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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Expressão intra e extracelular da proteína L1 de HPV 16, a partir da construção Ppiczal1h16 pPICZAαL1H16, em células de Pichia pastoris

CARVALHO, Janaine Cavalcanti 07 October 2011 (has links)
Submitted by Caroline Falcao (caroline.rfalcao@ufpe.br) on 2017-04-04T18:59:29Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) 2011-Dissertação-JanaineCarvalho.pdf: 1997829 bytes, checksum: 1182cc1385c167fb2f0bfaa773d3a959 (MD5) / Made available in DSpace on 2017-04-04T18:59:29Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) 2011-Dissertação-JanaineCarvalho.pdf: 1997829 bytes, checksum: 1182cc1385c167fb2f0bfaa773d3a959 (MD5) Previous issue date: 2011-10-07 / O câncer cervical é a segunda maior causa de mortes entre mulheres no mundo. Esta neoplasia maligna está relacionada com a presença do Papilomavírus Humano (HPV), sendo o tipo 16 responsável por 60% dos casos. O HPV infecta o tecido epitelial mucoso ou cutâneo e é responsável pelo aparecimento de verrugas ou papilomas benignos que tendem a regredir naturalmente na maioria dos casos, mas que ainda assim causam prejuízos aos indivíduos infectados e aos sistemas públicos de saúde, sendo a papilomatose considerada a doença sexualmente transmissível mais prevalente no mundo, tornando essencial a aplicação de estratégias de combate à esta infecção. Vacinas baseadas em Virus-like particles (VLPs), formadas a partir das proteínas capsidiais L1 e L2 - que induzem a formação de anticorpos neutralizantes - já estão comercialmente disponíveis. Contudo, possuem um preço elevado considerando, principalmente, os países em desenvolvimento. A imunidade humoral é direcionada contra os epítopos conformacionais da proteína L1 que compõe 90% da estrutura capsidial. Para produção das VLPs os genes das proteínas capsidiais são expressos em sistemas heterólogos e o produto resultante é purificado. A escolha de um sistema mais simples e barato para essa expressão é fundamental para a redução do custo das vacinas. Uma alternativa promissora é a levedura Pichia pastoris. Este trabalho propôs a produção extracelular e intracelular da proteína L1 de HPV16, que teve seu gene inserido no vetor pPCIZAα e pPCIZA, respectivamente. As construções pPICZAαL1H16 e pPICZAL1H16 foram integradas no genoma da levedura Pichia pastoris e a transcrição do gene L1 e a expressão da proteína foram confirmadas por RT-PCR e imunodetecção em Dot Blot. A busca de uma melhor expressão da proteína L1 de HPV 16, em células de P. pastoris, é uma etapa essencial na busca do desenvolvimento de uma estratégia vacinal mais economicamente viável baseada em VLPs. / The Cervical cancer is the second leading cause of death among women worldwide. This malignancy is related to the presence of human papillomavirus (HPV) being the type 16 responsible for 60% of the cases. HPV infects cutaneous or mucosal epithelial tissue and is responsible for the appearance of benign papillomas or warts that tend to regress naturally in most cases, but still cause damage to infected individuals and public health systems, with papillomatosis being considered the most prevalent sexually transmitted disease worldwide, making essential to implement strategies to combat this infection. Vaccines based on viruslike particles (VLPs), formed from the capsid proteins L1 and L2 - that induce the formation of neutralizing antibodies - are already commercially available. However, they are expensive considering mainly the developing countries. Humoral immunity is directed against conformational epitopes of the L1 protein which represents 90% of the capsid structure. In order to produce VLPs the capsid protein genes are expressed in heterologous systems and the resulting product is purified. The choice of a simpler and cheaper system for this expression is fundamental to reduce the cost of vaccines. A promising alternative is the Pichia pastoris yeast. This paper proposed the extracellular and intracellular generation of HPV16 L1 protein, which had its gene inserted into the vectors pPCIZAα e pPCIZA, respectively. The pPICZAαL1H16 and pPICZAL1H16 plasmids were integrated into the Pichia pastoris yeast genome and the L1 gene transcription and protein expression were confirmed by RT-PCR and immunodetection in Dot Blot. The search for better expression of HPV 16 L1 protein, in cells of P. pastoris, is an essential step in the quest to develop a more economically viable vaccine strategy based on VLPs.
12

Clonagem, expressão, purificação e caracterização das proteínas do capsídio viral do papilomavírus humano (HPV) / Cloning, expression, purification and characterization of human papillomavirus (HPV) capsid proteins

Chaves, Ágtha de Alencar Muniz 17 December 2012 (has links)
O Câncer Cervical é um importante problema de saúde pública, causando aproximadamente 270 milhões de mortes anuais. Atualmente, esse câncer é o segundo mais comum em mulheres no mundo, com os maiores índices de incidência ocorrendo nos países em desenvolvimento. O Câncer cervical tem como agente etiológico o Papilomavírus Humano (HPV). O vírus possui DNA circular duplo com genes que codificam oito proteínas, E1, E2, E4, E5, E6, E7 (não estruturais), e L1 e L2 (estruturais) que formam o capsídio viral. A proteína L1 quando produzida em sistema heterólgo de expressão tem a capacidade de auto-arranjo em partículas semelhantes ao vírus chamadas de VLPs (\"Vírus like Particles\"), que são a base das vacinas profiláticas disponíveis, Gardasil® e Cervarix®. Neste trabalho, foram produzidas VLPs da proteína L1 do HPV-16 na levedura metilotrófica Pichia pastoris utilizando dois tipos de vetores de expressão para leveduras, um epissomal e outro integrativo, para os trabalhos de purificação. Inicialmente as amostras obtidas ao final da purificação apresentaram degradação e agregação da proteína L1, além de contaminantes. O protocolo de purificação foi modificado e as amostras obtidas no final do processo de purificação não apresentaram degradação e nem agregação da proteína L1, embora ainda tenha sido detectada a presença de contaminantes e, portanto, as amostras obtidas estavam semi-purificadas. Uma segunda abordagem para o desenvolvimento de uma vacina alternativa foi realizada, na qual foram produzidos candidatos vacinais baseados na proteína L2 do Papilomavírus Humano (L2 do HPV-16, L2 do HPV-18 e L2 Multimérica), e também foram expressas proteínas fusionadas ao domínio ZZ de Staphylococcus aureus, utilizado neste caso como adjuvante. Em geral as proteínas de fusão, ainda que apresentando a fusão em sua forma funcional, geraram uma fraca indução de anticorpos IgG e de anticorpos neutralizantes. Pode-se observar uma produção de anticorpos neutralizantes contra pseudovírus homólogos e heterólogos que dependeu da combinação com os adjuvantes utilizados. Numa tentativa de maximizar a eficiência imunológica dos antígenos utilizados, um novo ensaio de imunização foi realizado com uma formulação conjunta contendo três proteínas (L2 do HPV-16, L2 do HPV-18 e L2 Multimérica), sendo também avaliadas as propriedades de três adjuvantes. A combinação da formulação vacinal com os adjuvantes gerou altos níveis de anticorpos L2-específicos, destacando-se as formulações com o hidróxido de alumínio/MPLA e com a vacina celular Pertussis low. Com a utilização desses adjuvantes, os níveis de anticorpos permaneceram elevados a longo termo. Pode-se observar a imunogenicidade de cada um dos antígenos dependeu de sua formulação com os adjuvantes testados. / Cervical cancer is one of the most important problems of public health, causing nearly 270 million deaths annually. Currently, cervical cancer is the second more common type in women worldwide and the highest incidences occuring in developing countries. Human papillomavirus (HPV) are the ethiologic agents of cervical cancer. HPV have a double-stranded circular DNA genome encoding eight viral proteins, E1, E2, E4, E5, E6, E7 (non-structural), and L1, L2 (structural), the last ones forming the viral capsid. L1 protein expressed in heterologous systems self-assembles into VLPs (\"Virus like Particles\"), the base of prophylactic vaccines available commercially, Gardasil and Cervarix. In this work, we produced VLPs of HPV-16 L1 protein in the methylotrophic yeast Pichia pastoris for purification assays. Initially, samples obtained from purification presented degradation and aggregation of L1 protein and also contaminants. The purification protocol was modified and samples obtained in the new process did not present degradation nor aggregation but the presence of some contaminants could still be detected. Therefore, samples obtained were semi-purified. A second approach to the development of an alternative vaccine was performed with the production of vaccine candidates based on the HPV L2 protein (HPV-16 L2, HPV-18 L2 and Multimeric L2) and we also expressed the same proteins fused to Staphyloccocus aureus ZZ domain, using it as an adjuvant. In general, the fused proteins induced low antibodies titer and low neutralizing antibodies titer when compared to other formulations. Neutralizing antibodies elicited against homologous and heterologous pseudovirus depended on the adjuvant used. In another approach, trying to enhance immunologic antigen efficiencies, an immunization assay was performed with a formulation containing L2 HPV- 16, L2 HPV-18 and Multimeric L2 and the properties of three adjuvants were assessed. The vaccine formulations adjuvanted with alum/MPLA and cellular Pertussis low vaccine induced the highest levels of L2-specific antibodies. In addition, the usage of adjuvants maintained the antibody levels in the long term. The immunogenicity of each antigen depends on the adjuvant combination used.
13

Příprava polyomavirových nanostruktur pro diagnostiku BK virových infekcí / Preparation of polyomaviral nanostructures for diagnostics of BK virus infections

Sekavová, Alžběta January 2017 (has links)
No description available.
14

Clonagem, expressão, purificação e caracterização das proteínas do capsídio viral do papilomavírus humano (HPV) / Cloning, expression, purification and characterization of human papillomavirus (HPV) capsid proteins

Ágtha de Alencar Muniz Chaves 17 December 2012 (has links)
O Câncer Cervical é um importante problema de saúde pública, causando aproximadamente 270 milhões de mortes anuais. Atualmente, esse câncer é o segundo mais comum em mulheres no mundo, com os maiores índices de incidência ocorrendo nos países em desenvolvimento. O Câncer cervical tem como agente etiológico o Papilomavírus Humano (HPV). O vírus possui DNA circular duplo com genes que codificam oito proteínas, E1, E2, E4, E5, E6, E7 (não estruturais), e L1 e L2 (estruturais) que formam o capsídio viral. A proteína L1 quando produzida em sistema heterólgo de expressão tem a capacidade de auto-arranjo em partículas semelhantes ao vírus chamadas de VLPs (\"Vírus like Particles\"), que são a base das vacinas profiláticas disponíveis, Gardasil® e Cervarix®. Neste trabalho, foram produzidas VLPs da proteína L1 do HPV-16 na levedura metilotrófica Pichia pastoris utilizando dois tipos de vetores de expressão para leveduras, um epissomal e outro integrativo, para os trabalhos de purificação. Inicialmente as amostras obtidas ao final da purificação apresentaram degradação e agregação da proteína L1, além de contaminantes. O protocolo de purificação foi modificado e as amostras obtidas no final do processo de purificação não apresentaram degradação e nem agregação da proteína L1, embora ainda tenha sido detectada a presença de contaminantes e, portanto, as amostras obtidas estavam semi-purificadas. Uma segunda abordagem para o desenvolvimento de uma vacina alternativa foi realizada, na qual foram produzidos candidatos vacinais baseados na proteína L2 do Papilomavírus Humano (L2 do HPV-16, L2 do HPV-18 e L2 Multimérica), e também foram expressas proteínas fusionadas ao domínio ZZ de Staphylococcus aureus, utilizado neste caso como adjuvante. Em geral as proteínas de fusão, ainda que apresentando a fusão em sua forma funcional, geraram uma fraca indução de anticorpos IgG e de anticorpos neutralizantes. Pode-se observar uma produção de anticorpos neutralizantes contra pseudovírus homólogos e heterólogos que dependeu da combinação com os adjuvantes utilizados. Numa tentativa de maximizar a eficiência imunológica dos antígenos utilizados, um novo ensaio de imunização foi realizado com uma formulação conjunta contendo três proteínas (L2 do HPV-16, L2 do HPV-18 e L2 Multimérica), sendo também avaliadas as propriedades de três adjuvantes. A combinação da formulação vacinal com os adjuvantes gerou altos níveis de anticorpos L2-específicos, destacando-se as formulações com o hidróxido de alumínio/MPLA e com a vacina celular Pertussis low. Com a utilização desses adjuvantes, os níveis de anticorpos permaneceram elevados a longo termo. Pode-se observar a imunogenicidade de cada um dos antígenos dependeu de sua formulação com os adjuvantes testados. / Cervical cancer is one of the most important problems of public health, causing nearly 270 million deaths annually. Currently, cervical cancer is the second more common type in women worldwide and the highest incidences occuring in developing countries. Human papillomavirus (HPV) are the ethiologic agents of cervical cancer. HPV have a double-stranded circular DNA genome encoding eight viral proteins, E1, E2, E4, E5, E6, E7 (non-structural), and L1, L2 (structural), the last ones forming the viral capsid. L1 protein expressed in heterologous systems self-assembles into VLPs (\"Virus like Particles\"), the base of prophylactic vaccines available commercially, Gardasil and Cervarix. In this work, we produced VLPs of HPV-16 L1 protein in the methylotrophic yeast Pichia pastoris for purification assays. Initially, samples obtained from purification presented degradation and aggregation of L1 protein and also contaminants. The purification protocol was modified and samples obtained in the new process did not present degradation nor aggregation but the presence of some contaminants could still be detected. Therefore, samples obtained were semi-purified. A second approach to the development of an alternative vaccine was performed with the production of vaccine candidates based on the HPV L2 protein (HPV-16 L2, HPV-18 L2 and Multimeric L2) and we also expressed the same proteins fused to Staphyloccocus aureus ZZ domain, using it as an adjuvant. In general, the fused proteins induced low antibodies titer and low neutralizing antibodies titer when compared to other formulations. Neutralizing antibodies elicited against homologous and heterologous pseudovirus depended on the adjuvant used. In another approach, trying to enhance immunologic antigen efficiencies, an immunization assay was performed with a formulation containing L2 HPV- 16, L2 HPV-18 and Multimeric L2 and the properties of three adjuvants were assessed. The vaccine formulations adjuvanted with alum/MPLA and cellular Pertussis low vaccine induced the highest levels of L2-specific antibodies. In addition, the usage of adjuvants maintained the antibody levels in the long term. The immunogenicity of each antigen depends on the adjuvant combination used.
15

Expressão de proteínas estruturais de Alphavirus em células S2 (D melanogaster) / Expression of Alphavirus structural proteins in the Drosophila Schneider 2 cell system

Puglia, Ana Lia Pradella 29 August 2018 (has links)
No grupo das doenças infecciosas emergentes e reemergentes, os arbovírus transmitidos por mosquitos, são considerados importantes desafios para a saúde pública. O alastramento mundial do vírus Chikungunya (CHIKV, Togaviridae, Alphavirus), acabou resultando na introdução do CHIKV no Brasil, através da transmissão zoonótica por mosquitos do gênero Aedes spp, particularmente Ae. aegypti e Ae. albopictus, duas espécies invasoras e cosmopolitas. Outro Alphavirus, o vírus Mayaro (MAYV) presente na região amazônica da América do Sul, vem apresentando indícios de uma real urbanização, elevando a preocupação sobre sua possível transmissão por mosquitos urbanos. Diante desse cenário, fica clara a necessidade da realização de estudos sobre estratégias de controle e prevenção da infecção por MAYV e CHIKV, uma vez que não há vacinas ou terapia antiviral específica para a infecção por esses arbovírus. Este projeto descreve pela primeira vez a eficiente expressão, purificação e análise de partículas semelhantes a vírus (VLP, virus-like particles) dos Alphavirus CHIKV e MAYV em células de inseto S2 (Drosophila melanogaster). Para esse fim, clonamos os genes das proteínas estruturais dos vírus MAYV e CHIKV em vetores para a expressão recombinante em células S2. Essa plataforma de expressão de proteínas provou ser adequada para o processamento de glicoproteínas do CHIKV e MAYV para produção de VLP, uma vez que detectamos a presença de partículas no sobrenadante do cultivo por Western blotting e Microscopia eletrônica de transmissão (TEM). Ainda, foi possível selecionar células para uma maior produção de VLP e estabelecer um método de purificação das partículas. / In the group of emerging and reemerging infectious diseases, mosquito-borne arboviruses are considered major public health challenges. The transmission of Chikungunya (CHIKV, Togaviridae, Alphavirus) in America continent was first reported in Central America and Caribbean region The CHIKV epidemics reached Brazil through zoonotic transmission by Aedes spp mosquitoes, particularly Ae. Aegypti and Ae. albopictus, two invasive and cosmopolitan species. Another Alphavirus, the Mayaro virus (MAYV) present mainly in the Amazon region has been showing evidence of a real urbanization, increasing concerns about its transmission by urban mosquitoes. Therefore, it is clear that studies on strategies for the control and prevention of MAYV and CHIKV infection are needed. Currently no vaccines or antiviral therapy specific for CHIKV and MAYV infection are available. This work describes for the first time an efficient expression, purification and analysis of virus-like particles (VLP) of CHIKV and MAYV Alphaviruses in S2 (Drosophila melanogaster) insect cells. The genes coding for the structural proteins of the MAYV and CHIKV viruses were cloned into vectors for recombinant expression in S2 cells. This platform proved to be suitable for the processing of CHIKV and MAYV glycoproteins and to produce VLP, since we detected the presence of particles in the culture supernatant by Western blotting and Transmission Electron Microscopy (TEM). Furthermore, it was possible to select cells for greater production of VLP and to establish a method for particle purification.
16

Biological and Immunological Characterization of Plant-Produced HIV-1 Gag/dgp41 Virus-Like Particles

January 2011 (has links)
abstract: Anti-retroviral drugs and AIDS prevention programs have helped to decrease the rate of new HIV-1 infections in some communities, however, a prophylactic vaccine is still needed to control the epidemic world-wide. Despite over two decades of research, a vaccine against HIV-1 remains elusive, although recent clinical trials have shown promising results. Recent successes have focused on highly conserved, mucosally-targeted antigens within HIV-1 such as the membrane proximal external region (MPER) of the envelope protein, gp41. MPER has been shown to play critical roles in the viral mucosal transmission, though this peptide is not immunogenic on its own. Gag is a structural protein configuring the enveloped virus particles, and has been suggested to constitute a target of the cellular immunity potentially controlling the viral load. It was hypothesized that HIV-1 enveloped virus-like particles (VLPs) consisting of Gag and a deconstructed form of gp41 comprising the MPER, transmembrane, and cytoplasmic domains (dgp41) could be expressed in plants. Plant-optimized HIV-1 genes were constructed and expressed in Nicotiana benthamiana by stable transformation, or transiently using a tobacco mosaic virus-based expression system or a combination of both. Results of biophysical, biochemical and electron microscopy characterization demonstrated that plant cells could support not only the formation of HIV-1 Gag VLPs, but also the accumulation of VLPs that incorporated dgp41. These particles were purified and utilized in mice immunization experiments. Prime-boost strategies combining systemic and mucosal priming with systemic boosting using two different vaccine candidates (VLPs and CTB-MPR - a fusion of MPER and the B-subunit of cholera toxin) were administered to BALB/c mice. Serum antibody responses against both the Gag and gp41 antigens could be elicited in mice systemically primed with VLPs and these responses could be recalled following systemic boosting with VLPs. In addition, mucosal priming with VLPs allowed for a robust boosting response against Gag and gp41 when boosted with either candidate. Functional assays of these antibodies are in progress to test the antibodies' effectiveness in neutralizing and preventing mucosal transmission of HIV-1. This immunogenicity of plant-based Gag/dgp41 VLPs represents an important milestone on the road towards a broadly-efficacious and inexpensive subunit vaccine against HIV-1. / Dissertation/Thesis / Ph.D. Molecular and Cellular Biology 2011
17

Immunogenic Subviral Particles Displaying Domain III of Dengue 2 Envelope Protein Vectored by Measles Virus

January 2015 (has links)
abstract: Vaccines against the arthropod-borne dengue virus (DENV) are still commercially nonexistent. A subunit immunization strategy may be of value, especially if a safe viral vector acts as a biologically active adjuvant. The DENV envelope protein (E), the main target for neutralizing immune responses, has three conformational domains. The immunoglobulin-like and independently folding domain III (DIII) contains epitopes that elicit highly specific neutralizing antibodies. The hepatitis B small surface antigen (HBsAg, S) was used as a scaffold to display DENV 2 DIII on a virus-like particle (VLP). A measles virus (MV) was engineered to vector HBsAg and the hybrid glycoprotein DIII-HBsAg in two different loci (DIII-S). Despite the relatively deleterious effect on replication caused by the insertion of two transcription cassettes, the recombinant virus MVvac2(DIII-S,S)P induced the secretion of DIII-S hybrid VLP with a similar sucrose density as HBsAg particles (1.10-1.12g/ml) and peaked at 48 h post-infection producing 1.3x106 TCID50/ml infectious MV units in vitro. A second recombinant virus, MVvac2(DIII-S)N, was engineered to vector only the hybrid DIII-S. However, it did not induce the secretion of hybrid HBsAg particles in the supernatant of infected cells. The immunogenicity of the recombinant viruses was tested in a MV-susceptible small animal model, the experimental group which received two 105 TCID50 I.P. doses of MVvac2(DIII-S,S)P in a 28 day interval developed a robust immune response against MV (1:1280), HBsAg (787 mIU/ml) and DENV2 (Log10 neutralization index of 1.2) on average. In summary, it is possible to display DENV E DIII on hybrid HBsAg particles vectored by MV that elicit an immune response. This forms the basis for a potential vaccine platform against DENV. / Dissertation/Thesis / Masters Thesis Biology 2015
18

Rekombinantní vakcíny proti solidním a hematologickým nádorům: vývoj a stanovení jejich účinnosti / Recombinant vaccines against solid and hematological cancer: development and monitoring of vaccines-induced immunity

Babiarová, Katarína January 2013 (has links)
K. Babiarová Ph.D. Thesis ABSTRACT Cancer immunotherapy is concerned generally with the activation of cancer immunity specific for tumor antigens (TA) produced by cancer cells. My PhD thesis focused on the development of different types of cancer vaccines expressing various TA and predominantly on the determination of the efficacy of these vaccines. For studying TA-specific cancer cellular immunity in mice immunized with these vaccines, I used mainly the ELISPOT-IFNγ assay. First, DNA, recombinant vaccinia virus (rVACV) and peptide vaccines against WT1 positive tumors were prepared. They consist of a fragment of WT1 protein with motifs predicted to bind to Db murine MHC class I. The administration of peptide vaccines by tattoo delivery in combination with unmethylated CpG motifs and anti-TGFβ monoclonal antibody was the most effective. Next, I was interested in the immunotherapy of chronic myeloid leukemia (CML). Hruskova et al. prepared the mouse polyomavirus-like particles (MPyV-VLP) carrying the junction region of BCR-ABL fusion protein (1). In our laboratory, there were constructed the other types of CML vaccines with the expression of the junction region of BCR-ABL fusion protein, such as DNA or rVACV, too. Prepared vaccines failed to induce effective cancer immune response. It seems that BCR-ABL...
19

Hyperthermia as a Cancer Treatment- From Theory to Practice

Fullerton, Graham 01 January 2018 (has links)
Using iron super-paramagnetic and ferromagnetic nanoparticles composed of Fe3O4 molecules, scientists analyze the effectiveness and practicality of this new treatment theory, hyperthermia. The problems of magnetic particle density, isothermal barriers/cellular cooling thresholds, and nanoparticle specific targeting are addressed in this review. Iron magnetic nanoparticles were chosen due to their relatively low biological reactivates and lack of subsequent cellular toxicity. However, there are significant heating problems associated with these magnetic nanoparticles due to their relative size and short thermal time constants or thermal half-lives. Effectively, these aforementioned issues create a phenomenon where cancerous cells, surrounded by unheated healthy tissue, exhibit properties similar to those of an isothermal barrier. As a result, target cells experience limited gross heating, which is localized to the area directly surrounding the active magnetic nanoparticle within the cytoplasm. The effects of isothermal barriers and HSP up regulation on particle-based hypothermia are profound and prevent therapeutic temperatures from being achieved in single cell heating limiting the applications for Fe3O4 magnetic nanoparticle hyperthermia applications. It has been shown that reaching a certain magnetic nanoparticle density within the cell can result in a larger heating capacity, though this effect is also dependent on the particle dispersion pattern within cytoplasm. It has yet to be concluded whether ferromagnetic particles or super-paramagnetic particles are superior or more practical for hyperthermic treatments as they each have distinct benefits, and further study is needed. Finally, the popular targeting mechanism associated with magnetic nanoparticle research, monoclonal antibodies, require that they have an organic coating (such as starch) as a means of both providing an organic binding point and as camouflage for avoiding host filtration pathways. Forgoing this organic coating could lead to increased particle density within the cell and the adoption of a more specific targeting mechanism such as virus like particles (VLPs) altered to target HSP’s could lead to an increase in yield. Furthermore the up regulation of HSPs in response to therapeutic temperature is problematic for the therapies practically.
20

Evaluation préclinique d'un protocole vaccinal anti-VIH utilisant des pseudo-particules rétrovirales recombinantes administrées par voies muqueuses et étude des mécanismes immunologiques associés / Preclinical evaluation of an HIV vaccine protocol using recombinant retroVirus -like particles administered by mucosal routes and study of the associated immunological mechanisms

Vazquez, Thomas 14 September 2016 (has links)
Malgré 30 ans de recherche aucun vaccin VIH n'a permis d'apporter une protection efficace et de manière stable. Au regard des échecs obtenus jusqu'à présent, de nouvelles formes vaccinales ont été développées. Parmi ces dernières les VLP présentent l'avantage notables d'être très immunogènes du fait de leur forme particulaire mimant les virus natifs, et sécuritaire puisque ne véhiculant pas de génome viral. Ce travail de thèse a pour objectif d’établir et d’évaluer une stratégie vaccinale utilisant ces VLP administrées par voies muqueuses dans le but d’initier une réponse humorale et cellulaire au niveau systémique et muqueux. Dans cette étude, nous avons montré que la voie muqueuse est indispensable pour l’induction d’une réponse locale forte. De plus, nos résultats révèlent que la forme particulaire de l’antigène est décisive dans la génération d’une immunité de qualité, générant une réponse TFH forte, une réponse cellulaire locale polyfonctionnelle ainsi qu’une réponse humorale forte et stable dans le temps, caractérisée par des anticorps de qualité.Cherchant à mieux caractériser la stratégie vaccinale établie, nous avons analysé les mécanismes de prise en charge des VLP et d’initiation de la réponse immunitaire après administration IN. Nous avons observé que de nombreuses cellules de l’immunité innée pulmonaire, notamment les macrophages alvéolaires et les neutrophiles, captaient massivement les VLP limitant alors la réponse TFH et potentiellement la réponse humorale qui en découle. Au final, ce travail de thèse aura permis de mettre en avant la voie d’immunisation muqueuse ainsi que la forme particulaire de l’antigène dans la mise en place d’un vaccin VIH. / Currently no HIV vaccine elicit full and stable protection against viral acquisition. In view of the failures until now, new vaccines strategies were developed. Among these, VLP have the advantage to be highly immunogenic because of their particulate structure mimicking native pathogens and safe because of the lack of viral genome.This thesis work aims to develop and evaluate a VLP-based vaccine strategy by mucosal administration in order to initiate systemic and local humoral and cellular responses. In this study, we showed that the mucosal administration is mandatory to generate a strong local immunity. Moreover, our results show that particular form of the antigen is crucial in the generation of the quality of the immune response, generating strong TFH response, polyfunctional T-cell responses in the mucosa and a strong and stable humoral response characterized by high-quality antibodies.We also investigated mechanisms involved in the generation of immune responses following IN VLP injections. We determined which cells take in charge VLP and their role in the followed immune responses. Our preliminary results show many innate immune cells in the lungs, such as alveolar macrophages and neutrophils, have an important role in the particles uptake, limiting TFH response and potentially the followed humoral response.Finally, this thesis work will show the determining role of the mucosal route of immunization and the particulate form antigen for the development of an HIV vaccine.

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