scholarly journals Pitfalls at Chemistry of Adenoviral Vector Vaccine against COVID-19 and how to Circumvent It.

2021 ◽  
Author(s):  
Amr Ahmed
Keyword(s):  
Gene Therapy ◽  
Adenoviral Vector ◽  
Liver Toxicity ◽  
Adenovirus Vector ◽  
Adenoviral Vectors ◽  
Zinc Binding ◽  
Lower Serum ◽  
Vector Vaccine ◽  
Zinc Chelator ◽  
First Time

ChAdOx1 nCoV-19 vaccine is an adenovirus vector vaccine that designed to provoke immunity against SARS-CoV-2. EDTA is a very potent zinc chelator which is used commonly in protein interaction studies. Exposure to EDTA even in lower concentrations may cause extreme stripping of zinc from many proteins, in-cluding zinc-binding proteins that described as a component of the largest and most complex gene superfamily in metazoans and the most common class of transcription factors. The zinc dissociation rates can vary greatly among these proteins. Another issue is the adenovirus in the vaccine. It can induce thrombocytopenia, a potentially serious complication of gene therapy protocols using this type of vector.PEGylation already induced significantly lower serum il-6 levels by 70% .We noted that the study by Katie et al studied immune response by a single dose of ChAdOx1 nCov-19 not included test of Il-6 (15)We conclude from previous studies that the PEGylating of adenoviral vectors can be promise tech-nology as safety profile as significantly reduced IL-6 and liver toxicity and how avoiding the pitfalls of chemistry and virology so the PEGylation since first time at 1999 introduced by O’Riordan,C.R et al (16) need more advancements

scholarly journals Pitfalls at Chemistry of Adenoviral Vector Vaccine against COVID-19 and how to Circumvent It.

2021 ◽  
Author(s):  
Amr Kamel Khalil Ahmed ◽  
Abdullah Alkattan
Keyword(s):  
Liver Toxicity ◽  
Ethylenediaminetetraacetic Acid ◽  
Adenovirus Vector ◽  
Adenoviral Vectors ◽  
Lower Serum ◽  
Vector Vaccine ◽  
Chloride Hexahydrate ◽  
Zinc Chelator ◽  
Inactive Ingredients ◽  
First Time

ChAdOx1 nCoV-19 vaccine is an adenovirus vector vaccine that designed to provoke immunity against SARS-CoV-2.This vaccine contains several inactive ingredients, including sodium chloride, magnesium chloride hexahydrate, ethanol, sucrose, and Ethylenediaminetetraacetic acid (EDTA).EDTA is a very potent zinc chelator which is used commonly in protein interaction studies. Exposure to EDTA even in lower concentrations may cause extreme stripping of zinc from many proteins, in-cluding zinc-binding proteins that described as a component of the largest and most complex gene superfamily in metazoans and the most common class of transcription factors.the EDTA-induced thrombocytopenia is a risk phenomenon caused by EDTA-dependent anti-platelet auto-antibodies that identify antigens modified by EDTA.Another issue is the adenovirus in the vaccine. It can induce thrombocytopenia, a potentially serious complication of gene therapy protocols using this type of vector.PEGylation already induced significantly lower serum il-6 levels by 70% (14)We noted that the study by Katie et al studied immune response by a single dose of ChAdOx1 nCov-19 not included test of Il-6 (15)We conclude from previous studies that the PEGylating of adenoviral vectors can be promise tech-nology as safety profile as significantly reduced IL-6 and liver toxicity and how avoiding the pitfalls of chemistry and virology so the PEGylation since first time at 1999 introduced by O’Riordan,C.R et al (16) need more advancements

scholarly journals Generation of an Adenovirus Vector Lacking E1, E2a, E3, and All of E4 except Open Reading Frame 3

1999 ◽  
Vol 73 (7) ◽  
pp. 6048-6055 ◽  
Author(s):  
Mario I. Gorziglia ◽  
Claudia Lapcevich ◽  
Soumitra Roy ◽  
Qiang Kang ◽  
Mike Kadan ◽  
...  
Keyword(s):  
Gene Therapy ◽  
Liver Toxicity ◽  
Adenovirus Vector ◽  
Open Reading Frame ◽  
Reading Frame ◽  
Rous Sarcoma ◽  
Sarcoma Virus ◽  
Adenovirus Vectors ◽  
Virus Promoter

ABSTRACT Toxicity and immunity associated with adenovirus backbone gene expression is an important hurdle to overcome for successful gene therapy. Recent efforts to improve adenovirus vectors for in vivo use have focused on the sequential deletion of essential early genes. Adenovirus vectors have been constructed with the E1 gene deleted and with this deletion in combination with an E2a, E2b, or E4 deletion. We report here a novel vector (Av4orf3nBg) lacking E1, E2a, and all of E4 except open reading frame 3 (ORF3) and expressing a β-galactosidase reporter gene. This vector was generated by transfection of a plasmid carrying the full-length vector sequence into A30.S8 cells that express E1 and E2a but not E4. Production was subsequently performed in an E1-, E2a-, and E4-complementing cell line. We demonstrated with C57BL/6 mice that the Av4orf3nBg vector effected gene transfer with an efficiency comparable to that of the Av3nBg (wild-type E4) vector but that the former exhibited a higher level of β-galactosidase expression. This observation suggests that E4 ORF3 alone is able to enhance RNA levels from the β-galactosidase gene when the Rous sarcoma virus promoter is used to drive transgene expression in the mouse liver. In addition, we observed less liver toxicity in mice injected with the Av4orf3nBg vector than those injected with the Av3nBg vector at a comparable DNA copy number per cell. This study suggests that the additional deletion of E4 in an E1 and E2a deletion background may be beneficial in decreasing immunogenicity and improving safety and toxicity profiles, as well as increasing transgene capacity and expression for liver-directed gene therapy.

scholarly journals Adenoviral vector vaccine platforms in the SARS-CoV-2 pandemic

npj Vaccines ◽  
2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Samir Andrade Mendonça ◽  
Reka Lorincz ◽  
Paul Boucher ◽  
David T. Curiel
Keyword(s):  
Adenoviral Vector ◽  
New Technologies ◽  
Rapid Development ◽  
Vaccination Campaign ◽  
Adenoviral Vectors ◽  
Molecular Characteristics ◽  
Vector Vaccine ◽  
Vector Systems ◽  
The Impact ◽  
Full Consideration

AbstractAdenoviral vectors have been explored as vaccine agents for a range of infectious diseases, and their ability to induce a potent and balanced immune response made them logical candidates to apply to the COVID-19 pandemic. The unique molecular characteristics of these vectors enabled the rapid development of vaccines with advanced designs capable of overcoming the biological challenges faced by early adenoviral vector systems. These successes and the urgency of the COVID-19 situation have resulted in a flurry of candidate adenoviral vector vaccines for COVID-19 from both academia and industry. These vaccines represent some of the lead candidates currently supported by Operation Warp Speed and other government agencies for rapid translational development. This review details adenoviral vector COVID-19 vaccines currently in human clinical trials and provides an overview of the new technologies employed in their design. As these vaccines have formed a cornerstone of the COVID-19 global vaccination campaign, this review provides a full consideration of the impact and development of this emerging platform.

scholarly journals Polyinosinic acid enhances delivery of adenovirus vectors in vivo by preventing sequestration in liver macrophages

2008 ◽  
Vol 89 (5) ◽  
pp. 1097-1105 ◽  
Author(s):  
Hidde J. Haisma ◽  
Jan A. A. M. Kamps ◽  
Gera K. Kamps ◽  
Josee A. Plantinga ◽  
Marianne G. Rots ◽  
...  
Keyword(s):  
Gene Therapy ◽  
Kupffer Cells ◽  
Transgene Expression ◽  
Liver Toxicity ◽  
Viral Vector ◽  
Adenovirus Vector ◽  
Liver Macrophages ◽  
Polyinosinic Acid

Adenovirus is among the preferred vectors for gene therapy because of its superior in vivo gene-transfer efficiency. However, upon systemic administration, adenovirus is preferentially sequestered by the liver, resulting in reduced adenovirus-mediated transgene expression in targeted tissues. In the liver, Kupffer cells are responsible for adenovirus degradation and contribute to the inflammatory response. As scavenger receptors present on Kupffer cells are responsible for the elimination of blood-borne pathogens, we investigated the possible implication of these receptors in the clearance of the adenovirus vector. Polyinosinic acid [poly(I)], a scavenger receptor A ligand, was analysed for its capability to inhibit adenovirus uptake specifically in macrophages. In in vitro studies, the addition of poly(I) before virus infection resulted in a specific inhibition of adenovirus-induced gene expression in a J774 macrophage cell line and in primary Kupffer cells. In in vivo experiments, pre-administration of poly(I) caused a 10-fold transient increase in the number of adenovirus particles circulating in the blood. As a consequence, transgene expression levels measured in different tissues were enhanced (by 5- to 15-fold) compared with those in animals that did not receive poly(I). Finally, necrosis of Kupffer cells, which normally occurs as a consequence of systemic adenovirus administration, was prevented by the use of poly(I). No toxicity, as measured by liver-enzyme levels, was observed after poly(I) treatment. From our data, we conclude that poly(I) can prevent adenovirus sequestration by liver macrophages. These results imply that, by inhibiting adenovirus uptake by Kupffer cells, it is possible to reduce the dose of the viral vector to diminish the liver-toxicity effect and to improve the level of transgene expression in target tissues. In systemic gene-therapy applications, this will have great impact on the development of targeted adenoviral vectors.

scholarly journals Human AdV-20-42-42, a promising novel adenoviral vector for gene therapy and vaccine product development

2021 ◽  
Author(s):  
Mónika Z. Ballmann ◽  
Svjetlana Raus ◽  
Ruben Engelhart ◽  
Győző L. Kaján ◽  
Abdelaziz Beqqali ◽  
...  
Keyword(s):  
Gene Therapy ◽  
Immune Responses ◽  
Adenoviral Vector ◽  
Vaccine Development ◽  
Coagulation Factor ◽  
Adenoviral Vectors ◽  
Factor X ◽  
Full Genome Sequencing ◽  
Binding Studies

Pre-existing immune responses towards adenoviral vector limit the use of a vector based on particular serotypes and its clinical applicability for gene therapy and/or vaccination. Therefore, there is a significant interest to vectorize novel adenoviral types that have low seroprevalence in the human population. Here, we describe the discovery and vectorization of a chimeric human adenovirus, which we call HAdV-20-42-42. Full genome sequencing revealed that this virus is closely related to human serotype 42, except for the penton-base which is derived from serotype 20. The HAdV-20-42-42 vector could be propagated stably to high titers on existing E1-complementing packaging cell lines. Receptor binding studies revealed that the vector utilized both CAR and CD46 as receptors for cell entry. Furthermore, the HAdV-20-42-42 vector was potent in transducing human and murine cardiovascular cells and tissues, irrespective of the presence of blood coagulation factor X. In vivo characterizations demonstrate that when delivered intravenously (i.v.) in mice, HAdV-20-42-42 mainly targeted the lungs, liver and spleen and triggered robust inflammatory immune response. Finally, we demonstrate that potent T-cell responses against vector-delivered antigens could be induced upon intramuscular vaccination in mice. In summary, from the data obtained we conclude that HAdV-20-42-42 provides a valuable addition to the portfolio of adenoviral vectors available to develop efficacious products in the fields of gene therapy and vaccination. IMPORTANCE Adenoviral vectors are currently under investigation for a broad range of therapeutic indications in diverse fields, such as oncology and gene therapy, as well as for vaccination both for human and veterinary use. A wealth of data shows that pre-existing immune responses may limit the use of a vector. Particularly in the current climate of global pandemic, there is a need to expand the toolbox with novel adenoviral vectors for vaccine development. Our data demonstrates that we have successfully vectorized a novel adenovirus type candidate with low seroprevalence. The cell transduction data and antigen-specific immune responses induced in vivo demonstrate that this vector is highly promising for the development of gene therapy and vaccine products.

scholarly journals Human AdV-20-42-42, a promising novel adenoviral vector for gene therapy and vaccine product development

2021 ◽  
Author(s):  
Mónika Z. Ballmann ◽  
Svjetlana Raus ◽  
Ruben Engelhart ◽  
Győző L. Kaján ◽  
Chantal van der Zalm ◽  
...  
Keyword(s):  
Gene Therapy ◽  
Immune Responses ◽  
Adenoviral Vector ◽  
Vaccine Development ◽  
Coagulation Factor ◽  
Adenoviral Vectors ◽  
Factor X ◽  
Full Genome Sequencing ◽  
Binding Studies

ABSTRACTPre-existing immune responses towards adenoviral vector limit the use of a vector based on particular serotypes and its clinical applicability for gene therapy and/or vaccination. Therefore, there is a significant interest to vectorize novel adenoviral types that have low seroprevalence in the human population. Here, we describe the discovery and vectorization of a chimeric human adenovirus, which we call HAdV-20-42-42. Full genome sequencing revealed that this virus is closely related to human serotype 42, except for the penton-base which is derived from serotype 20. The HAdV-20-42-42 vector could be propagated stably to high titers on existing E1-complementing packaging cell lines. Receptor binding studies revealed that the vector utilized both CAR and CD46 as receptors for cell entry. Furthermore, the HAdV-20-42-42 vector was potent in transducing human and murine cardiovascular cells and tissues, irrespective of the presence of blood coagulation factor X. In addition, the vector did not sequester in the liver upon intravenous administration in rodents. Finally, we demonstrate that potent T-cell responses against vector-delivered antigens could be induced upon vaccination. In summary, from the data obtained we conclude that HAdV-20-42-42 provides a valuable addition to the portfolio of adenoviral vectors available to develop safe and efficacious products in the fields of gene therapy and vaccination.IMPORTANCEAdenoviral vectors are currently under investigation for a broad range of therapeutic indications in diverse fields, such as oncology and gene therapy, as well as for vaccination both for human and veterinary use. A wealth of data shows that pre-existing immune responses may limit the use of a vector. Particularly in the current climate of global pandemic, there is a need to expand the toolbox with novel adenoviral vectors for vaccine development. Our data demonstrates that we have successfully vectorized a novel adenovirus serotype with low seroprevalence. The cell transduction data and antigen-specific immune responses induced in vivo demonstrate that this vector is highly promising for the development of gene therapy and vaccine products.

Systemic delivery of an adenoviral vector encoding canine factor VIII results in short-term phenotypic correction, inhibitor development, and biphasic liver toxicity in hemophilia A dogs

Blood ◽  
2001 ◽  
Vol 97 (1) ◽  
pp. 107-113 ◽  
Author(s):  
Angela M. Gallo-Penn ◽  
Pamela S. Shirley ◽  
Julie L. Andrews ◽  
Shawn Tinlin ◽  
Sandy Webster ◽  
...  
Keyword(s):  
Factor Viii ◽  
Adenoviral Vector ◽  
Hemophilia A ◽  
Liver Toxicity ◽  
Adenoviral Vectors ◽  
Systemic Delivery ◽  
Short Term ◽  
Inhibitor Development ◽  
Gene Therapy Approach

Abstract Canine hemophilia A closely mimics the human disease and has been used previously in the development of factor VIII (FVIII) protein replacement products. FVIII-deficient dogs were studied to evaluate an in vivo gene therapy approach using an E1/E2a/E3-deficient adenoviral vector encoding canine FVIII. Results demonstrated a high level of expression of the canine protein and complete phenotypic correction of the coagulation defect in all 4 treated animals. However, FVIII expression was short-term, lasting 5 to 10 days following vector infusion. All 4 dogs displayed a biphasic liver toxicity, a transient drop in platelets, and development of anticanine FVIII antibody. Canine FVIII inhibitor development was transient in 2 of the 4 treated animals. These data demonstrate that systemic delivery of attenuated adenoviral vectors resulted in liver toxicity and hematologic changes. Therefore, the development of further attenuated adenoviral vectors encoding canine FVIII will be required to improve vector safety and reduce the risk of immunologic sequelae, and may allow achievement of sustained phenotypic correction of canine hemophilia A.

A gene-deleted adenoviral vector results in phenotypic correction of canine hemophilia B without liver toxicity or thrombocytopenia

Blood ◽  
2003 ◽  
Vol 102 (7) ◽  
pp. 2403-2411 ◽  
Author(s):  
Anja Ehrhardt ◽  
Hui Xu ◽  
Aaron M. Dillow ◽  
Dwight A. Bellinger ◽  
Timothy C. Nichols ◽  
...  
Keyword(s):  
Gene Transfer ◽  
Adenoviral Vector ◽  
High Efficiency ◽  
Liver Toxicity ◽  
Normal Liver ◽  
Adenoviral Vectors ◽  
Factor Ix ◽  
Hemophilia B ◽  
Large Animal ◽  
Large Animal Models

Abstract Many approaches for treating hemophilia via gene transfer have been attempted in large animal models but all have potential drawbacks. Recombinant adenoviral vectors offer high-efficiency transfer of an episomal vector but have been plagued by the cytotoxicity/immunogenicity of early-generation vectors that contain viral genes. In our current study, we have used a nonintegrating helper-dependent (HD) adenoviral vector for liver-directed gene transfer to achieve hemostatic correction in a dog with hemophilia B. We measured plasma canine factor IX (cFIX) concentrations at a therapeutic range for up to 2.5 months and normalization of the whole blood clotting time (WBCT) for about a month. This was followed by a decrease and stabilized partial correction for 4.5 months. Hepatic gene transfer of a slightly lower dose of the HD vector resulted in WBCTs that were close to normal for 2 weeks, suggesting a dose threshold effect in dogs. In sharp contrast to other studies using first- or second-generation adenoviral vectors, we observed no vector-related elevation of liver enzymes, no fall in platelet counts, and normal liver histology. Taken together, this study demonstrates that injection of an adenoviral HD vector results in complete but transient phenotypic correction of FIX deficiency in canine models with no detectable toxicity. (Blood. 2003;102:2403-2411)

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