• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 86
  • 24
  • 22
  • 8
  • 7
  • 5
  • 2
  • 1
  • 1
  • 1
  • Tagged with
  • 190
  • 105
  • 47
  • 41
  • 37
  • 25
  • 24
  • 24
  • 20
  • 20
  • 18
  • 18
  • 16
  • 15
  • 14
  • 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.
31

Caractérisation de la réponse à l’instabilité des centromères (iCDR) déclenchée par la protéine ICP0 du Virus Herpès Simplex de type 1 (HSV-1) / Characterization of the interphase Centromere Damage Response (iCDR) triggered by the ICP0 protein of Herpes Simplex Virus Type 1 (HSV-1)

Sabra, Mirna 26 January 2010 (has links)
L’infection par le virus de l’herpès simplex de type 1 (HSV-1), un virus pathogène humain majeur, engendre la déstabilisation des centromères. Cette déstabilisation est induite par la protéine virale ICP0, et entraîne la dégradation par ICP0, via le protéasome, des protéines CENP-A, -B et CENP-C. Des résultats obtenus au laboratoire ont mis en évidence le phénomène iCDR (pour interphase Centromere Damage Response) qui implique la redistribution de la coïline, fibrillarine et SMN dans ces structures centromériques déstabilisées par ICP0 mais également par des drogues ou des siRNAs dirigés contre des constituants protéiques essentiels pour la stabilité des centromères. Il a été étudié leur interdépendance dans la réponse iCDR. Il a été ainsi démontré que la redistribution de SMN aux centromères déstabilisés est dépendante de : 1) la présence de la coïline aux centromères, et 2) de son interaction, via son domaine TUDOR, avec l’histone H3 méthylée sur la lysine K79 par l’enzyme Dot1L. L’équipe suggère donc l’hypothèse que ces protéines ont pour rôle de protéger l’ADN nu se trouvant aux centromères après dégradation des histones pour empêcher les cellules de rentrer en apoptose. Ces résultats ont mené à démontrer l’implication de certaines des protéines de l’iCDR et notamment la coïline, dans une réponse apoptotique générale suite à un stress UV. Ces protéines pourraient donc faire partie d’un mécanisme de contrôle qui serait défini comme un checkpoint centromérique / Infection by Herpes Simplex Virus type 1, a major pathogenic virus in human, has been shown to cause centromere destabilization. The infected cell protein 0 (ICP0) induces centromere destabilization and lead to proteasomal-dependent degradation of the proteins of the centromeres, CENP-A, -B and CENP-C. Recent data, obtained in our laboratory, highlights the interphase Centromere Damage Response (iCDR) phenomena. This phenomena involves centromeric accumulation and redistribution of the Cajal body-associated coilin and fibrillarin as well as the Survival Motor Neuron (SMN) proteins by ICP0 or by other drugs or siRNA targeting several constitutive centromere proteins known to play a major role in centromeres stabilization. Our data shows that SMN reditribution in the destabilized centromere is dependent of : 1) centromeric presence and accumulation of the coilin, 2) its interaction, via the TUDOR domain, with the methylated (Lys K79) histone H3. This methylation occurs in the presence of the Dot-1L enzyme. We hypothesize that these proteins play a critical role in safeguarding centromeric DNA to prevent the cells from apoptosis after Histone degradation. These observations, demonstrate the implication of certain iCDR proteins, more specifically the coilin, in the apoptotic response following a UV stress. In conclusion, these proteins could be part of a safeguard mechanism considered as a centromeric checkpoint
32

Interações neuro-imunes envolvidas na gênese da hipersensibilidade nociceptiva herpética e pós-herpética / Neuro-immune interactions involved in the genesis of herpetic and postherpetic nociceptive hypersensitivity

Silva, Jaqueline Raymondi 28 August 2014 (has links)
Herpes Zoster é uma doença causada pela reativação do vírus Varicela Zoster nos gânglios sensoriais, caracterizada pelo desenvolvimento de lesões na pele e dor. Não há modelos animais disponíveis para estudo da patofisiologia da doença. No entanto, um modelo murino que utiliza o HSV-1 tem sido usado para tal fim, visto que os animais desenvolvem lesões zosteriformes e desenvolvem hipersensibilidade na pata infectada. Não há dados na literatura acerca da resposta imune que se desenvolve nos gânglios da raiz dorsal destes animais. Logo, o objetivo deste trabalho foi o de avaliar células e mediadores inflamatórios presentes nos gânglios da raiz dorsal e sua relação com a hiperalgesia durante a infecção cutânea por HSV-1. Durante a fase aguda da infecção, os camundongos desenvolveram hiperalgesia nas patas ipsilaterais a partir do 3 dia pós-infecção, que perdurou até o 7 dia pós-infecção. A maior carga viral foi detectada nos gânglios L4, L5 e L6, os quais compõem o nervo ciático, que inerva a área infectada. O tratamento dos animais infectados com dexametasona ou fucoidina resultou na redução do comportamento de hiperalgesia, a partir do 5 dia pós-infecção, que corresponde ao período em que a migração de leucócitos passa a aumentar nos gânglios da raiz dorsal. Macrófagos, neutrófilos e linfócitos T CD4 foram detectados nos gânglios durante a infecção aguda. No entanto, linfócitos T CD8 estavam ausentes. A expressão do mRNA de TNF- e COX-2 estava aumentada nos gânglios, e o tratamento de animais infectados com drogas inibidoras de ambos resultou na redução da hiperalgesia. Os receptores do tipo Toll-like e da IL-1 não participam da geração da hipersensibilidade herpética. Após 50 dias da infecção, constatou-se que alguns animais apresentavam comportamento de hiperalgesia irreversível, semelhante à neuralgia pós-herpética humana (NPH). Não houve diferença significativa na incidência da NPH em animais de linhagens ou sexos diferentes. Ainda, o tratamento com drogas anticonvulsivantes e antidepressivas, mas não com morfina e anti-inflamatórios, resultou na redução transiente da hiperalgesia. Neste período, não há participação da inflamação na manutenção da hiperalgesia. A expressão de TNF- e COX-2 retorna aos níveis basais, e não são mais detectados neutrófilos e macrófagos. No entanto, a migração de linfócitos T CD4+ e CD8+ aos gânglios aumenta de maneira tempo-dependente. Durante a NPH, detectou-se uma intensa ativação das células satélites gliais, que contribuem para a manutenção da hiperalgesia pós-herpética. Nossos resultados demonstram que a manutenção hiperalgesia herpética é resultado da intensa resposta inflamatória que ocorre nos gânglios da raiz dorsal infectados, com aumento da produção de TNF- e COX-2, importantes mediadores para a hipersensibilidade. No entanto, durante a neuralgia pós-herpética, não há participação de células ou mediadores inflamatórios, mas de células da glia, as quais são importantes na manutenção da hiperalgesia. / Herpes Zoster is a disease caused by reactivation of varicella zoster virus in sensory ganglia, characterized by dermal rash and pain. There are no animal models available to study the pathophysiology of the disease. A murine model of HSV-1 infection on the hind paw skin has been used to study HZ, since mice develop HZ-like skin lesions and pain-related responses. There are no data available about the immune response in dorsal root ganglion (DRG) of these mice. Thus, the aim of this study was to evaluate cells and inflammatory mediators present in DRGs and its relationship with hiperalgesia during HSV-1 cutaneous infection. During the acute phase of infection, mice developed hyperalgesia in ipsilateral paws from 3 days post-infection, which persisted until 7 days post-infection. The highest viral load was detected in ganglia L4, L5 and L6. Treatment of infected mice with fucoidin or dexamethasone resulted in the reduction of hyperalgesic behavior, from the 5th post-infection day, which corresponds to the period in which leukocyte migration increase in the dorsal root ganglia. Macrophages, neutrophils and CD4 + T lymphocytes were detected in the ganglia during acute infection. However, CD8 + T lymphocytes were absent. The mRNA expression of TNF- and COX-2 was increased in dorsal root ganglia, and the treatment of infected mice with drugs that inhibits both mediators resulted in reduced hyperalgesia. The Toll-like receptors and IL-1 does not participate in the generation of herpetic hypersensitivity. After 50 days of infection, it was found that some animals presented irreversible hyperalgesic behavior, like human post-herpetic neuralgia (PHN). There was no significant difference in the incidence of PHN in animals of different genders or strains. Furthermore, treatment with anticonvulsant and antidepressant drugs, but not morphine and anti-inflammatory, resulted in transient reduction of hyperalgesia. In this period, there is no participation of inflammation in the hyperalgesia maintenance of. The expression of TNF- and COX-2 returns to baseline levels, and neutrophils and macrophages are no longer detected. However, the migration of CD4 + and CD8 + to ganglia increases in a time-dependent manner. During NPH, an intense activation of glial cells satellites was detected, that contributes to the maintenance of post-herpetic hyperalgesia. Our results demonstrate that herpetic hyperalgesia maintenance is a result of an intense inflammatory response that occurs in the infected dorsal root ganglia, with increased production of TNF- and COX-2. However, during post-herpetic neuralgia, there is involvement of glial cells, which are important in hyperalgesia maintenance.
33

Desenvolvimento e avaliação de composições precursoras de filmes formados in situ contendo anestésico para tratamento de infecções por Herpes simplex / Development and evaluation of film forming compositions for the treatment of Herpes vírus infections

Silva, Amanda Cristina Funari 23 March 2018 (has links)
As infecções causadas pelo Herpes simplex virus, tipo 1 e 2 (HSV-1 e HSV-2) são consideradas problema de saúde pública no mundo, com prevalência em dois terços da população mundial. A doença é caracterizada pelo aparecimento de vesículas que ocasionam dor e constrangimento ao portador, devido à aparência desagradável que apresentam. As infecções que levam a lesões orofaciais são geralmente ocasionadas pelo HSV-1, enquanto as genitais, pelo HSV-2. O tratamento de escolha baseia-se no uso de antivirais em géis ou pomadas, entretanto, recidivas são comuns e dependentes do estado imunológico do indivíduo, além de exposição a fatores hormonais ou ambientais. Os anestésicos locais diminuem a dor ocasionada pela lesão além de mostrarem ter propriedades antivirais. A forma semissólida facilita a aplicação e a sua transformação em uma película fina, após curto período de tempo, favorece a manutenção da formulação no local, com aspecto final mais discreto quando comparada às opções disponíveis. O objetivo desse trabalho foi desenvolver e avaliar in vitro e in vivo formulações contendo anestésicos para o tratamento do herpes labial. Para tanto, duas formulações semissólidas formadoras de filme foram desenvolvidas e avaliadas (F1 e F1T), contendo HPMC K100, lidocaína (LIDO) e prilocaína (PRILO) combinados a adjuvantes, na presença (F1T) ou não (F1) do promotor de absorção Transcutol®. A mistura de PRILO e LIDO acarretou na formação de uma mistura eutética (ME). Para quantificação dos fármacos a partir da formulação, um método analítico por CLAE (Cromatografia Líquida de Alta Eficiência) foi revalidado e atendeu aos parâmetros preconizados na literatura. A recuperação dos fármacos a partir da pele suína foi satisfatória. As formulações apresentaram homogeneidade na distribuição do conteúdo. A formação do filme in situ foi avaliada e ocorreu em aproximadamente 20 minutos. A adição do promotor de absorção aumentou a concentração dos fármacos no líquido receptor no experimento de permeação passiva in vitro, utilizando pele de orelha suína. E a quantidade de PRILO e LIDO quantificada no estrato córneo foi maior para a formulação sem o Transcutol®. As análises reológicas de cisalhamento contínuo e oscilatório classificaram as formulações como fluídos newtonianos e a F1T apresentou maior estruturação em relação a F1. A avaliação in vitro da multiplicação viral sugere atividade virucida para ambos os fármacos, com proteção a infecção superior a 80% para as concentrações de fármaco avaliadas. As formulações não apresentaram irritação dérmica ao exame macroscópico. O teste in vivo de eficácia comprovou a capacidade dos anestésicos em regredir as lesões causadas por HSV-1. Sendo assim, as formulações propostas mostraram-se boas alternativas ao tratamento de lesões labiais causadas pelo HSV-1. Análises estatísticas adequadas foram realizadas. / Infections by Herpes Simplex virus, type 1 and 2 (HSV 1 e HSV-2) are a public health problem in the world with prevalence of two thirds of the mundial population. This disease is characterized by painful vesicles and embarrassment because of wound appearance. Orofacial wounds are mostly caused by HSV-1 and genital wounds are by HSV-2. Nowadays, current treatment is based on the use of antiviral in cream and ointments but, recurrences are very common and depend of individual state of immunological system besides environmental factors. Topical anesthetics minimize the pain and have shown antiviral properties. The semisolid composition improves application and its transformation into a thin film, after a short period of time, favors the maintenance at the site with good final aspect compared to the currently available treatment options. In this research, we developed and evaluated in vitro and in vivo compositions containing topical anesthetics for treatment of labials herpes. The compositions were prepared using HPMC K100, lidocaine (LIDO) and prilocaine (PRILO) combined with adjuvants, with permeation promoter Transcutol® (F1T) or not (F1). The mix of PRILO and LIDO results in eutectic mixture. For quantified drugs in compositions an analytical method by HPLC (High Performance Liquid Chromatography) was revalidated with satisfactory parameters, as well the recovery of drug on porcine skin. The formulations were with homogeneous content and film formation occurs in approximately 20 minutes. The addition of Transcutol® results in more PRILO and LIDO in receptor medium for F1T at in vitro passive permeation study. The quantify of drugs in corneum layer is mayor in F1 than F1T. Rheological analyses shown the compositions are newtonians fluids and F1T has more cohesion than F1. Evaluation of in vitro viral multiplication suggests activity before virus infects host cells, with 80% of protection of infection for evaluated concentrations. None composition shown dermal irritation in macroscopical examination. The in vivo efficacy study proves the anesthetics capacity of regress the HSV-1 wounds. Therefore, the developed compositions are good alternatives for labialis herpes caused by HSV-1.
34

Relation entre l’expression des LAT et du gène RL2 pendant la latence du virus HSV-1 / Relationship between the expression of LAT and RL2 gene during HSV-1 latency

Huot, Nicolas 17 December 2012 (has links)
Le virus de l’herpès simplex de type 1 (HSV1) établit une infection latente dans le système nerveux de l'homme, au cours de laquelle un type de transcrits, appelés LATs (pour latency associated transcripts), s'accumule dans les neurones infectés. Le rôle clef des LATs dans le contrôle de la latence virale est reconnu. Cependant, depuis leur découverte dans les années 80, leur mécanisme d'action reste non élucidé.Le gène des LATs est transcrit en un LAT primaire de 8,3kb, qui est épissé, conduisant à la formation de deux LATs stables : le LAT2kb et le LAT1.5kb. De façon remarquable, le LAT2kb et le LAT1.5kb sont des introns. Leur stabilité est la conséquence d'un branchement non canonique qui se traduit par le maintien de la structure en lariat. Par ailleurs, la région du génome codant les LATs contient également le gène RL2 qui code ICP0, la protéine la plus en amont dans la cascade de réactivation du virus. Des études précédentes ont montré qu’au moment de la latence, des transcrits RL2 non épissés, s'accumulent au site principal de la latence (le ganglion de Gasser).Nous avons caractérisé ces transcrits non épissés du gène RL2 dans les tissus infectés de façon latente. Ils contiennent de façon reproductible l’intron 1 et sont d’autant plus abondants dans les tissus infectés de façon latente que les LAT s’accumulent. On peut ainsi distinguer plusieurs types de tissus infectés de façon latente, dont les deux exemples les plus représentatifs sont d’une part le ganglion de Gasser (forte expression des LAT et accumulation de transcrits RL2 non-épissés) et d’autre part le ganglion cervical supérieur (pas d’accumulation de LAT par rapport aux quantités exprimées pendant la phase aiguë de l’infection, et très peu d’expression dans transcrits non-épissés). Dans tous les cas, la réalité du caractère latent de l’infection était confirmé par la présence de génome viral sans expression de transcrits matures de gène viral précoce (représenté par celui de la thymidine kinase) ni tardif (gène UL18). Ces résultats suggèrent une relation entre la présence des LAT et l’accumulation de transcrits RL2 non-épissés, ce qui pourrait être en relation avec le maintien de l’infection à l’état latent dans ces tissus. / The herpes simplex virus type 1 (HSV-1) establishes a latent infection in the nervous system of humans, in which latency associated transcripts (LATs) accumulate in infected neurons. The key role of LATs in the control of viral latency is well established. However, since their discovery in the 80s, their mechanism of action remains unclear.The LAT gene is transcribed into a 8.3 kb primary LAT that is rapidly spliced, leading to the formation of two stable LATs; LAT2kb and LAT1.5kb. Remarkably, the LAT2kb and LAT1.5kb are introns. Their stability is the result of a non-canonical sequence of the branching point, which results in maintaining the lariat structure.Moreover, the region of the genome encoding the LATs also contains the RL2 gene, encoding ICP0 that acts upstream in the cascade of viral reactivation. Previous studies have shown that RL2 unspliced transcripts may accumulate in the main site of HSV-1 latency (trigeminal ganglia). We have characterized these unspliced transcripts RL2 gene in latently infected tissues. They reproducibly contain intron 1 and are particularly abundant in latently infected tissues where LATs also accumulate. We distinguished several types of latently infected tissues, the two most representative examples being the trigeminal ganglion (strong expression of LATs and accumulation of non-spliced transcripts RL2) and, in the opposite, the superior cervical ganglion (no accumulation of LAT compared with the amounts expressed during the acute phase of infection, and little expression in non-spliced RL2 transcripts). In all cases, the reality of the latent nature of the infection was confirmed by the presence of viral genome with no expression of mature transcripts from early viral gene (represented by the thymidine kinase gene) or late (UL18 gene).These results suggest a relationship between the presence of LAT and the accumulation of non-spliced RL2 transcripts, which could be related to the maintenance of latent infection in these tissues.
35

Caractérisation d’une nouvelle fonction de la protéine Us11 dans l’échappement à l’autophagie par le virus Herpès Simplex de type 1 / Characterization of a novel function of Us11 protein in HSV-1 escape from autophagy

Lussignol, Marion 26 March 2013 (has links)
L’autophagie est un mécanisme vacuolaire de dégradation de matériel cytoplasmique permettant le maintien de l’homéostasie cellulaire, mais elle peut être également activée par de nombreux stress, comme l’infection virale. Le virus de l’Herpès Simplex de type 1 (HSV 1) est capable de contrecarrer ce mécanisme de défense antivirale. HSV-1 possède une protéine ICP34.5 capable d’inhiber l’autophagie en se liant à Beclin 1, une protéine de la machinerie autophagique. Nous avons mis en évidence une deuxième protéine d’HSV-1 capable d’inhiber l’autophagie, la protéine tardive Us11, qui pourrait avoir un rôle complémentaire à celui d’ICP34.5 dans le contrôle de l’autophagie par le virus.Nous montrons que l’expression ectopique d’Us11 permet de bloquer l’autophagie induite par différents stimuli, et ce de manière similaire à ICP34.5. De plus, dans un contexte viral, l’expression précoce d’Us11 dans des cellules infectées par un virusICP34.5 permet un contrôle de l’autophagie comparable à celui d’un virus sauvage. Nous avons ensuite recherché le mécanisme d’action d’Us11. La protéine Us11 a été décrite comme pouvant interagir avec la kinase dépendante de l’ARN double brin PKR, empêchant ainsi la phosphorylation de son substrat eIF2, un facteur d’initiation de la traduction. Nous avons observé qu’en l’absence de PKR, Us11 n’est plus capable d’inhiber l’autophagie. Nous avons pu confirmer qu’Us11 a besoin de se lier à PKR pour exercer son activité inhibitrice par la construction de formes tronquées d’Us11, permettant de montrer l’importance de son domaine d’interaction avec PKR dans l’inhibition de l’autophagie. L’étude des formes tronquées d’Us11 a soulevé le fait que le domaine N-terminal était également nécessaire. Aucune interaction de ce domaine avec une protéine cellulaire n’a été identifiée à ce jour, mais il pourrait permettre l’interaction d’Us11 avec une autre protéine de la machinerie autophagique. Cependant, nous avons montré qu’Us11 n’interagissait pas avec Beclin 1 et n’avait pas d’effet sur la kinase mTOR, une autre voie importante de l’autophagie. Enfin, nous avons étudié la modulation de la voie PKR/eIF2 lors de la stimulation de l’autophagie par la carence, et nos résultats suggèrent que cette voie joue un rôle sous-estimé dans la réponse à la carence.Le mécanisme d’action de la protéine Us11, qui consiste en un blocage de l’autophagie en inhibant PKR, n’avait jamais été décrit auparavant. Ce travail ouvre de nombreuses perspectives dans l’étude de la voie PKR/eIF2 vis à vis de la régulation de l’autophagie, ainsi que dans la compréhension de l’implication de l’autophagie dans la neurovirulence d’HSV-1. / Autophagy is an evolutionary conserved vacuolar mechanism allowing to degrade cytoplasmic components and to maintaining cellular homeostasis, but it can also be triggered by a variety of stress-related conditions, including viral infection. The herpes simplex virus 1 (HSV-1) is able to counteract this antiviral mechanism. Notably, HSV-1 encodes a protein, IPC34.5, which inhibits autophagy through its interaction with the autophagy machinery protein Beclin 1. In the present work, we uncovered a second anti-autophagic protein from HSV-1, the late protein Us11, which likely plays a complementary role to ICP34.5 regarding the inhibition of autophagy by the virus. We demonstrated that ectopic expression of Us11 inhibited autophagy triggered by different stimuli, as observed for ICP34.5. Moreover, during viral infection, early expression of Us11 was sufficient to block autophagy in cells infected with a ICP34.5 virus, similarly to the wild-type virus. We then explored the mechanism of action of Us11. Us11 has been described as capable of interacting with the dsRNA-dependent kinase PKR, therefore preventing it to phosphorylate its substrate eIF2, a translation initiation factor. We demonstrated that Us11 was no longer able to inhibit autophagy when expressed in PKR-deficient cells. We confirmed that Us11 binding to PKR was necessary for its function by constructing various truncated forms of Us11 that showed that the PKR-binding domain was crucial. We also unveiled the importance of a domain located within the N-terminal part of Us11. This domain has no cellular molecular partner known, but it can allow Us11 to interact with another protein of the autophagy machinery. However, we further showed that Us11 did not interact with Beclin 1 nor affected the kinase activity of mTOR, another important pathway regulating autophagy. In our work, we also gained insights into regulatory mechanisms of starvation-induced autophagy.The inhibition of autophagy through the specific blockade of PKR by Us11 had never been previously described. This work thus paves the way for studying the involvement of PKR/eIF2 pathway in the regulation of autophagy and for exploring the role of autophagy in HSV-1 neurovirulence.
36

Polymorphic membrane protein expression in Chlamydia/HSV co-infected cells

Colgrove, Julia S 01 May 2014 (has links)
The Chlamydiaceae are a bacterial family that contains a single genus: Chlamydia. The genus Chlamydia consists of 9 species that are obligate, intracellular pathogens. Untreated C. trachomatis infections can lead to serious health ramifications, such as ectopic pregnancy, tubal factor infertility, pelvic inflammatory disease, and long-term pelvic pain. In this study, it was found that a primary antibody dilution of 1:400 using methanol fixed HeLA cells, as derived from Carrasco, et al. protocol, was only optimal for PMP-C staining. Pmp-A, Pmp-B, and Pmp-F were found to stain brighter with formaldehyde fixed, infected HeLa cells and using different primary antibody dilutions. The manuscript by Carrasco, et al., demonstrated that chlamydial persistence caused by penicillin-stressed conditions showed a decrease in Pmp-B and Pmp-C protein expression between 24-48 hpi, while Pmp-A and Pmp-F expression stayed the same under the stressful conditions. We hypothesized that under HSV- induced persistence the same results would occur. However, our data indicates that the chlamydial response to stressful conditions is not the same among persistence-inducers and implies that various inducers of persistence may affect PMP expression differently. Initially, we also hypothesized that PMP expression could be utilized as an indicator to determine whether an infected individual has a productive or persistent chlamydial infection. Due to the experiments’ results, PMP expression is most likely not a good marker to identify the type of chlamydial infection (ie. productive or persistent) in the host.
37

The role of the TGN in the transport of herpes simplex virus type I capsids

Mihai, Constantina January 2008 (has links)
Mémoire numérisé par la Division de la gestion de documents et des archives de l'Université de Montréal
38

AVALIAÇÃO DA EXPRESSÃO DA PROTEÍNA HspBP1 EM INFECÇÕES VIRAIS

Ceccim, Adrianne Del Fabro 29 March 2011 (has links)
Made available in DSpace on 2018-06-27T18:56:08Z (GMT). No. of bitstreams: 2 Adrianne Del Fabro Ceccim.pdf: 4991781 bytes, checksum: d1128fe71a2a03c2beaa42a7847dfedb (MD5) Adrianne Del Fabro Ceccim.pdf.jpg: 3245 bytes, checksum: 583d4670e00da5b265b326517cddf626 (MD5) Previous issue date: 2011-03-29 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Thousands of people die annually due to infections caused by some kind of virus, despite the large investment on development of technologies that improve the diagnostics and prognostics of virus diseases. However, there is a lack of methods for diagnosis that are more accurate, low cost and that handle problems such as the immunologic window, the bounds of different infection phases, as well as the low amount of virions. The Hsps 70 are molecular chaperones that are expressed in various situations of stress or heat, forming a highly preserved immunologic system. They are highly expressed in different kind of tumors and in some in almost all viral infections. In the same way, its co-chaperona, the heat chock protein 70 linked to protein 1 (HspBP1) is involved in tumors processes, such as the lung cancer and the neuroblastoma. Recently, it was identified as a marker for the prognostic of breast cancer. Despite having studies related to the expression of HspBP1 on cancers and on its prognostics, the studies of its expression in viral infections are rare. Due to the fact that this protein can be used as an indicator of cellular metabolic alteration and that the viral infection will induce the cellular stress, the modification of its expression during the viral cycle can predict a higher or lower replicative index. This property can be used as a tool in the viral diagnostic. The mainly objective of this study was to determine the pattern of expression of protein HspBP1 in cells that hosts HSV-1 (vero cells) in vitro using the Western-blotting and determine increasing or reduction on its expression. In addition, the levels of HspBP1 and antibodies agains HspBP1 in the serum of HIV infected people were analized by ELISA. The results in vitro showed that after the viral infection there was no different in the pattern of expression of the total protein, when analyzed by SDS-PAGE. However, using the Western-Blotting the expression of HspBP1 increased in the 48 hours after the infection, comparing with non-infected Vero cells. Seventy-two hours after infection the expression decreased. The results of HspBP1 protein by ELISA showed a significant increasing of this protein in the HIV infected group that also presented a high viral load and low number of T CD4+ lymphocytes, when compared with the groups with an undetected load of HIV infected and uninfected. Regarding the research of anti-HspBP1 the results showed an increase in serum protein from HIV infected people. In conclusion these results suggest that the expression of HspBP1 is increased in HIV infected people and it is followed by an increasing in antibody production against HspBP1 and decreasing in T CD4+ lymphocytes for high viral load. / Milhares de pessoas morrem anualmente por infecções causadas por algum tipo de vírus, mesmo que, nos últimos anos, se invista muito no desenvolvimento de tecnologias para aprimorar o diagnóstico e prognóstico de viroses. Entretanto, ainda existe uma carência de métodos diagnósticos mais sensíveis, de baixo custo, que contornem problemas como a janela imunológica, os limites de detecção em determinadas fases da infecção, assim como a baixa quantidade de vírions. As Hsps 70 são chaperonas moleculares que se expressam em várias situações de estresse e ou calor, constituindo um sistema genético altamente conservado, sendo altamente expressas em diversos tipos de tumores e em certos tipos de viroses. Do mesmo modo, a sua co-chaperona, a proteína de choque térmico 70 ligada à proteína 1 (HspBP1), está envolvida em processos tumorais, como no câncer de pulmão e no neuroblastoma, e recentemente, foi identificada como um marcador de prognóstico no câncer de mama. Embora existam estudos relacionando à expressão da HspBP1 no câncer e o prognóstico deste, os estudos de sua expressão em infecções virais são raros. Em razão dessa proteína poder ser utilizada como um indicador de alteração metabólica celular, e a infecção viral induzir estresse celular, a alteração de sua expressão durante o ciclo viral pode predizer um maior ou menor índice replicativo. Assim, essa propriedade pode ser utilizada como ferramenta no diagnóstico viral. Dessa forma, este trabalho teve como objetivo determinar o padrão de expressão da proteína HspBP1 em células hospedeiras do vírus HSV-1 (células Vero) in vitro através da técnica de Western-blotting, avaliando um provável aumento ou diminuição da sua expressão. Além disso, quantificar a proteína HspBP1 e os anticorpos IgG anti-HspBP1 no soro de indivíduos HIV positivos através da técnica de ELISA. Os resultados demonstraram que após a infecção viral não houve diferença no padrão de expressão de proteína total, quando analisados por SDS-PAGE. No entanto, pela técnica de Western-Blotting, a expressão de HspBP1 apresentou aumento nas 48 horas após a infecção em comparação com células Vero não infectadas. Setenta e duas horas após a infecção, a expressão diminuiu. Os resultados da pesquisa da proteína HspBP1 pelo teste ELISA mostraram que houve um aumento significativo dessa proteína no grupo dos indivíduos infectados pelo HIV apresentando carga viral alta e contagem de linfócitos T CD4+ baixos quando comparado com os grupos dos infectados pelo HIV com carga viral indetectável e com os não infectados. Em relação a pesquisa de anticorpos IgG anti-HspBP1 os resultados mostraram que houve um aumento da proteína em indivíduos infectados pelo HIV. Assim, esses resultados sugerem que a expressão HspBP1 está aumentada em indivíduos infectados pelo HIV, seguidos por um aumento na produção de anticorpos contra a HspBP1 e redução dos linfóctios T CD4+ para uma carga viral elevada.
39

PRODUÇÃO E ANÁLISE DOS EFEITOS IMUNOBIOLÓGICOS DE NANOCÁPSULAS POLIMÉRICAS DE NÚCLEO AQUOSO SOBRE CÉLULAS DENDRÍTICAS MURINAS

Possani, Liliane Medianeira Mayer 26 March 2015 (has links)
Submitted by MARCIA ROVADOSCHI (marciar@unifra.br) on 2018-08-16T20:02:22Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertacao_LilianeMedianeiraMayerPossani.pdf: 1773175 bytes, checksum: 0fea418092d5f10f54b9e5790226b20b (MD5) / Made available in DSpace on 2018-08-16T20:02:22Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertacao_LilianeMedianeiraMayerPossani.pdf: 1773175 bytes, checksum: 0fea418092d5f10f54b9e5790226b20b (MD5) Previous issue date: 2015-03-26 / Herpes is a condition caused by Herpes Simplex Virus types 1 (HSV-1) and 2 (HSV-2) which largely affects the global population. Both species can be transmitted through direct contact with infected lesions or biological fluids such as saliva and genital fluids. However, asymptomatic carriers can also transmit and excrete virus. Control of herpes is accomplished through the use of antiviral drugs, however, its extensive use has led to the emergence of resistant virus strains, particularly in immunocompromised patients. Because of that the development of an effective vaccine will not only control the disease, but also its etiologic agent. HSV-1 is an enveloped DNA viruses, and in this envelope there are viral glycoproteins that are responsible for the process of entering into the host cell. The mainly glycoproteins are B (gB) glycoprotein D (gD), glycoprotein H (gH) and glycoprotein L (gL). Glycoprotein B is the most studied protein and the reason for that is because its sequence is conserved among all herpesviruses and also is essential for the cell infection process. In this glycoprotein there is a fragment of 8 amino acid residues referred SSIEFARL. It is an immunodominant peptide responsible for inducing a strong T cell response upon infection process. This peptide is poorly immunogenic when adminstered without protection and or adjuvant. Thus, the nanobiotechnology can help for the development of a potent adjuvant to protect SSIEFARL and increase its immunogenicity. For this propouse, the production of previous developed polymeric nanocapsules (NCPs) with aqueous core was otimized and its physical and chemical parameters determined. After otimization, the encapsulation efficiency of SSIEFARL was evaluated and the interaction/compatibility of unloaded NCPs with cell in vitro were also determined. The NCPs presented unimodal distribution, low PDI (0.23±0.03), mean diameter of 267.5±51.6 and zeta potential -29.6±2.2, pH 7.2±0.3. The analyzes showed that 98% (97.7±1.5) of the particles in the sample were in the nanoscale and the a concentration of NCPs 6,07x1010/cm3. In vitro tests showed no cytotoxicity, and unload NCPs and in vivo tested suggest a cell migration to the site of injection and draning to the reagional lymph nodes, suggesting some adjuvant propertie. Taken together, the data suggest that the NCPs can be used in the development of an adjuvant system for the protection of SSIEFARL and development of a vaccine against HSV-1. / A herpes é uma patologia causada pelo Herpes Simplex Vírus dos tipos 1 (HSV-1) e 2 (HSV-2) que afeta grande parte da população mundial. Ambas as espécies podem ser transmitidas através de contato direto com lesões ou fluidos biológicos infectados, como saliva e fluidos genitais. No entanto, portadores assintomáticos também podem excretar e transmitir os vírus. O controle da herpes é realizado através do uso de medicamentos antivirais, porém seu uso extensivo, levou ao aparecimento de linhagens de vírus resistentes, principalmente em pacientes imunocomprometidos. Esse fato torna imprescindível o desenvolvimento de uma vacina que seja eficaz não só no controle da doença, mas também de seu agente etiológico. O HSV-1 é um vírus de DNA envelopado e, nesse envelope estão ancoradas glicoproteínas virais que são responsáveis pelo processo de entrada na célula hospedeira, sendo as principais glicoproteína B (gB), glicoproteína D (gD), glicoproteína H (gH) e glicoproteína L (gL). A gB é um dos principais alvos nas pesquisas por ser uma sequência conservada em todos os herpesvírus e essencial no processo de infecção da célula alvo. Nessa glicoproteína, há um fragmento constituído por 8 resíduos de aminoácidos denominado SSIEFARL. Trata-se de um peptídeo imunodominante responsável por induzir forte resposta de células T no processo de infecção. Porém, esse peptídeo, quando administrado livre, é fracamente imunogênico. Sendo assim, busca-se na nanobiotecnologia, o desenvolvimento de um adjuvante potente para proteger o peptídeo e aumentar sua imunogenicidade. Para isso, nanocápsulas poliméricas (NCPs) de núcleo aquoso previamente desenvolvidas, tiveram sua produção otimizada e seus parâmetros físico-químicos avaliados. Após o estabelecimento das condições ótimas de produção, foram analisados o encapsulamento do SSIEFARL e testes para verificar a interação das NCPs brancas com cultura celular. As NCPs apresentaram distribuição unimodal, baixo PDI (0,23 ± 0,03), diâmetro médio de 267,5±51,6 e potencial zeta -29,6±2,2, com pH 7,2±0,3. As análises mostraram que aproximadamente 98% (97,7±1,5) das partículas presentes na amostra estão na escala nanométrica em uma concentração de 6,07x1010 NCPs/cm3. Os testes in vitro não evidenciaram citotoxicidade, e as NCPs brancas apresentaram capacidade de induzir migração celular ao local da injeção com tendência à drenagem dessas células aos linfonodos, sugerindo bom efeito adjuvante. A partir desses resultados pode-se sugerir que as NCPs podem ser utilizadas no desenvolvimento de um sistema adjuvante para a proteção do SSIEFARL e desenvolvimento de uma vacina contra o HSV-1.
40

Interações neuro-imunes envolvidas na gênese da hipersensibilidade nociceptiva herpética e pós-herpética / Neuro-immune interactions involved in the genesis of herpetic and postherpetic nociceptive hypersensitivity

Jaqueline Raymondi Silva 28 August 2014 (has links)
Herpes Zoster é uma doença causada pela reativação do vírus Varicela Zoster nos gânglios sensoriais, caracterizada pelo desenvolvimento de lesões na pele e dor. Não há modelos animais disponíveis para estudo da patofisiologia da doença. No entanto, um modelo murino que utiliza o HSV-1 tem sido usado para tal fim, visto que os animais desenvolvem lesões zosteriformes e desenvolvem hipersensibilidade na pata infectada. Não há dados na literatura acerca da resposta imune que se desenvolve nos gânglios da raiz dorsal destes animais. Logo, o objetivo deste trabalho foi o de avaliar células e mediadores inflamatórios presentes nos gânglios da raiz dorsal e sua relação com a hiperalgesia durante a infecção cutânea por HSV-1. Durante a fase aguda da infecção, os camundongos desenvolveram hiperalgesia nas patas ipsilaterais a partir do 3 dia pós-infecção, que perdurou até o 7 dia pós-infecção. A maior carga viral foi detectada nos gânglios L4, L5 e L6, os quais compõem o nervo ciático, que inerva a área infectada. O tratamento dos animais infectados com dexametasona ou fucoidina resultou na redução do comportamento de hiperalgesia, a partir do 5 dia pós-infecção, que corresponde ao período em que a migração de leucócitos passa a aumentar nos gânglios da raiz dorsal. Macrófagos, neutrófilos e linfócitos T CD4 foram detectados nos gânglios durante a infecção aguda. No entanto, linfócitos T CD8 estavam ausentes. A expressão do mRNA de TNF- e COX-2 estava aumentada nos gânglios, e o tratamento de animais infectados com drogas inibidoras de ambos resultou na redução da hiperalgesia. Os receptores do tipo Toll-like e da IL-1 não participam da geração da hipersensibilidade herpética. Após 50 dias da infecção, constatou-se que alguns animais apresentavam comportamento de hiperalgesia irreversível, semelhante à neuralgia pós-herpética humana (NPH). Não houve diferença significativa na incidência da NPH em animais de linhagens ou sexos diferentes. Ainda, o tratamento com drogas anticonvulsivantes e antidepressivas, mas não com morfina e anti-inflamatórios, resultou na redução transiente da hiperalgesia. Neste período, não há participação da inflamação na manutenção da hiperalgesia. A expressão de TNF- e COX-2 retorna aos níveis basais, e não são mais detectados neutrófilos e macrófagos. No entanto, a migração de linfócitos T CD4+ e CD8+ aos gânglios aumenta de maneira tempo-dependente. Durante a NPH, detectou-se uma intensa ativação das células satélites gliais, que contribuem para a manutenção da hiperalgesia pós-herpética. Nossos resultados demonstram que a manutenção hiperalgesia herpética é resultado da intensa resposta inflamatória que ocorre nos gânglios da raiz dorsal infectados, com aumento da produção de TNF- e COX-2, importantes mediadores para a hipersensibilidade. No entanto, durante a neuralgia pós-herpética, não há participação de células ou mediadores inflamatórios, mas de células da glia, as quais são importantes na manutenção da hiperalgesia. / Herpes Zoster is a disease caused by reactivation of varicella zoster virus in sensory ganglia, characterized by dermal rash and pain. There are no animal models available to study the pathophysiology of the disease. A murine model of HSV-1 infection on the hind paw skin has been used to study HZ, since mice develop HZ-like skin lesions and pain-related responses. There are no data available about the immune response in dorsal root ganglion (DRG) of these mice. Thus, the aim of this study was to evaluate cells and inflammatory mediators present in DRGs and its relationship with hiperalgesia during HSV-1 cutaneous infection. During the acute phase of infection, mice developed hyperalgesia in ipsilateral paws from 3 days post-infection, which persisted until 7 days post-infection. The highest viral load was detected in ganglia L4, L5 and L6. Treatment of infected mice with fucoidin or dexamethasone resulted in the reduction of hyperalgesic behavior, from the 5th post-infection day, which corresponds to the period in which leukocyte migration increase in the dorsal root ganglia. Macrophages, neutrophils and CD4 + T lymphocytes were detected in the ganglia during acute infection. However, CD8 + T lymphocytes were absent. The mRNA expression of TNF- and COX-2 was increased in dorsal root ganglia, and the treatment of infected mice with drugs that inhibits both mediators resulted in reduced hyperalgesia. The Toll-like receptors and IL-1 does not participate in the generation of herpetic hypersensitivity. After 50 days of infection, it was found that some animals presented irreversible hyperalgesic behavior, like human post-herpetic neuralgia (PHN). There was no significant difference in the incidence of PHN in animals of different genders or strains. Furthermore, treatment with anticonvulsant and antidepressant drugs, but not morphine and anti-inflammatory, resulted in transient reduction of hyperalgesia. In this period, there is no participation of inflammation in the hyperalgesia maintenance of. The expression of TNF- and COX-2 returns to baseline levels, and neutrophils and macrophages are no longer detected. However, the migration of CD4 + and CD8 + to ganglia increases in a time-dependent manner. During NPH, an intense activation of glial cells satellites was detected, that contributes to the maintenance of post-herpetic hyperalgesia. Our results demonstrate that herpetic hyperalgesia maintenance is a result of an intense inflammatory response that occurs in the infected dorsal root ganglia, with increased production of TNF- and COX-2. However, during post-herpetic neuralgia, there is involvement of glial cells, which are important in hyperalgesia maintenance.

Page generated in 0.0526 seconds