multiepitope-based peptide vaccine may represent a potential candidate against coronavirus 2. However, further in vitro and in vivo verification are required.

scholarly journals The sequence at Spike S1/S2 site enables cleavage by furin and phospho-regulation in SARS-CoV2 but not in SARS-CoV1 or MERS-CoV

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Mihkel Örd ◽  
Ilona Faustova ◽  
Mart Loog
Keyword(s):  
Viral Entry ◽  
Spike Protein ◽  
Target Cells ◽  
The Novel ◽  
Novel Coronavirus ◽  
Cleavage Motif ◽  
Left Middle ◽  
Surprising Finding

Abstract The Spike protein of the novel coronavirus SARS-CoV2 contains an insertion 680SPRRAR↓SV687 forming a cleavage motif RxxR for furin-like enzymes at the boundary of S1/S2 subunits. Cleavage at S1/S2 is important for efficient viral entry into target cells. The insertion is absent in other CoV-s of the same clade, including SARS-CoV1 that caused the 2003 outbreak. However, an analogous cleavage motif was present at S1/S2 of the Spike protein of the more distant Middle East Respiratory Syndrome coronavirus MERS-CoV. We show that a crucial third arginine at the left middle position, comprising a motif RRxR is required for furin recognition in vitro, while the general motif RxxR in common with MERS-CoV is not sufficient for cleavage. Further, we describe a surprising finding that the two serines at the edges of the insert SPRRAR↓SV can be efficiently phosphorylated by proline-directed and basophilic protein kinases. Both phosphorylations switch off furin’s ability to cleave the site. Although phospho-regulation of secreted proteins is still poorly understood, further studies, supported by a recent report of ten in vivo phosphorylated sites in the Spike protein of SARS-CoV2, could potentially uncover important novel regulatory mechanisms for SARS-CoV2.

scholarly journals Susceptibilities of human ACE2 genetic variants in coronavirus infection

2021 ◽  
Author(s):  
Wenlin Ren ◽  
Yunkai Zhu ◽  
Jun Lan ◽  
Hedi Chen ◽  
Yuyan Wang ◽  
...  
Keyword(s):  
Viral Entry ◽  
Integrated Approach ◽  
Spike Protein ◽  
Nucleotide Polymorphisms ◽  
Coding Region ◽  
Angiotensin Converting Enzyme 2 ◽  
Coronavirus Infection ◽  
Ace2 Gene

The COVID-19 pandemic, caused by SARS-CoV-2, has resulted in more than 1603 million cases worldwide and 3.4 million deaths (as of May 2021), with varying incidences and death rates among regions/ethnicities. Human genetic variation can affect disease progression and outcome, but little is known about genetic risk factors for SARS-CoV-2 infection. The coronaviruses SARS-CoV, SARS-CoV-2 and HCoV-NL63 all utilize the human protein angiotensin-converting enzyme 2 (ACE2) as the receptor to enter cells. We hypothesized that the genetic variability in ACE2 may contribute to the variable clinical outcomes of COVID-19. To test this hypothesis, we first conducted an in silico investigation of single-nucleotide polymorphisms (SNPs) in the coding region of ACE2 gene. We then applied an integrated approach of genetics, biochemistry and virology to explore the capacity of select ACE2 variants to bind coronavirus spike protein and mediate viral entry. We identified the ACE2 D355N variant that restricts the spike protein-ACE2 interaction and consequently limits infection both in vitro and in vivo. In conclusion, ACE2 polymorphisms could modulate susceptibility to SARS-CoV-2, which may lead to variable disease severity.

scholarly journals Biochemical evidence of furin specificity and potential for phospho-regulation at Spike protein S1/S2 cleavage site in SARS-CoV2 but not in SARS-CoV1 or MERS-CoV

2020 ◽  
Author(s):  
Mihkel Örd ◽  
Ilona Faustova ◽  
Mart Loog
Keyword(s):  
Viral Entry ◽  
Spike Protein ◽  
Target Cells ◽  
The Novel ◽  
Novel Coronavirus ◽  
Cleavage Motif ◽  
Left Middle ◽  
Surprising Finding

AbstractThe Spike protein of the novel coronavirus SARS-CoV2 contains an insertion 680SPRRAR↓SV687 forming a cleavage motif RxxR for furin-like enzymes at the boundary of S1/S2 subunits. Cleavage at S1/S2 is important for efficient viral entry into target cells. The insertion is absent in other CoV-s of the same clade, including SARS-CoV1 that caused the 2003 outbreak. However, an analogous insertion was present in the Spike protein of the more distant Middle East Respiratory Syndrome coronavirus MERS-CoV. We show that a crucial third arginine at the left middle position, comprising a motif RRxR is required for furin recognition in vitro, while the general motif RxxR in common with MERS-CoV is not sufficient for cleavage. Further, we describe a surprising finding that the two serines at the edges of the insert SPRRAR↓SV can be efficiently phosphorylated by proline-directed and basophilic protein kinases. Both phosphorylations switch off furin’s ability to cleave the site. Although phosphoregulation of secreted proteins is still poorly understood, further studies, supported by a recent report of ten in vivo phosphorylated sites in the Spike protein of SARS-CoV2, could potentially uncover important novel regulatory mechanisms for SARS-CoV2.

scholarly journals Cell-Mimicking Nanodecoys Protect Lung Cells by Neutralization of SARS-CoV-2 Spike Proteins

2020 ◽  
Author(s):  
Zhenhua Li ◽  
Phuong-Uyen C. Dinh ◽  
Kristen D. Popowski ◽  
Halle Lutz ◽  
Zhenzhen Wang ◽  
...  
Keyword(s):  
Viral Entry ◽  
Human Lung ◽  
Spike Protein ◽  
Inhalation Therapy ◽  
Viral Receptor ◽  
Angiotensin Converting Enzyme 2 ◽  
Non Invasive ◽  
Global Pandemic ◽  
Integral Role

Abstract Coronavirus disease of 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has grown into a global pandemic, with no specific antiviral treatments or vaccines are yet approved. The viral receptor, angiotensin-converting enzyme 2 (ACE2), has been demonstrated to play an integral role in the pathogenesis of SARS-CoV-2, necessary for host cell viral entry. Inspired by this, we synthesized ACE2 nanodecoys from human lung spheroid cells (LSCs) capable of binding the Spike protein as a potential neutralization agent for SARS-CoV-2. Our results show LSC-nanodecoys has a high affinity and neutralization efficiency to both spike protein and chemically synthesized SARS-CoV-2 mimics. In addition, non-invasive inhalation therapy in mice showed successful delivery of the nanodecoy to the lungs, as well as in-vivo retention of the nanodecoys over 72 hours after a single administration. Furthermore, inhalation of nanodecoy accelerated the clearance of SARS-CoV-2 mimics from the lung and did not cause toxicity.

scholarly journals In-vivo Protection from SARS-CoV-2 infection by ATN-161 in k18-hACE2 transgenic mice

2021 ◽  
Author(s):  
Amruta Narayanappa ◽  
Elizabeth B Engler-Chiurazzi ◽  
Isabel C Murray-Brown ◽  
Timothy E Gressett ◽  
Ifechukwude J Biose ◽  
...  
Keyword(s):  
Protein Interactions ◽  
Viral Entry ◽  
Therapeutic Potential ◽  
Host Cells ◽  
Spike Protein ◽  
Cell Infection ◽  
Integrin Alpha5beta1 ◽  
Chemokine Ligand

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is an infectious disease that has spread worldwide. Current treatments are limited in both availability and efficacy, such that improving our understanding of the factors that facilitate infection is urgently needed to more effectively treat infected individuals and to curb the pandemic. We and others have previously demonstrated the significance of interactions between the SARS-CoV-2 spike protein, integrin alpha5beta1 and human ACE2 to facilitate viral entry into host cells in vitro. We previously found that inhibition of integrin alpha5beta1 by the clinically validated small peptide ATN-161 inhibits these spike protein interactions and cell infection in vitro. In continuation with our previous findings, here we have further evaluated the therapeutic potential of ATN-161 on SARS-CoV-2 infection in k18-hACE2 transgenic (SARS-CoV-2 susceptible) mice in vivo. We discovered that treatment with single- or repeated intravenous doses of ATN-161 (1 mg/kg) within 48 hours after intranasal inoculation with SARS-CoV-2 lead to a reduction of lung viral load, viral immunofluorescence and improved lung histology in a majority of mice 72 hours post-infection. Furthermore, ATN-161 reduced SARS-CoV-2-induced increased expression of lung integrin alpha 5 and alpha v (an alpha 5-related integrin that has also been implicated in SARS-CoV-2 interactions) as well as the C-X-C motif chemokine ligand 10 (Cxcl10), further supporting the potential involvement of these integrins, and the anti-inflammatory potential of ATN-161, respectively, in SARS-CoV-2 infection. To the best of our knowledge, this is the first study demonstrating the potential therapeutic efficacy of targeting integrin alpha5beta1 in SARS-CoV-2 infection in vivo and supports the development of ATN-161 as a novel SARS-CoV-2 therapy.

scholarly journals Exosome-Mediated mRNA Delivery For SARS-CoV-2 Vaccination

2020 ◽  
Author(s):  
Shang-Jui Tsai ◽  
Chenxu Guo ◽  
Nadia A. Atai ◽  
Stephen J. Gould
Keyword(s):  
Viral Vectors ◽  
Vaccine Development ◽  
Spike Protein ◽  
Interleukin 4 ◽  
Target Cells ◽  
Durable Response ◽  
Elevated Expression ◽  
Cellular Immune

AbstractBackgroundIn less than a year from its zoonotic entry into the human population, SARS-CoV-2 has infected more than 45 million people, caused 1.2 million deaths, and induced widespread societal disruption. Leading SARS-CoV-2 vaccine candidates immunize with the viral spike protein delivered on viral vectors, encoded by injected mRNAs, or as purified protein. Here we describe a different approach to SARS-CoV-2 vaccine development that uses exosomes to deliver mRNAs that encode antigens from multiple SARS-CoV-2 structural proteins.ApproachExosomes were purified and loaded with mRNAs designed to express (i) an artificial fusion protein, LSNME, that contains portions of the viral spike, nucleocapsid, membrane, and envelope proteins, and (ii) a functional form of spike. The resulting combinatorial vaccine, LSNME/SW1, was injected into thirteen weeks-old, male C57BL/6J mice, followed by interrogation of humoral and cellular immune responses to the SARS-CoV-2 nucleocapsid and spike proteins, as well as hematological and histological analysis to interrogate animals for possible adverse effects.ResultsImmunized mice developed CD4+, and CD8+ T-cell reactivities that respond to both the SARS-CoV-2 nucelocapsid protein and the SARS-CoV-2 spike protein. These responses were apparent nearly two months after the conclusion of vaccination, as expected for a durable response to vaccination. In addition, the spike-reactive CD4+ T-cells response was associated with elevated expression of interferon gamma, indicative of a Th1 response, and a lesser induction of interleukin 4, a Th2-associated cytokine. Vaccinated mice showed no sign of altered growth, injection-site hypersensitivity, change in white blood cell profiles, or alterations in organ morphology. Consistent with these results, we also detected moderate but sustained anti-nucleocapsid and anti-spike antibodies in the plasma of vaccinated animals.ConclusionTaken together, these results validate the use of exosomes for delivering functional mRNAs into target cells in vitro and in vivo, and more specifically, establish that the LSNME/SW1 vaccine induced broad immunity to multiple SARS-CoV-2 proteins.

scholarly journals Dalbavancin binds ACE2 to block its interaction with SARS-CoV-2 spike protein and is effective in inhibiting SARS-CoV-2 infection in animal models

Cell Research ◽  
2020 ◽  
Vol 31 (1) ◽  
pp. 17-24 ◽  
Author(s):  
Gan Wang ◽  
Meng-Li Yang ◽  
Zi-Lei Duan ◽  
Feng-Liang Liu ◽  
Lin Jin ◽  
...  
Keyword(s):  
Clinical Trials ◽  
Spike Protein ◽  
Drug Candidate ◽  
Peptide Drug ◽  
Converting Enzyme ◽  
Angiotensin Converting Enzyme 2 ◽  
High Affinity ◽  
Plasma Half Life

AbstractInfection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused a pandemic worldwide. Currently, however, no effective drug or vaccine is available to treat or prevent the resulting coronavirus disease 2019 (COVID-19). Here, we report our discovery of a promising anti-COVID-19 drug candidate, the lipoglycopeptide antibiotic dalbavancin, based on virtual screening of the FDA-approved peptide drug library combined with in vitro and in vivo functional antiviral assays. Our results showed that dalbavancin directly binds to human angiotensin-converting enzyme 2 (ACE2) with high affinity, thereby blocking its interaction with the SARS-CoV-2 spike protein. Furthermore, dalbavancin effectively prevents SARS-CoV-2 replication in Vero E6 cells with an EC50 of ~12 nM. In both mouse and rhesus macaque models, viral replication and histopathological injuries caused by SARS-CoV-2 infection are significantly inhibited by dalbavancin administration. Given its high safety and long plasma half-life (8–10 days) shown in previous clinical trials, our data indicate that dalbavancin is a promising anti-COVID-19 drug candidate.

scholarly journals Histopathological features of SARS-CoV-2 infection and relationships with organoid technology

2021 ◽  
Vol 49 (9) ◽  
pp. 030006052110443
Author(s):  
İrem İnanç ◽  
Esra Erdemli
Keyword(s):  
Viral Entry ◽  
Three Dimensional ◽  
Human Cells ◽  
Host Cells ◽  
Angiotensin Converting Enzyme 2 ◽  
Antiviral Compounds ◽  
Global Pandemic ◽  
Species Specific

Coronavirus disease 2019 (COVID-19) following infection by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has caused a global pandemic that is still having serious effects worldwide. This virus, which targets the lungs in particular, can also damage other tissues. Angiotensin converting enzyme 2 (ACE-2) plays a key role in viral entry into host cells. The presence of ACE-2 in various tissues may permit viral infection. Studies of COVID-19 often make use of postmortem tissues. Although this information provides various useful results, it is also necessary to conduct in vitro studies to understand optimal treatment approaches. Because the virus may show species-specific differences, in vitro technologies using human cells are particularly important. Organoid technologies, three-dimensional structures that can be obtained from human cells, are playing increasingly important roles in studies of SARS-CoV-2. This technology offers a significant advantage in terms of mimicking in vivo tissue structures and testing antiviral compounds. In this mini-review, we summarize studies of SARS-CoV-2 using both histopathological and organoid technology approaches.

scholarly journals Development of a novel hybrid alphavirus-SARS-CoV-2 particle for rapid in vitro screening and quantification of neutralization antibodies, antiviral drugs, and viral mutations

2020 ◽  
Author(s):  
Brian Hetrick ◽  
Sijia He ◽  
Linda D. Chilin ◽  
Deemah Dabbagh ◽  
Farhang Alem ◽  
...  
Keyword(s):  
Viral Entry ◽  
Neutralizing Antibodies ◽  
Protein S ◽  
Antiviral Drugs ◽  
Spike Protein ◽  
Structural Proteins ◽  
Rapid Screening ◽  
Target Cells ◽  
Rapid Monitoring

SUMMARYTimely development of vaccines and antiviral drugs are critical to control the coronavirus disease 2019 (COVID-19) global pandemic 1–6. Current methods for validation of vaccine efficacy involve the use of pseudoviruses, such as the SARS-CoV-2 spike protein (S) pseudotyped lentivirus or vesicular stomatitis virus (VSV), to quantify neutralizing antibodies for blocking viral infection 7–14. The process of pseudovirus infection and quantification is time consuming and can take days to complete. In addition, pseudoviruses contain structural proteins not native to SARS-CoV-2, which may alter particle properties in receptor binding and responses to antibody neutralization 15. Here we describe the development of a new hybrid alphavirus-SARS-CoV-2 particle (Ha-CoV-2) for rapid screening and quantification of neutralization antibodies and antiviral drugs. Ha-CoV-2 is a non-replicating SARS-CoV-2 virus-like particle, composed of only SARS-CoV-2 structural proteins (S, M, N, and E) and a RNA genome derived from a fast expressing alphavirus vector 16. We demonstrate that Ha-CoV-2 can rapidly and robustly express reporter genes in target cells within 3-5 hours following viral entry. We further validate the Ha-CoV-2 system for rapid quantification of neutralization antibodies and antiviral drugs. In addition, we assembled a Ha-CoV-2 particle bearing the D614G mutant spike protein, and found that the mutation led to an approximately 200% increase in virion infectivity. These results demonstrate that Ha-CoV-2 can also be applied for rapid monitoring and quantification of viral mutations for effects on neutralizing antibodies induced by vaccines.

scholarly journals An Ebola Virus-Like Particle-Based Reporter System Enables Evaluation of Antiviral DrugsIn Vivounder Non-Biosafety Level 4 Conditions

2016 ◽  
Vol 90 (19) ◽  
pp. 8720-8728 ◽  
Author(s):  
Dapeng Li ◽  
Tan Chen ◽  
Yang Hu ◽  
Yu Zhou ◽  
Qingwei Liu ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Viral Entry ◽  
Ebola Virus ◽  
Firefly Luciferase ◽  
Luciferase Reporter ◽  
Target Cells ◽  
Reporter System ◽  
Biosafety Level

ABSTRACTEbola virus (EBOV) is a highly contagious lethal pathogen. As a biosafety level 4 (BSL-4) agent, however, EBOV is restricted to costly BSL-4 laboratories for experimentation, thus significantly impeding the evaluation of EBOV vaccines and drugs. Here, we report an EBOV-like particle (EBOVLP)-based luciferase reporter system that enables the evaluation of anti-EBOV agentsin vitroandin vivooutside BSL-4 facilities. Cotransfection of HEK293T cells with four plasmids encoding the proteins VP40, NP, and GP of EBOV and firefly luciferase (Fluc) resulted in the production of Fluc-containing filamentous particles that morphologically resemble authentic EBOV. The reporter EBOVLP was capable of delivering Fluc into various cultured cells in a GP-dependent manner and was recognized by a conformation-dependent anti-EBOV monoclonal antibody (MAb). Significantly, inoculation of mice with the reporter EBOVLP led to the delivery of Fluc protein into target cells and rapid generation of intense bioluminescence signals that could be blocked by the administration of EBOV neutralizing MAbs. This BSL-4-free reporter system should facilitate high-throughput screening for anti-EBOV drugs targeting viral entry and efficacy testing of candidate vaccines.IMPORTANCEEbola virus (EBOV) researches have been limited to costly biosafety level 4 (BSL-4) facilities due to the lack of animal models independent of BSL-4 laboratories. In this study, we reveal that a firefly luciferase-bearing EBOV-like particle (EBOVLP) with typical filamentous EBOV morphology is capable of delivering the reporter protein into murine target cells bothin vitroandin vivo. Moreover, we demonstrate that the reporter delivery can be inhibited bothin vitroandin vivoby a known anti-EBOV protective monoclonal antibody, 13C6. Our work provides a BSL-4-free system that can facilitate thein vivoevaluation of anti-EBOV antibodies, drugs, and vaccines. The system may also be useful for mechanistic study of the viral entry process.

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