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1.
PLoS One ; 17(3): e0263671, 2022.
Article in English | MEDLINE | ID: covidwho-1742001

ABSTRACT

Novel therapeutic strategies are needed to control the SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) pandemic. Here, we present a protocol to anchor the SARS-CoV-2 spike (S-)protein in the cytoplasmic membranes of erythrocyte liposomes. A surfactant was used to stabilize the S-protein's structure in the aqueous environment before insertion and to facilitate reconstitution of the S-proteins in the erythrocyte membranes. The insertion process was studied using coarse grained Molecular Dynamics (MD) simulations. Liposome formation and S-protein anchoring was studied by dynamic light scattering (DLS), ELV-protein co-sedimentation assays, fluorescent microcopy and cryo-TEM. The Erythro-VLPs (erythrocyte based virus like particles) have a well defined size of ∼200 nm and an average protein density on the outer membrane of up to ∼300 proteins/µm2. The correct insertion and functional conformation of the S-proteins was verified by dose-dependent binding to ACE-2 (angiotensin converting enzyme 2) in biolayer interferometry (BLI) assays. Seroconversion was observed in a pilot mouse trial after 14 days when administered intravenously, based on enzyme-linked immunosorbent assays (ELISA). This red blood cell based platform can open novel possibilities for therapeutics for the coronavirus disease (COVID-19) including variants, and other viruses in the future.


Subject(s)
COVID-19 Vaccines , COVID-19 , Erythrocyte Membrane , Molecular Dynamics Simulation , SARS-CoV-2/immunology , Spike Glycoprotein, Coronavirus , Vaccines, Virus-Like Particle , Animals , COVID-19/immunology , COVID-19/prevention & control , COVID-19 Vaccines/chemistry , COVID-19 Vaccines/immunology , COVID-19 Vaccines/pharmacology , Erythrocyte Membrane/chemistry , Erythrocyte Membrane/immunology , Female , Liposomes , Mice , Pilot Projects , Protein Domains , Spike Glycoprotein, Coronavirus/chemistry , Spike Glycoprotein, Coronavirus/immunology , Spike Glycoprotein, Coronavirus/pharmacology , Vaccines, Virus-Like Particle/chemistry , Vaccines, Virus-Like Particle/immunology , Vaccines, Virus-Like Particle/pharmacology
2.
Cell Rep Med ; 3(2): 100528, 2022 02 15.
Article in English | MEDLINE | ID: covidwho-1649494

ABSTRACT

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has caused an ongoing global health crisis. Here, we present as a vaccine candidate synthetic SARS-CoV-2 spike (S) glycoprotein-coated lipid vesicles that resemble virus-like particles. Soluble S glycoprotein trimer stabilization by formaldehyde cross-linking introduces two major inter-protomer cross-links that keep all receptor-binding domains in the "down" conformation. Immunization of cynomolgus macaques with S coated onto lipid vesicles (S-LVs) induces high antibody titers with potent neutralizing activity against the vaccine strain, Alpha, Beta, and Gamma variants as well as T helper (Th)1 CD4+-biased T cell responses. Although anti-receptor-binding domain (RBD)-specific antibody responses are initially predominant, the third immunization boosts significant non-RBD antibody titers. Challenging vaccinated animals with SARS-CoV-2 shows a complete protection through sterilizing immunity, which correlates with the presence of nasopharyngeal anti-S immunoglobulin G (IgG) and IgA titers. Thus, the S-LV approach is an efficient and safe vaccine candidate based on a proven classical approach for further development and clinical testing.


Subject(s)
COVID-19 Vaccines/administration & dosage , COVID-19/prevention & control , SARS-CoV-2/immunology , Spike Glycoprotein, Coronavirus/immunology , Vaccination/methods , Vaccines, Virus-Like Particle/administration & dosage , Animals , Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , COVID-19/epidemiology , COVID-19/immunology , COVID-19/virology , COVID-19 Vaccines/immunology , Chlorocebus aethiops , Disease Models, Animal , HEK293 Cells , Humans , Immunoglobulin A/immunology , Immunoglobulin G/immunology , Liposomes , Macaca fascicularis , Male , Pandemics/prevention & control , Th1 Cells/immunology , Treatment Outcome , Vaccines, Virus-Like Particle/immunology , Vero Cells
3.
Sci Rep ; 12(1): 1005, 2022 01 19.
Article in English | MEDLINE | ID: covidwho-1635617

ABSTRACT

The pandemic of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) has caused a public health emergency, and research on the development of various types of vaccines is rapidly progressing at an unprecedented development speed internationally. Some vaccines have already been approved for emergency use and are being supplied to people around the world, but there are still many ongoing efforts to create new vaccines. Virus-like particles (VLPs) enable the construction of promising platforms in the field of vaccine development. Here, we demonstrate that non-infectious SARS-CoV-2 VLPs can be successfully assembled by co-expressing three important viral proteins membrane (M), envelop (E) and nucleocapsid (N) in plants. Plant-derived VLPs were purified by sedimentation through a sucrose cushion. The shape and size of plant-derived VLPs are similar to native SARS-CoV-2 VLPs without spike. Although the assembled VLPs do not have S protein spikes, they could be developed as formulations that can improve the immunogenicity of vaccines including S antigens, and further could be used as platforms that can carry S antigens of concern for various mutations.


Subject(s)
COVID-19 Vaccines/immunology , COVID-19/immunology , Coronavirus M Proteins/immunology , Coronavirus Nucleocapsid Proteins/immunology , SARS-CoV-2/immunology , Vaccines, Virus-Like Particle/immunology , Viroporin Proteins/immunology , COVID-19/prevention & control , COVID-19/virology , COVID-19 Vaccines/administration & dosage , Coronavirus M Proteins/genetics , Coronavirus M Proteins/metabolism , Coronavirus Nucleocapsid Proteins/genetics , Coronavirus Nucleocapsid Proteins/metabolism , Humans , Tobacco/immunology , Tobacco/metabolism , Tobacco/virology , Vaccines, Virus-Like Particle/genetics , Vaccines, Virus-Like Particle/metabolism , Viroporin Proteins/genetics , Viroporin Proteins/metabolism
4.
Proc Natl Acad Sci U S A ; 118(43)2021 10 26.
Article in English | MEDLINE | ID: covidwho-1481965

ABSTRACT

Self-amplifying RNA replicons are promising platforms for vaccine generation. Their defects in one or more essential functions for viral replication, particle assembly, or dissemination make them highly safe as vaccines. We previously showed that the deletion of the envelope (E) gene from the Middle East respiratory syndrome coronavirus (MERS-CoV) produces a replication-competent propagation-defective RNA replicon (MERS-CoV-ΔE). Evaluation of this replicon in mice expressing human dipeptidyl peptidase 4, the virus receptor, showed that the single deletion of the E gene generated an attenuated mutant. The combined deletion of the E gene with accessory open reading frames (ORFs) 3, 4a, 4b, and 5 resulted in a highly attenuated propagation-defective RNA replicon (MERS-CoV-Δ[3,4a,4b,5,E]). This RNA replicon induced sterilizing immunity in mice after challenge with a lethal dose of a virulent MERS-CoV, as no histopathological damage or infectious virus was detected in the lungs of challenged mice. The four mutants lacking the E gene were genetically stable, did not recombine with the E gene provided in trans during their passage in cell culture, and showed a propagation-defective phenotype in vivo. In addition, immunization with MERS-CoV-Δ[3,4a,4b,5,E] induced significant levels of neutralizing antibodies, indicating that MERS-CoV RNA replicons are highly safe and promising vaccine candidates.


Subject(s)
Coronavirus Infections/prevention & control , Middle East Respiratory Syndrome Coronavirus/genetics , Middle East Respiratory Syndrome Coronavirus/immunology , RNA, Viral/administration & dosage , Replicon , Viral Vaccines/administration & dosage , Animals , Antibodies, Neutralizing/biosynthesis , Antibodies, Viral/biosynthesis , Coronavirus Infections/genetics , Coronavirus Infections/immunology , Coronavirus Infections/virology , Defective Viruses/genetics , Defective Viruses/immunology , Female , Gene Deletion , Genes, env , Humans , Mice , Mice, Inbred C57BL , Mice, Transgenic , Middle East Respiratory Syndrome Coronavirus/pathogenicity , RNA, Viral/genetics , RNA, Viral/immunology , Vaccines, DNA , Vaccines, Virus-Like Particle/administration & dosage , Vaccines, Virus-Like Particle/genetics , Vaccines, Virus-Like Particle/immunology , Viral Vaccines/genetics , Viral Vaccines/immunology , Virulence/genetics , Virulence/immunology
5.
Curr Top Med Chem ; 21(14): 1235-1250, 2021 Oct 05.
Article in English | MEDLINE | ID: covidwho-1441869

ABSTRACT

BACKGROUND: Virus-like Particles (VLPs) are non-genetic multimeric nanoparticles synthesized through in vitro or in vivo self-assembly of one or more viral structural proteins. Immunogenicity and safety of VLPs make them ideal candidates for vaccine development and efficient nanocarriers for foreign antigens or adjuvants to activate the immune system. AIMS: The present study aimed to design and synthesize a chimeric VLP vaccine of the phage Qbeta (Qß) coat protein presenting the universal epitope of the coronavirus. METHODS: The RNA phage Qß coat protein was designed and synthesized, denoted as Qbeta. The CoV epitope, a universal epitope of coronavirus, was inserted into the C-terminal of Qbeta using genetic recombination, designated as Qbeta-CoV. The N-terminal of Qbeta-CoV was successively inserted into the TEV restriction site using mCherry red fluorescent label and modified affinity purified histidine label 6xHE, which was denoted as HE-Qbeta-CoV. Isopropyl ß-D-1-thiogalactopyranoside (IPTG) assessment revealed the expression of Qbeta, Qbeta-CoV, and HE-Qbeta-CoV in the BL21 (DE3) cells. The fusion protein was purified by salting out using ammonium sulfate and affinity chromatography. The morphology of particles was observed using electron microscopy. The female BALB/C mice were immunized intraperitoneally with the Qbeta-CoV and HE-Qbeta-- CoV chimeric VLPs vaccines and their sera were collected for the detection of antibody level and antibody titer using ELISA. The serum is used for the neutralization test of the three viruses of MHV, PEDV, and PDCoV. RESULTS: The results revealed that the fusion proteins Qbeta, Qbeta-CoV, and HE-Qbeta-CoV could all obtain successful expression. Particles with high purity were obtained after purification; the chimeric particles of Qbeta-CoV and HE-Qbeta-CoV were found to be similar to Qbeta particles in morphology and formed chimeric VLPs. In addition, two chimeric VLP vaccines induced specific antibody responses in mice and the antibodies showed certain neutralizing activity. CONCLUSION: The successful construction of the chimeric VLPs of the phage Qß coat protein presenting the universal epitope of coronavirus provides a vaccine form with potential clinical applications for the treatment of coronavirus disease.


Subject(s)
Antibodies, Neutralizing/immunology , Capsid Proteins/immunology , Coronavirus/immunology , Vaccines, Virus-Like Particle/immunology , Animals , Antigens, Viral/genetics , Antigens, Viral/immunology , Enzyme-Linked Immunosorbent Assay , Female , Mice, Inbred BALB C , Microscopy, Electron, Scanning , Phylogeny , Recombinant Fusion Proteins/genetics , Recombinant Fusion Proteins/isolation & purification , Recombinant Fusion Proteins/metabolism , Vaccines, Virus-Like Particle/genetics , Viral Proteins/genetics
6.
Chembiochem ; 22(22): 3199-3207, 2021 11 16.
Article in English | MEDLINE | ID: covidwho-1406083

ABSTRACT

Site-specific protein modifications are vital for biopharmaceutical drug development. Gluconoylation is a non-enzymatic, post-translational modification of N-terminal HisTags. We report high-yield, site-selective in vitro α-aminoacylation of peptides, glycoproteins, antibodies, and virus-like particles (VLPs) with azidogluconolactone at pH 7.5 in 1 h. Conjugates slowly hydrolyse, but diol-masking with borate esters inhibits reversibility. In an example, we multimerise azidogluconoylated SARS-CoV-2 receptor-binding domain (RBD) onto VLPs via click-chemistry, to give a COVID-19 vaccine. Compared to yeast antigen, HEK-derived RBD was immunologically superior, likely due to observed differences in glycosylation. We show the benefits of ordered over randomly oriented multimeric antigen display, by demonstrating single-shot seroconversion and best virus-neutralizing antibodies. Azidogluconoylation is simple, fast and robust chemistry, and should accelerate research and development.


Subject(s)
Azides/chemistry , COVID-19 Vaccines/chemistry , Gluconates/chemistry , Glycine/chemistry , Histidine/chemistry , Lactones/chemistry , Vaccines, Virus-Like Particle/chemistry , Antibodies, Neutralizing/chemistry , Antibodies, Neutralizing/immunology , Azides/immunology , COVID-19 Vaccines/immunology , Gluconates/immunology , Glycine/immunology , Histidine/immunology , Humans , Lactones/immunology , Models, Molecular , Molecular Structure , Vaccines, Virus-Like Particle/immunology
7.
Virology ; 559: 165-172, 2021 07.
Article in English | MEDLINE | ID: covidwho-1198236

ABSTRACT

SARS coronavirus 1 (SARS-CoV-1) causes a respiratory infection that can lead to acute respiratory distress characterized by inflammation and high levels of cytokines in the lung tissue. In this study we constructed a herpes simplex virus 1 replication-defective mutant vector expressing SARS-CoV-1 spike protein as a potential vaccine vector and to probe the effects of spike protein on host cells. The spike protein expressed from this vector is functional in that it localizes to the surface of infected cells and induces fusion of ACE2-expressing cells. In immunized mice, the recombinant vector induced antibodies that bind to spike protein in an ELISA assay and that show neutralizing activity. The spike protein expressed from this vector can induce the expression of cytokines in an ACE2-independent, MyD88-dependent process. These results argue that the SARS-CoV-1 spike protein intrinsically activates signaling pathways that induce cytokines and contribute directly to the inflammatory process of SARS.


Subject(s)
Antibodies, Neutralizing/immunology , Herpesvirus 1, Human/genetics , Immunity, Innate , SARS Virus/immunology , Spike Glycoprotein, Coronavirus/immunology , Animals , Antibodies, Neutralizing/blood , Antibodies, Viral/blood , Antibodies, Viral/immunology , Cell Fusion , Cell Line , Cytokines/immunology , Genetic Vectors , Humans , Mice , SARS Virus/genetics , Signal Transduction , Spike Glycoprotein, Coronavirus/genetics , Spike Glycoprotein, Coronavirus/metabolism , Vaccines, Virus-Like Particle/immunology , Viral Vaccines/immunology
8.
Curr Top Med Chem ; 21(14): 1235-1250, 2021 Oct 05.
Article in English | MEDLINE | ID: covidwho-1274595

ABSTRACT

BACKGROUND: Virus-like Particles (VLPs) are non-genetic multimeric nanoparticles synthesized through in vitro or in vivo self-assembly of one or more viral structural proteins. Immunogenicity and safety of VLPs make them ideal candidates for vaccine development and efficient nanocarriers for foreign antigens or adjuvants to activate the immune system. AIMS: The present study aimed to design and synthesize a chimeric VLP vaccine of the phage Qbeta (Qß) coat protein presenting the universal epitope of the coronavirus. METHODS: The RNA phage Qß coat protein was designed and synthesized, denoted as Qbeta. The CoV epitope, a universal epitope of coronavirus, was inserted into the C-terminal of Qbeta using genetic recombination, designated as Qbeta-CoV. The N-terminal of Qbeta-CoV was successively inserted into the TEV restriction site using mCherry red fluorescent label and modified affinity purified histidine label 6xHE, which was denoted as HE-Qbeta-CoV. Isopropyl ß-D-1-thiogalactopyranoside (IPTG) assessment revealed the expression of Qbeta, Qbeta-CoV, and HE-Qbeta-CoV in the BL21 (DE3) cells. The fusion protein was purified by salting out using ammonium sulfate and affinity chromatography. The morphology of particles was observed using electron microscopy. The female BALB/C mice were immunized intraperitoneally with the Qbeta-CoV and HE-Qbeta-- CoV chimeric VLPs vaccines and their sera were collected for the detection of antibody level and antibody titer using ELISA. The serum is used for the neutralization test of the three viruses of MHV, PEDV, and PDCoV. RESULTS: The results revealed that the fusion proteins Qbeta, Qbeta-CoV, and HE-Qbeta-CoV could all obtain successful expression. Particles with high purity were obtained after purification; the chimeric particles of Qbeta-CoV and HE-Qbeta-CoV were found to be similar to Qbeta particles in morphology and formed chimeric VLPs. In addition, two chimeric VLP vaccines induced specific antibody responses in mice and the antibodies showed certain neutralizing activity. CONCLUSION: The successful construction of the chimeric VLPs of the phage Qß coat protein presenting the universal epitope of coronavirus provides a vaccine form with potential clinical applications for the treatment of coronavirus disease.


Subject(s)
Antibodies, Neutralizing/immunology , Capsid Proteins/immunology , Coronavirus/immunology , Vaccines, Virus-Like Particle/immunology , Animals , Antigens, Viral/genetics , Antigens, Viral/immunology , Enzyme-Linked Immunosorbent Assay , Female , Mice, Inbred BALB C , Microscopy, Electron, Scanning , Phylogeny , Recombinant Fusion Proteins/genetics , Recombinant Fusion Proteins/isolation & purification , Recombinant Fusion Proteins/metabolism , Vaccines, Virus-Like Particle/genetics , Viral Proteins/genetics
9.
Int Immunopharmacol ; 96: 107763, 2021 Jul.
Article in English | MEDLINE | ID: covidwho-1258391

ABSTRACT

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative agent of the rapidly spreading pandemic COVID-19 in the world. As an effective therapeutic strategy is not introduced yet and the rapid genetic variations in the virus, there is an emerging necessity to design, evaluate and apply effective new vaccines. An acceptable vaccine must elicit both humoral and cellular immune responses, must have the least side effects and the storage and transport systems should be available and affordable for all countries. These vaccines can be classified into different types: inactivated vaccines, live-attenuated virus vaccines, subunit vaccines, virus-like particles (VLPs), nucleic acid-based vaccines (DNA and RNA) and recombinant vector-based vaccines (replicating and non-replicating viral vector). According to the latest update of the WHO report on April 2nd, 2021, at least 85 vaccine candidates were being studied in clinical trial phases and 184 candidate vaccines were being evaluated in pre-clinical stages. In addition, studies have shown that other vaccines, including the Bacillus Calmette-Guérin (BCG) vaccine and the Plant-derived vaccine, may play a role in controlling pandemic COVID-19. Herein, we reviewed the different types of COVID-19 candidate vaccines that are currently being evaluated in preclinical and clinical trial phases along with advantages, disadvantages or adverse reactions, if any.


Subject(s)
COVID-19 Vaccines/immunology , COVID-19/immunology , COVID-19/prevention & control , SARS-CoV-2/immunology , Adolescent , Adult , Aged , Aged, 80 and over , Animals , BCG Vaccine/immunology , COVID-19 Vaccines/administration & dosage , COVID-19 Vaccines/adverse effects , Drug Evaluation, Preclinical , Female , Humans , Male , Meta-Analysis as Topic , Middle Aged , Vaccines, DNA/immunology , Vaccines, Inactivated/immunology , Vaccines, Subunit/immunology , Vaccines, Virus-Like Particle/immunology , Viral Vaccines/immunology
10.
Commun Biol ; 4(1): 597, 2021 05 19.
Article in English | MEDLINE | ID: covidwho-1236095

ABSTRACT

The COVID-19 pandemic continues to wreak havoc as worldwide SARS-CoV-2 infection, hospitalization, and death rates climb unabated. Effective vaccines remain the most promising approach to counter SARS-CoV-2. Yet, while promising results are emerging from COVID-19 vaccine trials, the need for multiple doses and the challenges associated with the widespread distribution and administration of vaccines remain concerns. Here, we engineered the coat protein of the MS2 bacteriophage and generated nanoparticles displaying multiple copies of the SARS-CoV-2 spike (S) protein. The use of these nanoparticles as vaccines generated high neutralizing antibody titers and protected Syrian hamsters from a challenge with SARS-CoV-2 after a single immunization with no infectious virus detected in the lungs. This nanoparticle-based vaccine platform thus provides protection after a single immunization and may be broadly applicable for protecting against SARS-CoV-2 and future pathogens with pandemic potential.


Subject(s)
COVID-19 Vaccines/administration & dosage , COVID-19/immunology , COVID-19/prevention & control , Pandemics , SARS-CoV-2 , Animals , Antibodies, Neutralizing/biosynthesis , Antibodies, Viral/biosynthesis , COVID-19 Vaccines/genetics , COVID-19 Vaccines/immunology , Drug Delivery Systems , Female , Humans , Immunization/methods , Levivirus/genetics , Levivirus/immunology , Mesocricetus , Microscopy, Electron, Transmission , Models, Animal , Nanoparticles/administration & dosage , Nanoparticles/ultrastructure , Nanotechnology , Pandemics/prevention & control , Protein Engineering , SARS-CoV-2/immunology , Spike Glycoprotein, Coronavirus/administration & dosage , Spike Glycoprotein, Coronavirus/immunology , Vaccines, Combined/administration & dosage , Vaccines, Combined/genetics , Vaccines, Combined/immunology , Vaccines, Virus-Like Particle/administration & dosage , Vaccines, Virus-Like Particle/genetics , Vaccines, Virus-Like Particle/immunology
11.
Viruses ; 13(4)2021 03 24.
Article in English | MEDLINE | ID: covidwho-1231504

ABSTRACT

Influenza virus, a highly mutable respiratory pathogen, causes significant disease nearly every year. Current vaccines are designed to protect against circulating influenza strains of a given season. However, mismatches between vaccine strains and circulating strains, as well as inferior vaccine effectiveness in immunodeficient populations, represent major obstacles. In an effort to expand the breadth of protection elicited by influenza vaccination, one of the major surface glycoproteins, hemagglutinin (HA), has been modified to develop immunogens that display conserved regions from multiple viruses or elicit a highly polyclonal antibody response to broaden protection. These approaches, which target either the head or the stalk domain of HA, or both domains, have shown promise in recent preclinical and clinical studies. Furthermore, the role of adjuvants in bolstering the robustness of the humoral response has been studied, and their effects on the vaccine-elicited antibody repertoire are currently being investigated. This review will discuss the progress made in the universal influenza vaccine field with respect to influenza A viruses from the perspectives of both antigen and adjuvant, with a focus on the elicitation of broadly neutralizing antibodies.


Subject(s)
Adjuvants, Immunologic , Hemagglutinin Glycoproteins, Influenza Virus/immunology , Influenza A virus/immunology , Influenza Vaccines/immunology , Influenza, Human/prevention & control , Animals , Antibodies, Viral/immunology , Clinical Trials as Topic , Hemagglutinin Glycoproteins, Influenza Virus/genetics , Humans , Immunity, Humoral , Influenza Vaccines/genetics , Influenza, Human/immunology , Mice , Orthomyxoviridae Infections/immunology , Orthomyxoviridae Infections/prevention & control , Orthomyxoviridae Infections/virology , Vaccines, Virus-Like Particle/immunology
12.
Virology ; 557: 70-85, 2021 05.
Article in English | MEDLINE | ID: covidwho-1108783

ABSTRACT

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged into the human population in late 2019 and caused the global COVID-19 pandemic. SARS-CoV-2 has spread to more than 215 countries and infected many millions of people. Despite the introduction of numerous governmental and public health measures to control disease spread, infections continue at an unabated pace, suggesting that effective vaccines and antiviral drugs will be required to curtail disease, end the pandemic, and restore societal norms. Here, we review the current developments in antibody and vaccine countermeasures to limit or prevent disease.


Subject(s)
Antibodies, Viral/biosynthesis , COVID-19 Vaccines/immunology , COVID-19/prevention & control , Pandemics , SARS-CoV-2/immunology , Animals , COVID-19/epidemiology , COVID-19/immunology , COVID-19/therapy , COVID-19/virology , COVID-19 Vaccines/administration & dosage , COVID-19 Vaccines/biosynthesis , Clinical Trials as Topic , Disease Models, Animal , Genetic Vectors/chemistry , Genetic Vectors/immunology , Humans , Immunity, Innate/drug effects , Immunization, Passive/methods , Immunogenicity, Vaccine , Patient Safety , SARS-CoV-2/drug effects , SARS-CoV-2/pathogenicity , Vaccines, Attenuated , Vaccines, DNA , Vaccines, Subunit , Vaccines, Virus-Like Particle/administration & dosage , Vaccines, Virus-Like Particle/biosynthesis , Vaccines, Virus-Like Particle/immunology
13.
J Nanobiotechnology ; 19(1): 59, 2021 Feb 25.
Article in English | MEDLINE | ID: covidwho-1105715

ABSTRACT

Virus-like particles (VLPs) are virus-derived structures made up of one or more different molecules with the ability to self-assemble, mimicking the form and size of a virus particle but lacking the genetic material so they are not capable of infecting the host cell. Expression and self-assembly of the viral structural proteins can take place in various living or cell-free expression systems after which the viral structures can be assembled and reconstructed. VLPs are gaining in popularity in the field of preventive medicine and to date, a wide range of VLP-based candidate vaccines have been developed for immunization against various infectious agents, the latest of which is the vaccine against SARS-CoV-2, the efficacy of which is being evaluated. VLPs are highly immunogenic and are able to elicit both the antibody- and cell-mediated immune responses by pathways different from those elicited by conventional inactivated viral vaccines. However, there are still many challenges to this surface display system that need to be addressed in the future. VLPs that are classified as subunit vaccines are subdivided into enveloped and non- enveloped subtypes both of which are discussed in this review article. VLPs have also recently received attention for their successful applications in targeted drug delivery and for use in gene therapy. The development of more effective and targeted forms of VLP by modification of the surface of the particles in such a way that they can be introduced into specific cells or tissues or increase their half-life in the host is likely to expand their use in the future. Recent advances in the production and fabrication of VLPs including the exploration of different types of expression systems for their development, as well as their applications as vaccines in the prevention of infectious diseases and cancers resulting from their interaction with, and mechanism of activation of, the humoral and cellular immune systems are discussed in this review.


Subject(s)
COVID-19 Vaccines/therapeutic use , Antibodies, Neutralizing/immunology , COVID-19 Vaccines/biosynthesis , COVID-19 Vaccines/immunology , Humans , Immunity/physiology , SARS-CoV-2/immunology , SARS-CoV-2/pathogenicity , Vaccination/methods , Vaccines, Virus-Like Particle/biosynthesis , Vaccines, Virus-Like Particle/immunology , Vaccines, Virus-Like Particle/therapeutic use
15.
Viruses ; 12(12)2020 12 16.
Article in English | MEDLINE | ID: covidwho-993594

ABSTRACT

Baculovirus expression vectors are successfully used for the commercial production of complex (glyco)proteins in eukaryotic cells. The genome engineering of single-copy baculovirus infectious clones (bacmids) in E. coli has been valuable in the study of baculovirus biology, but bacmids are not yet widely applied as expression vectors. An important limitation of first-generation bacmids for large-scale protein production is the rapid loss of gene of interest (GOI) expression. The instability is caused by the mini-F replicon in the bacmid backbone, which is non-essential for baculovirus replication in insect cells, and carries the adjacent GOI in between attTn7 transposition sites. In this paper, we test the hypothesis that relocation of the attTn7 transgene insertion site away from the mini-F replicon prevents deletion of the GOI, thereby resulting in higher and prolonged recombinant protein expression levels. We applied lambda red genome engineering combined with SacB counterselection to generate a series of bacmids with relocated attTn7 sites and tested their performance by comparing the relative expression levels of different GOIs. We conclude that GOI expression from the odv-e56 (pif-5) locus results in higher overall expression levels and is more stable over serial passages compared to the original bacmid. Finally, we evaluated this improved next-generation bacmid during a bioreactor scale-up of Sf9 insect cells in suspension to produce enveloped chikungunya virus-like particles as a model vaccine.


Subject(s)
Baculoviridae/genetics , Genome, Viral , Genomic Instability , Homologous Recombination , Mutagenesis, Insertional , Recombinant Proteins/genetics , Transgenes , Animals , Bioreactors , Cell Line , Chikungunya virus/immunology , Genetic Engineering , Genetic Vectors/genetics , Insecta , Sf9 Cells , Vaccines, Virus-Like Particle/immunology
16.
Front Immunol ; 11: 583077, 2020.
Article in English | MEDLINE | ID: covidwho-886169

ABSTRACT

Despite the success of vaccination to greatly mitigate or eliminate threat of diseases caused by pathogens, there are still known diseases and emerging pathogens for which the development of successful vaccines against them is inherently difficult. In addition, vaccine development for people with compromised immunity and other pre-existing medical conditions has remained a major challenge. Besides the traditional inactivated or live attenuated, virus-vectored and subunit vaccines, emerging non-viral vaccine technologies, such as viral-like particle and nanoparticle vaccines, DNA/RNA vaccines, and rational vaccine design, offer innovative approaches to address existing challenges of vaccine development. They have also significantly advanced our understanding of vaccine immunology and can guide future vaccine development for many diseases, including rapidly emerging infectious diseases, such as COVID-19, and diseases that have not traditionally been addressed by vaccination, such as cancers and substance abuse. This review provides an integrative discussion of new non-viral vaccine development technologies and their use to address the most fundamental and ongoing challenges of vaccine development.


Subject(s)
Betacoronavirus/immunology , Communicable Diseases, Emerging/prevention & control , Coronavirus Infections/prevention & control , Pandemics/prevention & control , Pneumonia, Viral/prevention & control , Viral Vaccines/immunology , COVID-19 , COVID-19 Vaccines , Communicable Diseases, Emerging/virology , Coronavirus Infections/immunology , Nanoparticles , SARS-CoV-2 , Vaccination , Vaccines, DNA/immunology , Vaccines, Subunit/immunology , Vaccines, Virus-Like Particle/immunology
17.
Viruses ; 12(3)2020 02 28.
Article in English | MEDLINE | ID: covidwho-822450

ABSTRACT

Vaccination is one of the most effective public health interventions of the 20th century. All vaccines can be classified into different types, such as vaccines against infectious diseases, anticancer vaccines and vaccines against autoimmune diseases. In recent decades, recombinant technologies have enabled the design of experimental vaccines against a wide range of diseases using plant viruses and virus-like particles as central elements to stimulate protective and long-lasting immune responses. The analysis of recent publications shows that at least 97 experimental vaccines have been constructed based on plant viruses, including 71 vaccines against infectious agents, 16 anticancer vaccines and 10 therapeutic vaccines against autoimmune disorders. Several plant viruses have already been used for the development of vaccine platforms and have been tested in human and veterinary studies, suggesting that plant virus-based vaccines will be introduced into clinical and veterinary practice in the near future.


Subject(s)
Plant Viruses/genetics , Vaccines, Virus-Like Particle/genetics , Vaccines, Virus-Like Particle/immunology , Animals , Autoimmune Diseases/immunology , Autoimmune Diseases/therapy , Communicable Disease Control , Communicable Diseases/etiology , Communicable Diseases/immunology , Genetic Engineering , Genetic Vectors/administration & dosage , Genetic Vectors/genetics , Genetic Vectors/immunology , Humans , Hypersensitivity/immunology , Hypersensitivity/therapy , Neoplasms/immunology , Neoplasms/therapy , Plant Viruses/ultrastructure , Vaccines, Virus-Like Particle/therapeutic use , Vaccines, Virus-Like Particle/ultrastructure , Vaccinology/methods , Vaccinology/trends , Virion
18.
Hum Vaccin Immunother ; 17(4): 1122-1127, 2021 04 03.
Article in English | MEDLINE | ID: covidwho-802694

ABSTRACT

The world remains cautiously optimistic about a COVID-19 vaccine that is relatively safe and efficacious and that offers sufficient long-lasting protection/immunity by neutralizing the virus infectivity. However, key technical hurdles pertaining to antigen-adjuvant formulation, delivery, and manufacturing challenges of lipid nanoparticles (LNPs) for mRNA vaccines and stability of formulations need to be addressed for successful product development and stockpiling. In addition, the dosage form, the dosage level and regimen for eliciting a protective immune response remain to be established. The high dependence of global supply chains and demand-supply to sourcing quality raw materials, glassware and other supplies, along with the stress on existing production capacities and platform-specific manufacturing challenges could impede vaccine development and access. This article provides critical analysis of vaccine development processes and unit operations that can derail the pandemic response, and also extends to other emerging infectious disease development efforts - issues that take on added significance given the global mandate for an accelerated and at-risk development path to tackle the COVID-19 pandemic.


Subject(s)
COVID-19 Vaccines/immunology , COVID-19/prevention & control , Drug Development , Immunogenicity, Vaccine/immunology , SARS-CoV-2/immunology , Adjuvants, Immunologic/pharmacology , COVID-19/immunology , COVID-19 Vaccines/adverse effects , Humans , Vaccine Potency , Vaccines, DNA/immunology , Vaccines, Inactivated/immunology , Vaccines, Synthetic/immunology , Vaccines, Virus-Like Particle/immunology
19.
Virus Res ; 288: 198141, 2020 10 15.
Article in English | MEDLINE | ID: covidwho-725473

ABSTRACT

The recent outbreak of the betacoronavirus SARS-CoV-2 has become a significant concern to public health care worldwide. As of August 19, 2020, more than 22,140,472 people are infected, and over 781,135 people have died due to this deadly virus. In the USA alone, over 5,482,602 people are currently infected, and more than 171,823 people have died. SARS-CoV-2 has shown a higher infectivity rate and a more extended incubation period as compared to previous coronaviruses. SARS-CoV-2 binds much more strongly than SARS-CoV to the same host receptor, angiotensin-converting enzyme 2 (ACE2). Previously, several methods to develop a vaccine against SARS-CoV or MERS-CoV have been tried with limited success. Since SARS-CoV-2 uses the spike (S) protein for entry to the host cell, it is one of the most preferred targets for making vaccines or therapeutics against SARS-CoV-2. In this review, we have summarised the characteristics of the S protein, as well as the different approaches being used for the development of vaccines and/or therapeutics based on the S protein.


Subject(s)
Antibodies, Viral/biosynthesis , Betacoronavirus/immunology , Coronavirus Infections/prevention & control , Pandemics/prevention & control , Pneumonia, Viral/prevention & control , Spike Glycoprotein, Coronavirus/immunology , Viral Vaccines/immunology , Angiotensin-Converting Enzyme 2 , Antibody-Dependent Enhancement/drug effects , Betacoronavirus/drug effects , Betacoronavirus/pathogenicity , COVID-19 , COVID-19 Vaccines , Clinical Trials as Topic , Coronavirus Infections/epidemiology , Coronavirus Infections/immunology , Coronavirus Infections/virology , Genetic Vectors/chemistry , Genetic Vectors/immunology , Humans , Immunogenicity, Vaccine , Patient Safety , Peptidyl-Dipeptidase A/genetics , Peptidyl-Dipeptidase A/immunology , Peptidyl-Dipeptidase A/metabolism , Pneumonia, Viral/epidemiology , Pneumonia, Viral/immunology , Pneumonia, Viral/virology , Receptors, Virus/genetics , Receptors, Virus/immunology , Receptors, Virus/metabolism , SARS-CoV-2 , Spike Glycoprotein, Coronavirus/genetics , Spike Glycoprotein, Coronavirus/metabolism , Vaccines, Attenuated , Vaccines, DNA , Vaccines, Subunit , Vaccines, Virus-Like Particle/administration & dosage , Vaccines, Virus-Like Particle/biosynthesis , Vaccines, Virus-Like Particle/immunology , Viral Vaccines/administration & dosage , Viral Vaccines/biosynthesis
20.
Virus Res ; 288: 198114, 2020 10 15.
Article in English | MEDLINE | ID: covidwho-709007

ABSTRACT

The current COVID-19 pandemic has urged the scientific community internationally to find answers in terms of therapeutics and vaccines to control SARS-CoV-2. Published investigations mostly on SARS-CoV and to some extent on MERS has taught lessons on vaccination strategies to this novel coronavirus. This is attributed to the fact that SARS-CoV-2 uses the same receptor as SARS-CoV on the host cell i.e. human Angiotensin Converting Enzyme 2 (hACE2) and is approximately 79% similar genetically to SARS-CoV. Though the efforts on COVID-19 vaccines started very early, initially in China, as soon as the outbreak of novel coronavirus erupted and then world-over as the disease was declared a pandemic by WHO. But we will not be having an effective COVID-19 vaccine before September, 2020 as per very optimistic estimates. This is because a successful COVID-19 vaccine will require a cautious validation of efficacy and adverse reactivity as the target vaccinee population include high-risk individuals over the age of 60, particularly those with chronic co-morbid conditions, frontline healthcare workers and those involved in essentials industries. Various platforms for vaccine development are available namely: virus vectored vaccines, protein subunit vaccines, genetic vaccines, and monoclonal antibodies for passive immunization which are under evaluations for SARS-CoV-2, with each having discrete benefits and hindrances. The COVID-19 pandemic which probably is the most devastating one in the last 100 years after Spanish flu mandates the speedy evaluation of the multiple approaches for competence to elicit protective immunity and safety to curtail unwanted immune-potentiation which plays an important role in the pathogenesis of this virus. This review is aimed at providing an overview of the efforts dedicated to an effective vaccine for this novel coronavirus which has crippled the world in terms of economy, human health and life.


Subject(s)
Antibodies, Viral/biosynthesis , Betacoronavirus/immunology , Coronavirus Infections/prevention & control , Pandemics/prevention & control , Pneumonia, Viral/prevention & control , Viral Vaccines/immunology , Angiotensin-Converting Enzyme 2 , Betacoronavirus/drug effects , Betacoronavirus/pathogenicity , COVID-19 , COVID-19 Vaccines , Clinical Trials as Topic , Coronavirus Infections/epidemiology , Coronavirus Infections/immunology , Coronavirus Infections/therapy , Coronavirus Infections/virology , Genetic Vectors/chemistry , Genetic Vectors/immunology , Humans , Immunity, Innate/drug effects , Immunization, Passive/methods , Immunogenicity, Vaccine , Patient Safety , Peptidyl-Dipeptidase A/genetics , Peptidyl-Dipeptidase A/immunology , Peptidyl-Dipeptidase A/metabolism , Pneumonia, Viral/epidemiology , Pneumonia, Viral/immunology , Pneumonia, Viral/virology , Receptors, Virus/genetics , Receptors, Virus/immunology , Receptors, Virus/metabolism , SARS-CoV-2 , Vaccines, Attenuated , Vaccines, DNA , Vaccines, Subunit , Vaccines, Virus-Like Particle/administration & dosage , Vaccines, Virus-Like Particle/biosynthesis , Vaccines, Virus-Like Particle/immunology , Viral Vaccines/administration & dosage , Viral Vaccines/biosynthesis
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