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1
Fuller, Maria. "A gene transfer system derived from human immunodeficiency virus type 1 (HIV-1)." Title page, table of contents, list of abbreviations and epitome only, 2001. http://web4.library.adelaide.edu.au/theses/09PH/09phf9669.pdf.
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Grzybowski, Brad. "A pseudotyped viral vector : hPIV3-HIV-1." Thesis, Georgia Institute of Technology, 2003. http://hdl.handle.net/1853/20932.
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Gelinas, Jean-Francois. "Enhancement of lentiviral vector production through alteration of virus-cell interactions." Thesis, University of Oxford, 2016. https://ora.ox.ac.uk/objects/uuid:9921b8b4-e2b5-4eec-9efc-6036765c8d55.
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Gene therapy is the introduction or alteration of genetic material with the intention to treat disease. To support this aim, viruses have been modified, with elements linked to viral pathogenicity removed from their genome and replaced by the genetic material to be delivered. Gene therapy vectors based on lentiviruses have many advantages, such as the ability to transduce non-dividing cells and to target specific cell types via pseudotyping. They have been successfully used in ex vivo clinical trials for several haematopoietic stem cell disorders. Lentiviral vectors, however, suffer from substantially lower titres than the more popular adeno-associated virus (AAV)-based vectors and therefore have limited applicability for in vivo gene therapy which requires much greater quantities of virus. The main aim of this thesis was to investigate strategies to improve lentiviral vector productivity during manufacture, in order to increase the likelihood of lentiviruses being adopted for disease treatment. Initial experiments were based on the lentiviral vector manufacturing process currently being developed by the United Kingdom Cystic Fibrosis Gene Therapy Consortium for the generation of highly concentrated, purified lentivirus for clinical use. Supplementation of FreeStyle 293 Expression Medium used during upstream processing was attempted, but none of the assessed supplements led to significant increases in lentiviral vector production. Investigation into intrinsic immunity to viral infection indicated that over-expression of the protein kinase RNA-activated (PKR) led to lower production titres, but over-expression of its inhibitors was not successful at increasing titres. The focus then shifted to reducing, or 'knocking-down', inhibitory factors present in the host cells, which could adversely affect viral titres. Investigation of the published HIV-1 literature revealed a possible 152 candidate inhibitory factors described as having a negative impact on HIV-1 replication in the late stages of the life cycle of the virus. A novel siRNA screen was developed to assess the effect of âknock-down' of inhibitory factors on lentiviral vector titre. Application of the screen to 89 candidate inhibitory factors identified nine genes which, when knocked-down, resulted in increased lentiviral vector production by more than 40%. Further work will be necessary to understand the role of the inhibitory factors in lentiviral vector production, but novel cell lines in which genes encoding these factors have been permanently deleted from producer cells could lead to higher titres, reducing costs in the manufacture of lentiviral vectors and making in vivo gene therapy more feasible from a health economics perspective.
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Elmén, Joacim. "Nucleic acid based therapeutic approaches /." Stockholm, 2005. http://diss.kib.ki.se/2005/91-7140-047-8/.
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Morin, Nicolas. "Expression of mutated HIV-1 Gag-Pol proteins and their effects on virus replication and infectiousness, implications for gene therapy." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape16/PQDD_0015/MQ37152.pdf.
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Mackler, Randi Michelle. "Understanding Prototype Foamy Virus Integrase Site Selection, Activity, and Stability." The Ohio State University, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=osu1542306356468134.
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ALVES, Neyla Maria Pereira. "Influência de polimorfismos de base única (SNPs) no gene do receptor de vitamina D (VDR) na resposta à Terapia Antirretroviral (TARV) de pessoas vivendo com Vírus da Imunodeficiência Humana tipo 1 (HIV-1)." Universidade Federal de Pernambuco, 2015. https://repositorio.ufpe.br/handle/123456789/16120.
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HIV/aids (Vírus da Imunodeficiência Humana/aids) é considerado uma pandemia, envolvendo mais de 70 milhões de infecções e 35 milhões de mortes desde o primeiro relato na década de 80. O HIV tipo 1 (HIV-1) infecta principalmente linfócitos T CD4+ e linhagens de macrófagos, tendo sua patogenicidade definida pela depleção de LT CD4+. Além disso, a condição de infecção por HIV-1 é bastante complexa e dependente de diversos fatores relacionados à variabilidade dos indivíduos no que diz respeito à suscetibilidade à infecção e à progressão para a aids, sendo observada a ativação imunológica generalizada. Envolvida na modulação das respostas imunes inata e adaptativa encontra-se a vitamina D, que desempenha papel no metabolismo mineral e apresenta efeito pleiotrópico no crescimento e diferenciação celulares. Seus efeitos imunológicos são dados a partir da ligação com o receptor de vitamina D (VDR) de diversas células, regulando a liberação de citocinas, a função e proliferação de linfócitos T e a produção de peptídeos antimicrobianos como a catelicidina. O VDR atua modulando a ação dessa vitamina induzindo a resposta imune local e variações genéticas presentes no gene codificador do VDR podem levar à diminuição de sua atividade e, consequentemente, ao prejuízo para o papel da vitamina D. Nos indivíduos infectados pelo HIV, os níveis de deficiência dessa vitamina são altos e fatores como raça, insuficiência renal, pouca exposição à luz ultravioleta e exposição as drogas anti-HIV, como o Efavirenz, estão associados a essa deficiência, respectivamente, sendo determinantes para a susceptibilidade à infecção pelo HIV e a predição da progressão da doença. Sendo assim, neste trabalho foram estudados seis polimorfismos de base única (SNPs) (rs3890733, rs476048, rs1540339, rs2248098, rs2228570 e rs11568820) presentes no gene do receptor de vitamina D (VDR) e sua influência na resposta dos pacientes à Terapia Antirretroviral (TARV). Foram recrutados 107 pacientes acompanhados e tratados no Hospital Dia do Instituto de Medicina Integral Professor Fernando Figueira (IMIP), subdivididos em quatro grupos: I- Sucesso Terapêutico, II- Falha Terapêutica, III- Sucesso Imunológico, IV- Falha Imunológica, e analisadas variáveis clínicas e epidemiológicas, como gênero, idade, peso e etnia. Não foram observadas associações estatísticas nas análises isoladas entre os polimorfismos dos genes do VDR com a falha virológica ou a resposta imunológica. Porém, nas análises multivariadas, o genótipo C/C do rs1540339 mostrou-se associado com o gênero no sucesso virológico (OR=0,08, p=0,04). Em adição, a análise envolvendo peso, etnia e gênero e o rs3890733 mostrou associação com a resposta imunológica para os genótipos C/C e T/T no modelo sobredominante (OR=0,21, p=0,024). Os resultados indicam a importância do receptor de vitamina D em infecções por HIV-1 e poderão contribuir para o entendimento da variabilidade das respostas dos pacientes à TARV.
HIV/aids (Human Immunodeficiency Virus/aids) is considered a pandemic, involving more than 70 million infections and 35 million deaths since the first report in the 80’s. HIV type 1 (HIV-1) infects mainly T lymphocytes CD4 + and macrophage lineages, and their pathogenicity is defined by the depletion of CD4 +. Furthermore, the condition of HIV- 1 infection is very complex and dependent on many factors related to the individual variability, regarding the susceptibility to infection and progression to AIDS, generalized immune activation being observed. Involved in the modulation of innate and adaptive immune responses is vitamin D, which plays a role in mineral metabolism and has pleiotropic effects on cell growth and differentiation. Their immune effects are data from binding to the vitamin D receptor (VDR) in various cells, regulating the release of cytokines, the function and proliferation of T lymphocytes and the production of antimicrobial peptides as cathelicidin. The VDR acts modulating the action of vitamin D by inducing local immune responses and genetic variations present in the VDR encoding gene can lead to reduction of its activity and consequently, disfunction in the role of vitamin D. In HIV-infected individuals, this vitamin deficiency levels are high and factors such as race, kidney failure, lower exposure to ultraviolet light and exposure to anti- HIV drugs, such as Efavirenz, are associated with this deficiency, being determinants on the susceptibility to HIV infection as well as prediction of disease progression. Therefore, in this work we studied six single nucleotide polymorphisms (SNPs) (rs3890733, rs476048, rs1540339, rs2248098, rs2228570 and rs11568820) present in the D vitamin receptor gene (VDR) and its influence on patients’ response to Antiretroviral Therapy (ART). We recruited 107 patients followed from the Hospital Day Integrative Medicine Institute Professor Fernando Figueira (IMIP), subdivided into four groups: I. Therapeutic Success, II. Therapeutic Failure, III. Immune Success, IV. Immune Failure, and analyzed clinical and epidemiological variables, such as gender, age, weight and ethnicity. No statistically significant associations were observed in the isolated analyzes between polymorphisms of the VDR gene with therapeutic failure or immune response. However, in multivariate analyzes, the rs1540339 C/C genotype was associated with gender in therapeutic success (OR = 0.08, p = 0.04). In addition, analysis involving weight, ethnicity and gender and the rs3890733 showed association with the immune response to the C/C genotype and T/T in overdominant model (OR = 0.21, p = 0.024). The results indicate the importance of vitamin D receptor in HIV- 1 infections and may contribute to the understanding of variability of patient’s various responses to ART.
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Costa, Matthew R. "FC Receptor-Mediated Activities of Env-Specific Monoclonal Antibodies Generated from Human Volunteers Receiving a DNA Prime-Protein Boost HIV Vaccine: A Dissertation." eScholarship@UMMS, 2010. http://escholarship.umassmed.edu/gsbs_diss/866.
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Human immunodeficiency type 1 (HIV-1) is able to elicit broadly potent neutralizing antibodies in a very small subset of individuals only after several years’ infection and as a result, vaccines that elicit these types of antibodies have been difficult to design. The RV144 trial showed that a moderate protection is possible, which may correlate with antibody dependent cellular cytotoxicity (ADCC) activity. Previous studies in the Lu lab demonstrated that in an HIV-1 vaccine phase I trial, DP6-001, a polyvalent Env DNA prime-protein boost formulation, could elicit potent and broadly reactive, gp120-specific antibodies with positive neutralization activities along with multiple Fc mediated effector functions. I developed a protocol for the production and analysis of HIV-1 Env-specific human monoclonal antibodies (mAbs) isolated from these DP6-001 vaccinees. By utilizing a labeled gp120 bait to isolate Env specific B cells, paired heavy and light chain immunoglobulin (Ig) genes were cloned and allowed for the production of monoclonal antibodies with specificity for gp120. By using this protocol, 13 isolated mAbs from four DP6-001 vaccinees showed broad binding activities to gp120 proteins of diverse subtypes, both autologous and heterologous to vaccine immunogens, with mostly conformational epitopes and a few V3 and C5 specific mAbs. Equally cross-reactive Fc-mediated functional activities, including ADCC and antibody dependent cellular phagocytosis (ADCP), were present with both immune sera and isolated mAbs, confirming the induction of non-neutralizing functional antibodies by the DNA prime- protein boost vaccination. Elicitation of broadly reactive mAbs by vaccination in healthy human volunteers confirms the value of the polyvalent formulation in this HIV-1 vaccine design.
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Costa, Matthew R. "FC Receptor-Mediated Activities of Env-Specific Monoclonal Antibodies Generated from Human Volunteers Receiving a DNA Prime-Protein Boost HIV Vaccine: A Dissertation." eScholarship@UMMS, 2016. https://escholarship.umassmed.edu/gsbs_diss/866.
Full textAbstract:
Human immunodeficiency type 1 (HIV-1) is able to elicit broadly potent neutralizing antibodies in a very small subset of individuals only after several years’ infection and as a result, vaccines that elicit these types of antibodies have been difficult to design. The RV144 trial showed that a moderate protection is possible, which may correlate with antibody dependent cellular cytotoxicity (ADCC) activity. Previous studies in the Lu lab demonstrated that in an HIV-1 vaccine phase I trial, DP6-001, a polyvalent Env DNA prime-protein boost formulation, could elicit potent and broadly reactive, gp120-specific antibodies with positive neutralization activities along with multiple Fc mediated effector functions. I developed a protocol for the production and analysis of HIV-1 Env-specific human monoclonal antibodies (mAbs) isolated from these DP6-001 vaccinees. By utilizing a labeled gp120 bait to isolate Env specific B cells, paired heavy and light chain immunoglobulin (Ig) genes were cloned and allowed for the production of monoclonal antibodies with specificity for gp120. By using this protocol, 13 isolated mAbs from four DP6-001 vaccinees showed broad binding activities to gp120 proteins of diverse subtypes, both autologous and heterologous to vaccine immunogens, with mostly conformational epitopes and a few V3 and C5 specific mAbs. Equally cross-reactive Fc-mediated functional activities, including ADCC and antibody dependent cellular phagocytosis (ADCP), were present with both immune sera and isolated mAbs, confirming the induction of non-neutralizing functional antibodies by the DNA prime- protein boost vaccination. Elicitation of broadly reactive mAbs by vaccination in healthy human volunteers confirms the value of the polyvalent formulation in this HIV-1 vaccine design.
10
Chen, Yuxin. "Characterization of Envelope-Specific Antibody Response Elicited by HIV-1 Vaccines: A Dissertation." eScholarship@UMMS, 2001. http://escholarship.umassmed.edu/gsbs_diss/760.
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Despite 30 years of intensive research，an effective human immunodeficiency virus (HIV) vaccine still remains elusive. The desirable immune response capable of providing protection against HIV acquisition is still not clear. The accumulating evidence learned from a recent vaccine efficacy correlate study not only confirmed the importance of antibody responses, but also highlighted potential protective functions of antibodies with a broad repertoire of HIV-1 epitope specificities and a wide range of different antiviral mechanisms. This necessitates a deep understanding of the complexity and diversity of antibody responses elicited by HIV-1 vaccines. My dissertation characterizes antibody response profiles of HIV-1 Env antibodies elicited by several novel immunogens or different immunization regimens, in terms of magnitude, persistence, epitope specificity, binding affinity, and biological function.
First, to overcome the challenge of studying polyclonal sera without established assays, we expanded a novel platform to isolate Env-specific Rabbit mAbs (RmAb) elicited by DNA prime-protein boost immunization. These RmAbs revealed diverse epitope specificity and cross-reactivity against multiple gp120 antigens from more than one subtype, and several had potent and broad neutralizing activities against sensitive Tier 1 viruses. Further, structural analysis of two V3 mAbs demonstrated that a slight shift of the V3 epitope might have a dramatic impact on their neutralization activity. All of these observations provide a useful tool to study the induction of a desired type of antibody by different immunogens or different immunization regimens.
Since heavily glycosylated HIV Env protein is a critical component of an HIV vaccine, we wanted to determine the impact of the HIV Env-associated glycan shield on antibody responses. We were able to produce Env proteins with a selective and homogeneous pattern of N-glycosylation using a glycoengineered yeast cell line. Antigenicity of these novel Env proteins was examined by well-characterized human mAbs. Immunogenicity studies showed that they were immunogenic and elicited gp120- specific antibody responses. More significantly, sera elicited by glycan-modified gp120 protein immunogens revealed better neutralizing activities and increased diversity of epitopes compared to sera elicited by traditional gp120 produced in Chinese Hamster Ovary (CHO) cells.
Further, we examined the impact of the delivery order of DNA and protein immunization on antibody responses. We found that DNA prime-protein boost induced a comparable level of Env-specific binding Abs at the peak immunogenicity point to codelivery of DNA. However, antibody responses from DNA prime-protein boost had high avidity and diverse specificities, which improved potency and breadth of neutralizing Abs against Tier 1 viruses. Our data indicate that DNA vaccine priming of the immune system is essential for generation of high-quality antibodies.
Additionally, we determined the relative immunogenicity of gp120 and gp160 Env in the context of DNA prime-protein boost vaccination to induce high-quality antibody responses. Immunized sera from gp120 DNA primed animals, but not those primed with gp160 DNA, presented with distinct antibody repertoire specificities, a high magnitude of CD4 binding site-directed binding capabilities as well as neutralizing activities. We confirmed the importance of using the gp120 Env form at the DNA priming phase, which directly determined the quality of antibody response.
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Chen, Yuxin. "Characterization of Envelope-Specific Antibody Response Elicited by HIV-1 Vaccines: A Dissertation." eScholarship@UMMS, 2015. https://escholarship.umassmed.edu/gsbs_diss/760.
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Despite 30 years of intensive research，an effective human immunodeficiency virus (HIV) vaccine still remains elusive. The desirable immune response capable of providing protection against HIV acquisition is still not clear. The accumulating evidence learned from a recent vaccine efficacy correlate study not only confirmed the importance of antibody responses, but also highlighted potential protective functions of antibodies with a broad repertoire of HIV-1 epitope specificities and a wide range of different antiviral mechanisms. This necessitates a deep understanding of the complexity and diversity of antibody responses elicited by HIV-1 vaccines. My dissertation characterizes antibody response profiles of HIV-1 Env antibodies elicited by several novel immunogens or different immunization regimens, in terms of magnitude, persistence, epitope specificity, binding affinity, and biological function.
First, to overcome the challenge of studying polyclonal sera without established assays, we expanded a novel platform to isolate Env-specific Rabbit mAbs (RmAb) elicited by DNA prime-protein boost immunization. These RmAbs revealed diverse epitope specificity and cross-reactivity against multiple gp120 antigens from more than one subtype, and several had potent and broad neutralizing activities against sensitive Tier 1 viruses. Further, structural analysis of two V3 mAbs demonstrated that a slight shift of the V3 epitope might have a dramatic impact on their neutralization activity. All of these observations provide a useful tool to study the induction of a desired type of antibody by different immunogens or different immunization regimens.
Since heavily glycosylated HIV Env protein is a critical component of an HIV vaccine, we wanted to determine the impact of the HIV Env-associated glycan shield on antibody responses. We were able to produce Env proteins with a selective and homogeneous pattern of N-glycosylation using a glycoengineered yeast cell line. Antigenicity of these novel Env proteins was examined by well-characterized human mAbs. Immunogenicity studies showed that they were immunogenic and elicited gp120- specific antibody responses. More significantly, sera elicited by glycan-modified gp120 protein immunogens revealed better neutralizing activities and increased diversity of epitopes compared to sera elicited by traditional gp120 produced in Chinese Hamster Ovary (CHO) cells.
Further, we examined the impact of the delivery order of DNA and protein immunization on antibody responses. We found that DNA prime-protein boost induced a comparable level of Env-specific binding Abs at the peak immunogenicity point to codelivery of DNA. However, antibody responses from DNA prime-protein boost had high avidity and diverse specificities, which improved potency and breadth of neutralizing Abs against Tier 1 viruses. Our data indicate that DNA vaccine priming of the immune system is essential for generation of high-quality antibodies.
Additionally, we determined the relative immunogenicity of gp120 and gp160 Env in the context of DNA prime-protein boost vaccination to induce high-quality antibody responses. Immunized sera from gp120 DNA primed animals, but not those primed with gp160 DNA, presented with distinct antibody repertoire specificities, a high magnitude of CD4 binding site-directed binding capabilities as well as neutralizing activities. We confirmed the importance of using the gp120 Env form at the DNA priming phase, which directly determined the quality of antibody response.
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Singwi, Sanjeev. "HIV gene therapy using nucleases." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape7/PQDD_0001/MQ46100.pdf.
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Saccardo, Paolo. "Development of artificial viruses for nanomedicine and gene therapy." Doctoral thesis, Universitat Autònoma de Barcelona, 2015. http://hdl.handle.net/10803/287907.
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La convergencia de diversas disciplinas como la biotecnología, biología molecular e ingeniería genética en el desarrollo de vehículos terapéuticos a escala nanometrica para la entrega de moléculas terapeuticas, se plantea como una herramienta con un elevado potencial en el campo de la nanomedicina. El mayor reto de estos nanovehiculos es permitir una eficaz entrega de ácidos nucleicos, proteínas o incluso fármacos, con una elevada especificidad celular para poder así disminuir la dosis administrada y por eso reducir sus toxicidad. En el caso de los ácidos nucleicos, la especificidad de entrega y la protección de los mismos de las nucleasas son los puntos clave para prever el desarrollo de estos sistemas. Sin embargo, el uso de vectores virales que parecían contener todos los elementos necesarios para aplicar la terapia génica extensivamente, ha topado con serios problemas de toxicidad e inmunogenicidad que limitan su uso. Así pues, el desarrollo de vectores de entrega no víricos, degradables y de diverso origen como dendrímeros, liposomas, polímeros, proteínas modulares o virus-like particles (VLPs), entre otros, se ha revelado como un campo de investigación que promete aportar las herramientas necesarias para desarrollar vehículos auto ensamblables “inteligentes” capaces de superar las barreras impuestas por el sistema biológico y llegar al tejido o compartimiento celular diana sin provocar las reacciones adversas que limitan el utilizo de sistemas virales.
En el óptica de estudiar la optimización de nanovehiculos autoensamblabels de origen proteicos para la terapia génica, hemos explorado por un lado la caracterización de VLPs obtenidas mediante la expresión del la proteína VP1 de la capside viral del human JC virus tanto en E.coli, como en células de insecto. Por otro lado hemos estudiado la optimización del proceso de producción y autoensamblado de proteínas multifuncionales y evaluado su capacidad de unir y proteger los acidos nucleicos de la degradación por parte de proteasas.
Así pues, diferentes entornos genéticos del sistema de control de calidad en E. coli han evidenciado la alteración del rendimiento de producción y de calidad conformacional en el ensamblado de las VLPs del virus JC. En este tesis hemos explorado los efectos de la chaperona DnaK en la producción y calidad conformacional de las VLPs formadas por la proteína VP1 a través de tres cepas caracterizadas por la presencia/ausencia/sobre expresión de la chaperona DnaK. Se ha observado que la ausencia de esta chaperona promueve una mayor rendimiento de producción pero al mismo tiempo ha demostrado efectos negativos en el ensamblaje de las VLPs.
El mismo concepto se ha aplicado en estudios en células de insecto, co-produciendo la proteína VP1 y las chaperonas bacterianas DnaK/DnaJ. En este caso el rendimiento de producción se ha visto afectado por la presencia de las chaperonas contrariamente a la calidad conformacional que se ha visto beneficiada.
Paralelamente, estudios sobre las propiedad arquitectónicas de la proteína modular R9-GFP-H6 y sus interacciones con el ADN ha permitido establecer las condiciones optímales para la interacción de sus dominios peliotropicos, resultante en el auto ensamblado de esta proteína en complejos ADN/nanoparticulas capaces de proteger el ADN de la acción de proteasas. Además se ha propuesto un modelo bioinformática de las nanoestructuras estudiadas. Consecuentemente a la caracterización de la R9-GFP-H6, diferentes modelos de proteína modula auto-ensamblables derivada de esta han sido estudiados para evaluar sus eficacias a la hora de unir y transportar ADN al núcleo celular. En esta tesis se ha propuesto una modificación del protocolo de purificación que permite aumentar sensiblemente la eficacia de las diferentes nanoparticulas implicadas.
Por lo tanto, en todos estos trabajos, queda reflejado que el desarrollo de virus artificiales para nanomedicina y terapia génica es un proceso fascinante y multidisciplinario donde las nanoparticulas de origen proteicos, sean proteínas modulares o virus like particles, están siendo concebidas como una herramienta extremadamente potente para la obtención de productos eficientes, seguros y comercialmente atractivos. Con esta tesis, entonces, se pretende entrar a fondo en las técnicas de desarrollo y mejora del proceso productivo de novedosas nanoestructuras proteicas para sus utilizo en nanomedicina.The convergence of different field as biotechnology, molecular biology and genetic engineering in the development of a nano-scale therapeutical vector became matter of interest because of their nanomedical applications. The major challenge of nanovectors is obtain a good delivery of nucleic acid, therapeutic proteins or drugs, with high cell specificity and low side effects. In this way, viral vectors allow an extremely efficient delivery but are also responsible of severe side effects. Because of this main limitation, the development of artificial virus derived from either dendrimers, liposomes, polymers, modular proteins or virus like particles (VLPs) is considered an interesting and promising research field. In this thesis we expose our studies in the optimization of protein self-assembling nanoparticles. From one side we produced and characterized VLPs derived form the major capsid protein VP1 of the human JC virus both in E. coli and insect cells protein factories. On the other side we studied the optimization of the self-assembling and the purification process of multi-domain self-assembling proteins derived by paradigmatic protein R9-GFP-H6, which is described to form nanoparticles. Different genetic backgrounds for protein quality control system in E. coli have shown to alter the protein production yield and conformational quality of artificial virus assembly. We discuss in this thesis the effects of the prokaryotic DnaK chaperone on VP1 production yield and VLPs conformation quality. For this purpose we used three genetic backgrounds including, wild type expression, over-expression and absence of expression of DnaK molecular chaperone. Surprisingly, in the absence of the molecular chaperone the production yield of VP1 is enhanced but has negative effects on VLPs assembly. Moreover we tested different buffer formulations in order to establish the optimal salt concentration and pH for VLP organization, stabilization and conformation. The same concept where applied for insect cell system, exploring the effects in yield and conformational quality of VP1 hJCV VLPs upon re-hosting DnaK/DnaJ chaperones. Results showed a lowering in production yield upon chaperone co-expression but an increase in VLPs conformational quality. At the same time architectural properties of the paradigm protein R9-GFP-H6 and its interactions with DNA were studied in order to obtain a suitable protein-based artificial virus for gene delivery. It has been observed that in presence of DNA and at slightly acidic pH, R9-GFP-H6 proteins organize in two distinct populations. Microscopy observations showed a supramolecular organization of DNA/nanoparticle complexes, revealing the 9 Arginine and 6 Histidines blocks as promising pleyotropic domains. Moreover, in optimized conditions, R9-GFP-H6 protein has also showed an effective DNA protection against proteases. Finally, we purposed potential structural models of R9-GFP-H6/DNA complexes, based on bioinformatics analysis and experimental data. Subsequently we explored the nucleic acid contaminants in non-viral protein based nanovector production process of R9-GFP-H6 derivative proteins. Enzymatic downstream treatment with nucleases has revealed a good strategy to solve the limitations derived from nucleic acid contamination. All together, these works allows having a general overview of non-viral nanoparticles approach in gene delivery and permitting to understand better the difficulties in the production process. With this thesis, then, we claim to discuss and develop newly production and purification methods in order to develop efficient artificial virus for nanomedicine and gene therapy.
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Domingo, i. Espín Joan. "Development and characterization of artificial viruses for gene therapy." Doctoral thesis, Universitat Autònoma de Barcelona, 2013. http://hdl.handle.net/10803/123204.
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Els riscos biològics associats a la teràpia gènica viral limiten el ple desenvolupament de vectors virals i plantegen importants problemes a la seva incorporació en assajos clínics. La teràpia gènica no viral representa una alternativa segura als virus naturals per al lliurament dirigida de gens a cèl·lules, tot i els baixos nivells d'expressió gènica obtinguts que és l’obstacle principal per la seva aplicació terapèutica. Els diferents tipus de vectors no virals que s'han desenvolupat fins ara, inclouen els basats en liposomes, dendrímers o proteïnes. Recentment, el concepte de "virus artificial” s'ha proposat per descriure nanocomplexes per al lliurament de gens que imiten les funcions virals pertinents per a la captació del gen i el tràfic intracel·lular. Entre ells, els basats en proteïnes i construïts a través de principis modulars permeten la incorporació, en un únic polipèptid, de diferents proteïnes o dominis de proteïnes amb funcions similars a virus, és a dir, la unió i la condensació a ADN, la unió al receptor, la internalització, l’escapament endosomal, la localització nuclear i l’alliberament del material transportat.
Hem desenvolupat una sèrie de vehicles proteics modulars formades per diferents dominis funcionals que són capaços d'entrar en les cèl·lules a través de la unió un receptor específic i promoure nivells importants de l'expressió gènica.
En aquesta tesi s'analitza aquest enfocament amb dos articles de revisió i es demostra amb tres treballs originals.The biological risks associated to viral gene therapy limit the full development of viral vectors and pose major concerns to their incorporation into clinical trials. Non-viral gene therapy represents a safe alternative to natural viruses for cell targeted gene delivery, although the low gene expression levels achieved by non-viral vectors are a main obstacle for their therapeutic application. Different types of non-viral vectors have been developed up to date, including those based in liposomes, dendrimers or proteins. Recently, the ‘Artificial virus’ concept has been proposed to describe nanocomplexes for gene delivery that mimic the viral functions relevant to gene uptake and intracellular trafficking. Among them, those based on proteins and constructed through modular principles allow the incorporation, in a single polypeptide, of different proteins or protein domains with virus-like functions, namely DNA binding and condensation, receptor binding, internalization, endosomal escape, nuclear targeting and uncoating. We have developed a series of protein-only modular vehicles composed by different functional domains that are able to enter cells through specific receptor binding and promotes important levels of transgene expression. In this thesis this approach is discussed with two review articles and demonstrated with three original papers.
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Zeicher, Marc. "Oncolytic viruses cancer therapy." Doctoral thesis, Universite Libre de Bruxelles, 2008. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/210439.
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Wild-type viruses with intrinsic oncolytic capacity in human includes DNA viruses like some autonomous parvoviruses and many RNA viruses. Recent advances in molecular biology have allowed the design of several genetically modified viruses, such as adenovirus and herpes simplex virus that specifically replicate in, and kill tumor cells. However, still several hurdles regarding clinical limitations and safety issues should be overcome before this mode of therapy can become of clinical relevance. It includes limited virus spread in tumor masses, stability of virus in the blood, trapping within the liver sinusoids, transendothelial transfer, and/or vector diffusion of viral particles to tumor cells, limited tumor transduction, immune-mediated inactivation or destruction of the virus. For replication-competent vectors without approved antiviral agents, suicide genes might be used as fail-safe mechanism. Cancer stem cells are a minor population of tumor cells that possess the stem cell property of self-renewal. Therefore, viruses that target the defective self-renewal pathways in cancer cells might lead to improved outcomes.In this thesis, data we generated in the field of oncolytic autonomous parvoviruses are presented.
We replaced capsid genes by reporter genes and assessed expression in different types of human cancer cells and their normal counterparts, either at the level of whole cell population, (CAT ELISA) or at the single cell level, (FACS analysis of Green Fluorescent Protein). Cat expression was substantial (up to 10000 times background) in all infected tumor cells, despite variations according to the cell types. In contrast, no gene expression was detected in similarly infected normal cells, (with the exception of an expression slightly above background in fibroblasts.). FACS analysis of GFP expression revealed that most tumor cells expressed high level of GFP while no GFP positive normal cells could be detected with the exception of very few (less than 0.1%) human fibroblast cells expressing high level of GFP. We also replace capsid genes by genes coding for the costimulatory molecules B7-1 and B7-2 and show that, upon infection with B7 recombinant virions, only tumor cells display the costimulatory molecules and their immunogenicity was increased without any effect on normal cells. Using a recombinant MVM containig the Herpes Simplex thymidine kinase gene, we could get efficient killing of most tumor cell types in the presence of ganciclovir, whithout affecting normal proliferating cells. We also produced tetracycline inducible packaging cell lines in order to improve recombinant vectors yields. The prospects and limitations of these different strategies will be discussed.
An overview is given of the general mechanisms and genetic modifications by which oncolytic viruses achieve tumor cell-specific replication and antitumor efficacy. However, as their therapeutic efficacy in clinical trials is still not optimal, strategies are evaluated that could further enhance the oncolytic potential of conditionally replicating viruses in conjunction with other standard therapies.
Another exciting new area of research has been the harnessing of naturally tumor-homing cells as carrier cells to deliver oncolytic viruses to tumors. The trafficking of these tumor-homing cells (stem cells, immune cells and cancer cells), which support proliferation of the viruses, is mediated by specific chemokines and cell adhesion molecules and we are just beginning to understand the roles of these molecules. Finally, we will explore some ways deserving further study in order to be able to utilize various oncolytic viruses for effective cancer treatment.
Doctorat en sciences, Spécialisation biologie moléculaire
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Hemmerling, Deborah Ruth. "Retroviral vectors for anti-HIV gene therapy." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape8/PQDD_0004/NQ39538.pdf.
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Yager, Nicole Leanne. "Natural and therapy-induced immune control of HIV-1." Thesis, University of Oxford, 2011. http://ora.ox.ac.uk/objects/uuid:e07f3022-4e14-4844-90ac-8d6f52a40a5a.
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The human immunodeficiency virus (HIV)-specific cytotoxic T-lymphocyte (CTL) response is important in the control of HIV-1 infection. Due to the virus having a high rate of mutation, immune pressure can select for variants that are no longer recognised by CTLs to dominate the viral quasispecies. This is similar to how antiretroviral resistance emerges. HIV-1 is therefore adapting to both human leukocyte antigen (HLA)-restricted immune responses and antiretroviral therapy. This thesis initially focused on the natural CTL response to an HLA-B*51-restricted epitope in integrase. This HLA class I allele is associated with slow progression to AIDS; however, as no CTL-driven escape mutation has been fully defined within this integrase epitope, we cannot determine what contributes to the association of HLA-B*51 and natural control of infection. By longitudinally studying a cohort of early HIV-infected individuals, we observed the emergence of polymorphisms that abrogate a CTL response to this epitope. CTL escape may also prove to be the downfall of current immunotherapy strategies attempting to combat HIV infection. T cell receptors (TCRs) have been genetically modified to enhance their binding affinity to an HLA-A*02-peptide complex and transduced into CD8+ cells to create an HIV adoptive therapy. We demonstrate through in vitro selection pressure assays that escape from these cells may be a difficult task for the virus given that the TCR is able to recognise the majority of variants of this epitope. Antigen processing mutations may represent the only option for escape. How this may translate clinically will only be determined through in vivo studies, which must be meticulously monitored. Finally, when this high affinity TCR was fused to an anti-CD3 single chain variable fragment to create proteins capable of redirecting non-HIV-specific CTLs to HIV-infected cells, we found that the result was specific lysis. These proteins may supersede the use of TCR-transduced cells when used in synergy with antiretroviral therapy.
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McKnight, Aine Veronica. "Tropism and neutralization of human and simian immunodeficiency viruses." Thesis, Institute of Cancer Research (University Of London), 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.244796.
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Hotchkiss, Graham. "Towards ribozyme-mediated gene therapy of HIV-1 infections /." Stockholm, 2000. http://diss.kib.ki.se/2000/91-628-4007-X/.
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Tsafa, Effrosyni. "Broad strategies into engineering superior targeted gene therapy vectors derived from bacteriophage viruses." Thesis, Imperial College London, 2016. http://hdl.handle.net/10044/1/61571.
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Chemotherapy is the most commonly used treatment for cancer. While chemotherapeutic drugs such as doxorubicin provide cure in some cases, chemotherapy is toxic and has serious side-effects. Another disadvantage is that some types of cancer develop resistance to chemotherapy. Lowering the doses of these drugs will make them safer but would decrease their efficacy. A solution to this would be to combine low doses of these anticancer drugs with a safe anticancer approach. Cancer gene therapy is an alternative and promising approach of cancer treatment. In our group we are using the adeno-associated virus/phage, named AAVP vector, which is a hybrid vector between AAV and phage genomes. AAVP vector was engineered to display the RGD4C peptide which binds to αv integrin receptors overexpressed in tumors. AAVP vector has been proven to be safe and efficient vector for targeted gene delivery to tumors, upon intravenous administration. The aim of my project was to combine low-dose of doxorubicin with AAVP vector in order to investigate the drug effects on the AAVP-mediated tumor cell killing. We also tested the combination of AAVP with the natural dietary genistein, an isoflavone present in soy, regarded as a phytoestrogen and proven for its anti-cancer activity. Epidemiological studies have shown that a soy-rich diet has cancer-preventive effects. We found that combination of low doses (non-toxic) of doxorubicin or genistein with RGD4C-AAVP-guided gene therapy resulted in greater tumor cell killing than treatment with doxorubicin, genistein or the targeted vector alone. In addition, we uncovered the mechanism that doxorubicin and genistein increased the transduction efficiency of AAVP vectors. In conclusion, our results suggest that the combined treatment of doxorubicin or genistein with targeted RGD4C-AAVP gene therapy is a novel, promising, non-invasive and, importantly, safer treatment approach. Therefore, this combined treatment should be considered for future preclinical studies to assess its efficacy in vivo in tumor-bearing animals.
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Kotsopoulou, Ekaterini. "The unusual HIV-1 codon bias as a tool for anti-HIV strategies." Thesis, University of Oxford, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.312106.
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Kelly, Gloria Domingo. "Repression of Tat-transactived HIV-LTR directed gene expression by E1A 12S oncoprotein." Thesis, Georgia Institute of Technology, 1994. http://hdl.handle.net/1853/25227.
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Bockstael, Olivier. "Evaluation of gene transfer strategies using recombinant adeno-associated viruses for Parkinson's disease cell and gene therapy." Doctoral thesis, Universite Libre de Bruxelles, 2010. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/210010.
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La maladie de Parkinson se caractérise entre autres par une dégénérescence progressive des neurones dopaminergiques de la substance noire pars compacta (SNpc) qui innervent le striatum. Cette dégénération entraîne une baisse de la sécrétion de dopamine dans le striatum qui est responsable de la majorité des symptômes moteurs de la maladie de Parkinson. Plusieurs approches ont été étudiées pour le traitement de la maladie de Parkinson :i) restaurer une synthèse de dopamine dans le striatum par une greffe striatale de neurones dopaminergique ou par un transfert striatal de gènes impliqués dans la synthèse de la dopamine ;ii) protéger et stimuler les neurones dopaminergiques survivants dans la substance noire pars compacta des patients ;iii) corriger les déséquilibres de la boucle motrice engendrés par la baisse de stimulation dopaminergique du striatum ;iv) stimuler et recruter des progéniteurs cérébraux pour les faire se différencier en neurones dopaminergiques dans le striatum. Toutes ces approches thérapeutiques peuvent impliquer des transferts de gènes.Les vecteurs dérivés des virus adéno-associés (rAAV) constituent des outils de choix pour le transfert de gènes dans les tissus cérébraux. Par ailleurs, de nombreuses applications nécessitent une régulation de l’expression du transgène. Nous disposons au laboratoire d’un vecteur rAAV inductible à la tétracycline (rAAV-TetON).
Nous décrivons dans ce travail :
i) le comportement du vecteur rAAV dérivé du sérotype 1 d’AAV utilisant la cassette d’expression TetON (rAAV2/1-TetON) comparé à celui du rAAV2/1 utilisant un promoteur constitutif pour l’expression du transgène (rAAV2/1-pCMV) dans le striatum et le mésencéphale (contenant la substance noire). A l’aide d’un vecteur rAAV2/1-TetON exprimant le GDNF, nous montrons que nous pouvons moduler le niveau d’expression du transgène dans le striatum par la dose d’inducteur administré aux animaux. Par ailleurs, nous montrons que le rAAV2/1-TetON présente dans le striatum une efficacité de transduction moindre que le rAAV2/1-pCMV mais qu’il présente un profil de biosécurité supérieur au rAAV2/1-pCMV car il limite fortement l’expression du transgène hors du striatum. De plus, le rAAV2/1-TetON n’entraîne pas de recrutement de lymphocytes T ni d’activation de la microglie dans le striatum. Lorsqu’il est injecté dans le mésencéphale, le vecteur rAAV2/1-TetON, contrairement au rAAV2/1-pCMV présente une expression préférentielle dans les neurones dopaminergiques de la SNpc et de l’aire tégmentale ventrale (VTA).
ii) le comportement des vecteurs rAAV2/1-pCMV et scAAV2/1-pCMV (vecteur « self-complémentaire » permettant une expression du transgène indépendamment de la synthèse du second brin du génome viral) dans la région neurogénique de la zone sous-ventriculaire (ZSV). Nous avons montré que les vecteurs rAAV2/1 infectent efficacement la ZSV et s’y expriment rapidement. Les vecteurs scAAV2/1 s’expriment plus rapidement dans la ZSV que les vecteurs rAAV2/1 (expression maximum à 24h et 48h, respectivement). De plus, les vecteurs rAAV2/1 présentent une efficacité de transfection importante pour les progéniteurs neuraux en prolifération (cellules C, transient amplifying progenitors) et les neuroblastes en migration (cellules A) mais pas pour les cellules souches neurales (cellules B). Nous observons, par ailleurs, que les rAAV2/1 induisent une baisse transitoire de la prolifération de la ZSV. Cet effet est indépendant de l’expression du génome et dépend donc probablement de la capside virale de nos vecteurs. De plus, cette baisse de prolifération n’induit pas d’apoptose. A long terme, nous observons des cellules exprimant le transgène dans la zone granulaire du bulbe olfactif, indiquant que la transduction des progéniteurs de la ZSV n’interfère pas avec leurs capacités de migration et de différenciation.
iii) l’efficacité de différents sérotypes de rAAV pour le transfert de gènes dans les cellules progénitrices neurales (NPC) in vitro. Nous avons montré que les rAAV peuvent transduire des NPC mais que l’efficacité spécifique des différents sérotypes testés varie en fonction de la région du cerveau fœtal et de l’espèce dont les NPC sont issues. Par ailleurs, les rAAV induisent une réduction drastique de la prolifération des cultures de NPC dépendante du sérotype de rAAV utilisé mais pas de l’origine fœtale des NPC ou de l’espèce dont elles sont issues.
Doctorat en Sciences biomédicales et pharmaceutiques
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Maijgren, Steffensson Catharina. "Preclinical studies of ribozyme-mediated gene therapy for HIV-1 /." Stockholm : Karolinska institutet, 2004. http://diss.kib.ki.se/2004/91-7349-883-1/.
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De, Silva Shamika Udayangi. "Chimeric adenoviruses as potential gene therapy vectors for HIV vaccination." Thesis, Royal Holloway, University of London, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.435928.
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Chan, E. "Lentiviral gene therapy for HIV using TRIM-cyclophilin restriction factors." Thesis, University College London (University of London), 2012. http://discovery.ucl.ac.uk/1362851/.
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Lentiviral vector delivery of anti-HIV elements could provide the basis of alternative therapies against HIV, potentially providing long term protection after a single intervention. Some primate species have evolved restriction factors formed by the fusion of TRIM5α and Cyclophilin A (TRIM5Cyp) following retrotransposition of CypA cDNA into the TRIM5 gene, which provide potent resistance against certain lentiviruses. We have designed humanised versions of these proteins combining both TRIM5 and TRIM21 with CypA, and investigated their potential for use in gene therapy against HIV-1. Both TRIM5- and TRIM21-Cyp fusion proteins provided strong restriction of HIV-1 in all of the systems tested, including primary human T cells. However, TRIM5Cyp was shown to disrupt the antiretroviral effect of endogenous TRIM5α and rescue murine retrovirus infection, whereas TRIM21Cyp caused no interference. In contrast, neither TRIM5CypA nor TRIM21CypA expression affected the antiviral activity of endogenous TRIM21. In addition to TRIMCyp restriction factors, a second anti-HIV strategy was investigated using zinc finger nucleases (ZFNs) to knockout the HIV-1 co-receptor, CCR5. ZFNs introduce a double stranded break into the CCR5 gene, which can be restored by homology directed repair. Provision of a green fluorescent protein (GFP) or TRIM21Cyp donor template exploits this repair mechanism to allow site specific integration at the CCR5 locus, although at low efficiency. Using integrating vectors, we have shown that TRIMCyp mediated restriction is so potent that no additional inhibition was conferred by CCR5 knockout. In conclusion, delivery of TRIMCyp genes using lentiviral vectors could form the basis of an intracellular vaccination strategy against HIV-1, with TRIM21Cyp having benefits by maintaining endogenous TRIM function. With further optimisation to improve efficiency, this could be combined with ZFNs for site specific integration of the transgene and knockout of CCR5 to provide a dual method of HIV-1 inhibition.
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Landazuri, Natalia. "Enhanced gene transfer using polymer-complexed retrovirus vectors." Thesis, Georgia Institute of Technology, 2001. http://hdl.handle.net/1853/20677.
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Wang, Xiaoxia. "Molecular studies on the action of APOBEC3G against HIV-1 and development of an APOBEC-based anti-HIV approach." American Society for Microbiology, 2011. http://hdl.handle.net/1993/23226.
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Currently, the HIV pandemic remains a major global health challenge. In order to effectively control and cure HIV-1 infection, it is necessary to perform greater research on host-HIV interactions and develop novel preventive and therapeutic approaches. The human cytidine deaminase APOBEC3G (A3G) is the first identified host restriction factor, which can serve as an initial line of defense against HIV-1 by inducing lethal mutations on proviral DNA and disrupting viral reverse transcription and integration.
In order to better understand the action of A3G on HIV-1 replication, my study was focused on characterizing the interplay between A3G and HIV-1 reverse transcriptase (RT). The results indicated that A3G directly bound to RT, which contributed to A3G-mediated inhibition of viral reverse transcription. Overexpression of the RT-binding polypeptide A3G65-132 was able to disrupt wild-type A3G and RT interaction, consequently attenuating the anti-HIV effect of A3G on HIV replication.
While the potent antiviral activities of A3G make it an attractive candidate for gene therapy, the actions of A3G can be counteracted by HIV-1 Vif during wild-type HIV infection. In order to overcome Vif-mediated blockage and maximize the antiviral activity of A3G, this protein was fused with a virus-targeting polypeptide (R88) derived from HIV-1 Vpr, and various mutations were then introduced into R88-A3G fusion protein. Results showed that Vif binding mutants R88-A3GD128K and R88-A3GP129A exhibited very potent antiviral activity, and blocked HIV-1 replication in a CD4+ T lymphocyte cell line as well as human primary cells. In an attempt to further determine their potential against drug resistant viruses and viruses produced from latently infected cells, R88-A3GD128K was chosen and delivered by an inducible lentiviral vector system. Expression of R88-A3GD128K in actively and latently HIV-1 infected cells was shown to be able to inhibit the replication of both drug sensitive and resistant strains of HIV-1.
In conclusion, this thesis has demonstrated one of the mechanisms that how A3G can disrupt HIV-1 reverse transcription. Meanwhile, an A3G-based anti-HIV-1 strategy has been developed, which provides a proof-of-principle for a new gene therapy approach against this deadly virus.
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Marais, Melanie. "A descriptive study to evaluate the effect of guidelines used by counsellors to improve adherence to antiretroviral therapy in the private sector." Thesis, University of the Western Cape, 2006. http://etd.uwc.ac.za/index.php?module=etd&.
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Coulibaly, Tata Safiatou. "Double approche à la thérapie anti-tumorale à l'aide de vecteurs lentiviraux." Thesis, Strasbourg, 2017. http://www.theses.fr/2017STRAJ087/document.
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Le traitement du cancer par thérapie génique nécessite d’une part des gènes suicides efficaces et, d’autre part, l’adressage spécifique de ces gènes aux cellules cancéreuses. J'ai d'abord caractérisé un nouveau gène suicide dérivé de la désoxycytidine kinase humaine (dCK) : le M36. Comparé à la dCK, le M36 permet une meilleure sensibilisation des certaines cellules cancéreuses aux traitements avec différents chimiothérapeutiques comme la gemcitabine et la cytarabine. Ces résultats sont particulièrement encourageants pour l'élimination des cellules cancéreuses résistantes à ces traitements du fait d’un défaut de la dCK. Dans une deuxième partie, je me suis intéressée à l'adressage spécifique des transgènes aux cellules cancéreuses par les vecteurs lentiviraux. J'ai travaillé à la preuve de concept qu’une enveloppe (Env) VIH modifiée peut permettre un tel ciblage. J'ai généré une Env qui a fortement diminué son tropisme naturel et qui comporte un motif liant le marqueur tumoral modèle HER2Cancer gene therapy requires the use of an effective suicide gene and the specific targeting of cancer cells. In my PhD work, I have first characterized a new potential suicide gene derived from human deoxycytidine kinase (dCK): M36. Compared to dCK, M36 improves sensitization of certain cancer cells to treatment with chemotherapeutic compounds as gemcitabine and AraC. These results are particularly encouraging for the elimination of cancer cells resistant to the treatment because of a defect with dCK. In a second part, I have worked at the proof of concept that a modified HIV envelope can allow specific targeting of cancer cells by lentiviral vectors. During this work, I have generated a CD4i envelope with a strongly diminished natural tropism and that carries a motif known to bind the model cell surface cancer marker HER2. This envelope constitutes a good starting material to be improved by evolution in cell culture to obtain specific targeting of HER2+ cells
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Wiles, Karen Anna, and n/a. "Coxsackie and Adenovirus Receptor (CAR) expression is a potential limiting factor in adenoviral oncotheraphy." University of Otago. Dunedin School of Medicine, 2007. http://adt.otago.ac.nz./public/adt-NZDU20070619.161353.
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Novel approaches to cancer treatment in the context of Gene Therapy have been gaining popularity as an alternative to conventional therapies which have proven to lack specificity, resulting in tumour cell resistance, tumour progression and mortality. As a consequence the use of adenoviruses has been widely developed not only as a replication deficient vector for gene therapy but also as a replication competent oncolytic agent designed to selectively target and kill tumour cells. Unfortunately their success in clinical application has been limited, and it has been suggested that a lack of the primary viral attachment receptor 'CAR' could be a barrier to infection by limiting access to target cells. If Ad/CAR binding is the rate limiting step for successful Ad therapy, it is essential to establish a CAR expression profile in normal and tumour tissue, and in tumour progression, to enable more effective targeted therapy. Furthermore, in the context of using adenovirus as an anticancer strategy by exploiting its replicative lysis, it is important to explore whether Ad success is affected by CAR expression and to identify factors downstream of CAR that may be influential in this process.
In the first experimental chapter, an in vivo immunohistochemical analysis of tissue array slides determined CAR expression in a range of normal and tumour tissue. CAR was differentially expressed dependent on cell of origin, with normal stem cells and basal cells displaying very high CAR, signifying its importance in early development and differentiation. Epithelial cells were also high in CAR but its expression was negligible in mesenchymal, lymphoid and neural cells. This trend was also reflected in most tumour tissue albeit with a general decrease in CAR compared to corresponding normal tissue of the same organ. An exception was the blastic tumours which displayed high CAR reflecting their embryonic state of derivation. CAR expression also decreased in high grade, poorly differentiated tumours of the prostate, stomach and breast compared to their well differentiated counterparts.
In the second experimental chapter, a more comprehensive study of breast cancer biopsy specimens was undertaken, to determine both the expression of CAR and the tumour suppressor gene p53 in relation to tumour grade. The rationale being that both loss of CAR expression and p53 mutation (resulting in loss of function), have been associated with tumour progression. It is possible that CAR and p53 interact directly or indirectly and may be modulated by each other. This study revealed a decrease in both CAR and hormone receptor expression and an increase in p53 'mutational' status with increasing tumour grade. These three factors when compared independently to tumour grade are statistically significant associations, implying that CAR expression and hormone responsiveness decrease with tumour progression and p53 function is compromised or lost via mutation. There was also a significant association between CAR expression and hormone receptor status, however a significant association between CAR expression and p53 status within the tumour grades was not found.
Treatment outcome with Ads will also depend on defining factors downstream of CAR attachment that affect adenovirus 'permissivity', which is ultimately measured by viral replication and cell death, relying on the bystander effect to eradicate all tumour cells. The in vitro analysis revealed statistically significant associations between CAR receptor expression, 'infectivity' (virus infection) and permissivity. Cell lines that were more susceptible to Ad5 were generally of epithelial origin, had high CAR, and were easily infected. However there were exceptions and CAR was not the sole determinant in adenovirus cell entry nor in its ability to replicate and kill the cell. Permissivity was also related to p53 status. Thus, although CAR expression may indeed be a limiting factor, it is apparent that a combination of other events contributes to a deficient infection, especially in the deregulated tumour environment.
The results presented in this thesis clearly demonstrate that there is more to the story of 'CAR' which hints that its role in viro-oncotherapy is not limited solely to its function as an attachment receptor for adenovirus but may also involve its function as a cell adhesion molecule and signal transducer. The further elucidation of these aspects of CAR�s potential role in the scheme of tumour biology may alter the course and strategy of cancer therapy in the future.
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De, Villiers Tania. "Characterisation of the HIV-1 subtype C Env gene and the expression of the Env protein from selected isolates in mammalian cells." Thesis, Stellenbosch : Stellenbosch University, 2003. http://hdl.handle.net/10019.1/53329.
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Thesis (MSc)--Stellenbosch University, 2000.ENGLISH ABSTRACT: At the end of 2002, human immunodeficiency virus (HIV) had infected 42 million people worldwide. The morbidity and mortality rate, as well as the epidemic proportions of the disease have led to concentrated scientific efforts to reveal the disease's pathogenesis and develop effective preventative and treatment measures. Advances have been made to inhibit viral replication by suppressing the virus' ability to replicate by developing antiretroviral treatments, although development of a save and effective vaccine is the only way to stem the pandemic. Advances in vaccine design, animal models and clinical research have led to the creation of promising candidate vaccines to counter this rampage, but most of these vaccines entering phase I-III clinical trials are based mainly only subtype B genomes. HIV-1 subtype C is the most commonly transmitted subtype worldwide, and is the predominant subtype in India, China, East and Southern Africa. A subtype C vaccine is critical for the developing nations such as South Africa, where antiretroviral therapies are largely unaffordable. The envelope gene (env) is an attractive target as immunogen to be included in a HIV vaccine. The envelope protein (Env) elicits neutralising antibodies and cytotoxic T-Iymphocyte (CTl) responses. This protein will therefore be useful in creating a humoral and cellular immune response in the host. A shortage in characterised subtype C env gene sequences from South Africa was recognised, and this study focussed on the characterisation of generated sequences, as well as the expression of selected env genes. These immunogens were created for possible use in a prime-boost vaccine modality. The env genes from recent circulating strains in South Africa were amplified by polymerase chain reaction (PCR). The genes were then cloned for sequencing and expression purposes. Phylogenetic relationships were determined by comparing the sequences to reference subtype strains and subtype C strains. Expression of the genes was assessed by Western Blot in 293 cells with HIV- 1 positive patient sera. Sequence analysis showed a more conserved third variable (V3) loop in South African subtype C sequences, with a more variable region downstream from the loop. The crown sequence (GPGQ) and positions of uncharged or negatively charged residues in the V3 loop indicated a non-syncytium-inducing (NSI) phenotype for the isolates. Phylogenetic analysis showed the sequences to all belong to the C subtype, and further that the sequences were not recombinant, which was confirmed by recombination analysis. The intersample diversity observed for strains from South Africa was significantly higher than distances observed to the subtype C consensus sequence. The South African sequences were distributed across several subclusters in a subtype C phylogenetic tree, highlighting the concept that these infections represent a more longstanding epidemic with multiple introductions from different geographic areas. Western Blot with HIV-1 positive patient sera showed the expression of uncleaved gp160 Env proteins, which were Rev dependent. This study has generated much needed subtype C South African env gene sequences that can be used as basis for modification for use as immunogens in a South African vaccine.
AFRIKAANSE OPSOMMING: Teen die einde van 2002 was 42 miljoen mense wêreldwyd geïnfekteer met die menslike immuniteitsgebrekvirus (MIV). Die dode- en sterfte syfers, asook die skaal van die epidemie, het gelei tot 'n wetenskaplike poging om die siekte se patogenese te openbaar en om effektiewe voorkomende en terapeutiese middels te ontwikkel. Vordering is reeds gemaak om die virus se replikasie te hinder deur die ontwerp van antivirale middels, alhoewel die ontwikkeling van 'n doeltreffende en veilige entstof die enigste manier is om die pandemie te stuit. As gevolg van die vordering in entstof ontwerp, diere modelle en kliniese navorsing is belowende kandidaat entstowwe wat die infeksie kan teenwerk ontwikkel, maar die meeste van hierdie enstowwe wat vir fase I-III kliniese proewe gebruik word is gebaseer op subtipe B genome. MIV-subtipe C is wêreldwide die algemeenste subtipe wat oorgedra word en is die oorheersende subtipe in lande soos Indië, China, oostelike en suidelike Afrika. 'n Subtipe C entstof word dringend benodig in ontwikkelende lande soos Suid-Afrika waar antivirale middels onbekostigbaar is. Die membraangeen is 'n aanloklike teiken om as immunogeen in 'n MIV entstof te dien. Die membraanproteïen lok neutraliserende teenliggame en sitotoksiese T-limfosiet reaksies uit. Die proteïen sal dus 'n humorale en sellulêre immuunrespons in die gasheer ontlok. 'n Tekort aan gekarakteriseerde subtipe C membraangeen volgordes van Suid-Afrika is opgemerk, en dus fokus hierdie studie op die karakterisering van gegenereerde volgordes, asook die uitdrukking van geselekteerde membraangene. Die immunogene is geskep om moontlik gebruik te word in 'n stimuleer-versterkingsenstof toedieningstrategie. Die membraangene van onlangs sirkulerende virusstamme in Suid-Afrika was geamplifiseer deur polimerase kettingreaksie (PKR). Die gene is daarna gekloneer vir beide volgordebepalings en uitdrukkingdoeleindes. Filogenetiese verhoudings is uitgewerk deur die volgordes met verwysingsstamme en subtipe C stamme te vergelyk. Uitdrukking van die gene is waargeneem in 293 selle deur die Westerse kladtegniek te gebruik met MIV-1 positiewe pasiëntsera as teenliggaam. Volgorde-analise het aangetoon dat die derde varieerbare (V3) lus meer gekonserveer is, en dat die gedeelte wat op die lus volg meer varieerbaar is. Die kroonvolgorde (GPGQ) asook posisies van ongelaaide of negatief gelaaide aminosure in die V3 lus het aangedui dat die isolate 'n nie-syncytia induserende fenotipe het. Filogenetiese analise het aangedui dat al die volgordes subtipe C is en dat die volgordes nie rekombinant is nie. Dit is ook deur rekombinasie analise bewys. Die inter-monster diversiteit van die Suid-Afrikaanse volgordes was hoër as die waargenome afstand vanaf die subtipe C konsensus volgorde. Die Suid-Afrikaanse volgordes is versprei oor verskeie subgroepe in 'n subtipe C boom, wat die konsep dat hierdie infeksies 'n meer gevestigde epidemie voorstel waar veelvuldige infeksies met verskillende geografiese oorspronge plaasgevind het beklemtoon. Die Westerse klad het ongeprosesseerde gp160 membraanproteïne aangetoon wat Rev afhanklik was. Hierdie studie het hoogs benodigde subtipe C Suid-Afrikaanse volgordes van membraangene geproduseer. Die volgordes kan as basis dien om die gene te modifiseer sodat dit gebruik kan word as immunogene in 'n entstof vir Suid-Afrika.
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Turrell, Susan. "Development of Herpesvirus saimiri as a cancer gene therapy vector : production of 2 recombinant viruses." Thesis, University of Leeds, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.534844.
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McKechnie, Victoria Margaret. "Variation in the NS5A gene of Hepatitis C Virus in response to interferon alpha therapy." Thesis, University of Glasgow, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.301364.
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Chono, Hideto. "Development of retroviral vector technology and application to HIV-1 gene therapy." Kyoto University, 2012. http://hdl.handle.net/2433/157729.
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Chen, Renxiang. "Studies of HIV-1 mutagenesis during drug therapy and the molecular determinants of HIV-1 variation." Connect to this title online, 2004. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1092663963.
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Thesis (Ph. D.)--Ohio State University, 2004.Document formatted into pages. Includes bibliographical references. Abstract available online via OhioLINK's ETD Center; full text release delayed at author's request until 2005 Aug. 16.
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Mathew, Suneeth Fiona, and n/a. "Understanding genetic recoding in HIV-1 : the mechanism of -1 frameshifting." University of Otago. Department of Biochemistry, 2008. http://adt.otago.ac.nz./public/adt-NZDU20081006.115352.
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The human immunodeficiency virus type 1 (HIV-1) uses a mechanism of genetic recoding known as programmed ribosomal frameshifting to translate the proteins encoded by the pol gene. The pol gene overlaps the preceding gag gene in the -1 reading frame relative to gag. It contains neither a start codon nor an internal ribosome entry site (IRES) to initiate translation of its proteins. Rather the host ribosomes are forced to pause due to tension placed on the mRNA when they encounter a specific secondary structural element in the mRNA. This tension is relieved by disruption of the contacts between the mRNA codons and tRNA anticodons at a �slippery� sequence within the ribosomal decoding centre. Re-pairing of the tRNAs occurs in the new -1 frame after movement of the mRNA backwards by one nucleotide, allowing the ribosome to translate the pol gene as a Gag-Pol polyprotein. A change in ratio of Gag to Gag-Pol proteins affects viral assembly, and most significantly dramatically reduces viral infectivity.
The prevailing model for the mechanism of -1 frameshifting has focussed on a pre-translocational event, where slippage occurs when the slippery sequence is within the ribosomal A and P sites. This model precludes a contribution from the codon immediately downstream of the slippery sequence leading into the secondary structural element. I have termed this the �intercodon�. Often at frameshifting sites it is a termination codon, whereas in HIV-1 it is a glycine codon, GGG. When the intercodon within the frameshift element was changed from the wild-type GGG to a termination codon UGA, the efficiency of frameshifting decreased 3-4-fold in an in vivo assay in cultured human cells. This result mimicked previous data in the group within bacterial cells and cultured monkey COS-7 cells. Changing the first nucleotide of the intercodon to each of the three other bases altered frameshifting to varying degrees, but not following expected patterns for base stacking effects. Such a result would support a post-translocational model for -1 frameshifting. It suggested that the intercodon might be within the ribosomal A site before frameshifting, and that the slippery sequence was therefore within the P and E sites.
This was investigated by modulating the expression of decoding factors for the intercodon - the release factor eRF1 and cognate suppressor tRNAs when it was either of the UGA or UAG termination codons, and tRNA[Gly] for the native GGG glycine codon. These were predicted to affect frameshifting only if slippage were occurring when the ribosomal elongation cycle was in the post-translocational state. Overexpression of tRNA[Gly] gave inconsistent effects on frameshifting in vivo, implying that its concentration may not be limiting within the cell. When eRF1 was overexpressed or depleted by RNAi, significant functional effects of decreased or increased stop codon readthrough respectively were documented. Expression of suppressor tRNAs increased readthrough markedly in a stop codon-specific manner. These altered levels of eRF1 expression were able to modulate the +1 frameshifting efficiency of the human antizyme gene. Overexpression of eRF1 caused significant reduction of frameshifting of the HIV-1 element with the UAG or UGA intercodon. Depletion of the protein by contrast had unexplained global effects on HIV-1 frameshifting. Suppressor tRNAs increased frameshifting efficiency at the UAG or UGA specifically in a cognate manner. These results strongly indicate that a post-translocational mechanism of frameshifting is used to translate the HIV-1 Gag-Pol protein.
A new model (�almost� post-translocational) has been proposed with -1 frameshifting occurring for 1 in 10 or 20 ribosomal passages during the end stages of translocation, because of opposing forces generated by translocation and by resistance to unwinding of the secondary structural element. With translocation still incomplete the slippery sequence is partially within the E and P sites, and the intercodon partially within the A site. The nature of the intercodon influences frameshifting efficiency because of how effectively the particular decoding factor is able to bind to the partially translocated intercodon and maintain the normal reading frame.
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Kambole, Mercy Mulenga. "The attitudes of physiotherapists in Gaborone and Ramotswa, Botswana, towards treating people living with HIV/AIDS." Thesis, University of the Western Cape, 2007. http://etd.uwc.ac.za/index.php?module=etd&action=viewtitle&id=gen8Srv25Nme4_7700_1256285107.
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Physiotherapists are increasingly treating peole living with HIV/AIDS. However, there is little information which has been reported on their attitudes in providing treatment to people with HIV/AIDS or what facilitates positive attitudes. The aim of this study was to determine attitudes of physiotherapists towards treating people living with HIV/AIDS in Botswana.
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Medina, Maria Fe C. "Strategies for isolation and expression of ribozymes for use in HIV gene therapy." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape2/PQDD_0025/NQ49949.pdf.
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Adams, Gregor Barr. "The development of a haemopoietic stem cell gene therapy for HIV-1 infection." Thesis, Imperial College London, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.325184.
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Kim, Vic Narry. "Analysis of components of HIV in the development of new gene transfer systems." Thesis, University of Oxford, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.389043.
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Huang, Kuan-Hsiang Gary. "The impact of host and therapy mediated selection on HIV-1 evolution." Thesis, University of Oxford, 2010. http://ora.ox.ac.uk/objects/uuid:b49d0d79-75c9-4314-92ae-1f1789ac7d42.
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The Human immunodeficiency virus (HIV) pandemic has resulted in a heavy global disease burden, and clinically causes Acquired Immuno-Deficiency Syndrome (AIDS). The development of highly active antiretroviral therapy (HAART) has achieved remarkable control of the rapidly evolving HIV. However, HIV remains neither curable nor preventable by vaccine, and in the developing regions worst affected by HIV, HAART remains inaccessible to most patients. Furthermore, the change in both immunology and viral evolution during chronic HIV infection and its relation to AIDS pathogenesis remains unknown. Following the failure of recent HIV vaccines, it is believed that a better understanding of host-pathogen interaction is vital to advance therapeutic (vaccine and drug) design. In this thesis, I have performed an investigation of viral adaptation in response to different selection forces during advanced HIV infection and AIDS. The thesis first examined a case study that reveals the potential role of B cell-mediated neutralising antibody (NAb) in chronic HIV infection through the unexpected effect of B cell depletion agent, anti-CD20 (Rituximab). Here, longitudinal results have shown that viral load (VL), env gene diversity, and NAb sensitive strains increased during B cell and NAb depletion as a result of Rituximab administration, and reversed as B cells recovered. The study provides preliminary evidence to support the idea that NAb may be effective at suppressing HIV. The rest of the thesis focused on the cross-sectional cohort at Bloemfontein, South Africa (n=1491), a resource-limited region affected by the pandemic. Here, we used methods that include molecular and pretherapy drug resistance epidemiology, mathematical modelling, phylogenetically adjusted bioinformatics analysis and in vitro viral replication capacity (VRC) assay to study materials including cohort demography, plasma samples, CD4 cell count, VL, viral genetic sequences and host human leukocyte antigen (HLA) tissue types. Our analysis was further augmented by the additional data kindly contributed by our neighbouring Durban cohort collaborators (n=775), which also includes an IFN! ELISPOT assay that measures cytotoxic T lymphocyte (CTL) responses. Using the HIV pol sequencing data and phylogenetic analysis we confirmed that the local molecular epidemiology is similar to the circulating strains documented in the regional database. However, the pretherapy drug resistance mutation screening results have revealed an unexpected high incidence of drug-induced viral mutants in the AIDS patients with CD4 counts <100 cells/μl. According to mathematical modelling, this finding is attributable to additional sources of antiretroviral therapy exposure, which warrants public health caution. The investigation then focused on studying the changes in HLA class I mediated CTL selection and viral evolution as CD4 counts are reduced in AIDS. Interestingly we have noted evidence that suggest weakening CTL immune selection against gag during AIDS is associated with increased viral fitness (measured by VRC) and reversion of previous immune-escape mutations which conferred high fitness costs. In conclusion, this thesis compared different sources of host and drug mediated HIV selection and its implication for viral evolution. The identification of more bottleneck sites conferring high fitness costs to the selection of escape mutants is expected to be helpful in the design of future therapeutics (via vaccine, drug, immune therapy, or public health strategy). As we have learnt from the principle of combinational ARV, it would be desirable for a vaccine to select HIV at multiple sites of high escape-mutation fitness cost, hence offering protective effect.
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Dias, Florencio Leite Gabriella. "Recombinant Adeno-Associated Viruses : process development and gene transfer application for muscular dystrophy." Thesis, Université Paris-Saclay (ComUE), 2017. http://www.theses.fr/2017SACLV051/document.
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L'intérêt de l’utilisation des vecteurs viraux comme le Adeno-Associated Virus recombinant (rAAV) dans la recherche pour le traitement des maladies génétiques a conduit à une évolution rapide des méthodes de production d'AAV au cours des deux dernières décennies (Ayuso et al., 2010). Leur large biodisponibilité in vivo et leur efficacité à long terme dans les tissus postmitotiques en font de bons candidats pour de nombreuses applications de transfert de gènes. En plus, la spécificité du traitement peut être augmentée lorsque le sérotype correct est choisi pour cibler un tissu spécifique. Parmi les méthodes de production actuellement utilisées, la tri-transfection de cellules embryonnaires humaines rénales 293 (HEK293) reste la plus populaire pour l'échelle de recherche; Et la production de rAAV médiée par des baculovirus pour des échelles plus importantes. L'importance croissante des vecteurs viraux dans l'application pratique de la thérapie génique exige l'amélioration des processus de production, en particulier en ce qui concerne les rendements et la pureté du produit final. Mon travail au cours de ces quatre années a été axé sur deux points principaux: (1) améliorer les processus biotechnologiques employés dans la production de rAAV pour la recherche et les échelles d'étude préclinique et (2) tester in vitro et in vivo les applications pour le rAAV dans le l’édition de genome. L'édition de gènes médiée par des nucléases spécialement conçues offre de nouveaux espoirs pour le traitement de plusieurs maladies héréditaires monogéniques. Récemment découvert, le système CRISPR Cas9 (Clustered Regular Interspaced Short Palindromic Repeats) fournit des outils importants nécessaires pour corriger les mutations par homologie. Notre modèle canonique est la souris mdx, un modèle animal naturel de la dystrophie musculaire de Duchenne (DMD). Les mutations DMD, qui conduisent à l'absence de protéine dystrophine, entraînent une myopathie progressive et fatale. Plusieurs stratégies, allant des stratégies pharmacologiques aux stratégies de saut-d’éxon, ont tenté de renverser le phénotype et ralentisser la progression de la maladie, mais les résultats ne sont pas encore satisfaisants. Ce nouvel et puissant outil d'édition de génome peut être vectorisé par rAAV. Les résultats de la première partie ont été publiés en 2015 et 2016 et seront présentés sous la forme d'articles et pour la deuxième partie, je présenterai les résultats préliminaires et les perspectives du travail qui se poursuivra dans le laboratoireThe interest of recombinant Adeno-Associated Virus (rAAV) vectors for research and clinical purposes in the treatment of genetic diseases have led to the rapid evolution of methods for AAV production in the last two decades (Ayuso et al., 2010). Their broad in vivo biodistribution and long-term efficacy in postmitotic tissues make them good candidates for numerous gene transfer applications. In addition, the specificity of the treatment can be increased when the right serotype is chosen to target a specific tissue. Among the production methods currently in use, tri-transfection of human embryonic kidney 293 (HEK293) cells remains the most popular for research scale; and rAAV production mediated by baculoviruses for larger scales. The increasing importance of viral vectors in the practical application of gene therapy demands the improvement of production processes, especially when it concerns the yields and purity of the final product. My work during these four years was focused in two main points: (1) improve biotechnological processes employed in rAAV production for research and pre-clinical study scales and (2) test in vitro and in vivo the applications for rAAV in the field of genome editing. Gene-editing mediated by engineered nucleases offers new hopes for the treatment of several monogenic inherited diseases. Recently discovered, the CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats) Cas9 system provides important tools needed to correct by homology-directed repair mutations. Our canonical model is the mdx mouse, a naturally occurring animal model of Duchenne Muscular Dystrophy (DMD). DMD mutations, which lead to the absence of the protein dystrophin, results in a progressive and fatal myopathy. Several strategies, from pharmacological to exon-skipping strategies, have attempt to revert the phenotype and slow down the disease progress, however results are not yet satisfactory. This new and powerful genome editing tool can be vectorized by rAAV. Results for the first part were published in 2015 and 2016 and will be presented in the form of articles and for the second part I will present preliminary results and perspectives for the work that will be continued in the lab
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Bazan, Peregrino Miriam. "Combining regulatory angiogenic gene therapy and virotherapy for the treatment of breast cancer." Thesis, University of Oxford, 2007. http://ora.ox.ac.uk/objects/uuid:550c6509-a52e-4770-8bff-dae2071c3ade.
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This thesis describes the design of a virotherapy strategy capable of destroying both breast cancer vasculature and tumour cells, using an oncolytic adenovirus expressing angiogenesis-regulating proteins. Five oncolytic adenoviruses were compared to identify the best virotherapy agent for breast cancer, including measurement of cytotoxicity in vitro, and replication, intra-tumoural spread and anticancer efficacy in vivo. The viruses tested were Ad-dl922-947 (targets G1-S checkpoint defects); Ad-Onyx-015 and Ad-Onyx-017 (target p53/mRNA nuclear export defects); Ad-vKH1 (targets Wnt pathway defects) and AdEHE2F (targets estrogen receptor/G1-S checkpoint/hypoxia signalling defects). AdEHE2F demonstrated optimal oncolytic activity and selectivity against breast cancer, accordingly this virus was engineered to express potent regulatory angiogenic proteins, namely soluble Flt1 and soluble Delta like-4 (Dll4). sFlt1 is the soluble extra-cellular domain of VEGFR1 and binds to and sequesters VEGF-A, thereby preventing VEGFR2 stimulation which is crucial to trigger angiogenesis. sDll4 is the soluble extracellular domain of Dll4 and has been previously shown to block Dll4/Notch signalling. Dll4/Notch signalling increases a chaotic and non-functional angiogenesis which ultimately delays tumour growth. Importantly, VEGF and Dll4 are the only angiogenesis genes reported to be haploinsufficient in vascular development and both have been shown to have a good anti-tumour effect. sFlt1 and sDll4 genes were substituted for the viral genes E3 6.7K/gp19K of AdEHE2F, thereby using endogenous adenoviral machinery to drive production. The activities of AdEHE2F viruses expressing either sFlt1 or sDll4 were compared in vitro and in vivo. sFlt1 (expressed from AdEHE2F) inhibited endothelial cell proliferation and sprouting whereas sDll4 increased proliferation and branching in vitro. In vivo AdEHE2F expressing sFlt1 or sDll4 both showed superior anticancer activity compared to parental AdEHE2F, indicating at least additive efficacy between virotherapy and regulatory angiogenic approaches.
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Ui, Masahiro. "Protection of Macaques Vaccinated with Gene-Deleted HIV-1/SIVmac Chimeric Viruses(SHIVs)Having HIV-1 Env against a Gene-Intact SHIV : a Potential of Live-Attenuated Vaccines for AIDS." Kyoto University, 2000. http://hdl.handle.net/2433/181021.
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Kyoto University (京都大学)0048
新制・課程博士
博士(人間・環境学)
甲第8455号
人博第85号
11||153(吉田南総合図書館)
新制||人||21(附属図書館)
UT51-2000-F359
京都大学大学院人間・環境学研究科人間・環境学専攻
(主査)教授 速水 正憲, 教授 池永 満生, 教授 松井 正文
学位規則第4条第1項該当
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Mustafa, Farah. "HIV-1 Sequences in the Establishment of Chronic Virus Producers: a Thesis." eScholarship@UMMS, 1993. https://escholarship.umassmed.edu/gsbs_diss/38.
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Human immunodeficiency virus type 1 (HIV-1) infections have different patterns of expression in different T-cell lines. HIV-1 encodes regulatory as well as structural genes. The role of HIV-1 regulatory gene expression in determining different patterns of infection was explored in four T-cell lines: C8166, H9, A3.01, and Jurkat. The hypothesis being tested was that differences in the expression of regulatory genes would determine differences in the kinetics of infection.
To study patterns of regulatory and structural gene expression, RNA was isolated from cultures infected with HIV-1-NL4-3 (NL4-3). During the early and acute phases of infection, the absolute amounts of viral RNA differed in the four T-cell lines. However, the relative proportions of messages for regulatory and structural genes were similar. Thus, differences in the kinetics of infection in C8166, H9, A3.01 and Jurkat cells were not determined by differences in the relative levels of expression of regulatory and structural genes.
Analyses of RNA samples from the chronic phase of infection revealed the consistent appearance of novel RNase sensitive sites in H9 and Jurkat cultures. These marked the emergence of viral variants with high ability to establish chronic virus producers. These variants were specifically selected in the chronic phase since they did not undergo selection during serial passage of the virus through the lytic phase of infection. Sequence analysis of the region with the novel RNase sensitive sites revealed the co-mapping of nucleotide changes with each of the novel sites. Most of these differences represented a sense mutation in tat and the abrogation of the initiator methionine of vpu. However, the selected mutations in tat and vpuwere not sufficient, by themselves, to affect the ability of NL4-3 to establish chronic virus producers (Chapters I and II).
Further studies on the roles of viral sequences in the chronic phase of infection were undertaken using constructed viruses. Two molecularly cloned viruses, NL4-3 and HIV-1-HXB-2 (HXB-2), were used as parents. NL4-3 has a low ability to establish chronic virus producers. In contrast, HXB-2 has a high ability to establish chronic virus producers. NL4-3 encodes all known HIV-1 genes, whereas HXB-2 is defective for three auxiliary genes: vpr, vpu, and nef. In addition, both viruses differ at other positions throughout the genome. The first series of constructed viruses tested whether differences in auxiliary gene expression determined differences in the ability of NL4-3 and HXB-2 to establish chronic virus producers. NL4-3 mutants containing all possible combinations of the three defective genes in HXB-2 were constructed. Analysis of the ability of these mutants to establish chronic virus producers revealed that vpr and neflimit the ability of NL4-3 to establish chronic virus producers. This was shown by viruses with defects in both of these genes having high ability to establish chronic virus producers (Chapter III).
The second series of constructs tested for the roles of non-auxiliary as well as auxiliary gene sequences on chronic virus production by creating recombinants between NL4-3 and HXB-2. Tests of these recombinants revealed that a gag, pol, vif, and vpr fragment could affect the ability of fragments containing defective auxiliary genes to establish chronic virus producers. Taken together, these results indicate that vpr, nef, and 5' internal sequences play important roles in determining the ability to establish chronic virus producers (Chapter IV).
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Lipinski, Daniel Mark. "Neuroprotection of cone photoreceptors in retinitis pigmentosa." Thesis, University of Oxford, 2013. http://ora.ox.ac.uk/objects/uuid:aee440bc-f990-4216-9d43-63902ff0fc52.
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Retinitis pigmentosa (RP) is a genetically and phenotypically heterogeneous condition that affects approximately 1 in 4000 individuals worldwide. The most common presentation of RP is a rod-cone dystrophy, where the degeneration of cone photoreceptors occurs secondary to advanced rod loss, leading to a significant decline in central vision and a corresponding reduction in patient quality of life. The mechanisms underlying secondary cone loss are poorly understood, particularly in disorders where the gene defect is unknown or manifest only in rod photoreceptors. Consequently, the thesis presented herein proceeds on several fronts. First, in the long term a greater understanding of the causes underlying cone loss in RP is likely to be beneficial, and so in chapter one a dominant cone degeneration is characterized using intrinsically fluorescent cone photoreceptors to track the degenerative process. Second, as we develop a greater understanding of the genetic etiology underlying RP it is likely that the number of large genes identified as being causative will increase. As currently there is no efficient way to deliver large genes to photoreceptors, chapter two explores the use of alternate viral vectors that might be used to deliver a large therapeutic transgene. Lastly, whilst our understanding of cone loss in RP remains incomplete, it is necessary to develop a broadly applicable therapy to slow or attenuate further cone loss in RP patients regardless of the underlying cause. In chapters three and four we examine the use of low molecular weight "growth factors‟, such as ciliary neurotrophic factor (CNTF), to preserve cone photoreceptors long-term using a rhodopsin knockout model of RP.
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Thobias, Anna. "Exploration of factors associated with poor adherence among patients receiving antiretroviral therapy at Katutura State Hospital Communicable Disease Clinic in Khomas region, Namibia /." Online access, 2008. http://etd.uwc.ac.za/usrfiles/modules/etd/docs/etd_gen8Srv25Nme4_2455_1273775841.pdf.
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Arteaga, H. Jose. "Strategies of gene and immune therapy for tumors and viral diseases /." Stockholm, 2003. http://diss.kib.ki.se/2003/91-7349-528-x.
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Tsang, Shirley Xiaoman. "TATA-dependent repression of human immunodeficiency virus Type-1 transcription by the Adenovirus E1A 243R oncoprotein." Diss., Georgia Institute of Technology, 1996. http://hdl.handle.net/1853/25325.
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