Browsing by Author "Rutkowska, Daria A"

Now showing 1 - 7 of 7
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    Hepatitis B core-based virus-like particles: A platform for vaccine development in plants
    (2021-03) Vahdat, MM; Hemmati, F; Ghorbani, A; Rutkowska, Daria A; Afsharifar, A; Eskandari, MH; Rezaei, N; Niazi, A
    Virus-like particles (VLPs) are a class of structures formed by the self-assembly of viral capsid protein subunits and contain no infective viral genetic material. The Hepatitis B core (HBc) antigen is capable of assembling into VLPs that can elicit strong immune responses and has been licensed as a commercial vaccine against Hepatitis B. The HBc VLPs have also been employed as a platform for the presentation of foreign epitopes to the immune system and have been used to develop vaccines against, for example, influenza A and Foot-and-mouth disease. Plant expression systems are rapid, scalable and safe, and are capable of providing correct post-translational modifications and reducing upstream production costs. The production of HBc-based virus-like particles in plants would thus greatly increase the efficiency of vaccine production. This review investigates the application of plant-based HBc VLP as a platform for vaccine production.
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    Immunogenic profile of a plant-produced nonavalent African horse sickness viral protein 2 (VP2) vaccine in IFNAR-/-mice
    (2024-04) O’Kennedy, Martha M; Roth, Robyn; Ebersohn, K; Du Plessis, LH; Mamputha, Sipho; Rutkowska, Daria A; Du Preez, Ilse; Verschoor, JA; Lemmer, Yolandy
    A safe, highly immunogenic multivalent vaccine to protect against all nine serotypes of African horse sickness virus (AHSV), will revolutionise the AHS vaccine industry in endemic countries and beyond. Plant-produced AHS virus-like particles (VLPs) and soluble viral protein 2 (VP2) vaccine candidates were developed that have the potential to protect against all nine serotypes but can equally well be formulated as mono- and bi-valent formulations for localised outbreaks of specific serotypes. In the first interferon a/ß receptor knock-out (IFNAR-/-) mice trial conducted, a nine-serotype (nonavalent) vaccine administered as two pentavalent (5 µg per serotype) vaccines (VLP/VP2 combination or exclusively VP2), were directly compared to the commercially available AHS live attenuated vaccine. In a follow up trial, mice were vaccinated with an adjuvanted nine-serotype multivalent VP2 vaccine in a prime boost strategy and resulted in the desired neutralising antibody titres of 1:320, previously demonstrated to confer protective immunity in IFNAR-/- mice. In addition, the plant-produced VP2 vaccine performed favourably when compared to the commercial vaccine. Here we provide compelling data for a nonavalent VP2-based vaccine candidate, with the VP2 from each serotype being antigenically distinguishable based on LC-MS/MS and ELISA data. This is the first preclinical trial demonstrating the ability of an adjuvanted nonavalent cocktail of soluble, plant-expressed AHS VP2 proteins administered in a prime-boost strategy eliciting high antibody titres against all 9 AHSV serotypes. Furthermore, elevated T helper cells 2 (Th2) and Th1, indicative of humoral and cell-mediated memory T cell immune responses, respectively, were detected in mouse serum collected 14 days after the multivalent prime-boost vaccination. Both Th2 and Th1 may play a role to confer protective immunity. These preclinical immunogenicity studies paved the way to test the safety and protective efficacy of the plant-produced nonavalent VP2 vaccine candidate in the target animals, horses.
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    Plant-derived VLP: A worthy platform to produce vaccine against SARS-CoV-2
    (2021-11) Hemmati, F; Hemmati-Dinarvand, M; Karimzade, M; Rutkowska, Daria A; Eskandari, MH; Khanizadeh, S; Afsharifar, A
    After its emergence in late 2019 SARS-CoV-2 was declared a pandemic by the World Health Organization on 11 March 2020 and has claimed more than 2.8 million lives. There has been a massive global effort to develop vaccines against SARS-CoV-2 and the rapid and low cost production of large quantities of vaccine is urgently needed to ensure adequate supply to both developed and developing countries. Virus-like particles (VLPs) are composed of viral antigens that self-assemble into structures that mimic the structure of native viruses but lack the viral genome. Thus they are not only a safer alternative to attenuated or inactivated vaccines but are also able to induce potent cellular and humoral immune responses and can be manufactured recombinantly in expression systems that do not require viral replication. VLPs have successfully been produced in bacteria, yeast, insect and mammalian cell cultures, each production platform with its own advantages and limitations. Plants offer a number of advantages in one production platform, including proper eukaryotic protein modification and assembly, increased safety, low cost, high scalability as well as rapid production speed, a critical factor needed to control outbreaks of potential pandemics. Plant-based VLP-based viral vaccines currently in clinical trials include, amongst others, Hepatitis B virus, Influenza virus and SARS-CoV-2 vaccines. Here we discuss the importance of plants as a next generation expression system for the fast, scalable and low cost production of VLP-based vaccines.
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    Plant-produced Bluetongue chimaeric VLP vaccine candidates elicit serotype-specific immunity in sheep
    (Elsevier BV, 2019-09) Mokoena, NB; Moetlhoa, B; Rutkowska, Daria A; Mamputha, Sipho; Dibakwane, VS; Tsekoa, Tsepo L; O’Kennedy, Martha M
    Bluetongue (BT) is a hemorrhagic non-contagious, biting midge-transmitted disease of wild and domestic ruminants that is caused by bluetongue virus (BTV). Annual vaccination plays a pivotal role in BT disease control in endemic regions. Due to safety concerns of the current BTV multivalent live attenuated vaccine (LAV), a safe efficacious new generation subunit vaccine such as a plant-produced BT virus-like particle (VLP) vaccine is imperative. Previously, homogenous BTV serotype 8 (BTV-8) VLPs were successfully produced in Nicotiana benthamiana plants and provided protective immunity in sheep. In this study, combinations of BTV capsid proteins from more than one serotype were expressed and assembled to form chimaeric BTV-3 and BTV-4 VLPs in N. benthamiana plants. The assembled homogenous BTV-8, as well as chimaeric BTV-3 and chimaeric BTV-4 VLP serotypes, were confirmed by SDS-PAGE, Transmission Electron microscopy (TEM) and protein confirmation using liquid chromatography-mass spectrometry (LC-MS/MS) based peptide sequencing. As VP2 is the major determinant eliciting protective immunity, the percentage coverage and number of unique VP2 peptides detected in assembled chimaeric BT VLPs were used as a guide to assemble the most appropriate chimaeric combinations. Both plant-produced chimaeric BTV-3 and BTV-4 VLPs were able to induce long-lasting serotype-specific neutralizing antibodies equivalent to the monovalent LAV controls. Antibody levels remained high to the end of the trial. Combinations of homogenous and chimaeric BT VLPs have great potential as a safe, effective multivalent vaccine with the ability to distinguish between vaccinated and infected individuals (DIVA) due to the absence of non-structural proteins.
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    Protective immunity of plant-produced African horse sickness virus serotype 5 chimaeric virus-like particles (VLPs) and viral protein 2 (VP2) vaccines in IFNAR-/- mice
    (2022-08) O'Kennedy, Maretha M; Coetzee, P; Koekemoer, O; Du Plessis, L; Lourens, CW; Kwezi, Lusisizwe; Du Preez, Ilse; Mamputha, Sipho; Rutkowska, Daria A; Lemmer, Yolandy
    Next generation vaccines have the capability to contribute to and revolutionise the veterinary vaccine industry. African horse sickness (AHS) is caused by an arbovirus infection and is characterised by respiratory distress and/or cardiovascular failure and is lethal to horses. Mandatory annual vaccination in endemic areas curtails disease occurrence and severity. However, development of a next generation AHSV vaccine, which is both safe and efficacious, has been an objective globally for years. In this study, both AHSV serotype 5 chimaeric virus-like particles (VLPs) and soluble viral protein 2 (VP2) were successfully produced in Nicotiana benthamiana ΔXT/FT plants, partially purified and validated by gel electrophoresis, transmission electron microscopy and liquid chromatography-mass spectrometry (LC-MS/MS) based peptide sequencing before vaccine formulation. IFNAR-/- mice vaccinated with the adjuvanted VLPs or VP2 antigens in a 10 µg prime-boost regime resulted in high titres of antibodies confirmed by both serum neutralising tests (SNTs) and enzyme-linked immunosorbent assays (ELISA). Although previous studies reported high titres of antibodies in horses when vaccinated with plant-produced AHS homogenous VLPs, this is the first study demonstrating the protective efficacy of both AHSV serotype 5 chimaeric VLPs and soluble AHSV-5 VP2 as vaccine candidates. Complementary to this, coating ELISA plates with the soluble VP2 has the potential to underpin serotype-specific serological assays.
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    Safety and immunogenicity of plant-produced African horse sickness virus-like particles in horses
    (BioMed Central, 2018-10) Dennis, SJ; O'Kennedy, Maretha M; Rutkowska, Daria A; Tsekoa, Tsepo L; Lourens, Carina W; Hitzeroth, II; Meyers, AE; Rybicki, EP
    African horse sickness (AHS) is caused by multiple serotypes of the dsRNA AHSV and is a major scourge of domestic equids in Africa. While there are well established commercial live attenuated vaccines produced in South Africa, risks associated with these have encouraged attempts to develop new and safer recombinant vaccines. Previously, we reported on the immunogenicity of a plant-produced AHS serotype 5 virus-like particle (VLP) vaccine, which stimulated high titres of AHS serotype 5-specific neutralizing antibodies in guinea pigs. Here, we report a similar response to the vaccine in horses. This is the first report demonstrating the safety and immunogenicity of plant-produced AHS VLPs in horses.
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    The use of plant viral nanoparticles in cancer biotherapy—A review
    (2024-12) Komane, MD; Kayoka-Kabongo, PN; Rutkowska, Daria A
    Cancer is a major global health problem that poses significant challenges. Conventional cancer therapies often have severe side effects, necessitating the development of novel therapeutic approaches that are more effective and less toxic. The utilization of plant viral nanoparticles is one of the more promising strategies for cancer biotherapy. Plant viral nanoparticles exhibit advantageous properties, including safety, high stability, rapid production and scalability, biocompatibility and biodegradability, structural uniformity, inherent immunogenicity, ease of modification and high update efficacy as well as lower cost implications, making them attractive vehicles for health applications. Various studies have demonstrated the efficacy of plant viral nanoparticles in targeted therapeutic drug/molecule delivery, tumor imaging and immunotherapy, highlighting their potential as a versatile platform for cancer biotherapy. The drawbacks of plant viral nanoparticles include their perceived ability to induce a hypersensitive/allergic immune response, nonwell-defined regulatory approval processes as well as the reluctance of pharmaceutical companies to adapt their manufacturing processes to facilitate plant-based expression. This review discusses applications of plant virus-derived nanoparticles in cancer therapeutics and prospects for translating these findings into clinical practice.