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  1. Article: Production, Characterization, and Assessment of Permanently Cationic and Ionizable Lipid Nanoparticles for Use in the Delivery of Self-Amplifying RNA Vaccines.

    Kairuz, Dylan / Samudh, Nazia / Ely, Abdullah / Arbuthnot, Patrick / Bloom, Kristie

    Pharmaceutics

    2023  Volume 15, Issue 4

    Abstract: Africa bears the highest burden of infectious diseases, yet the continent is heavily reliant on First World countries for the development and supply of life-saving vaccines. The COVID-19 pandemic was a stark reminder of Africa's vaccine dependence and ... ...

    Abstract Africa bears the highest burden of infectious diseases, yet the continent is heavily reliant on First World countries for the development and supply of life-saving vaccines. The COVID-19 pandemic was a stark reminder of Africa's vaccine dependence and since then great interest has been generated in establishing mRNA vaccine manufacturing capabilities on the African continent. Herein, we explore alphavirus-based self-amplifying RNAs (saRNAs) delivered by lipid nanoparticles (LNPs) as an alternative to the conventional mRNA vaccine platform. The approach is intended to produce dose-sparing vaccines which could assist resource-constrained countries to achieve vaccine independence. Protocols to synthesize high-quality saRNAs were optimized and in vitro expression of reporter proteins encoded by saRNAs was achieved at low doses and observed for an extended period. Permanently cationic or ionizable LNPs (cLNPs and iLNPs, respectively) were successfully produced, incorporating saRNAs either exteriorly (saRNA-Ext-LNPs) or interiorly (saRNA-Int-LNPs). DOTAP and DOTMA saRNA-Ext-cLNPs performed best and were generally below 200 nm with good PDIs (<0.3). DOTAP and DDA saRNA-Int-cLNPs performed optimally, allowing for saRNA amplification. These were slightly larger, with higher PDIs as a result of the method used, which will require further optimization. In both cases, the N:P ratio and lipid molar ratio had a distinct effect on saRNA expression kinetics, and RNA was encapsulated at high percentages of >90%. These LNPs allow the delivery of saRNA with no significant toxicity. The optimization of saRNA production and identification of potential LNP candidates will facilitate saRNA vaccine and therapeutic development. The dose-sparing properties, versatility, and manufacturing simplicity of the saRNA platform will facilitate a rapid response to future pandemics.
    Language English
    Publishing date 2023-04-07
    Publishing country Switzerland
    Document type Journal Article
    ZDB-ID 2527217-2
    ISSN 1999-4923
    ISSN 1999-4923
    DOI 10.3390/pharmaceutics15041173
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  2. Article ; Online: Advancing mRNA technologies for therapies and vaccines: An African context.

    Kairuz, Dylan / Samudh, Nazia / Ely, Abdullah / Arbuthnot, Patrick / Bloom, Kristie

    Frontiers in immunology

    2022  Volume 13, Page(s) 1018961

    Abstract: Synthetic mRNA technologies represent a versatile platform that can be used to develop advanced drug products. The remarkable speed with which vaccine development programs designed and manufactured safe and effective COVID-19 vaccines has rekindled ... ...

    Abstract Synthetic mRNA technologies represent a versatile platform that can be used to develop advanced drug products. The remarkable speed with which vaccine development programs designed and manufactured safe and effective COVID-19 vaccines has rekindled interest in mRNA technology, particularly for future pandemic preparedness. Although recent R&D has focused largely on advancing mRNA vaccines and large-scale manufacturing capabilities, the technology has been used to develop various immunotherapies, gene editing strategies, and protein replacement therapies. Within the mRNA technologies toolbox lie several platforms, design principles, and components that can be adapted to modulate immunogenicity, stability,
    MeSH term(s) Humans ; RNA, Messenger/genetics ; COVID-19 Vaccines ; COVID-19/prevention & control ; Vaccines ; Technology
    Chemical Substances RNA, Messenger ; COVID-19 Vaccines ; Vaccines
    Language English
    Publishing date 2022-10-24
    Publishing country Switzerland
    Document type Journal Article ; Review ; Research Support, Non-U.S. Gov't
    ZDB-ID 2606827-8
    ISSN 1664-3224 ; 1664-3224
    ISSN (online) 1664-3224
    ISSN 1664-3224
    DOI 10.3389/fimmu.2022.1018961
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  3. Article ; Online: Diversity of Dysregulated Long Non-Coding RNAs in HBV-Related Hepatocellular Carcinoma.

    Samudh, Nazia / Shrilall, Creanne / Arbuthnot, Patrick / Bloom, Kristie / Ely, Abdullah

    Frontiers in immunology

    2022  Volume 13, Page(s) 834650

    Abstract: Infection with the hepatitis B virus (HBV) continues to pose a major threat to public health as approximately 292 million people worldwide are currently living with the chronic form of the disease, for which treatment is non-curative. Chronic HBV ... ...

    Abstract Infection with the hepatitis B virus (HBV) continues to pose a major threat to public health as approximately 292 million people worldwide are currently living with the chronic form of the disease, for which treatment is non-curative. Chronic HBV infections often progress to hepatocellular carcinoma (HCC) which is one of the world's leading causes of cancer-related deaths. Although the process of hepatocarcinogenesis is multifaceted and has yet to be fully elucidated, several studies have implicated numerous long non-coding RNAs (lncRNAs) as contributors to the development of HCC. These host-derived lncRNAs, which are often dysregulated as a consequence of viral infection, have been shown to function as signals, decoys, guides, or scaffolds, to modulate gene expression at epigenetic, transcriptional, post-transcriptional and even post-translational levels. These lncRNAs mainly function to promote HBV replication and oncogene expression or downregulate tumor suppressors. Very few lncRNAs are known to suppress tumorigenesis and these are often downregulated in HCC. In this review, we describe the mechanisms by which lncRNA dysregulation in HBV-related HCC promotes tumorigenesis and cancer progression.
    MeSH term(s) Animals ; Carcinoma, Hepatocellular/genetics ; Carcinoma, Hepatocellular/metabolism ; Carcinoma, Hepatocellular/virology ; Gene Expression Regulation, Neoplastic ; Hepatitis B/genetics ; Hepatitis B/metabolism ; Hepatitis B/virology ; Hepatitis B virus/genetics ; Hepatitis B virus/physiology ; Host-Pathogen Interactions ; Humans ; Liver Neoplasms/genetics ; Liver Neoplasms/metabolism ; Liver Neoplasms/virology ; RNA, Long Noncoding/genetics ; RNA, Long Noncoding/metabolism
    Chemical Substances RNA, Long Noncoding
    Language English
    Publishing date 2022-01-28
    Publishing country Switzerland
    Document type Journal Article ; Research Support, Non-U.S. Gov't ; Review
    ZDB-ID 2606827-8
    ISSN 1664-3224 ; 1664-3224
    ISSN (online) 1664-3224
    ISSN 1664-3224
    DOI 10.3389/fimmu.2022.834650
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  4. Article ; Online: Hepatitis B virus: promising drug targets and therapeutic implications.

    Maepa, Mohube Betty / Bloom, Kristie / Ely, Abdullah / Arbuthnot, Patrick

    Expert opinion on therapeutic targets

    2021  Volume 25, Issue 6, Page(s) 451–466

    Abstract: ... ...

    Abstract Introduction
    MeSH term(s) Antiviral Agents/pharmacology ; Antiviral Agents/therapeutic use ; DNA, Circular ; DNA, Viral ; Hepatitis B virus ; Humans ; Pharmaceutical Preparations ; Virus Replication
    Chemical Substances Antiviral Agents ; DNA, Circular ; DNA, Viral ; Pharmaceutical Preparations
    Language English
    Publishing date 2021-04-19
    Publishing country England
    Document type Journal Article ; Research Support, Non-U.S. Gov't ; Review
    ZDB-ID 2055208-7
    ISSN 1744-7631 ; 1472-8222
    ISSN (online) 1744-7631
    ISSN 1472-8222
    DOI 10.1080/14728222.2021.1915990
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  5. Article ; Online: Recent Advances Using Genetic Therapies Against Infectious Diseases and for Vaccination.

    Galy, Anne / Berkhout, Ben / Breckpot, Karine / Pichon, Chantal / Bloom, Kristie / Kiem, Hans-Peter / Mühlebach, Michael D / McCune, Joseph M

    Human gene therapy

    2023  Volume 34, Issue 17-18, Page(s) 896–904

    Abstract: The development of prophylatic or therapeutic medicines for infectious diseases is one of the priorities for health organizations worldwide. Innovative solutions are required to achieve effective, safe, and accessible treatments for most if not all ... ...

    Abstract The development of prophylatic or therapeutic medicines for infectious diseases is one of the priorities for health organizations worldwide. Innovative solutions are required to achieve effective, safe, and accessible treatments for most if not all infectious diseases, particularly those that are chronic in nature or that emerge unexpectedly over time. Genetic technologies offer versatile possibilities to design therapies against pathogens. Recent developments such as mRNA vaccines, CRISPR gene editing, and immunotherapies provide unprecedented hope to achieve significant results in the field of infectious diseases. This review will focus on advances in this domain, showcasing the cross-fertilization with other fields (
    MeSH term(s) Humans ; Communicable Diseases/genetics ; Communicable Diseases/therapy ; Genetic Therapy ; Vaccination ; Cloning, Molecular ; Clustered Regularly Interspaced Short Palindromic Repeats
    Language English
    Publishing date 2023-08-28
    Publishing country United States
    Document type Journal Article ; Review ; Research Support, Non-U.S. Gov't
    ZDB-ID 1028152-6
    ISSN 1557-7422 ; 1043-0342
    ISSN (online) 1557-7422
    ISSN 1043-0342
    DOI 10.1089/hum.2023.123
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  6. Article ; Online: Self-amplifying RNA vaccines for infectious diseases.

    Bloom, Kristie / van den Berg, Fiona / Arbuthnot, Patrick

    Gene therapy

    2020  Volume 28, Issue 3-4, Page(s) 117–129

    Abstract: Vaccinology is shifting toward synthetic RNA platforms which allow for rapid, scalable, and cell-free manufacturing of prophylactic and therapeutic vaccines. The simple development pipeline is based on in vitro transcription of antigen-encoding sequences ...

    Abstract Vaccinology is shifting toward synthetic RNA platforms which allow for rapid, scalable, and cell-free manufacturing of prophylactic and therapeutic vaccines. The simple development pipeline is based on in vitro transcription of antigen-encoding sequences or immunotherapies as synthetic RNA transcripts, which are then formulated for delivery. This approach may enable a quicker response to emerging disease outbreaks, as is evident from the swift pursuit of RNA vaccine candidates for the global SARS-CoV-2 pandemic. Both conventional and self-amplifying RNAs have shown protective immunization in preclinical studies against multiple infectious diseases including influenza, RSV, Rabies, Ebola, and HIV-1. Self-amplifying RNAs have shown enhanced antigen expression at lower doses compared to conventional mRNA, suggesting this technology may improve immunization. This review will explore how self-amplifying RNAs are emerging as important vaccine candidates for infectious diseases, the advantages of synthetic manufacturing approaches, and their potential for preventing and treating chronic infections.
    MeSH term(s) COVID-19/epidemiology ; COVID-19/genetics ; COVID-19/immunology ; COVID-19/prevention & control ; COVID-19 Vaccines/genetics ; COVID-19 Vaccines/immunology ; COVID-19 Vaccines/therapeutic use ; Humans ; RNA, Viral/genetics ; RNA, Viral/immunology ; RNA, Viral/therapeutic use ; SARS-CoV-2/genetics ; SARS-CoV-2/immunology ; Vaccination
    Chemical Substances COVID-19 Vaccines ; RNA, Viral
    Keywords covid19
    Language English
    Publishing date 2020-10-22
    Publishing country England
    Document type Journal Article ; Review
    ZDB-ID 1191036-7
    ISSN 1476-5462 ; 0969-7128
    ISSN (online) 1476-5462
    ISSN 0969-7128
    DOI 10.1038/s41434-020-00204-y
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  7. Article: Recent Update on the Role of Circular RNAs in Hepatocellular Carcinoma.

    Ely, Abdullah / Bloom, Kristie / Maepa, Mohube Betty / Arbuthnot, Patrick

    Journal of hepatocellular carcinoma

    2021  Volume 8, Page(s) 1–17

    Abstract: After being overlooked for decades, circular RNAs (circRNAs) have recently generated considerable interest. circRNAs play a role in a variety of normal and pathological biological processes, including hepatocarcinogenesis. Many circRNAs contribute to ... ...

    Abstract After being overlooked for decades, circular RNAs (circRNAs) have recently generated considerable interest. circRNAs play a role in a variety of normal and pathological biological processes, including hepatocarcinogenesis. Many circRNAs contribute to hepatocarcinogenesis through sponging of microRNAs (miRs) and disruption of cellular signaling pathways that play a part in control of cell proliferation, metastasis and apoptosis. In most cases, overexpressed circRNAs sequester miRs to cause de-repressed translation of mRNAs that encode oncogenic proteins. Conversely, low expression of circRNAs has also been described in hepatocellular carcinoma (HCC) and is associated with inhibited production of tumor suppressor proteins. Other functions of circRNAs that contribute to hepatocarcinogenesis include translation of truncated proteins and acting as adapters to regulate influence of transcription factors on target gene expression. circRNAs also affect hepatocyte transformation indirectly. For example, the molecules regulate immune surveillance of cancerous cells and influence the liver fibrosis that commonly precedes HCC. Marked over- or under-expression of circRNA expression in HCC, with correlating plasma concentrations, has diagnostic utility and assays of these RNAs are being developed as biomarkers of HCC. Although knowledge in the field has recently surged, the myriad of described effects suggests that not all may be vital to hepatocarcinogenesis. Nevertheless, investigation of the role of circRNAs is providing valuable insights that are likely to contribute to improved management of a serious and highly aggressive cancer.
    Language English
    Publishing date 2021-01-27
    Publishing country New Zealand
    Document type Journal Article ; Review
    ZDB-ID 2780784-8
    ISSN 2253-5969
    ISSN 2253-5969
    DOI 10.2147/JHC.S268291
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  8. Article ; Online: A convenient method to generate and maintain poly(A)-encoding DNA sequences required for in vitro transcription of mRNA.

    Arbuthnot, Patrick / Ely, Abdullah / Bloom, Kristie

    BioTechniques

    2019  Volume 66, Issue 1, Page(s) 37–39

    Abstract: Generating mRNA in vitro to encode therapeutic or cell-modifying proteins is rapidly gaining favor. An important factor that determines efficiency of translation from in vitro transcribed mRNA is the length of the 3' poly(A) sequence. However, ... ...

    Abstract Generating mRNA in vitro to encode therapeutic or cell-modifying proteins is rapidly gaining favor. An important factor that determines efficiency of translation from in vitro transcribed mRNA is the length of the 3' poly(A) sequence. However, reproducibly generating and maintaining templates from circular plasmids to have consistent lengths of the homo poly(A) sequences is challenging. The procedure reported here entails repeated restriction digestion with type IIS enzymes, ligation and circular plasmid propagation. The homopolymeric sequence of approximately 100 bp that is generated using the method is approximately equal to the number of 3' A residues found in the mRNA of  mammalian cells. Evaluating expression in vivo of a reporter transcript produced using this method showed efficient expression in vivo.
    MeSH term(s) DNA, Circular ; Deoxyribonucleases, Type II Site-Specific/genetics ; Deoxyribonucleases, Type II Site-Specific/metabolism ; Genetic Techniques ; Plasmids ; Poly A/genetics ; RNA, Messenger/genetics ; Transcription, Genetic
    Chemical Substances DNA, Circular ; RNA, Messenger ; Poly A (24937-83-5) ; endodeoxyribonuclease SapI (EC 3.1.21.-) ; endodeoxyribonuclease ScaI (EC 3.1.21.-) ; Deoxyribonucleases, Type II Site-Specific (EC 3.1.21.4)
    Language English
    Publishing date 2019-02-25
    Publishing country England
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 48453-2
    ISSN 1940-9818 ; 0736-6205
    ISSN (online) 1940-9818
    ISSN 0736-6205
    DOI 10.2144/btn-2018-0120
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  9. Article ; Online: A convenient method to generate and maintain poly(A)-encoding DNA sequences required for in vitro transcription of mRNA

    Patrick Arbuthnot / Abdullah Ely / Kristie Bloom

    BioTechniques, Vol 66, Iss 1, Pp 37-

    2019  Volume 39

    Abstract: Generating mRNA in vitro to encode therapeutic or cell-modifying proteins is rapidly gaining favor. An important factor that determines efficiency of translation from in vitro transcribed mRNA is the length of the 3′ poly(A) sequence. However, ... ...

    Abstract Generating mRNA in vitro to encode therapeutic or cell-modifying proteins is rapidly gaining favor. An important factor that determines efficiency of translation from in vitro transcribed mRNA is the length of the 3′ poly(A) sequence. However, reproducibly generating and maintaining templates from circular plasmids to have consistent lengths of the homo poly(A) sequences is challenging. The procedure reported here entails repeated restriction digestion with type IIS enzymes, ligation and circular plasmid propagation. The homopolymeric sequence of approximately 100 bp that is generated using the method is approximately equal to the number of 3′ A residues found in the mRNA of mammalian cells. Evaluating expression in vivo of a reporter transcript produced using this method showed efficient expression in vivo.
    Keywords in vitro transcription ; mRNA ; plasmid ; poly(A) ; type IIS restriction enzymes ; Biology (General) ; QH301-705.5
    Subject code 570
    Language English
    Publishing date 2019-01-01T00:00:00Z
    Publisher Future Science Ltd
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  10. Article ; Online: Silencing hepatitis B virus covalently closed circular DNA: The potential of an epigenetic therapy approach.

    Singh, Prashika / Kairuz, Dylan / Arbuthnot, Patrick / Bloom, Kristie

    World journal of gastroenterology

    2019  Volume 27, Issue 23, Page(s) 3182–3207

    Abstract: Global prophylactic vaccination programmes have helped to curb new hepatitis B virus (HBV) infections. However, it is estimated that nearly 300 million people are chronically infected and have a high risk of developing hepatocellular carcinoma. As such, ... ...

    Abstract Global prophylactic vaccination programmes have helped to curb new hepatitis B virus (HBV) infections. However, it is estimated that nearly 300 million people are chronically infected and have a high risk of developing hepatocellular carcinoma. As such, HBV remains a serious health priority and the development of novel curative therapeutics is urgently needed. Chronic HBV infection has been attributed to the persistence of the covalently closed circular DNA (cccDNA) which establishes itself as a minichromosome in the nucleus of hepatocytes. As the viral transcription intermediate, the cccDNA is responsible for producing new virions and perpetuating infection. HBV is dependent on various host factors for cccDNA formation and the minichromosome is amenable to epigenetic modifications. Two HBV proteins, X (HBx) and core (HBc) promote viral replication by modulating the cccDNA epigenome and regulating host cell responses. This includes viral and host gene expression, chromatin remodeling, DNA methylation, the antiviral immune response, apoptosis, and ubiquitination. Elimination of the cccDNA minichromosome would result in a sterilizing cure; however, this may be difficult to achieve. Epigenetic therapies could permanently silence the cccDNA minichromosome and promote a functional cure. This review explores the cccDNA epigenome, how host and viral factors influence transcription, and the recent epigenetic therapies and epigenome engineering approaches that have been described.
    MeSH term(s) DNA, Circular/genetics ; DNA, Viral/genetics ; Epigenesis, Genetic ; Hepatitis B/genetics ; Hepatitis B/prevention & control ; Hepatitis B virus/genetics ; Hepatitis B, Chronic/genetics ; Humans ; Liver Neoplasms ; Virus Replication
    Chemical Substances DNA, Circular ; DNA, Viral
    Language English
    Publishing date 2019-11-14
    Publishing country United States
    Document type Journal Article ; Review
    ZDB-ID 2185929-2
    ISSN 2219-2840 ; 1007-9327
    ISSN (online) 2219-2840
    ISSN 1007-9327
    DOI 10.3748/wjg.v27.i23.3182
    Database MEDical Literature Analysis and Retrieval System OnLINE

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