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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.
181

Deregulation of TLR9 signalling pathway in human keratinocytes by E6 and E7 oncoproteins from beta human papillomavirus type 38 / Les oncoprotéines E6 et E7 du papillome humain de type 38 modifient la réponse cellulaire induite par les UV en inhibant l'expression du récepteur Toll-like 9

Pacini, Laura 08 December 2016 (has links)
Les virus du papillome humain (HPV) sont des virus à ADN double-brin encapsidés appartenant à la famille des Papillomaviridae ayant un tropisme distinct pour les épithéliums squameux de type muqueux ou cutanés. Jusqu'à présent, plus de 200 types de HPV ont été isolés et regroupés dans un arbre phylogénétique composé de 5 genres nommés alpha, beta, gamma, mu et nu. Parmi eux, les types HPV muqueux à haut risque appartenant au genre alpha ont été associés au cancer du col de l'utérus ainsi qu'à des sous-groupes de carcinomes ano-génitaux et de la tête et du cou. Ces virus sont responsables d'environ 5% de tous les cancers viro-induits. Les types bêta du HPV ont un tropisme pour la peau et pourraient être impliqués dans le développement du cancer de la peau non mélanique (NMSC), en association avec la lumière ultraviolette (UV). Ainsi, les modèles expérimentaux in vitro et in vivo ont démontré les propriétés de transformation des oncoprotéines E6 et E7 du type HPV bêta 38. De plus, des études sur le modèle de souris transgénique, où E6 et E7 du HPV38 sont exprimés au niveau de la couche basale non différenciée de l'épithélium sous le contrôle du promoteur du gène humain de la kératine (K14), ont montré une très forte susceptibilité de la peau à la carcinogenèse induite par les UV par rapport aux animaux de type sauvage. Tout aussi important que leur capacité à promouvoir la transformation cellulaire, les virus oncogènes ont développé différentes stratégies pour prendre le dessus sur le système immunitaire de l'hôte, favorisant ainsi l'établissement d'une infection persistante. Par conséquent, savoir si des virus oncogènes potentiels ont la capacité d'interférer avec la réponse immunitaire pourrait fournir des preuves supplémentaires de leur implication dans la cancérogenèse humaine. Ici, nous montrons que les oncoprotéines E6 et E7 de HPV38 suppriment l'expression de Tolllike 9 (TLR9), récepteur des ADN double-brins, en favorisant l'accumulation de ΔNp73α, un antagoniste de p53 et p73. Des expériences d'immunoprécipitation de la chromatine ont montré que ΔNp73α fait partie d'un complexe de régulation négative transcriptionnelle qui se lie à un élément de réponse NF-kappaB dans le promoteur TLR9. Fait intéressant, l'expression ectopique de TLR9 dans des cellules HPV38 E6E7 a entraîné une accumulation des inhibiteurs du cycle cellulaire p21WAF1/Cip1 et p27kip1, une réduction de l'activité kinase associée à CDK2 et l'inhibition de la prolifération cellulaire. Ensemble, ces données indiquent que TLR9 est impliqué dans d'autres événements, en plus de la réponse immunitaire innée. Par conséquent, nous avons constaté que le traitement des kératinocytes humains primaires (HPK) avec différents stress cellulaires, par exemple l'irradiation aux UV, la doxorubicine et le traitement H2O2, conduisent à une induction de la transcription de TLR9. Cet évènement induit par les UV est arbitré par le recrutement de plusieurs facteurs de transcription sur le promoteur TLR9, tels que p53, NF-kappaB p65 et c-Jun. L'expression de E6 et E7 de HPV38 affecte fortement le recrutement de ces facteurs de transcription sur le promoteur TLR9, avec comme conséquence l'affaiblissement de l'expression du gène TLR9. En résumé, nos données montrent que HPV38, de manière similaire à d'autres virus avec une activité oncogénique bien connue, peut inhiber 'expression de TLR9. Plus important encore, nous mettons en évidence une nouvelle fonction de TLR9 dans le contrôle de la réponse cellulaire aux stress et nous montrons que E6 et E7 de HPV38 sont capables d'interférer avec un tel mécanisme. Ces résultats confirment le rôle des types HPV bêta dans la carcinogenèse de la peau, en fournissant des informations supplémentaires sur leur contribution précise dans le processus multi-étapes de développement du cancer / The human papillomaviruses (HPV) consist of a group of capsid-enclosed double-stranded deoxyribonucleic acid (dsDNA) viruses from the Papillomaviridae family that display a distinct tropism for mucosal or cutaneous squamous epithelia. Until now, more than 200 types of HPV have been isolated and grouped into a phylogenetic tree composed of 5 genera (alpha, beta, gamma, mu and nu papillomaviruses). Among them, the mucosal high-risk HPV types that belong to the genus alpha have been associated with cervical cancer as well as a subset of anogenital and head and neck carcinomas. They are responsible for approximately 5% of all virus-induced cancers. Beta HPV types have a skin tropism and have been suggested to be involved, together with ultraviolet light (UV), in the development of non-melanoma skin cancer (NMSC). For instance, in vitro and in vivo experimental models highlight the transforming properties of beta HPV38 E6 and E7. Specifically, studies of transgenic mouse model, where HPV38 E6 and E7 are expressed in the undifferentiated basal layer of epithelia under the control of the Keratin 14 (K14) promoter, showed a very high susceptibility to UV-induced skin carcinogenesis in comparison to the wild-type animals. Equally important as their ability to promote cellular transformation, oncogenic viruses have different strategies to overtake the host immune system thus guaranteeing persistent infection. Therefore, understanding whether potential oncogenic viruses have the ability to interfere with the immune response could provide additional evidence relating to their involvement in human carcinogenesis. Here, we show that the E6 and E7 oncoproteins from HPV38 suppress the expression of the dsDNA innate immune sensor Toll-like receptor 9 (TLR9) by promoting the accumulation of ΔNp73α, an antagonist of p53 and p73. Chromatin immunoprecipitation experiments showed that ΔNp73α is part of a negative transcriptional regulatory complex that binds to a NF-κB responsive element within the TLR9 promoter. Interestingly, ectopic expression of TLR9 in HPV38 E6E7 cells resulted in an accumulation of the cell cycle inhibitors p21WAF/Cip1 and p27Kip1, reduction of CDK2-associated kinase activity and inhibition of cellular proliferation. Together these data indicate that TLR9 is involved in additional events, besides the innate immune response. Accordingly, we observed that the treatment of human primary keratinocytes (HPKs) with different cellular stresses, e.g. UV irradiation, doxorubicin and H2O2 treatment, results in TLR9 up-regulation. This UVinduced event is mediated by the recruitment of several transcription factors to the TLR9 promoter, such as p53, NF-kB p65 and c-Jun. The expression of HPV38 E6 and E7 strongly affect the recruitment of these transcription factors to the TLR9 promoter, with consequent impairment of TLR9 gene expression. In summary, our data show that HPV38, similarly to other viruses with well-known oncogenic activity, can down-regulate TLR9. Most importantly, we highlight a novel function of TLR9 in controlling the cellular response to stresses and we show that HPV38 E6 and E7 are able to interfere with such mechanism. These findings further support the role of beta HPV types in skin carcinogenesis, providing additional insight into their precise contribution to the multistep process of cancer development
182

Factors Associated with Sexually Transmitted Infections (STIs) and Multiple STI Co-infections: Results from the EVRI HIV Prevention Preparedness Trial

Pokharel, Ubin 15 March 2016 (has links)
Objective: The objective of this study was to describe the prevalence of sexually transmitted co-infections and assess factors associated with a single infection and co-infections. Methods: A total of 388 women were included in this study. At enrollment of the EVRI trial women were tested for five STIs: Human papilloma virus (HPV), Chlamydia trachomatis, Neisseria gonorrhoeae, Herpes simplex virus-2 (HSV-2) and Treponema pallidum. Prevalence of STI infections and proportion of women with different combinations of co-infections were calculated. Factors associated with single infection and STI co-infection were assessed using a polytomous logistic regression model and odds ratio (OR) and 95% confidence intervals (95% CI) were reported as the measure of association. Results: Prevalence of a single STI and concurrent STI co-infections were high. Prevalence of chlamydia was 33%, syphilis 6%, HSV-2 46% and HPV 71%. The most common STI co-infection pattern was HPV-HSV (32%), followed by HPV-chlamydia (17%). The odds of single STI compared to no STIs was significantly lower for women who had education level of grade 7 compared to women who had some college or technical education (OR 0.16, 95% CI: 0.03-0.79).The odds of a single STI compared to no STIs were significantly higher (OR 3.02, 95% CI: 1.05-8.64) and the odds of concurrent STIs compared to no infection were significantly higher (OR 3.86, 95% CI: 1.42-10.48) for women with three or more lifetime partners compared to one life time partner. Conclusions: STIs, single and multiple concurrent infections, are common among this cohort of South African women. These results strengthen the recommendation that STI screening and treatment needs to be a component of multiple intervention strategies among high-risk women residing in communities with high STI prevalence.
183

Analyse comparative du transcriptome et miRNone des cancers de l'oropharynx en fonction du statut HPV16 / Comparative analysis of the transcriptome and mirnome of oropharyngeal cancers according to HPV16 status

Mirghani, Haitham 15 September 2014 (has links)
Avec plus de 600 000 nouveaux cas par an, les cancers des voies aéro-digestives supérieures (VADS) se classent au sixième rang mondial. Ces cancers, traditionnellement causés par la consommation chronique de tabac et d’alcool, connaissent depuis une trentaine d’années de profonds changements épidémiologiques. Alors que l’incidence des cancers développés dans la cavité orale, le larynx et l’hypopharynx tend à se stabiliser voire à régresser en raison de la diminution du tabagisme, ceux développés dans l’oropharynx sont en nette augmentation. Cette augmentation est attribuée aux papillomavirus oncogènes et notamment au génotype 16 (HPV16). Les cancers de l’oropharynx (COP) HPV-induits représentent une pathologie distincte des autres cancers des VADS tant au niveau épidémiologique, clinique, histologique que biologique. Ils affectent des sujets plus jeunes, sont extrêmement lymphophiles et leur pronostic est significativement meilleur. L’émergence de ces cancers impose dès aujourd’hui de réfléchir à des stratégies diagnostiques, thérapeutiques et de surveillance spécifiques. Néanmoins, ces objectifs ne pourront être pleinement atteints qu’à condition de mieux comprendre leur histoire naturelle ainsi que leurs mécanismes oncogéniques propres. L’objectif de ce travail est de contribuer à une meilleure compréhension des mécanismes biologiques distinguant les COP HPV-induits de leurs homologues HPV-négatifs sur la base de l’analyse de leur profil d’expression génomique. A partir d’une cohorte de 38 COP, sélectionnés sur des critères stricts, nous avons identifié un set d’ARNm et de miRNA dont l’expression est exclusivement corrélée au statut HPV. L’analyse fonctionnelle de ces sets confirme que les bases biologiques des COP varient en fonction de leur statut HPV et confortent au niveau moléculaire des données cliniques et pathologiques déjà connues ou fortement suspectées (différenciation tumorale, infiltration lymphocytaire…). Cette étude souligne également le rôle potentiel de plusieurs voies de signalisation dont les dérégulations contribueraient au développement de ces tumeurs. L’exploration plus approfondie de ces voies pourrait à terme permettre de mieux comprendre ces tumeurs et avoir d’éventuelles retombées thérapeutiques. / Head and neck squamous cell carcinomas (HNSCCs) represent the sixth most common form of cancer with an annual incidence of approximately 600,000 new cases worldwide. Tobacco and alcohol abuse are the traditional risk factors. Whilst the incidence of oral cavity, larynx and hypopharynx cancers is stabilizing or falling, because of a drop in tobacco consumption, those arising in the oropharynx are on the increase. This epidemiologic change has been attributed to high-risk human papillomavirus and particularly to type 16 (HPV16), which is now recognized as a causative agent in a growing subset of oropharyngeal squamous cell carcinomas (OPSCCs).HPV-induced OPSCCs represent a distinct subgroup, separate from other HNSCCs, with unique epidemiologic, clinical, pathological and molecular characteristics. They affect young patients, are highly lymphophilic and have markedly improved survival outcomes compared to those with HPV-negative HNSCC. The emergence of these cancers demands special attention, as in the coming years diagnosis, treatment and follow up in HNSCC may vary according to HPV status. However, these objectives will not be fully achieved without a better understanding of their natural history and specific oncogenic mechanisms. The goal of this work is to contribute to a better understanding of the biological basis that differentiates HPV-induced OPSCCs from their HPV-negative counterparts. To this end, we have investigated global changes in gene expression in a cohort of 38 strictly selected OPSCCs. We have identified a set of mRNA and miRNA that discriminated between OPSCCs solely according to HPV16 status. The functional analysis of these 2 sets confirms that the biological basis of OPSCCs varies according to their HPV status and consolidates at the molecular level known or suspected clinical and pathological data (e.g tumoral differentiation, lymphoid infiltrations…). This study highlights the potential role of several pathways that, once deregulated, could contribute to the development of HPV-induced OPSCC. Further investigation is required for a more comprehensive understanding of the biological properties of HPV related OPSCCs. These properties may be exploited to develop novel therapeutic agents.
184

Modulation of the innate immune response by the oncoviruses EBV and HPV / Modulation des réponses immunitaires innées par les oncovirus EBV et HPV

Parroche, Peggy 13 December 2011 (has links)
Le cancer représente la deuxième cause de mortalité dans les pays industrialisés. Il a été démontré que 20% des cancers sont d'origine infectieuse. Nous nous sommes intéressés à deux oncovirus HPV (virus du papillome humain) et EBV (Epstein-Barr Virus) responsable du cancer de l'utérus et de divers lymphome B réciproquement. Les événements clés pour le développement d'un cancer viro-induit sont la persistance du virus via la dérégulation des réponses immunitaires et l'induction d'une instabilité gé¬nomique via une dérégulation du cycle cellulaire. Nous avons donc cherché si EBV était capable d'altérer la réponse immunitaire innée. Nous avons montré que EBV était capable d'inhiber TLR9 un acteur clef de la réponse immunitaire innée. Comme TLR9 est inhibé dans un certain nombre de cancers, nous nous sommes demandé si ce récepteur pouvait également, avoir un rôle dans l'oncogenèse. Nous avons montré que la réexpression de TLR9 induisait un ralentissement transitoire de la prolifération cellulaire. Nous nous sommes par la suite intéressés aux mécanismes de dérégulation du cycle cellulaire induits par E6 une oncoprotéine de HPV16. Nous avons trouvé un nouveau mécanisme d'inhibition de l'inhibiteur du cycle cellulaire, p21. HPV16E6 se lie et inhibe les fonctions de du facteur de transcription p150Sal2, ce qui induit une inhibition de p21 dans un contexte p53 indépendant / Cancer represents the second most common cause of death in industrialized countries. Epidemiological and biological studies have now conclusively proved that a variety of infectious agents constitute one of the main causes of cancer worldwide. It has been pointed out that more than 20% of cancers are from infectious origin. HPV high-risk mucosal types are associated to 98% of all cervical cancer cases. Regarding EBV, over 90% of the world’s population is infected and can give rise to malignancies such as Burkitt lymphoma or Hodgkin disease.(Young and Rickinson 2004) Keys features for oncoviruses to induce cancer are firstly to per¬sist by dampening host immune responses and to induce genomic instability in the host by altering the regulation of the cell cycle leading the infected cells to an uncontrolled proliferation. The purpose of this thesis was to find new mechanisms by which EBV and HPV can promote carcinogenesis. We have shown that EBV can alter the regulation and expression of TLRs, the key effectors molecules of the innate immune response. EBV infection of human primary B cells resulted in the inhibition of TLR9 functionality. Our study described a mechanism used by EBV to suppress the host immune response by deregulating the TLR9 transcript through LMP1-mediated NF-κB activation. As TLR was found deregulated in many cancers, we hypothesized that TLR9 may also a direct role in the process of cell cycle control and that loss of its expression may lead to transformation of the cell. Our overall objective here was to study the role of TLR9 in suppressing the events that initiates transformation of epithelial cells in the setting of cervical cancer (virus-associated) and in head and neck cancer (non–virus-associated). A third project dealt with the mechanism cell cycle deregulation by the oncoprotein E6 which expressed during infection with HPV16. We reported that HPV16E6 targets the cellular factor p150Sal2, which positively regulates p21 transcription. HPV16E6 associates with p150Sal2, inducing its functional inhibition by preventing its binding to cis elements on the p21 promoter. These data described a novel mechanism by which HPV16E6 induces cell cycle deregulation with a p53-independent pathway preventing G1/S arrest and allowing cellular proliferation and efficient viral DNA replication
185

Avaliação e correlação do perfil de expressão do oncogene E5 do papilomavírus humano e do miRNA- 203 do hospedeiro na carcinogênese cervical

OLIVEIRA, Talita Helena Araújo de 07 March 2016 (has links)
Submitted by Fabio Sobreira Campos da Costa (fabio.sobreira@ufpe.br) on 2017-07-12T15:28:57Z No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) Dissertação Final - talita.pdf: 2175488 bytes, checksum: 400478ce39315d3a295c2c268c514539 (MD5) / Made available in DSpace on 2017-07-12T15:28:57Z (GMT). No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) Dissertação Final - talita.pdf: 2175488 bytes, checksum: 400478ce39315d3a295c2c268c514539 (MD5) Previous issue date: 2016-03-07 / CNPQ / O HPV é o principal fator transformadordo câncer cervical. No seu ciclo viral é expressa a oncoproteína E5, responsável por várias alterações na célula hospedeira e,foi sugerido in vitro, que ela altera a proliferação celular através da regulação negativa do microRNA-203, que em condições normais atua inibindo a proliferação e condicionando a diferenciação dos queratinócitos. Entretanto os mecanismos que envolvem E5 e o microRNA-203 ainda não estão bem elucidados. Este estudo tem como objetivo avaliar o perfil de expressão da oncoproteína E5 e do microRNA-203 em biópsias de colo uterino, observando a existência de correlação entre ambos. A expressão gênica relativa do microRNA-203 e E5 nas amostras clínicas (n=90), referente a todas as etapas da carcinogênese cervical (Normal, NIC I, NIC II, NIC III e câncer), foi obtida por qPCR.As análises mostraram uma diminuição do perfil de expressão do microRNA-203 no câncer em comparação com amostras normais (p<0,01) enquanto o RNAm de E5 do HPV 16 aumentou sua expressão em NIC III e no câncer em relação a lesões de baixo grau (NIC I) (p<0,001 e p<0,01, respectivamente). Os resultados apontam que o microRNA-203 está regulado negativamente no câncer cervical, porém sem correlação estatisticamente significante com a expressão de E5. O perfil apresentado nos diferentes estágios sugere que omicroRNA-203e o oncogene E5 são capazes de diferenciar estágios da carcinogênese cervical. / The Human papillomavirus (HPV) is the main transforming factor in cervical cancer. The HPV expresses the oncoprotein E5 which is responsible for several changes in the host cells and recent in vitro studies have suggested that it plays a role in the regulation of cell proliferation through microRNA-203. This microRNA acts by inhibiting cell proliferation and stimulating cell differentiation in normal conditions. However, the mechanisms involving E5 and microRNA-203 are not yet well elucidated. The aim of the present study is to evaluate both E5 and microRNA-203 expression profiles in biopsies of women from Pernambuco andobserve if there is any correlations between them. Expression of microRNA-203 in clinical samples (n=90), observed at all carcinogenic process (Normal, CIN I, CIN II, CIN III and cancer), was obtained by real-time qPCR. The analysis here performed demonstrates a decreased expression of microRNA-203 in cancer samples when compared to the normal ones (p<0,01) while E5 increased its expression in CIN III and cancer when compared to low-grad lesion (CIN I) (p<0,001 and p<0,01, respectively). Our data shows that miR-203 is downregulated in cancer, although no statistical significant correlation was found between its expression and E5.Both expression profiles suggest their ability to differentiatelesions.
186

Produção de antígenos imunizantes em sistema de expressão procarioto para o desenvolvimento de estratégias profilático-terapêutica contra o Papilomavírus Humano

SILVA, Anna Jéssica Duarte 04 March 2016 (has links)
Submitted by Fabio Sobreira Campos da Costa (fabio.sobreira@ufpe.br) on 2017-07-12T15:56:43Z No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) Dissertação_Anna_Jessica_PPGG.pdf: 2035458 bytes, checksum: 6a4bc578c9eaea104302f33af03c3f21 (MD5) / Made available in DSpace on 2017-07-12T15:56:43Z (GMT). No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) Dissertação_Anna_Jessica_PPGG.pdf: 2035458 bytes, checksum: 6a4bc578c9eaea104302f33af03c3f21 (MD5) Previous issue date: 2016-03-04 / CNPQ / A infecção pelo Papilomavírus Humano, além de representar uma doença sexualmente transmissível altamente disseminada, é responsável por 5% dos cânceres em humanos, destacando o câncer cervical com altos índices de incidência e mortalidade. Embora comprovadamente eficazes, as vacinas vigentes não combatem infecções já estabelecidas e apresentam um elevado custo de produção. Esse cenário revela a necessidade de estratégias vacinais alternativas. O presente trabalho propõe a expressão de diferentes genes recombinantes em Escherichia coli, uma plataforma biotecnológica econômica, de fácil manipulação e de alto rendimento. Os genes recombinantes utilizados foram: L1 de HPV16 e construções quiméricas basedas na substituição de epítopos da oncoproteína E5 na alça h4 e na região C-terminal de L1, com potencial para geração de antígenos profiláticoterapêuticos e na substituição de epítopos da proteína L2 na região da alça h4 para avaliação de possível neutralização cruzada. Após subclonagem em pGEM-T, esses genes foram clonados em vetor de expressão pAE e linhagens de Escherichia coli BL21 e Rosetta foram transformadas com os vetores de expressão gerados. A confirmação da produção das proteínas se deu por Western blot, a partir de extratos de culturas induzidas com IPTG. Otimizações nos protocolos de indução, lise e preparo das amostras foram realizadas ao longo dos experimentos. Os resultados obtidos demonstraram a produção dos antígenos recombinantes, e deverão ser validados em futuros ensaios imunológicos quanto à capacidade de induzir respostas imunes em animais desafiados. / Human papillomavirus infection, besides to represent a widespread sexually transmitted disease, is responsible for 5% of cancers in humans, highlighting cervical cancer with high rates of incidence and mortality. Although proven effective, the existing vaccines do not eliminate infections already established and have a high cost of production. This scenario shows the need for alternative vaccine strategies. This study proposes the expression of different recombinant genes in Escherichia coli, an economic, easy handling and high performance biotechnology platform. Recombinant genes used were: L1 of HPV16 and chimeric basedas constructions in replacement E5 oncoprotein epitopes on h4 loop and L1 C-terminal region, with the potential to generate prophylactic-therapeutic antigens and replacing L2 protein epitopes in loop region h4 for evaluation of possible cross-neutralization. After subcloning in pGEM-T, these genes were cloned into vector pAE expression and Escherichia coli BL21 and Rosetta were transformed with the expression vectors generated. Confirmation of protein production was performed by Western blot from extracts of cultures induced with IPTG. Optimizations in the induction protocols, lysis and preparation of the samples were carried out throughout the experiments. The results demonstrated the production of recombinant antigens and should be validated in future immunological assays for the ability to induce immune responses in challenged animals.
187

Efeito da rapamicina em culturas organotípicas de queratinócitos que expressam oncoproteínas de papiloma vírus humano tipo 16 / Effect of rapamycin in organotypic cultures of keratinocytes expressing oncoproteins of Papillomavirus type 16

Tatiana Rabachini 14 December 2007 (has links)
A infecção por HPV de alto risco é considerada um dos principais fatores de risco para o desenvolvimento do carcinoma do colo uterino, um das neoplasias mais freqüentes em mulheres de todo o mundo. As oncoproteínas E6 e E7 de HPV-16 são capazes de induzir a degradação dos genes supressores de tumor p53 e pRb, respectivamente. Mais do que isso, a expressão dessas oncoproteínas está relacionada a alterações na via de PI3K/AKT/mTOR. A proteína quinase mTOR apresenta importante papel no controle da tradução de proteínas e é considerada o principal mediador entre crescimento celular e proliferação. A ativação de mTOR é correlacionada à fosforilação das proteínas eIF4G1 e 4EBP1, aumentando assim a taxa de síntese de proteínas. A Rapamicina é um inibidor específico de mTOR e seus análogos apresentam potente atividade antiproliferativa em um grande número de células tumorais e tumores gerados em animais. Uma vez que as proteínas E6 e E7 são capazes de interagir com diversas proteínas da via que controla a atividade de mTOR optamos por investigar o efeito da rapamicina na proliferação de culturas organotípicas de queratinócitos expressando esses genes. Também avaliamos o efeito dos genes E6 e E7 na atividade de mTOR após o tratamento com essa droga. Para geração de culturas organotípicas de queratinócitos infectamos essas células com vetores retrovirais recombinantes contendo os genes E6 e E7 de HPV-16 em conjunto ou separadamente. Nós também avaliamos o papel da degradação de p53 e pRb na resposta à rapamicina através da utilização de mutantes de E6 e E7 incapazes de induzir a degradação dessas proteínas celulares. Após a infecção dos queratinócitos, os mesmos foram semeados em uma matriz de colágeno. Após 6 dias as culturas foram tratadas com 100ng/ml de rapamicina e permaneceram 60h em contato com a droga. Para análise por imunohistoquímica os tecidos foram fixados em formalina tamponada e emblocados em parafina. A reação de imunohistoquímica foi realizada utilizando os anticorpos contra BrdU, p-4EBP1 (ser 65), p-eIF4G1 (ser 1188) e pAKT (ser 473). Os resultados obtidos ilustram que a rapamicina apresenta efeito antiproliferativo em culturas de queratinócitos contendo o vetor vazio. Por outro lado, culturas contendo o gene E7 são resistentes ao efeito antiproliferativo dessa droga. Essa resistência parece estar relacionada à capacidade de E7 induzir a degradação da proteína pRb, uma vez que em queratinócitos expressando o mutante de E7, incapaz de induzir a degradação dessa proteína, não foi observada resistência. Além disso, a fosforilação de eIF4G e 4EBP1 indica que a expressão de E7 impede que a rapamicina seja capaz de inibir a atividade de mTOR. Esses resultados mostram, pela primeira vez, que o efeito antiproliferativo da rapamicina pode ser superado pela expressão de uma proteína viral, no caso a proteína E7 de HPV-16. / High-risk HPV infection has a major etiologic role in development and progression of cervical cancer, one of the most frequent forms of cancer among women worldwide. HPV-16 E6 and E7 oncoproteins are able to induce degradation of p53 and pRb tumor suppressor proteins respectively. Moreover, the expression of these oncoproteins is related to alterations in the PI3K/AKT/mTOR pathway. The cellular kinase mammalian target of Rapamycin (mTOR) is an important regulator of the cellular protein synthesis machinery and has emerged as a principal mediator of cell growth and proliferation. mTOR activation has been shown to stimulates eIF4G1 and 4EBP1 phosphorylation, thus increasing the rate of protein synthesis. Rapamycin is a specific inhibitor of mTOR signaling pathway and its analogues have demonstrated impressive activity against a broad range of human cancer derived cell lines in culture and in human tumor xenograft models. Since E6 and E7 target several proteins controlling the mTOR pathway we aimed to investigate the effect of Rapamycin in the proliferation of organotypic raft cultures expressing these genes. We also evaluated the effect of E6 and E7 genes in mTOR activity after rapamycin treatment. To generate organotypic culture of keratinocytes we infect these cells with recombinant retroviruses containing HPV-16 E6 and E7 together or separately. We also analyzed the role of p53 and pRb degradation in rapamycin responsiveness by using E6 and E7 mutants lacking the hability to inactivate these cellular proteins. After infection, keratinocytes were seeded on to a collagen matrix. After 6 days, these cultures were treated with 100ng/ml of Rapamycin for 60 hours. BrdU was added in the last 12 hours to evaluate proliferation. For immunohistochemistry analysis tissues were fixed in buffered formalin and embedded in paraffin. Immunohistochemistry reactions against BrdU, p-4EBP1 (ser 65), p-eIF4G1 (ser 1188) and p-AKT (ser 473) were performed The results show that proliferation of organotypic cultures of keratinocytes transduced with empty vector is inhibited by Rapamycin. On the other hand, cultures generated with keratinocytes transduced with E7 gene were completely resistance to the antiproliferative effect of Rapamycin. Moreover, we found that this antiproliferative effect was dependent of Rb degradation since the cells transduced with E7 mutant unable do induce Rb degradation were sensitive. In addition, eIF4G and 4EBP1 phosphorylation indicates that E7 expression impairs mTOR inhibition by rapamycin. AKT phosphorilation indicates that rapamycin resistance could be dependent of Rb inactivation induced by E7 expression. These results show for the first time that the Rapamycin antiproliferative effect is bypassed by the expression of a viral oncogene, in this case the HPV-16 E7. Moreover, E7 expression impairs rapamycin to inactivate mTOR.
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Génotypage des papillomavirus humains par séquençage haut-débit : conséquences dans le dépistage du cancer du col de l’utérus et apport conceptuel au virome cutané / HPV genotyping by high-throughput sequencing : consequences in cervical cancer screening and conceptual contribution to human skin virome

Molet, Lucie 18 May 2018 (has links)
Les papillomavirus humains (HPV) sont classés en 5 genres α, β, γ, µ et η. Leur génome comprend six gènes précoces dont deux oncogènes E6 et E7 et deux gènes tardifs codant les protéines de capside. Les β- et γ-HPV constituent une part importante du virome cutané. Généralement asymptomatiques ils peuvent se manifester par des papillomatoses et sont associés à certains cancers de la peau, en particulier chez l’immunodéprimé. Les α-HPV ont un tropisme muqueux ; les α-HPV à haut risque (HR) HPV16 et 18 sont impliqués dans 99% des cancers du col de l’utérus.La détection des α-HR-HPV dans les frottis cervico-utérins (FCU) lors d’atypie cellulaire de signification indéterminée (ASCUS) constitue une information décisive dans le dépistage du cancer du col de l’utérus, bien que les tests de génotypage ne ciblent que les types les plus fréquents. Le génotypage des β- et γ-HPV devient nécessaire pour l’étude du virome notamment dans des contextes de susceptibilité aux pathogénies HPV (syndrome WHIM : Warts, Hypogammaglobulimemia, Infections and Myelokathexis). Cet immunodéficit congénital rare causé par une mutation gain de fonction du récepteur CXCR4 se manifeste dans 70% des cas par des papillomatoses cutanées étendues et ano-génitales évoluant souvent en cancer. Des études du laboratoire ont identifié le rôle intrinsèque de l’axe CXCL12/CXCR4 dérégulé dans la pathogénie virale en démontrant notamment l’action bénéfique du blocage de cet axe par un antagoniste de CXCR4 (AMD3100) in vitro et in vivo sur l’oncogenèse due à HPV.Nos objectifs étaient : (i) d’identifier dans des FCU ASCUS, les HPV dont le génotype n’avait pu être déterminé (HPV-X) par un test classique (INNO-LiPA HPV Genotyping Extra II®), (ii) de caractériser le virome HPV d’un patient atteint de WHIM au cours d’un essai thérapeutique par AMD3100 administré à titre compassionnel pendant 7 mois avec pour objectif d’évaluer son impact sur les anomalies associées à HPV.Dans les deux cas, nous avons mis au point une méthode de génotypage par séquençage haut débit sur Illumina Miseq®. La distribution des génotypes et leur polymorphisme nucléotidique ont été étudiés par analyses comparatives et phylogénétiques. (i) Notre stratégie a permis d’identifier dans 54 ASCUS/HPV-X étudiés une majorité d'HPV bas risque réalisant dans 41% des cas une infection à multiples génotypes (2 à 7), et aussi l’existence de quasi-espèces (41% des FCU) comprenant jusqu’à 17 variants pour un même génotype. Ainsi, de probables compétitions ou défauts d’hybridation des variants minoritaires peuvent expliquer le manque de performance du test INNO-LiPA. (ii) Chez le patient WHIM, le séquençage a été complété par des qPCR spécifiques de types, permettant une étude qualitative et quantitative. L’AMD3100 n’a pas modifié qualitativement le virome HPV cutané composé de 16 types, principalement des β- et γ-HPV, déjà présents 3 ans auparavant dans des verrues cutanées analysées rétrospectivement. En revanche, l’analyse quantitative montre des modifications en proportion relative des génomes viraux suggérant un effet du traitement sur l‘expression de certains types pouvant être associés sélectivement à la papillomatose. A cet égard, un des HPV composant le virome cutané du patient qui se trouve être un des deux seuls types présents dans une biopsie profonde de verrue, étaye l’hypothèse d’une sélection dans le processus lésionnel. De plus, les protéines oncogènes E6 et E7 de ce virus présentent des mutations, en comparaison à la séquence du génome HPV de référence, qui pourraient favoriser le potentiel pathogène de ce varian; hypothèse en cours d’investigation.En conclusion, les techniques de séquençage haut débit que nous avons développées ont permis de mieux caractériser la composition du virome HPV démontrant à la fois sa complexité en génotypes viraux ou en dérivés de ceux-ci (concept de quasi-espèces) et sa dynamique d’évolution qui pourraient sous-tendre le potentiel pathogène de ce virome HPV. / Human papillomaviruses (HPV) are classified into 5 genera α, β, γ, μ and η. Their genome comprises six early genes including two oncogenes E6 and E7, and two late genes encoding the L1 and L2 capsid proteins. β- and γ-HPV constitute an important part of the cutaneous virome; usually asymptomatic, they can manifest as papillomatosis like warts and are associated with certain skin cancers, especially in immunocompromised patients. α-HPV has a mucosal tropism; high-risk (HR) α-HPV16 and 18 are involved in 99% of cervical cancers.Detection of α-HR-HPV in cervical samples guide the management of women whose Pap smear result shows atypical squamous cells of undetermined significance (ASCUS), although genotyping targets only the most common HPV types. Genotyping of β- and γ-HPV becomes necessary for the study of the virome especially in contexts of susceptibility to HPV pathogenesis (i.e. WHIM syndrome (for Warts, Hypogammaglobulimemia, Infections and Myelokathexis)). WHIM syndrome is a rare congenital immunodeficiency caused by a gain-of-function mutation of the CXCR4 receptor of the chemokine CXCL12 and manifests in 70% of cases by extensive cutaneous papillomatosis and ano-genital lesions that often evolve into cancer. Studies in our laboratory have identified the intrinsic role of the dysregulated CXCL12/CXCR4 axis in viral pathogenesis by demonstrating in particular the beneficial action of the blocking of this axis by an antagonist of CXCR4 (AMD3100) in vitro and in vivo on HPV-associated oncogenesis.Our objectives were: (i) to identify HPV whose genotype could not be determined (HPV-X) by a conventional test (INNO-LiPA HPV Genotyping Extra II®) in cervical samples with Pap smear report of ASCUS (ii) to characterize the HPV virome of a patient suffering from WHIM syndrom during a 7-month compassionate AMD3100 clinical trial to assess its impact on HPV-associated abnormalities.In both cases, we have developed a high-throughput sequencing genotyping method on Illumina Miseq®. The distribution of genotypes and their nucleotide polymorphism were studied by comparative and phylogenetic analyzes. (i) Our strategy identified in the 54 investigated ASCUS/HPV-X a majority of low-risk HPV, achieving a multiple infection (2 to 7 genotypes) in 41% of cases, and also the existence of quasi-species (41% of FCU) comprising up to 17 variants for the same genotype. Thus, probable competitions or hybridization defects of the minority variants may explain the lack of performance of the INNO-LiPA test. (ii) In the WHIM patient, sequencing was supplemented with type-specific qPCRs, allowing a qualitative and quantitative study. AMD3100 did not qualitatively modify the cutaneous HPV virome composed of 16 types, mainly β- and γ-HPV. In contrast, the quantitative analysis shows changes in the relative proportions of viral genomes suggesting a treatment effect on the expression of certain types that can be selectively associated with. papillomatosis. In this respect, one of the HPVs belonging to the cutaneous virome of the patient was found to be one of only two types present in a deep wart biopsy. This result supports the hypothesis of HPV selection in the lesion process. In addition, the oncogenic proteins E6 and E7 of this virus have mutations which could promote the pathogenic potential of this viral variant in comparison with the sequence of the reference HPV genome; a hypothesis that is under investigation.In conclusion, the high throughput sequencing techniques that we have developed have made it possible to better characterize the composition of the HPV virome demonstrating both its complexity in viral genotypes or in derivatives (i.e. quasi-species concept). The dynamics of which may underlie the pathogenic potential of this HPV virome.
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Ett nej är alltid ett nej, men inte när man vaccinerar : En kvalitativ intervjustudie om skolsköterskors syn på sin roll som vaccinationsförespråkare / Never take no for an answer : A qualitative content analysis about school nurses’ attitudes as opinion leaders regarding vaccinations

Landin, Jannica, Sundelöf, Marie January 2020 (has links)
Bakgrund: HPV är den vanligaste sexuellt överförbara infektionen i Sverige. Flickor vaccineras redan mot HPV, från hösten 2020 kommer pojkar vaccineras. Vaccinationstäckningen är lägre än övriga vaccin i vaccinationsprogrammet. Information och rekommendation från vårdgivare har visat sig ha betydelse för vaccinationstäckningen. Syftet: Studiens syfte var att beskriva skolsköterskors syn på sin roll som vaccinationsförespråkare vid införandet av HPV-vaccination till pojkar i det allmänna vaccinationsprogrammet för barn. Metod: Kvalitativ metod användes i studien. Semistrukturerade intervjuer med åtta skolsköterskor verksamma i Stockholmsområdet genomfördes. Resultatet analyserades med kvalitativ innehållsanalys. Resultat: Analysen resulterade i fyra kategorier; Betydelsen av att ge information, Utmaningar med att vara vaccinationsförespråkare, Betydelsen av egen kunskap, Ansvar som vaccinationsförespråkare. Ur resultatet framträdde temat Ett livräddande engagemang. Konklusion: HPV-infektioner spelar en stor roll för uppkomsten av cancer och orsakar många dödsfall varje år. Skolsköterskors arbete för att uppnå en hög vaccinationstäckning har därför stor betydelse och kan i förlängningen ses som en insats som förhindrar lidande och räddar liv. För att uppnå hög vaccinationstäckning måste skolsköterskor ha goda kunskaper för att ge aktuell och adekvat information till elever och vårdnadshavare. Vaccinets sexuella koppling, relationen till vårdnadshavare och samhällets syn på vaccinet ses av skolsköterskorna som utmaningar för nå en hög vaccinationstäckning. / Background: Human papillomavirus (HPV) is the most common sexually transmitted disease in Sweden. Girls are already vaccinated against HPV and from the autumn of 2020 boys will be initiated. The vaccine uptake is lower compared to other vaccines in the national vaccination program. Information and recommendation from healthcare providers has been proven to be important for vaccine uptake. Aim: The aim of the study was to describe school nurses view on their role as opinion leaders during introduction of HPV-vaccine to boys in the national vaccination program for children. Method: A qualitative methodology was used in the study. Semi-structured interviews with eight school nurses active around Stockholm were accomplished. The results were analyzed by content analysis. Results: The analysis resulted in four categories; The importance of giving information, Challenges being an opinion leader, The importance of individual up to date knowledge and Responsibility as an opinion leader. From the result a theme appeared A lifesaving commitment. Conclusion: HPV-infections plays an important role for the appearance of cancer and causes many deaths each year. School nurses’ assignment to achieve high vaccination uptake has a major importance and may in long term prevent suffering and save life. To achieve high vaccine uptake school nurses need knowledge to be able to give current and adequate information to students and parents. The sexual connection, the relationship to parents and society’s view on the vaccine are seen as challenges to achieve a high vaccine uptake by the school nurses.
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Analýza spotřeby a spontánního hlášení nežádoucích účinků vakcín proti lidskému papilomaviru / Analysis of utilisation and spontaneous adverse events reports related to human papillomavirus vaccines

Schrommová, Tereza January 2021 (has links)
Analysis of utilisation and spontaneous adverse events reports related to human papillomavirus vaccines Author: Tereza Schrommová Supervisor: PharmDr. Eva Zimčíková, Ph.D. Department of Social and Clinical Pharmacy, Faculty of Pharmacy in Hradec Králové, Charles University INTRODUCTION: HPV vaccination is one of the most effective types of prevention against the human papillomavirus infection that can lower the probability of its incidence up to 80-90 %. Besides the benefits of vaccination, there can also occur among many individuals certain risks and adverse effects. Spontaneous adverse events reports are used to identify these serious and unexpected adverse effects, their monitoring leads to increasing safety of therapy. Drug consumption is monitored to uncover the ratio of population exposure to certain drug during specific time in specific socioeconomic group. OBJECTIVE: The objective of this diploma was analysis of spontaneous adverse events reports of vaccines against the human papillomavirus that are registered in database of State Institute for Drug Control in the period from May 2007 to October 2017. Another aim of this work was to evaluate consumption of HPV vaccines in the Czech Republic in the period from 2006 to 2019 using data from State Institute for Drug Control again. METHODS:...

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