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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 α/β 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. [ABSTRACT FROM AUTHOR]

This work explores the potential use of cadmium‐based quantum dots (QDs) coupled to mycolic acids (MAs) as a fluorescent probe to detect anti‐MA antibodies which are biomarkers for tuberculosis (TB). The use of free MAs as antigens for the serodiagnosis of TB is known but has not been developed into a point of care test. This study focuses on the synthesis, solubility, and lateral flow of QDs coupled to MAs. Water‐soluble CdSe/ZnS QDs capped with l‐cysteine were synthesised and covalently coupled to MAs via amide linkages to form a water‐soluble fluorescent probe: MA‐CdSe/ZnS QDs. The MA‐CdSe/ZnS QDs showed broad absorption bands and coupling, confirmed by the presence of amide bonds in the Fourier‐transform infrared (FTIR) spectrum, resulting in a blue shift in fluorescence. Powder X‐ray diffraction (XRD) revealed a shift and increase in the number of peaks for MA‐CdSe/ZnS QDs relative to the L‐cys‐CdSe/ZnS QDs, suggesting that coupling changed the crystal structure. The average particle size of MA‐CdSe/ZnS QDs was ~3.0 nm. Visual paper‐based lateral flow of MA‐CdSe/ZnS QDs was achieved on strips of nitrocellulose membrane with both water and membrane blocking solution eluents. The highly fluorescent MA‐CdSe/ZnS QDs showed good water solubility and lateral flow, which are important properties for fluorescence sensing applications. [ABSTRACT FROM AUTHOR]

It has in recent years been reported that microemulsion (ME) delivery systems provide an opportunity to improve the efficacy of a therapeutic agent whilst minimising side effects and also offer the advantage of favourable treatment regimens. The prostate‐specific membrane antigen (PSMA) targeting agents PSMA‐11 and PSMA‐617, which accumulate in prostate tumours, allow for [68Ga]Ga3+‐radiolabelling and positron emission tomography/computed tomography (PET) imaging of PSMA expression in vivo. We herein report the formulation of [68Ga]Ga‐PSMA‐617 into a ME ≤40 nm including its evaluation for improved cellular toxicity and in vivo biodistribution. The [68Ga]Ga‐PSMA‐617‐ME was tested in vitro for its cytotoxicity to HEK293 and PC3 cells. [68Ga]Ga‐PSMA‐617‐ME was administered intravenously in BALB/c mice followed by microPET/computed tomography (CT) imaging and ex vivo biodistribution determination. [68Ga]Ga‐PSMA‐617‐ME indicated negligible cellular toxicity at different concentrations. A statistically higher tolerance towards the [68Ga]Ga‐PSMA‐617‐ME occurred at 0.125 mg/mL by HEK293 cells compared with PC3 cells. The biodistribution in wild‐type BALB/C mice showed the highest amounts of radioactivity (%ID/g) presented in the kidneys (31%) followed by the small intestine (10%) and stomach (9%); the lowest uptake was seen in the brain (0.5%). The incorporation of [68Ga]Ga‐PSMA‐617 into ME was successfully demonstrated and resulted in a stable nontoxic formulation as evaluated by in vitro and in vivo means. [ABSTRACT FROM AUTHOR]

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 α/β 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., Competing Interests: The authors have read the journal’s policy and have the following competing interests: Plant-produced chimaeric Orbivirus VLPs is patent protected (PCT/IB2017/052236, WO 2017/182958 A1, US 11,053,509 B2, ARIPO AP 6697 registered, invented by authors DR and MMO). The AHSV VP2 fusions proteins are protected by a patent application (PCT/IB2023/058808, invented by MMO and YL). This does not alter our adherence to PLOS ONE policies on sharing data and materials. There are no additional patents, products in development or marketed products associated with this research to declare, (Copyright: © 2024 O’Kennedy et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

This work explores the potential use of cadmium-based quantum dots (QDs) coupled to mycolic acids (MAs) as a fluorescent probe to detect anti-MA antibodies which are biomarkers for tuberculosis (TB). The use of free MAs as antigens for the serodiagnosis of TB is known but has not been developed into a point of care test. This study focuses on the synthesis, solubility, and lateral flow of QDs coupled to MAs. Water-soluble CdSe/ZnS QDs capped with l-cysteine were synthesised and covalently coupled to MAs via amide linkages to form a water-soluble fluorescent probe: MA-CdSe/ZnS QDs. The MA-CdSe/ZnS QDs showed broad absorption bands and coupling, confirmed by the presence of amide bonds in the Fourier-transform infrared (FTIR) spectrum, resulting in a blue shift in fluorescence. Powder X-ray diffraction (XRD) revealed a shift and increase in the number of peaks for MA-CdSe/ZnS QDs relative to the L-cys-CdSe/ZnS QDs, suggesting that coupling changed the crystal structure. The average particle size of MA-CdSe/ZnS QDs was ~3.0 nm. Visual paper-based lateral flow of MA-CdSe/ZnS QDs was achieved on strips of nitrocellulose membrane with both water and membrane blocking solution eluents. The highly fluorescent MA-CdSe/ZnS QDs showed good water solubility and lateral flow, which are important properties for fluorescence sensing applications., (© 2021 John Wiley & Sons Ltd.)

It has in recent years been reported that microemulsion (ME) delivery systems provide an opportunity to improve the efficacy of a therapeutic agent whilst minimising side effects and also offer the advantage of favourable treatment regimens. The prostate-specific membrane antigen (PSMA) targeting agents PSMA-11 and PSMA-617, which accumulate in prostate tumours, allow for [ 68 Ga]Ga 3+ -radiolabelling and positron emission tomography/computed tomography (PET) imaging of PSMA expression in vivo. We herein report the formulation of [ 68 Ga]Ga-PSMA-617 into a ME ≤40 nm including its evaluation for improved cellular toxicity and in vivo biodistribution. The [ 68 Ga]Ga-PSMA-617-ME was tested in vitro for its cytotoxicity to HEK293 and PC3 cells. [ 68 Ga]Ga-PSMA-617-ME was administered intravenously in BALB/c mice followed by microPET/computed tomography (CT) imaging and ex vivo biodistribution determination. [ 68 Ga]Ga-PSMA-617-ME indicated negligible cellular toxicity at different concentrations. A statistically higher tolerance towards the [ 68 Ga]Ga-PSMA-617-ME occurred at 0.125 mg/mL by HEK293 cells compared with PC3 cells. The biodistribution in wild-type BALB/C mice showed the highest amounts of radioactivity (%ID/g) presented in the kidneys (31%) followed by the small intestine (10%) and stomach (9%); the lowest uptake was seen in the brain (0.5%). The incorporation of [ 68 Ga]Ga-PSMA-617 into ME was successfully demonstrated and resulted in a stable nontoxic formulation as evaluated by in vitro and in vivo means., (© 2019 John Wiley & Sons, Ltd.)