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Utilização de shRNA anti-hexon, anti-IVa2 e anti-pol durante a produção de vírus adeno-associado como estratégia de eliminar Adenovírus helper: prova de princípio / Use of shRNAs directed against key adenoviral targets as an inhibitor of Helper Viruses: first stepMarlous Vinicius Gomes Lana 26 January 2016 (has links)
O Adenovírus (Ad) é um agente etiológico que causa infecções em diversas espécies e também pode ser utilizado na forma de vetor como ferramenta tecnológica para terapia gênica. O Controle sobre a replicação de Ad pode trazer beneficio para o combate de infecções e para as tecnologias de transferência genica. Porém, poucas ferramentas existem que podem inibir a replicação de Ad. Uma aplicação importante seria a inibição da replicação de Adenovírus helper utilizado na produção de Vírus Adenoassociado recombinante (rAAV), assim minimizando contaminação da produção de rAAV com o virus helper. Dessa maneira o objetivo desse trabalho foi investigar se há inibição da replicação do Ad mediada por RNA de interferência (RNAi) direcionada para alvos adenovirais chaves. Para isso foram construídos vetores lentivirais que codificam shRNAs para os genes hexon, IVa2 e pol. Em seguida foram criadas linhagens que expressam constitutivamente os shRNAs em 293T, células onde os vetores adenovirais conseguem se replicar. Os shRNAs específicos para hexon e IVa2 promoverem significantemente a redução dos níveis destes mRNAs conforme revelado utilizando RT-qPCR para quantificação dos transcritos adenovirais. Em seguida, knockdown do gene hexon se mostrou promissor em inibir a replicação do Ad, visto como redução de vírus produzido em células 293T anti-hexon. O knockdown do transcrito de hexon e a redução em replicação de Adenovírus foram mais acentuados após cell sorting e obtenção de clones celulares a partir da linhagem anti-hexon. O clone anti-hexon mostrou significante redução na quantidade de partículas adenovirais visualizadas por microscopia eletrônica e redução de 92% das partículas infecciosas em relação a 293T quando a produção foi realizada em larga escala. Esses resultados indicam que a tecnologia de shRNA para inibir a replicação do Ad é promissora e representa o primeiro passo de desenvolvimento de uma estratégia para a produção de rAAV livre de contaminação com Ad helper / Adenovirus (ad) is an etiologic agent that causes infections in diverse species and can also be used as a technologic resource, such as a vector applied in gene therapy. Control over Ad replication could be beneficial for the combat of infections and for the technology of gene transfer. However, few tools exist that may useful for the inhibition of Ad replication. One important application would be to impede replication of helper adenovirus utilized in the production of recombinant Adenoassociated Virus (rAAV), thus minimizing the contamination of the rAAV production with helper virus. The objective of the study was to investigate the use of RNA interference (RNAi) directed against key adenoviral targets as an inhibitor of Ad replication. For this, lentiviral vectors encoding shRNAs for hexon, IVa2 and pol were constructed. Next, constitutive expression of the shRNAs was established in 293T cells, the parental cell line that is permissive for adenovirus replication. The shRNAs specific for hexon or IVa2 significantly promoted reduction in the level of these mRNAs as revealed by RT-qPCR quantification of the adenoviral transcripts. Next, knockdown of hexon was shown to be promising as an inhibitor of Ad replication, seen as the reduction of Ad produced in the 293T anti-hexon cell line. Both the knockdown of the hexon transcript and reduction in adenovirus replication were accentuated after cell sorting and isolation of cellular clones from the anti-hexon cell line. The anti-hexon clone showed significant reduction in the quantity of adenovirus particles when visualized by electron microscopy and 92% fewer infectious particles as compared to the parental 293T cells when full scale production was made. These results indicate that the use of shRNA technology for the inhibition of Ad replication is promising and represents the first step for the development of a strategy for the production of rAAV free from helper virus contamination
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Estudo epidemiológico da doença diarréica aguda associada aos adenovírus, em Juiz de Fora, Minas Gerais, no período 2007-2010Reis, Thais Aparecida Vieira 29 June 2012 (has links)
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Previous issue date: 2012-06-29 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / FAPEMIG - Fundação de Amparo à Pesquisa do Estado de Minas Gerais / A doença diarréica aguda (DDA) é, ainda hoje, uma das principais causas de morbidade e mortalidade infantil, nos países em desenvolvimento. Na diarreia aguda não bacteriana, os adenovírus entéricos constituem um dos importantes agentes etiológicos da doença. Os adenovírus humanos (HAdV) pertencem à família Adenoviridae e ao gênero Mastadenovirus, cujos membros estão classificados em 7 espécies (A-G) e 54 sorotipos. Dentre estes, os sorotipos 40 e 41, ambos da espécie F, são os mais comumente associados com a DDA. Considerando-se, então, a importância da DDA em países em desenvolvimento, o grande número de casos que não são esclarecidos e o pouco conhecimento sobre a infecção e a participação dos HAdV na gênese da DDA, em Juiz de Fora, Minas Gerais, foi realizado o presente estudo. Entre janeiro de 2007 e dezembro de 2010, foram analisados 395 espécimes fecais diarréicos, provenientes de indivíduos de várias idades, atendidos em serviços ambulatoriais e hospitalizados. A presença dos HAdV foi detectada pela reação de PCR , utilizando-se os iniciadores específicos e a caracterização molecular das amostras positivas foi feita pelo seqüenciamento e análise filogenética das sequências parciais do gene do Hexon. Para as análises estatísticas, foi utilizado o programa SPSS versão 13.0, tendo se adotado um valor de significância como p<0,05. A prevalência da infecção por HAdV, no período 2007-2010, foi de 10,9% (43/395). Os resultados mostraram que não houve correlação significante entre a procedência da amostra (ambulatorial X hospitalar) e a ocorrência da infecção (p=0,152), o mesmo tendo sido observado em relação ao gênero do indivíduo infectado (p=0,393). Por outro lado, a maioria dos casos positivos foi detectada em crianças de até 24 meses de idade, mostrando uma correlação estatisticamente significante entre a idade dos indivíduos infectados e a ocorrência da infecção (p=0,007). Na maioria dos casos de infecção pelo HAdV (36/43), este foi o único agente viral detectado, no entanto, foram observados casos de coinfecção HAdV/Rotavirus (5/43) e HAdV/Norovirus (2/43). A análise filogenética das sequências parciais do gene do Hexon, de 35 amostras positivas, revelou que todas agruparam com amostras de HAdV da espécie F, sorotipo 41, confirmando assim, a associação de HAdV entéricos, nos casos estudados. Este levantamento epidemiológico revelou a presença e a circulação destes vírus na população de Juiz de Fora, no período avaliado, bem como sua importante participação na gênese da DDA, permitindo assim, esclarecer uma boa parte dos casos da doença, que normalmente ficaria sem definição etiológica. / Acute diarrheal disease (ADD) is still the major cause of child morbidity and mortality in developing countries. Among the non-bacterial diarrhea, enteric adenoviruses are one of the most important etiologic agents of disease. Human adenoviruses (HAdV) belongs to the Adenoviridae family and Mastadenovirus genus. The virus are classified into seven species (A-G) and 54 serotypes. Among them, serotypes 40 and 41, both of the species F, are the most commonly associated with ADD. Taking in consideration the importance of the DDA in developing countries, the large number of cases that don’t have the etiologic agent identified and the lack of knowledge about the participation of HAdV infection and the pathogenesis of ADD, we performed this study in Juiz de Fora, Minas Gerais. Between January of 2007 and December of 2010 395 diarrheal fecal specimens originating from individuals of various ages treated in ambulatory and hospitalized were analyzed. The presence of HAdV was detected by PCR, using specific primers, and molecular characterization of positive samples was performed by sequencing and phylogenetic analysis of partial sequences of the hexon gene. For statistical analyzes, we used SPSS version 13.0, adopting a value of p <0.05 as significant. The prevalence of infection by HAdV between 2007-2010 was 10.9% (43/395). The results showed no significant correlation between the origin of the sample (hospital X ambulatory) and the occurrence of infection (p = 0.152), and the same was observed in relation to gender of the infected person (P=0,393). Moreover, the majority of positive cases was detected in children under 24 months of age, showing a statistically significant correlation between the age of the infected individuals and the occurrence of infection (p=0,007). In most cases of infection HAdV (36/43), this was the only viral agent detected, however, cases of co-infection HAdV / Rotavirus (5/43) and HAdV /Norovirus (2/43) were identified. Phylogenetic analysis of partial sequences of the hexon gene from 35 positive samples revealed that all samples clustered with HAdV species F, serotypes 41, confirming the association of enteric HAdV in the cases of this study. This epidemiological survey revealed the presence and circulation of these viruses in the population of Juiz de Fora in the period studied, as well as its important role in the genesis of the DDA, our data identified a good number of cases of the disease, which normally remains unidentified.
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Atividade do interferon tipo I suíno na proteção contra o vírus da febre aftosa (FMDV) / Activity of swine type i interferon in protection against foot-and-mouth disease virus (FMDV)Botton, Sonia de Avila 08 March 2005 (has links)
Conselho Nacional de Desenvolvimento Científico e Tecnológico / The objective of this study is to evaluate the adjuvant effect of interferon alpha (IFNα) in swine vaccinated with a recombinant replication-defective adenovirus containing foot-and-mouth disease virus (FMDV) protein coding regions, as well as to understand the molecular mechanisms involved in the interaction of FMDV with its host. In the first part of this thesis, the adjuvant effect of pIFNα was evaluated in swine vaccinated with a recombinant vaccine delivered by a human adenovirus type 5 (Ad5) vector containing FMDV capsid (P1-2A) and 3Cpro proteinase coding regions (Ad5-A24). Swine were separated into 5 groups and inoculated with low (5x108 PFU) or high (5x109 PFU) doses of Ad5-A24 in the presence or absence of pIFNα (Ad5-pIFN, 109 PFU). Control animals received 6x109 PFU of an Ad5 vector containing the glycoprotein gene of vesicular stomatitis virus (Ad5-VSNJV-G). All swine were challenged at 42 days post vaccination (dpv) with FMDV-A24. Prior to challenge, blood samples were examined for IFN production, induction of IFN-induced genes (ISG s), FMDV-specific neutralizing antibodies and FMDV-specific antibody isotypes. After challenge, a number of parameters were analyzed including clinical score, viremia, lymphopenia and antibodies against FMDV structural (S) and non-structural (NS) proteins. The results indicate that both groups that received high-dose Ad5-A24 developed an FMDV-specific neutralizing antibody response by 14-21 dpv, which was maintained until the day of challenge. Both high-dose groups developed high levels of IgG1 and IgG2, however the IgG1 response was higher. The high-dose Ad5-A24 with IFN group developed higher levels of IgG1 than the group administered only high-dose Ad5-A24 and this difference was statistically significant. Antiviral activity and IFNα were detected in the groups that received IFN. The three ISG s examined, PKR, OAS and Mx1, were detected by real time RT-PCR in leukocytes from Ad5-pIFNα-vaccinated swine. After challenge, all animals in the control group developed early viremia, vesicular lesions, considerable lymphopenia and antibodies to FMDV NS proteins. The animals that received low-dose Ad5-A24 without IFN had similar clinical signs, except that fewer animals had viremia. In contrast, pigs inoculated with the low-dose Ad5-A24 and IFNα had a delayed onset of vesicular lesions and only one animal had detectable viremia. Animals vaccinated with high-dose Ad5-A24 without IFNα had no viremia, showed fewer lesions, one animal had no lesions, and delayed onset of disease compared to the low-dose Ad5-A24 groups. Four of five pigs vaccinated with high-dose Ad5-A24 and IFNα were completely protected from disease and only one animal in this group had a vesicular lesion restricted to the site of challenge virus inoculation. The results indicate that IFNα enhances the level of protection induced by the Ad5-FMD vaccine against homologous FMDV, supporting the use of IFNα as a potential adjuvant in FMD vaccination strategies. To investigate the effect of FMDV infection on the induction of the host IFN-α/β response, swine cells were infected with wild-type (WT) FMDV and a mutant FMDV lacking the L proteinase (Lpro) coding region (A12-LLV) at different multiplicities of infection. The synthesis of IFN-α and IFN-β mRNAs and three well characterized ISG s, PKR, OAS, and Mx1 mRNA, were evaluated by real time RT-PCR. A12-LLV infection resulted in significantly higher levels of induction of IFN-β mRNA as compared to WT virus infected cells, while IFN-α mRNA was not induced after either infection. The increased levels of IFN-β mRNA in A12-LLV-infected cells correlated with higher levels of induction of PKR, OAS and Mx1 mRNAs and antiviral activity. By using RNA interference (RNAi) technology to knock-down PKR mRNA expression, it was possible to demonstrate that the yield of A12-LLV was increased up to 200-fold, supporting the role of PKR as an inhibitor of FMDV replication. These results confirm that Lpro down regulates the innate immune response to FMDV infection at multiple levels. Previous studies indicated that control was at the translation initiation level by Lpro cleavage of translation initiation factor eIF-4G. The present data demonstrates that regulation also occurs at the level of transcription by inhibition of IFN-β mRNA induction through an unknown mechanism. / Esse trabalho tem como objetivo avaliar o efeito adjuvante do interferon alfa suíno em animais imunizados com uma vacina recombinante de um adenovírus defectivo contendo as regiões codificadoras das proteínas do FMDV, bem como investigar alguns dos aspectos moleculares envolvidos na interação FMDV e a célula hospedeira em uma espécie susceptível. Na primeira fase do trabalho, o efeito adjuvante do interferon alfa suíno (pIFNα) foi avaliado em suínos imunizados com uma vacina recombinante, tendo como vetor o adenovirus humano tipo 5 (Ad5), contendo regiões do capsídeo do FMDV A24 e da proteinase 3Cpro do FMDV A12 (Ad5-A24). Os suínos foram separados em 5 grupos e inoculados com baixa (5x108 PFU) e alta (5x109 PFU) dosagem de Ad5-A24 na presença ou na ausência de pIFNα (Ad5pIFNα, 109 PFU). O grupo controle foi inoculado com 6x109 PFU da glicoproteína do vírus da estomatite vesicular (VSV) cepa New Jersey (Ad5VSNJV-G). Todos os suínos foram desafiados aos 42 dias pós-vacinação (dpv) com FMDV-A24. Após a inoculação, as amostras de sangue foram examinadas para a produção de IFN, a indução de genes induzidos pelo IFN e os anticorpos neutralizantes e resposta de imunoglobulinas específicos para o FMDV. Depois do desafio um número de parâmetros foram analisados incluindo a avaliação clínica, viremia, linfopenia; além dos anticorpos contra as proteínas estruturais e não estruturais do FMDV. Os resultados obtidos indicam que ambos os grupos que receberam Ad5-A24 em alta dosagem desenvolveram níveis de anticorpos neutralizantes pelos 14-21 dpv, que foram mantidos até o dia do desafio. Os níveis de IgG1 foram maiores que de IgG2 nesses dois grupos, sendo que a IgG1 é considerada a mais relevante para conferir proteção ao FMDV. Dentre esses grupos, o que recebeu o IFN apresentou níveis significativamente mais altos desta imunoglobulina. Atividade antiviral e o IFNα foram detectados nos animais que receberam o IFN. A respeito da presença dos genes induzidos pelo IFN nos leucócitos dos suínos vacinados com Ad5-pIFNα, todos os três genes incluídos neste estudo, PKR, OAS e Mx1, foram detectados pelo real time RT-PCR. Após o desafio todos os animais do controle desenvolveram viremia, linfopenia, lesões vesiculares e os anticorpos contra as proteínas não estruturais do FMDV. Os animais que receberam baixa dose de Ad5-A24 sem IFN tiveram sinais clínicos similares, exceto que poucos animais desenvolveram viremia. Porém, os suínos inoculados com a mesma dose da vacina de Ad5-A24 com o IFN apresentaram as lesões vesiculares com início tardio e somente um animal teve detectável viremia. Os animais vacinados com a alta dose de Ad5-A24 sem IFN não tiveram nenhuma viremia e poucas lesões foram detectadas tardiamente após a inoculação do FMDV. Quatro dos cinco suínos, que receberam a alta dose da vacina com o IFN, foram protegidos da doença e somente um animal neste grupo teve uma lesão vesicular, restrita ao local do inoculação do vírus por ocasião do desafio. Esses resultados indicam que IFNα realça o nível da proteção induzido pela vacina do adenovírus-FMD contra o FMDV homólogo, suportando o uso do IFNα como um adjuvante potencial em estratégias de vacinação de FMD. Para avaliar os efeitos da infecção pelo vírus da FMD na indução da resposta de IFNα⁄β do hospedeiro, células de origem suína foram previamente infectadas em diferentes multiplicidades de infecção com o FMDV e com um vírus mutante que teve o gene que codifica a protease L ou Lpro deletado, o FMDLLV. A síntese de mRNA do IFNα e β bem como de três dos genes induzidos pelo IFN, PKR, OAS e Mx1 foram avaliados por real time RT-PCR. A infecção das células pelo FMDLLV induziu altos níveis de mRNA do IFNβ quando comparados com os do FMDV original. Contudo, não foi possível detectar os níveis de mRNA do IFNα na presença de ambos os vírus. O aumento nos níveis de mRNA do IFNβ foi relacionado ao aumento nos níveis de indução dos mRNAs de PKR, OAS e Mx1, assim como dos altos níveis de atividade antiviral. Pelo uso da tecnologia de interferência do RNA, usando siRNA (silencing RNA) para bloquear a expressão do mRNA da PKR, foi possível demonstrar que o título do FMDLLV aumentou cerca de 200 vezes. Desta forma foi possível confirmar o papel desta proteína como um inibidor da replicação do FMDV. Os resultados obtidos demonstram que a Lpro tem um importante papel na regulação da resposta imunológica inata do hospedeiro quando da infecção pelo FMDV em vários níveis. Estudos anteriormente realizados indicaram que o controle era efetuado ao nível da tradução pela clivagem do eIF4G. Os dados obtidos neste trabalho indicam que a regulação também ocorre ao nível da transcrição e pela inibição da indução do IFNβ através de um mecanismo ainda não conhecido.
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Studium genetických a infekčních rizikových faktorů v patogenezi obezity u českých adolescentů / Study of genetic and infectious risk factors in the pathogenesis of obesity in Czech adolescents.Dušátková, Lenka January 2016 (has links)
4 Abstract The prevalence of obesity and its related cardiometabolic complications in children remains high across the world. Obesity is a multifactorial disease caused by interaction between genes and environmental factors. Genome-wide association studies have discovered several single nucleotide polymorphisms associated with obesity. A causal role of infection in the pathogenesis of obesity has also been considered, particularly the role of adenovirus 36 (Adv36). The aim of the Ph.D. thesis was to investigate the associations of obesity susceptibility loci (TMEM18, SH2B1, KCTD15, PCSK1, BDNF, SEC16B, MC4R, FTO) and Adv36 infection with obesity-related characteristics and complications in the Czech adolescent population. The results are described in eight publications, of which six are original papers and two are reviews. Studies were performed on a cohort of Czech adolescents recruited either from the general population (1,533 individuals from the epidemiological study) and from in-patient or outpatient weight management clinics (562 overweight/obese individuals underwent an intervention). The results demonstrated an association of TMEM18, SEC16B and FTO gene variants with obesity. Some variants of the genes involved in hypothalamic regulation of energy homeostasis − MC4R, BDNF, PCSK1 − were related to...
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iLocks: a novel tool for RNA assays with improved specificityKrzywkowski, Tomasz January 2017 (has links)
The Central Dogma of molecular biology describes a framework for how genetic information is transferred in cells, placing RNA as a messenger between DNA and translated proteins. During the last years, interest in RNA research has grown tremendously due to the increasing understanding and recognition of the importance of RNA in regulation of gene expression, biochemical catalysis, and genome integrity surveillance. Most importantly, RNA content, unlike DNA, changes constantly, fine-tuning the cellular response to match the environmental conditions. There is a clear potential for RNA biomarkers, reflecting both the natural and pathological conditions in vivo. Various methods have been developed to study RNA, of which the most common tools and techniques are described in this thesis. Since many of these gold standard methods are based on detecting RNA derivative (cDNA), there is a wide scope for efficient alternative tools directly targeting RNA. In Paper I, the spatiotemporal expression of human adenovirus-5 mRNA in epithelial and blood cells infected with the virus has been studied. For this, padlock probes and rolling circle amplification (RCA) were used to visualize, quantify and analyse both viral and host cell cDNAs in different infection scenarios, at single cell level. In Paper II, direct RNA detection fidelity has been evaluated using padlock probes. A novel type of probe (iLock) that is activated on RNA via invasive cleavage mechanism, prior to RCA was developed in this approach. Using iLocks, a substantial improvement of direct RNA sensing fidelity has been observed. In Paper III, RNA modifications were introduced in otherwise DNA iLock probes to enhance the probes’ efficiency on miRNAs. Using chimeric iLock probes, multiplexed differentiation of conserved miRNA family members were performed with next- generation sequencing-by-ligation readout. Efficient replication of chimeric probes used in Paper III implies that the Phi29 DNA polymerase readily accepts RNA-containing circles as amplification substrates. In Paper IV, real-time RCA monitoring for measurement of amplification rates and analysis of amplification patterns of various RNA-containing circles was achieved. Moreover, the RCA products were sequenced as a proof for the reverse-transcriptase activity of the Phi29 DNA polymerase. This thesis effectively contributes to a better understanding of mechanisms influencing RNA detection with, but not limited to, padlock probes. It expands the available RNA analyses toolkit with novel strategies and solutions, which can be potentially adapted for RNA-focused research, in general and molecular diagnostics, in particular. / <p>At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 3: Manuscript. Paper 4: Manuscript.</p>
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Construção e caracterização de vetor adenoviral com promotor responsivo ao seu próprio transgene p53 e sua comparação com um vetor de promoção constitutiva. / Construction and characterization of an adenoviral vector responsive to its own p53 transgene in a comparison with a constitutive promoter vector.Rafael Bento da Silva Soares 22 March 2011 (has links)
Em sua maioria, estratégias de transferência gênica utilizam arranjos com promotores e transgenes funcionando de maneira independente entre si, como é o caso do amplamente utilizado promotor CMV. Nosso grupo foge dessa linha de promotores/transgenes independentes. Desenvolvemos uma nova estratégia de transferência gênica que combina estrategicamente a atividade do transgene e o do promotor de expressão gênica, onde o promotor foi modificado com a inserção do elemento PG, responsívo a p53. Neste trabalho construímos um novo vetor adenoviral (AdPGp53) contendo o gene da proteína supressora de tumor p53 cuja expressão é controlada por ela própria através do elemento PG. Em comparação com um vetor adenoviral que possui o gene da p53 sob ação do promotor tradicional CMV (AdCMVp53), o vetor AdPGp53 apresentou expressão superior de p53 em células humanas de carcinoma de próstata PC3, maior morte celular in vitro e parece ter diminuído o ritmo de crescimento tumoral in vivo em um modelo xenográfico de células PC3 em camundongos atímicos. / The majority of gene therapy strategies in use today are based on promoters and transgenes that work independently, and an example of this is the widely used CMV promoter. Our group breaks way from the use of independent promoter/transgene activity. We developed a new gene transfer strategy which combines the transgene activity and the promoter of gene expression. This was achieved by the insertion of the PG element, which is a p53-responsive enhancer, in the promoter. In the present work we built a new adenoviral vector (AdPGp53) containing the p53 tumor suppressor gene, whose expression is controlled by the p53 protein itself through the PG element. In comparative experiments, in which we used our AdPGp53 vector and another adenoviral vector, with a p53 gene and a traditional CMV promoter (AdCMVp53), our vector showed superior p53 expression in PC3 human prostate cancer cells, superior cell death in vitro and a tendency in diminishing tumor growth in an in vivo xenograft model in nude mice injected with PC3 cells.
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SIRT7 and ATM are Barriers to a Productive Adenovirus E4 Mutant InfectionStanley, Gabrielle 22 November 2021 (has links)
No description available.
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From the centrosome to the nuclear envelope and beyond: insights into the role of CRM1 in adenoviral genome deliveryLagadec, Floriane 31 May 2021 (has links)
Les adénovirus (AdV) sont des virus à ADN se répliquant dans le noyau de la cellule hôte. Pour pouvoir se répliquer, ils détournent la machinerie cellulaire à leur profit. Au cours de l’entrée dans la cellule, les particules virales utilisent la machinerie de transport des microtubules pour rejoindre le noyau. Les AdV interagissent avec la dynéine, moteur moléculaire associé aux microtubules, pour être transportés vers le compartiment nucléaire. Ils se lient alors aux pores nucléaires, structures ancrées dans l’enveloppe nucléaire (EN). Une fois aux pores nucléaires, les capsides virales se désassemblent pour libérer et importer leur génome. Les mécanismes de détachement des microtubules, de translocation nucléaire et d’import du génome des AdV impliquent des facteurs de la machinerie de transport nucléocytoplasmique. Cependant, le mécanisme exact utilisé par les virus pour atteindre les pores nucléaires n’est pas clairement défini. Le transport nucléocytoplasmique est composé de différents facteurs et est hautement régulé dans les cellules. Le transport actif de cargos est dû à des facteurs d’import et d’export interagissant avec RanGTP. Le principal facteur d’export est CRM1 et il est connu pour être essentiel dans la translocation des AdV vers l’EN. L’inhibition de CRM1 par la Leptomycine B conduit à l’accumulation des AdV au centrosome, le principal Centre Organisateur des Microtubules (COMT) des cellules de mammifères. Nous avons donc étudié le rôle de CRM1 dans la libération du génome adénoviral. Nous avons analysé l’interaction des AdVs avec le COMT et nous avons observé que l’absence de facteurs cytoplasmiques ainsi que la perte d’intégrité des microtubules n’affectaient pas leur accumulation au COMT. En revanche, nous avons identifié et caractérisé un mutant de CRM1, qui reste fonctionnel pour l’export physiologique de cargo mais qui induit un retard important dans la translocation des AdV vers l’EN. Nous avons utilisé l’imagerie sur cellules vivantes pour analyser l’infection de l’AdV dans des cellules mitotiques et ceci a permis de révéler le rôle de CRM1 dans la libération du génome de ce virus. Nous avons également identifié un partenaire viral potentiel pour CRM1 parmi les protéines associées au génome viral, la Terminal Protein (TP). Cette protéine possède un signal d’export nucléaire et est un substrat de CRM1. Nos données soulignent le rôle de CRM1 comme un médiateur essentiel au désassemblage total de la capside adénovirale, qui favorise la libération du génome et son import.
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Evaluation and performance comparison between two commercial multiplex gastroenteritis diagnostic systems in a routine laboratory settingRabe, Nasim Estelle January 2021 (has links)
Abstract Background: Gastroenteritis is a common infection and the leading cause of morbidity worldwide and is mostly caused by viruses. Outbreaks appear in both developed and developing countries and result in large economic costs. Rapid detection is important for appropriate treatment, control and to prevent the spread of infection. Objective: Evaluation and performance comparison between the BioFire®FilmArray® Torch System gastrointestinal panel and the Molecular BD MAXTMenteric viral panel to indicate a multiplex method for viral gastroenteritis diagnostic in a routine laboratory setting. Material and methods: In this study, 58 different samples were used which consisted of selected stool specimens from patients who were tested and treated for gastroenteritis infection at Uppsala Academic Hospital and Norrlands University Hospital in Umeå during 2018-2021, samples from Quality control for molecular diagnostics viral gastroenteritis EQA pilot study during 2018-2019 and cultivated strains of different adenovirus species from 2018. All samples were analyzed with both systems for comparison of detected pathogens. Results: Sensitivity and specificity values were 95% and 100% respectively for the BioFire®FilmArray®Torch System and 100% and 93.3% for the BD MAXTMSystem. Conclusions: Bothsystems are rapid and adequate diagnostic tools. The BioFire®FilmArray®Torch System with greater coverage has the ability of detecting more pathogens and is more promising particularly in the occasional infection circumstance. The BD MAXTMSystem demonstrated almost the same results and seems to be a better option in times of an outbreak when the numbers of patients are significantly higher.
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Necrostatin-1 Protects Against Glutamate-Induced Glutathione Depletion and Caspase-Independent Cell Death in HT-22 CellsXu, Xingshun, Chua, Chu C., Kong, Jiming, Kostrzewa, Richard M., Kumaraguru, Udayasankar, Hamdy, Ronald C., Chua, Balvin H.L. 01 December 2007 (has links)
Glutamate, a major excitatory neurotransmitter in the CNS, plays a critical role in neurological disorders such as stroke and Parkinson's disease. Recent studies have suggested that glutamate excess can result in a form of cell death called glutamate-induced oxytosis. In this study, we explore the protective effects of necrostatin-1 (Nec-1), an inhibitor of necroptosis, on glutamate-induced oxytosis. We show that Nec-1 inhibits glutamate-induced oxytosis in HT-22 cells through a mechanism that involves an increase in cellular glutathione (GSH) levels as well as a reduction in reactive oxygen species production. However, Nec-1 had no protective effect on free radical-induced cell death caused by hydrogen peroxide or menadione, which suggests that Nec-1 has no antioxidant effects. Interestingly, the protective effect of Nec-1 was still observed when cellular GSH was depleted by buthionine sulfoximine, a specific and irreversible inhibitor of glutamylcysteine synthetase. Our study further demonstrates that Nec-1 significantly blocks the nuclear translocation of apoptosis-inducing factor (a marker of caspase-independent programmed cell death) and inhibits the integration of Bcl-2/adenovirus E1B 19 kDa-interacting protein 3 (a pro-death member of the Bcl-2 family) into the mitochondrial membrane. Taken together, these results demonstrate for the first time that Nec-1 prevents glutamate-induced oxytosis in HT-22 cells through GSH related as well as apoptosis-inducing factor and Bcl-2/adenovirus E1B 19 kDa-interacting protein 3-related pathways.
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