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1.
Viruses ; 14(3)2022 03 06.
Article in English | MEDLINE | ID: covidwho-1765949

ABSTRACT

Gene therapy and vaccine development need more novel adenovirus vectors. Here, we attempt to provide strategies to construct adenovirus vectors based on restriction-assembly for researchers with little experience in this field. Restriction-assembly is a combined method of restriction digestion and Gibson assembly, by which the major part of the obtained plasmid comes from digested DNA fragments instead of PCR products. We demonstrated the capability of restriction-assembly in manipulating the genome of simian adenovirus 1 (SAdV-1) in this study. A PCR product of the plasmid backbone was combined with SAdV-1 genomic DNA to construct an infectious clone, plasmid pKSAV1, by Gibson assembly. Restriction-assembly was performed repeatedly in the steps of intermediate plasmid isolation, modification, and restoration. The generated adenoviral plasmid was linearized by restriction enzyme digestion and transfected into packaging 293 cells to rescue E3-deleted replication-competent SAdV1XE3-CGA virus. Interestingly, SAdV1XE3-CGA could propagate in human chronic myelogenous leukemia K562 cells. The E1 region was similarly modified to generate E1/E3-deleted replication-defective virus SAdV1-EG. SAdV1-EG had a moderate gene transfer ability to adherent mammalian cells, and it could efficiently transduce suspension cells when compared with the human adenovirus 5 control vector. Restriction-assembly is easy to use and can be performed without special experimental materials and instruments. It is highly effective with verifiable outcomes at each step. More importantly, restriction-assembly makes the established vector system modifiable, upgradable and under sustainable development, and it can serve as the instructive method or strategy for the synthetic biology of adenoviruses.


Subject(s)
Adenoviruses, Human , Adenoviruses, Simian , Adenoviridae/genetics , Adenoviruses, Human/genetics , Adenoviruses, Simian/genetics , Animals , DNA , Genetic Vectors/genetics , Humans , Mammals
2.
Cell ; 185(5): 896-915.e19, 2022 03 03.
Article in English | MEDLINE | ID: covidwho-1670278

ABSTRACT

The emerging SARS-CoV-2 variants of concern (VOCs) threaten the effectiveness of current COVID-19 vaccines administered intramuscularly and designed to only target the spike protein. There is a pressing need to develop next-generation vaccine strategies for broader and long-lasting protection. Using adenoviral vectors (Ad) of human and chimpanzee origin, we evaluated Ad-vectored trivalent COVID-19 vaccines expressing spike-1, nucleocapsid, and RdRp antigens in murine models. We show that single-dose intranasal immunization, particularly with chimpanzee Ad-vectored vaccine, is superior to intramuscular immunization in induction of the tripartite protective immunity consisting of local and systemic antibody responses, mucosal tissue-resident memory T cells and mucosal trained innate immunity. We further show that intranasal immunization provides protection against both the ancestral SARS-CoV-2 and two VOC, B.1.1.7 and B.1.351. Our findings indicate that respiratory mucosal delivery of Ad-vectored multivalent vaccine represents an effective next-generation COVID-19 vaccine strategy to induce all-around mucosal immunity against current and future VOC.


Subject(s)
COVID-19 Vaccines/administration & dosage , COVID-19/prevention & control , Immunity, Mucosal , Administration, Intranasal , Animals , Antibodies, Viral/blood , Antibodies, Viral/immunology , B-Lymphocytes/immunology , B-Lymphocytes/metabolism , COVID-19/virology , COVID-19 Vaccines/immunology , Cytokines/blood , Genetic Vectors/genetics , Genetic Vectors/immunology , Genetic Vectors/metabolism , Mice , Mice, Inbred BALB C , Mice, Inbred C57BL , Neutralization Tests , Nucleocapsid/genetics , Nucleocapsid/immunology , Nucleocapsid/metabolism , Pan troglodytes , SARS-CoV-2/genetics , SARS-CoV-2/immunology , SARS-CoV-2/isolation & purification , Spike Glycoprotein, Coronavirus/genetics , Spike Glycoprotein, Coronavirus/immunology , Spike Glycoprotein, Coronavirus/metabolism , T-Lymphocytes/immunology , T-Lymphocytes/metabolism
3.
Emerg Microbes Infect ; 11(1): 438-441, 2022 Dec.
Article in English | MEDLINE | ID: covidwho-1662090

ABSTRACT

Mucosal immunity provides a potential for preventing initial infection and stopping subsequent transmission of SARS-CoV-2. Here, we examined the safety and immunogenicity of a replication-defective adenovirus type-5 vectored vaccine (Ad5-nCov) encoding SARS-CoV-2 spike protein delivered by nebulization inhalation in rhesus macaques. The vaccine-associated clinical pathology and toxicity were not observed in the NHP model. The extensive safety study indicated that Ad5-nCoV was mainly confined to the organs related to respiratory system and was rapidly cleared away from the system. Our results showed that Ad5-nCoV delivered by inhalation robustly elicited both systematic and mucosal immune responses against SARS-nCoV-2 and variants. Thus, Ad5-nCoV inhalation may provide an effective, safe and non-invasive vaccination strategy for the control of SARS-CoV-2.


Subject(s)
Adenoviridae/immunology , COVID-19 Vaccines/immunology , COVID-19/immunology , Genetic Vectors/immunology , Immunity, Mucosal , SARS-CoV-2/immunology , Spike Glycoprotein, Coronavirus/immunology , Adenoviridae/genetics , Administration, Inhalation , Animals , COVID-19/prevention & control , COVID-19/virology , COVID-19 Vaccines/administration & dosage , COVID-19 Vaccines/genetics , Disease Models, Animal , Genetic Vectors/genetics , Humans , Immunogenicity, Vaccine , Macaca mulatta , SARS-CoV-2/genetics , Spike Glycoprotein, Coronavirus/administration & dosage , Spike Glycoprotein, Coronavirus/genetics
4.
Drug Metab Pharmacokinet ; 42: 100432, 2022 Feb.
Article in English | MEDLINE | ID: covidwho-1597676

ABSTRACT

Replication-incompetent adenovirus (Ad) vectors have been widely used as gene delivery vehicles in both gene therapy studies and basic studies for gene function analysis due to their highly advantageous properties, which include high transduction efficiencies, relatively large capacities for transgenes, and high titer production. In addition, Ad vectors induce moderate levels of innate immunity and have relatively high thermostability, making them very attractive as potential vaccine vectors. Accordingly, it is anticipated that Ad vectors will be used in vaccines for the prevention of infectious diseases, including Ebola virus disease and acquired immune deficiency syndrome (AIDS). Much attention is currently focused on the potential use of an Ad vector vaccine for coronavirus disease 2019 (COVID-19). In this review, we describe the basic properties of an Ad vector, Ad vector-induced innate immunity and immune responses to Ad vector-produced transgene products. Development of novel Ad vectors which can overcome the drawbacks of conventional Ad vector vaccines and clinical application of Ad vector vaccines to several infectious diseases are also discussed.


Subject(s)
Adenovirus Vaccines , COVID-19 , Communicable Diseases , Vaccines , Adenoviridae/genetics , Genetic Vectors/genetics , Humans , SARS-CoV-2
5.
Front Immunol ; 12: 795741, 2021.
Article in English | MEDLINE | ID: covidwho-1581316

ABSTRACT

Glycan-masking the vaccine antigen by mutating the undesired antigenic sites with an additional N-linked glycosylation motif can refocus B-cell responses to desired epitopes, without affecting the antigen's overall-folded structure. This study examined the impact of glycan-masking mutants of the N-terminal domain (NTD) and receptor-binding domain (RBD) of SARS-CoV-2, and found that the antigenic design of the S protein increases the neutralizing antibody titers against the Wuhan-Hu-1 ancestral strain and the recently emerged SARS-CoV-2 variants Alpha (B.1.1.7), Beta (B.1.351), and Delta (B.1.617.2). Our results demonstrated that the use of glycan-masking Ad-S-R158N/Y160T in the NTD elicited a 2.8-fold, 6.5-fold, and 4.6-fold increase in the IC-50 NT titer against the Alpha (B.1.1.7), Beta (B.1.351) and Delta (B.1.617.2) variants, respectively. Glycan-masking of Ad-S-D428N in the RBD resulted in a 3.0-fold and 2.0-fold increase in the IC-50 neutralization titer against the Alpha (B.1.1.7) and Beta (B.1.351) variants, respectively. The use of glycan-masking in Ad-S-R158N/Y160T and Ad-S-D428N antigen design may help develop universal COVID-19 vaccines against current and future emerging SARS-CoV-2 variants.


Subject(s)
Antigens, Viral/immunology , COVID-19/immunology , Epitopes/immunology , Protein Interaction Domains and Motifs/immunology , SARS-CoV-2/immunology , Spike Glycoprotein, Coronavirus/immunology , Adenoviridae/genetics , Animals , Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , Antibody Formation/immunology , COVID-19/prevention & control , COVID-19/virology , COVID-19 Vaccines/genetics , COVID-19 Vaccines/immunology , Disease Models, Animal , Dose-Response Relationship, Immunologic , Female , Genetic Engineering , Genetic Vectors/genetics , Humans , Immunization , Mice , Neutralization Tests , Polysaccharides , SARS-CoV-2/genetics , Spike Glycoprotein, Coronavirus/chemistry , Spike Glycoprotein, Coronavirus/genetics , Spike Glycoprotein, Coronavirus/metabolism , Structure-Activity Relationship
6.
Biomed Pharmacother ; 146: 112527, 2022 Feb.
Article in English | MEDLINE | ID: covidwho-1559074

ABSTRACT

Coronavirus disease 2019 (COVID-19) has a devastating impact on global populations triggered by a highly infectious viral sickness, produced by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The third major cause of mortality in the United States, following heart disease and cancer in 2020, was undoubtedly COVID-19. The centers for disease control and prevention (CDC) and the world health organization (WHO) separately developed a categorization system for differentiating new strains of SARS-CoV-2 into variants of concern (VoCs) and variants of interest (VoIs) with the continuing development of various strains SARS-CoV-2. By December 2021, five of the SARS-CoV-2 VoCs were discovered from the onset of the pandemic depending on the latest epidemiologic report by the WHO: Alpha (B.1.1.7), Beta (B.1.351), Gamma (P.1), Delta (B.1.617.2), and Omicron (B.1.1.529). Mutations in the receptor-binding domain (RBD) and n-terminal domain (NTD) have been found throughout all five identified VoCs. All strains other than the delta mutant are often found with the N501Y mutation situated on the RBD, resulting in higher binding between the spike protein and angiotensin-converting enzyme 2 (ACE2) receptors, enhanced viral adhesion, and following the entrance to host cells. The introduction of these new strains of SRAS-CoV-2 is likely to overcome the remarkable achievements gained in restricting this viral disease to the point where it is presented with remarkable vaccine developments against COVID-19 and strong worldwide mass immunization initiatives. Throughout this literature review, the effectiveness of current COVID-19 vaccines for managing and prohibiting SARS-CoV-2 strains is thoroughly described.


Subject(s)
COVID-19 Vaccines/administration & dosage , COVID-19/prevention & control , Genetic Vectors/administration & dosage , SARS-CoV-2/drug effects , Vaccines, Synthetic/administration & dosage , /administration & dosage , Angiotensin-Converting Enzyme 2/antagonists & inhibitors , Angiotensin-Converting Enzyme 2/genetics , Angiotensin-Converting Enzyme 2/metabolism , Animals , COVID-19/genetics , COVID-19/metabolism , COVID-19 Vaccines/genetics , COVID-19 Vaccines/metabolism , Genetic Variation/genetics , Genetic Vectors/genetics , Genetic Vectors/metabolism , Humans , SARS-CoV-2/genetics , SARS-CoV-2/metabolism , Treatment Outcome , Vaccines, Synthetic/genetics , Vaccines, Synthetic/metabolism , /metabolism
7.
J Virol ; 95(22): e0096621, 2021 10 27.
Article in English | MEDLINE | ID: covidwho-1561933

ABSTRACT

The high pathogenicity of SARS-CoV-2 requires it to be handled under biosafety level 3 conditions. Consequently, Spike protein-pseudotyped vectors are a useful tool to study viral entry and its inhibition, with retroviral, lentiviral (LV), and vesicular stomatitis virus (VSV) vectors the most commonly used systems. Methods to increase the titer of such vectors commonly include concentration by ultracentrifugation and truncation of the Spike protein cytoplasmic tail. However, limited studies have examined whether such a modification also impacts the protein's function. Here, we optimized concentration methods for SARS-CoV-2 Spike-pseudotyped VSV vectors, finding that tangential flow filtration produced vectors with more consistent titers than ultracentrifugation. We also examined the impact of Spike tail truncation on transduction of various cell types and sensitivity to convalescent serum neutralization. We found that tail truncation increased Spike incorporation into both LV and VSV vectors and resulted in enhanced titers but had no impact on sensitivity to convalescent serum. In addition, we analyzed the effect of the D614G mutation, which became a dominant SARS-CoV-2 variant early in the pandemic. Our studies revealed that, similar to the tail truncation, D614G independently increases Spike incorporation and vector titers, but this effect is masked by also including the cytoplasmic tail truncation. Therefore, the use of full-length Spike protein, combined with tangential flow filtration, is recommended as a method to generate high titer pseudotyped vectors that retain native Spike protein functions. IMPORTANCE Pseudotyped viral vectors are useful tools to study the properties of viral fusion proteins, especially those from highly pathogenic viruses. The Spike protein of SARS-CoV-2 has been investigated using pseudotyped lentiviral and VSV vector systems, where truncation of its cytoplasmic tail is commonly used to enhance Spike incorporation into vectors and to increase the titers of the resulting vectors. However, our studies have shown that such effects can also mask the phenotype of the D614G mutation in the ectodomain of the protein, which was a dominant variant arising early in the COVID-19 pandemic. To better ensure the authenticity of Spike protein phenotypes when using pseudotyped vectors, we recommend using full-length Spike proteins, combined with tangential flow filtration methods of concentration if higher-titer vectors are required.


Subject(s)
Genetic Vectors/physiology , SARS-CoV-2/genetics , Spike Glycoprotein, Coronavirus/genetics , Animals , Antibodies, Neutralizing/immunology , Cell Line , Genetic Vectors/genetics , Genetic Vectors/immunology , Humans , Lentivirus/genetics , Mutation , SARS-CoV-2/immunology , Spike Glycoprotein, Coronavirus/immunology , Vesicular stomatitis Indiana virus/genetics , Viral Load/genetics
9.
Adv Sci (Weinh) ; 8(23): e2103266, 2021 12.
Article in English | MEDLINE | ID: covidwho-1479368

ABSTRACT

Activation of endothelial cells following severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is thought to be the primary driver for the increasingly recognized thrombotic complications in coronavirus disease 2019 patients, potentially due to the SARS-CoV-2 Spike protein binding to the human angiotensin-converting enzyme 2 (hACE2). Vaccination therapies use the same Spike sequence or protein to boost host immune response as a protective mechanism against SARS-CoV-2 infection. As a result, cases of thrombotic events are reported following vaccination. Although vaccines are generally considered safe, due to genetic heterogeneity, age, or the presence of comorbidities in the population worldwide, the prediction of severe adverse outcome in patients remains a challenge. To elucidate Spike proteins underlying patient-specific-vascular thrombosis, the human microcirculation environment is recapitulated using a novel microfluidic platform coated with human endothelial cells and exposed to patient specific whole blood. Here, the blood coagulation effect is tested after exposure to Spike protein in nanoparticles and Spike variant D614G in viral vectors and the results are corroborated using live SARS-CoV-2. Of note, two potential strategies are also examined to reduce blood clot formation, by using nanoliposome-hACE2 and anti-Interleukin (IL) 6 antibodies.


Subject(s)
Blood Coagulation/physiology , SARS-CoV-2/isolation & purification , Spike Glycoprotein, Coronavirus/metabolism , Angiotensin-Converting Enzyme 2/chemistry , Angiotensin-Converting Enzyme 2/genetics , Angiotensin-Converting Enzyme 2/metabolism , Antibodies/chemistry , Antibodies/immunology , Antibodies/metabolism , COVID-19/diagnosis , COVID-19/virology , Endothelial Cells/chemistry , Endothelial Cells/cytology , Endothelial Cells/metabolism , Fibrin/chemistry , Fibrin/metabolism , Genetic Vectors/genetics , Genetic Vectors/metabolism , Humans , Interleukin-6/immunology , Liposomes/chemistry , Microfluidics/methods , Mutation , Nanoparticles/chemistry , Platelet Aggregation , SARS-CoV-2/metabolism , Spike Glycoprotein, Coronavirus/analysis , Spike Glycoprotein, Coronavirus/genetics
10.
Stem Cell Res Ther ; 11(1): 448, 2020 10 23.
Article in English | MEDLINE | ID: covidwho-1388825

ABSTRACT

Gene therapy is being investigated for a range of serious lung diseases, such as cystic fibrosis and emphysema. Recombinant adeno-associated virus (rAAV) is a well-established, safe, viral vector for gene delivery with multiple naturally occurring and artificial serotypes available displaying alternate cell, tissue, and species-specific tropisms. Efficient AAV serotypes for the transduction of the conducting airways have been identified for several species; however, efficient serotypes for human lung parenchyma have not yet been identified. Here, we screened the ability of multiple AAV serotypes to transduce lung bud organoids (LBOs)-a model of human lung parenchyma generated from human embryonic stem cells. Microinjection of LBOs allowed us to model transduction from the luminal surface, similar to dosing via vector inhalation. We identified the naturally occurring rAAV2 and rAAV6 serotypes, along with synthetic rAAV6 variants, as having tropism for the human lung parenchyma. Positive staining of LBOs for surfactant proteins B and C confirmed distal lung identity and suggested the suitability of these vectors for the transduction of alveolar type II cells. Our findings establish LBOs as a new model for pulmonary gene therapy and stress the relevance of LBOs as a viral infection model of the lung parenchyma as relevant in SARS-CoV-2 research.


Subject(s)
Dependovirus/genetics , Genetic Therapy/methods , Human Embryonic Stem Cells/cytology , Lung Diseases/therapy , Organoids/cytology , Cell Line , Dependovirus/immunology , Gene Transfer Techniques , Genetic Vectors/genetics , Humans , Lung/metabolism , Models, Biological , Parenchymal Tissue/cytology
11.
Viruses ; 13(8)2021 07 28.
Article in English | MEDLINE | ID: covidwho-1376988

ABSTRACT

The human adenovirus phylogenetic tree is split across seven species (A-G). Species D adenoviruses offer potential advantages for gene therapy applications, with low rates of pre-existing immunity detected across screened populations. However, many aspects of the basic virology of species D-such as their cellular tropism, receptor usage, and in vivo biodistribution profile-remain unknown. Here, we have characterized human adenovirus type 49 (HAdV-D49)-a relatively understudied species D member. We report that HAdV-D49 does not appear to use a single pathway to gain cell entry, but appears able to interact with various surface molecules for entry. As such, HAdV-D49 can transduce a broad range of cell types in vitro, with variable engagement of blood coagulation FX. Interestingly, when comparing in vivo biodistribution to adenovirus type 5, HAdV-D49 vectors show reduced liver targeting, whilst maintaining transduction of lung and spleen. Overall, this presents HAdV-D49 as a robust viral vector platform for ex vivo manipulation of human cells, and for in vivo applications where the therapeutic goal is to target the lung or gain access to immune cells in the spleen, whilst avoiding liver interactions, such as intravascular vaccine applications.


Subject(s)
Adenoviruses, Human/genetics , Genetic Therapy/methods , Genetic Vectors/genetics , Adenoviruses, Human/classification , Adenoviruses, Human/metabolism , Animals , Cell Line , Genes, Reporter , Genetic Therapy/instrumentation , Genetic Vectors/metabolism , Humans , Liver/virology , Lung/virology , Mice , Phylogeny , Spleen/virology , Transduction, Genetic
12.
Genes (Basel) ; 12(8)2021 08 16.
Article in English | MEDLINE | ID: covidwho-1376780

ABSTRACT

Despite the World Anti-Doping Agency (WADA) ban on gene doping in the context of advancements in gene therapy, the risk of EPO gene-based doping among athletes is still present. To address this and similar risks, gene-doping tests are being developed in doping control laboratories worldwide. In this regard, the present study was performed with two objectives: to develop a robust gene-doping mouse model with the human EPO gene (hEPO) transferred using recombinant adenovirus (rAdV) as a vector and to develop a detection method to identify gene doping by using this model. The rAdV including the hEPO gene was injected intravenously to transfer the gene to the liver. After injection, the mice showed significantly increased whole-blood red blood cell counts and increased expression of hematopoietic marker genes in the spleen, indicating successful development of the gene-doping model. Next, direct and potentially indirect proof of gene doping were evaluated in whole-blood DNA and RNA by using a quantitative PCR assay and RNA sequencing. Proof of doping could be detected in DNA and RNA samples from one drop of whole blood for approximately a month; furthermore, the overall RNA expression profiles showed significant changes, allowing advanced detection of hEPO gene doping.


Subject(s)
Doping in Sports , Erythropoietin/genetics , Genetic Therapy , Genetic Vectors/genetics , Adenoviridae/genetics , Animals , Athletes , Erythropoietin/therapeutic use , Genetic Vectors/therapeutic use , Humans , Mice , Mice, Transgenic , Models, Animal
13.
Int J Mol Sci ; 22(14)2021 Jul 14.
Article in English | MEDLINE | ID: covidwho-1323263

ABSTRACT

Efficient delivery of genetic material into cells is a critical process to translate gene therapy into clinical practice. In this sense, the increased knowledge acquired during past years in the molecular biology and nanotechnology fields has contributed to the development of different kinds of non-viral vector systems as a promising alternative to virus-based gene delivery counterparts. Consequently, the development of non-viral vectors has gained attention, and nowadays, gene delivery mediated by these systems is considered as the cornerstone of modern gene therapy due to relevant advantages such as low toxicity, poor immunogenicity and high packing capacity. However, despite these relevant advantages, non-viral vectors have been poorly translated into clinical success. This review addresses some critical issues that need to be considered for clinical practice application of non-viral vectors in mainstream medicine, such as efficiency, biocompatibility, long-lasting effect, route of administration, design of experimental condition or commercialization process. In addition, potential strategies for overcoming main hurdles are also addressed. Overall, this review aims to raise awareness among the scientific community and help researchers gain knowledge in the design of safe and efficient non-viral gene delivery systems for clinical applications to progress in the gene therapy field.


Subject(s)
Gene Transfer Techniques , Genetic Diseases, Inborn/therapy , Genetic Therapy/methods , Genetic Vectors/administration & dosage , Nanoparticles/administration & dosage , Animals , Genetic Diseases, Inborn/genetics , Genetic Vectors/genetics , Humans
14.
Emerg Microbes Infect ; 10(1): 1574-1588, 2021 Dec.
Article in English | MEDLINE | ID: covidwho-1320287

ABSTRACT

A safe and effective vaccine is urgently needed to control the unprecedented COVID-19 pandemic. Four adenovirus-vectored vaccines expressing spike (S) protein have been approved for use. Here, we generated several recombinant chimpanzee adenovirus (AdC7) vaccines expressing S, receptor-binding domain (RBD), or tandem-repeat dimeric RBD (RBD-tr2). We found vaccination via either intramuscular or intranasal route was highly immunogenic in mice to elicit both humoral and cellular immune responses. AdC7-RBD-tr2 showed higher antibody responses compared to either AdC7-S or AdC7-RBD. Intranasal administration of AdC7-RBD-tr2 additionally induced mucosal immunity with neutralizing activity in bronchoalveolar lavage fluid. Either single-dose or two-dose mucosal administration of AdC7-RBD-tr2 protected mice against SARS-CoV-2 challenge, with undetectable subgenomic RNA in lung and relieved lung injury. AdC7-RBD-tr2-elicted sera preserved the neutralizing activity against the circulating variants, especially the Delta variant. These results support AdC7-RBD-tr2 as a promising COVID-19 vaccine candidate.


Subject(s)
Adenoviridae/genetics , Antibodies, Viral/blood , COVID-19 Vaccines/immunology , Spike Glycoprotein, Coronavirus/immunology , Administration, Intranasal , Animals , Antibodies, Neutralizing/blood , COVID-19 , COVID-19 Vaccines/administration & dosage , COVID-19 Vaccines/genetics , Chlorocebus aethiops , Female , Genetic Vectors/genetics , HEK293 Cells , Humans , Immunogenicity, Vaccine , Injections, Intramuscular , Mice , Mice, Inbred BALB C , Pan troglodytes/virology , Protein Binding , SARS-CoV-2/genetics , SARS-CoV-2/immunology , Spike Glycoprotein, Coronavirus/administration & dosage , Spike Glycoprotein, Coronavirus/genetics , Vaccination , Vero Cells
16.
Methods Enzymol ; 660: 321-339, 2021.
Article in English | MEDLINE | ID: covidwho-1309118

ABSTRACT

Described here is the use of piggyBac transposase generated HEK293 stable cell pools for doxycycline-inducible protein production. The key benefits of the system are that low amounts of plasmid DNA are needed for transfection, high levels of protein expression can be achieved also for toxic proteins at robust scalability and reproducibility and the recombinant cell line can be stored as frozen cell bank. Transfection, selection, expression and purification of enhanced green fluorescence protein (eGFP) and SARS-CoV-2 Spike protein are described in this chapter.


Subject(s)
COVID-19 , Transposases , DNA Transposable Elements/genetics , Genetic Vectors/genetics , HEK293 Cells , Humans , Plasmids/genetics , Reproducibility of Results , SARS-CoV-2 , Spike Glycoprotein, Coronavirus , Transfection , Transposases/genetics , Transposases/metabolism
17.
Int J Mol Sci ; 21(19)2020 Oct 05.
Article in English | MEDLINE | ID: covidwho-1299430

ABSTRACT

The Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) genome editing system has been the focus of intense research in the last decade due to its superior ability to desirably target and edit DNA sequences. The applicability of the CRISPR-Cas system to in vivo genome editing has acquired substantial credit for a future in vivo gene-based therapeutic. Challenges such as targeting the wrong tissue, undesirable genetic mutations, or immunogenic responses, need to be tackled before CRISPR-Cas systems can be translated for clinical use. Hence, there is an evident gap in the field for a strategy to enhance the specificity of delivery of CRISPR-Cas gene editing systems for in vivo applications. Current approaches using viral vectors do not address these main challenges and, therefore, strategies to develop non-viral delivery systems are being explored. Peptide-based systems represent an attractive approach to developing gene-based therapeutics due to their specificity of targeting, scale-up potential, lack of an immunogenic response and resistance to proteolysis. In this review, we discuss the most recent efforts towards novel non-viral delivery systems, focusing on strategies and mechanisms of peptide-based delivery systems, that can specifically deliver CRISPR components to different cell types for therapeutic and research purposes.


Subject(s)
CRISPR-Cas Systems/genetics , Gene Editing/methods , Genetic Therapy/trends , Genetic Vectors/genetics , Genetic Vectors/therapeutic use , Humans
18.
Virus Res ; 302: 198466, 2021 09.
Article in English | MEDLINE | ID: covidwho-1253729

ABSTRACT

Vigorous vaccination programs against SARS-CoV-2-causing Covid-19 are the major chance to fight this dreadful pandemic. The currently administered vaccines depend on adenovirus DNA vectors or on SARS-CoV-2 mRNA that might become reverse transcribed into DNA, however infrequently. In some societies, people have become sensitized against the potential short- or long-term side effects of foreign DNA being injected into humans. In my laboratory, the fate of foreign DNA in mammalian (human) cells and organisms has been investigated for many years. In this review, a summary of the results obtained will be presented. This synopsis has been put in the evolutionary context of retrotransposon insertions into pre-human genomes millions of years ago. In addition, studies on adenovirus vector-based DNA, on the fate of food-ingested DNA as well as the long-term persistence of SARS-CoV-2 RNA/DNA will be described. Actual integration of viral DNA molecules and of adenovirus vector DNA will likely be chance events whose frequency and epigenetic consequences cannot with certainty be assessed. The review also addresses problems of remaining adenoviral gene expression in adenoviral-based vectors and their role in side effects of vaccines. Eventually, it will come down to weighing the possible risks of genomic insertions of vaccine-associated foreign DNA and unknown levels of vector-carried adenoviral gene expression versus protection against the dangers of Covid-19. A decision in favor of vaccination against life-threatening disease appears prudent. Informing the public about the complexities of biology will be a reliable guide when having to reach personal decisions about vaccinations.


Subject(s)
Adenoviridae/genetics , COVID-19 Vaccines/genetics , COVID-19/prevention & control , Genome, Human/genetics , Pandemics , SARS-CoV-2/immunology , Vaccination , COVID-19/epidemiology , COVID-19/virology , DNA, Viral/genetics , Gene Expression , Genetic Vectors/genetics , Humans , RNA, Messenger/genetics , RNA, Viral/genetics , SARS-CoV-2/genetics
19.
Nucleosides Nucleotides Nucleic Acids ; 40(6): 665-706, 2021.
Article in English | MEDLINE | ID: covidwho-1226496

ABSTRACT

The outbreak of a novel coronavirus responsible for the severe acquired respiratory syndrome: SARS-CoV-2, also known as coronavirus disease 2019: COVID-19, represents a pandemic threat that has been declared a public health emergency of international concern. The CoV spike (S) glycoprotein is a key target for diagnostic, development of antibodies, entry inhibitors, and vaccines. COVID-19 also recognizes angiotensin-converting enzyme 2 (ACE2) as its host receptor binding to viral S protein. Several antiviral drugs and vaccines have been evaluated for the treatment and prevention of the infection by the virus. To facilitate medical countermeasure development, the problems associated with antiviral drugs and vaccines development for containing the spread of COVID-19 are discussed. There is an urgent need to study deeply on the structure, mutations, and function of COVID-19 as well as its pathophysiology from a large population. Construction of expression vectors for any protein targeting to the cell plasma membrane via the glycosyl-phosphatidylinositol, GPI, anchor for studying intermolecular interactions, as described in Ref. # 62 (Nguyen, K. V., Naviaux, R. K., Nyhan, W. L. Lesch-Nyhan disease: I. Construction of expression vectors for hypoxanthine-guanine phosphoribosyltransferase (HGprt) enzyme and amyloid precursor protein (APP). Nucleosides Nucleotides Nucleic Acids 2020, 39, 905-922), between the S protein of COVID-19 as well as its variants and ACE2 could be useful in antiviral drugs and vaccines development.


Subject(s)
Antiviral Agents/pharmacology , COVID-19 Vaccines/genetics , COVID-19 Vaccines/immunology , COVID-19/drug therapy , COVID-19/prevention & control , Genetic Vectors/genetics , Glycosylphosphatidylinositols/metabolism , Antiviral Agents/therapeutic use , COVID-19/genetics , COVID-19/metabolism , Gene Expression , Humans
20.
Hum Gene Ther ; 32(11-12): 541-562, 2021 06.
Article in English | MEDLINE | ID: covidwho-1216585

ABSTRACT

Severe acute respiratory syndrome (SARS) is a newly emerging infectious disease (COVID-19) caused by the novel coronavirus SARS-coronavirus 2 (CoV-2). To combat the devastating spread of SARS-CoV-2, extraordinary efforts from numerous laboratories have focused on the development of effective and safe vaccines. Traditional live-attenuated or inactivated viral vaccines are not recommended for immunocompromised patients as the attenuated virus can still cause disease via phenotypic or genotypic reversion. Subunit vaccines require repeated dosing and adjuvant use to be effective, and DNA vaccines exhibit lower immune responses. mRNA vaccines can be highly unstable under physiological conditions. On the contrary, naturally antigenic viral vectors with well-characterized structure and safety profile serve as among the most effective gene carriers to provoke immune response via heterologous gene transfer. Viral vector-based vaccines induce both an effective cellular immune response and a humoral immune response owing to their natural adjuvant properties via transduction of immune cells. Consequently, viral vectored vaccines carrying the SARS-CoV-2 spike protein have recently been generated and successfully used to activate cytotoxic T cells and develop a neutralizing antibody response. Recent progress in SARS-CoV-2 vaccines, with an emphasis on gene therapy viral vector-based vaccine development, is discussed in this review.


Subject(s)
COVID-19 Vaccines/pharmacology , Genetic Vectors , Vaccines, Attenuated/pharmacology , Vaccines, Synthetic/pharmacology , Viral Structural Proteins/chemistry , Adenoviridae/genetics , Genetic Therapy/methods , Genetic Vectors/chemistry , Genetic Vectors/genetics , Humans , Lentivirus/genetics , SARS-CoV-2/genetics , Vaccines, DNA/pharmacology , Viral Structural Proteins/genetics , Viral Structural Proteins/metabolism
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