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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Investigation of the immunostimulatory activity and vaccine potential of lipid encapsulated plasmid DNA and oligodeoxynucleoties

Wilson, Kaley 05 1900 (has links)
DNA vaccines offer unique promise as a means of generating immunity against infectious and malignant disease. Unfortunately a number of obstacles, including rapid degradation of naked plasmid DNA (pDNA), poor cellular uptake by antigen presenting cells (APCs) and subsequent low levels of gene expression have limited the ability of DNA vaccines to raise sufficient immune responses towards the target antigen. This thesis is focused on investigating the immunostimulatory potential of liposomal nanoparticulate (LN) formulations of pDNA (stabilized plasmid lipid particles; SPLP) and cytosine-guanine oligodeoxynucleotides (CpG-ODN; LN CpG-ODN), and examining their ability to act together as a non-viral DNA vaccine in attempt to address the shortcomings of current DNA vaccine approaches. One focus of this thesis concerns investigating the immunostimulatory activity of LN formulations of CpG-ODN and pDNA. It is shown that despite dramatic differences in pharmacokinetics and biodistribution of LN CpG-ODN following intravenous (i.v.) and subcutaneous (s.c.) administration the resultant immune response is very similar, which is concluded to be due to the intrinsic ability of APCs to sequester LN CpG- ODN. In addition, it is demonstrated that lipid encapsulation dramatically enhances the immunostimulatory potential of pDNA and it is observed that SPLP maintains immunostimulatory activity in Toll-like receptor 9 (TLR9) knock-out mice. Together theses findings highlight the need for DNA-based therapies to consider both TLR9-dependent and -independent immunostimulatory activities of pDNA when constructing non-viral vectors. Furthermore, a new role for SPLP as a non-viral gene delivery vehicle for the generation of a systemically administered genetic vaccine in the presence of LN CpG-ODN is introduced. The ability of vaccination with SPLP to act prophylactically, to protect mice from tumour challenge, and therapeutically, in a novel vaccination strategy where the antigen is expressed at the tumour site as a result of SPLP-mediated transfection, is explored, demonstrating that in the presence of LN CpG-ODN SPLP possesses potential as a non-viral delivery system for DNA-based cancer vaccines. In summary, this work represents a substantial advance in the understanding of the immunostimulatory potential of both SPLP and LN CpG-ODN and provides insight into their ability to work together as a non-viral DNA vaccine.
2

Immunostimulatory effects and delivery of oligodeoxynucleotides containing CpG motifs (CpG-ODN) in neonatal broiler chickens

Joze Taghavi Shirazi, Azita 30 April 2008
Oligodeoxynucleotides containing CpG motifs (CpG-ODN) have been shown to stimulate the innate immune system against a variety of bacterial, viral, and protozoan infections in a variety of vertebrate species. The objectives of this study were to investigate the immunostimulatory effect of CpG-ODN against Salmonella Typhimurium infection and the formulation and delivery of CpG-ODN by the in ovo route. Day-old broiler chicks or embryonated eggs (day 18th of incubation) received either 50 g of CpG-ODN, 50 g of non-CpG-ODN, or saline. At day four-post hatch, all birds were subcutaneously inoculated by Salmonella Typhimurium. Clinical signs, pathology, bacterial isolations from the air sacs, and mortality were observed for ten days following challenge. The survival rate of the birds that received CpG-ODN via in ovo or in vivo treatments was significantly higher than the control group. Salmonella Typhimurium level in the peripheral blood and pathology were significantly lower (p < 0.001) in CpG-ODN group compared to the control group. In order to investigate the effect of formulation of CpG-ODN, embryonated eggs (day 18th of incubation) were inoculated with either 50 g of CpG-ODN alone or CpG-ODN formulated with polyphosphazene, liposome, or Emulsigen®. Four days after administration of CpG-ODN formulations, the birds were challenged with E. coli by subcutaneous injection. Clinical signs, pathology, bacterial isolations from the air sacs, and mortality were observed for seven days following challenge. The birds that received either CpG-ODN or CpG-ODN formulated with polyphosphazene had significantly higher survival rates (30 and 60%) compared to the birds in groups receiving either non-CpG-ODN or saline. Bacterial loads in the air sacs were lower in groups treated with formulated CpG-ODN compared to the CpG-ODN alone or control groups. However, formulation of CpG-ODN with liposomes or Emulsigen® did not increase the immunoprotective effect against E. coli infection. We showed that treatment with CpG-ODN protects neonatal chickens against an intracellular bacterial infection and that co-treatment of CpG-ODN with polyphosphazene enhances the immunoprotective effect of CpG-ODN.
3

Immunostimulatory effects and delivery of oligodeoxynucleotides containing CpG motifs (CpG-ODN) in neonatal broiler chickens

Joze Taghavi Shirazi, Azita 30 April 2008 (has links)
Oligodeoxynucleotides containing CpG motifs (CpG-ODN) have been shown to stimulate the innate immune system against a variety of bacterial, viral, and protozoan infections in a variety of vertebrate species. The objectives of this study were to investigate the immunostimulatory effect of CpG-ODN against Salmonella Typhimurium infection and the formulation and delivery of CpG-ODN by the in ovo route. Day-old broiler chicks or embryonated eggs (day 18th of incubation) received either 50 g of CpG-ODN, 50 g of non-CpG-ODN, or saline. At day four-post hatch, all birds were subcutaneously inoculated by Salmonella Typhimurium. Clinical signs, pathology, bacterial isolations from the air sacs, and mortality were observed for ten days following challenge. The survival rate of the birds that received CpG-ODN via in ovo or in vivo treatments was significantly higher than the control group. Salmonella Typhimurium level in the peripheral blood and pathology were significantly lower (p < 0.001) in CpG-ODN group compared to the control group. In order to investigate the effect of formulation of CpG-ODN, embryonated eggs (day 18th of incubation) were inoculated with either 50 g of CpG-ODN alone or CpG-ODN formulated with polyphosphazene, liposome, or Emulsigen®. Four days after administration of CpG-ODN formulations, the birds were challenged with E. coli by subcutaneous injection. Clinical signs, pathology, bacterial isolations from the air sacs, and mortality were observed for seven days following challenge. The birds that received either CpG-ODN or CpG-ODN formulated with polyphosphazene had significantly higher survival rates (30 and 60%) compared to the birds in groups receiving either non-CpG-ODN or saline. Bacterial loads in the air sacs were lower in groups treated with formulated CpG-ODN compared to the CpG-ODN alone or control groups. However, formulation of CpG-ODN with liposomes or Emulsigen® did not increase the immunoprotective effect against E. coli infection. We showed that treatment with CpG-ODN protects neonatal chickens against an intracellular bacterial infection and that co-treatment of CpG-ODN with polyphosphazene enhances the immunoprotective effect of CpG-ODN.
4

Investigation of the immunostimulatory activity and vaccine potential of lipid encapsulated plasmid DNA and oligodeoxynucleoties

Wilson, Kaley 05 1900 (has links)
DNA vaccines offer unique promise as a means of generating immunity against infectious and malignant disease. Unfortunately a number of obstacles, including rapid degradation of naked plasmid DNA (pDNA), poor cellular uptake by antigen presenting cells (APCs) and subsequent low levels of gene expression have limited the ability of DNA vaccines to raise sufficient immune responses towards the target antigen. This thesis is focused on investigating the immunostimulatory potential of liposomal nanoparticulate (LN) formulations of pDNA (stabilized plasmid lipid particles; SPLP) and cytosine-guanine oligodeoxynucleotides (CpG-ODN; LN CpG-ODN), and examining their ability to act together as a non-viral DNA vaccine in attempt to address the shortcomings of current DNA vaccine approaches. One focus of this thesis concerns investigating the immunostimulatory activity of LN formulations of CpG-ODN and pDNA. It is shown that despite dramatic differences in pharmacokinetics and biodistribution of LN CpG-ODN following intravenous (i.v.) and subcutaneous (s.c.) administration the resultant immune response is very similar, which is concluded to be due to the intrinsic ability of APCs to sequester LN CpG- ODN. In addition, it is demonstrated that lipid encapsulation dramatically enhances the immunostimulatory potential of pDNA and it is observed that SPLP maintains immunostimulatory activity in Toll-like receptor 9 (TLR9) knock-out mice. Together theses findings highlight the need for DNA-based therapies to consider both TLR9-dependent and -independent immunostimulatory activities of pDNA when constructing non-viral vectors. Furthermore, a new role for SPLP as a non-viral gene delivery vehicle for the generation of a systemically administered genetic vaccine in the presence of LN CpG-ODN is introduced. The ability of vaccination with SPLP to act prophylactically, to protect mice from tumour challenge, and therapeutically, in a novel vaccination strategy where the antigen is expressed at the tumour site as a result of SPLP-mediated transfection, is explored, demonstrating that in the presence of LN CpG-ODN SPLP possesses potential as a non-viral delivery system for DNA-based cancer vaccines. In summary, this work represents a substantial advance in the understanding of the immunostimulatory potential of both SPLP and LN CpG-ODN and provides insight into their ability to work together as a non-viral DNA vaccine.
5

Investigation of the immunostimulatory activity and vaccine potential of lipid encapsulated plasmid DNA and oligodeoxynucleoties

Wilson, Kaley 05 1900 (has links)
DNA vaccines offer unique promise as a means of generating immunity against infectious and malignant disease. Unfortunately a number of obstacles, including rapid degradation of naked plasmid DNA (pDNA), poor cellular uptake by antigen presenting cells (APCs) and subsequent low levels of gene expression have limited the ability of DNA vaccines to raise sufficient immune responses towards the target antigen. This thesis is focused on investigating the immunostimulatory potential of liposomal nanoparticulate (LN) formulations of pDNA (stabilized plasmid lipid particles; SPLP) and cytosine-guanine oligodeoxynucleotides (CpG-ODN; LN CpG-ODN), and examining their ability to act together as a non-viral DNA vaccine in attempt to address the shortcomings of current DNA vaccine approaches. One focus of this thesis concerns investigating the immunostimulatory activity of LN formulations of CpG-ODN and pDNA. It is shown that despite dramatic differences in pharmacokinetics and biodistribution of LN CpG-ODN following intravenous (i.v.) and subcutaneous (s.c.) administration the resultant immune response is very similar, which is concluded to be due to the intrinsic ability of APCs to sequester LN CpG- ODN. In addition, it is demonstrated that lipid encapsulation dramatically enhances the immunostimulatory potential of pDNA and it is observed that SPLP maintains immunostimulatory activity in Toll-like receptor 9 (TLR9) knock-out mice. Together theses findings highlight the need for DNA-based therapies to consider both TLR9-dependent and -independent immunostimulatory activities of pDNA when constructing non-viral vectors. Furthermore, a new role for SPLP as a non-viral gene delivery vehicle for the generation of a systemically administered genetic vaccine in the presence of LN CpG-ODN is introduced. The ability of vaccination with SPLP to act prophylactically, to protect mice from tumour challenge, and therapeutically, in a novel vaccination strategy where the antigen is expressed at the tumour site as a result of SPLP-mediated transfection, is explored, demonstrating that in the presence of LN CpG-ODN SPLP possesses potential as a non-viral delivery system for DNA-based cancer vaccines. In summary, this work represents a substantial advance in the understanding of the immunostimulatory potential of both SPLP and LN CpG-ODN and provides insight into their ability to work together as a non-viral DNA vaccine. / Medicine, Faculty of / Biochemistry and Molecular Biology, Department of / Graduate
6

The Potential of Coelomocyte Chemotaxis as an Immune Biomarker in the Earthworm, Lumbricus terrestris

Mota, Jennifer A. 12 1900 (has links)
Coelomocyte migration responses, both random and chemotatic, were examined in the earthworm Lumbricus terrestris. Coelomocyte random migration patterns towards non-stimulatory, non-chemotatic solutions were described. Migration responses to immunostimulatory agents lipopolysaccharides (LPS), N-formly-methionyl-leucyl-phenylalanine (FMLP), sheep erythrocytes, Saccharomyces cerevisiae, Aeromonas hydrophila, Eisenia fetida and Rhabditis pellio were characterized. Chemotaxis was reported to LPS, FMLP, sheep erythrocytes, S. cerivesae and E. fetida. Bio-indicator potential of chemotaxis is discussed relative to variability in migration responses.
7

Elucidation and optimization of the interaction of nanostructured DNA and immune cells. / ナノ構造化DNAと免疫細胞との相互作用の解明と最適化に関する研究

Ohtsuki, Shozo 26 March 2018 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(薬科学) / 甲第21045号 / 薬科博第88号 / 新制||薬科||10(附属図書館) / 京都大学大学院薬学研究科薬科学専攻 / (主査)教授 髙倉 喜信, 教授 山下 富義, 教授 小野 正博 / 学位規則第4条第1項該当 / Doctor of Pharmaceutical Sciences / Kyoto University / DFAM
8

Fungal Biomass Valorization for Obtaining Functional Food-Related Materials / Valorización de biomasa fúngica para la obtención de materiales funcionales de interés en alimentación

Pérez Bassart, Zaida 22 September 2024 (has links)
Tesis por compendio / [ES] El objetivo de esta tesis doctoral ha sido proporcionar conocimientos fundamentales y prácticos relacionados con la valorización de la biomasa de setas, para comprender la relación estructura-funcionalidad de extractos acuosos ricos en ß-glucanos, en términos de capacidad inmunorreguladora, antioxidante y antiviral, así como las propiedades tecnológicas (gelificantes y emulsionantes). El objetivo de esta tesis doctoral también ha sido explorar la viabilidad de dicha biomasa en el desarrollo de materiales compostables para el envasado de alimentos. Inicialmente, se aplicó un proceso de extracción secuencial, que implicaba varios tratamientos consecutivos tanto acuosos con y sin temperatura como alcalinos, aplicados a setas de gran consumo (P. ostreatus, L. edodes y G. frondosa), con la finalidad de comprender cómo las diferencias iniciales en la composición y la arquitectura de la pared celular afectaban a la extracción de ß-glucano. A partir de los resultados obtenidos, se analizó en profundidad la aplicación potencial de extractos acuosos, ricos en ß-glucanos, del género Pleurotus, explorando cómo la composición de los extractos y la complejidad estructural de ß-glucanos afectaban a su capacidad inmunorreguladora. Los resultados evidenciaron que tanto Pleurotus ostreatus como sus estipes mostraron los mejores resultados, con una actividad inmunoestimulante mucho mayor que las otras especies de Pleurotus exploradas. En la segunda parte de esta tesis, se evaluaron las propiedades funcionales (antivirales y antioxidantes) y tecnológicas (gelificantes y emulsionantes) de los extractos acuosos de ß-glucano, purificados y sin purificar, de Pleurotus ostreatus y sus estipes. El proceso de purificación, como era de esperar, incrementó el porcentaje en carbohidratos (con un mayor aumento en los estipes), lo que se tradujo en una mayor viscosidad y capacidad gelificante. Además, el extracto obtenido de los estipes mostró una fuerte actividad antiviral frente a norovirus murino, probablemente atribuida a la mayor complejidad estructural de sus ß-glucanos. Aunque la presencia de proteínas en los extractos acuosos de ß-glucanos potenció sus propiedades emulsionantes, esta propiedad fue dependiente de la accesibilidad de la proteína para adsorberse en la interfase O/W, lo que también afectó a la viscosidad de las emulsiones resultantes. La quitina y los ß-glucanos son dos de los principales carbohidratos de las setas, y tienen un gran potencial en la formación de materiales de envasado. En la última parte de esta tesis, se investigó la viabilidad de la biomasa de residuos de setas para desarrollar materiales de envasado de alimentos biodegradables y compostables. Los resultados mostraron que la composición de la biomasa de champiñón y las temperaturas de procesado tuvieron un impacto en las propiedades fisicoquímicas de los films desarrollados y, todas fueron biodesintegrables en condiciones de compostaje según la norma ISO 20200. Por lo tanto, esta tesis doctoral representa un importante avance en la valorización de la biomasa de setas (seta entera y estipes) y pone de relieve su idoneidad para desarrollar nuevos ingredientes funcionales y materiales de envasado para aplicaciones alimentarias y de envasado de alimentos. / [CA] L'objectiu d'aquesta tesi ha sigut proporcionar els coneixements fonamentals i pràctics relacionats amb la valorització de la biomassa de bolets, per a comprendre la relació estructura-funcionalitat d'extractes aquosos rics en ß-glucans, en termes de capacitat immunoreguladora, antioxidant i antiviral, així com de les propietats tecnològiques (gelificants i emulsionants). L'objectiu d'aquesta tesi ha estat també l'exploració de la viabilitat d'aquesta biomassa pel desenvolupament de materials compostables per a l'envasat d'aliments. Inicialment, es va aplicar un procés d'extracció seqüencial, que implicava diversos tractaments consecutius, tant aquosos amb temperatura i sense, com alcalins, aplicats a bolets de gran consum (P. ostreatus, L. edodes i G. frondosa), per tal de comprendre com les diferències inicials en la composició i l'arquitectura de la paret cel·lular afectaven l'extracció de ß-glucà. A partir dels resultats obtinguts, es va analitzar en profunditat la potencial aplicació d'extractes aquosos, rics en ß-glucans, del gènere Pleurotus, explorant així com la composició dels extractes i la complexitat structural dels ß-glucans afectaven a la seua capacitat immunoreguladora. Els resultats van evidenciar que tant Pleurotus ostreatus com les seues estipes mostraren els millors resultats, amb una activitat immunoestimulant molt més gran que la obtinguda per a les altres espècies de Pleurotus explorades. A la segona part d'aquesta tesi, es van avaluar les propietats funcionals (antivirals i antioxidants) i tecnològiques (gelificants i emulsionants) dels extractes aquosos de ß-glucà, purificats i sense purificar, de Pleurotus ostreatus i les seues estipes. El procés de purificació, com calia esperar, va incrementar el percentatge en carbohidrats (amb un major augment en els estipes), cosa que es va traduir en una major viscositat i capacitat gelificant. A més, l'extracte obtingut dels estipes va mostrar una forta activitat antiviral contra norovirus murí, probablement atribuïda a la complexitat estructural més gran dels seus ß-glucans. Tot i que la presència de proteïnes en els extractes aquosos de ß-glucans va potenciar les seues propietats emulsionants, aquesta propietat va ser dependent de l'accessibilitat de la proteïna per adsorbir-se a la interfase O/W, cosa que també va afectar la viscositat de les emulsions resultants. La quitina i els ß-glucans són dos dels principals carbohidrats dels bolets, i tenen un gran potencial en la formació de materials d'envasament. Així, a la darrera part d'aquesta tesi, es va investigar la viabilitat de la biomassa de residus de bolets per desenvolupar materials biodegradables i compostables d'envasat d'aliments. Els resultats van mostrar que la composició de la biomassa de bolets i les temperatures de processament van tenir un impacte en les propietats fisicoquímiques de les pel·lícules desenvolupades i, totes elles van ser biodesintegrables en condicions de compostatge segons la norma ISO 20200. Per tant, aquesta tesi doctoral representa un important pas endavant en la valorització de la biomassa de bolets (sencers i estipes) i posa en relleu la seua idoneïtat per desenvolupar nous ingredients funcionals i materials d'envasament per a aplicacions alimentàries i d'envasat d'aliments. / [EN] This doctoral thesis was aimed at providing fundamental and practical knowledge related to the valorisation of underexploited mushroom biomass, in order to understand the structure-function relationship of ß-glucan aqueous extracts in terms of immunoregulatory, antioxidant and antiviral capacity as well as technological (gelling and emulsifying) properties. It was also the aim of this PhD thesis to explore the feasibility of mushroom biomass to develop compostable food packaging materials. Initially, a sequential fractionation process, involving several consecutive cold or hot aqueous and alkaline treatments, was applied to widely consumed mushrooms (P. ostreatus, L. edodes and G. frondosa), in order to understand how the initial differences in composition and cell wall architecture affected ß-glucan extraction. Based on the results, the potential application of ¿-glucan aqueous extracts from Pleurotus genus was deeply analysed, thus exploring how the composition of the extracts and structural complexity of ¿-glucans affected their immunoregulatory capacity. The results evidenced that both Pleurotus ostreatus and its stipes showed the best results, with a much higher immunostimulant activity than the other explored Pleurotus species. In the second part of the thesis, functional (antiviral and antioxidant) and technological (gelling and emulsifying) properties of purified and unpurified¿¿-glucan aqueous extracts from Pleurotus ostreatus and its stipes were evaluated. The purification process, as expected, increased the carbohydrates content (greater in those obtained from the stipes), which resulted in a greater viscosity and gelling capacity. Furthermore, the extract obtained from the stipes showed a strong antiviral activity against murine norovirus, probably ascribed to the higher structural complexity of ß-glucans. Although the presence of proteins in the ¿-glucan aqueous extracts enhanced their emulsifying properties, it depended on the accessibility of the protein to adsorb at the O/W interphase, which also affected the viscosity of the resulting emulsions. Chitin and ß-glucans are two of the major carbohydrates of mushrooms, having a great potential in the formation of packaging materials. Thus, in the last part of this thesis, the feasibility of mushroom waste biomass to develop biodegradable and compostable food packaging materials was investigated. The results showed that the composition of mushroom biomass and the processing temperatures had an impact on the physicochemical properties of the developed films and, all of them were biodisintegrated under composting conditions according to ISO 20200. Therefore, this PhD thesis represents a significant step forward in the understanding of the discarded mushroom biomass (whole biomass and stipes) for valorisation purposes and highlights its suitability to develop new cost-efficient functional ingredients and packaging materials for food and food packaging applications. / This work was performed with the financial support of the CIEN project BIOPRO from “Centro para el Desarrollo Tecnológico Industrial” (CDTI), Ministry of Science and Innovation, Government of Spain. The Accreditation as Center of Excellence Severo Ochoa CEX2021-001189-S funded by MCIN/AEI/10.13039/501100011033 is also fully acknowledged. his study forms part of the AGROALNEXT programme and was supported by MCIN with funding from European Union NextGenerationEU (PRTR-C17. I1) and by Generalitat Valenciana. Synchrotron experiments were performed at NCD beamline at ALBA Synchrotron with the collaboration of ALBA staff (proposal 2,022,025,569). IF was supported by a postdoctoral contract grant for the requalification of the Spanish university system from the Ministry of Universities of the Government of Spain, financed by the European Union (NextGeneration EU) (MS21-006). / Pérez Bassart, Z. (2024). Fungal Biomass Valorization for Obtaining Functional Food-Related Materials [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/203841 / Compendio

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