Thesis (M.S.) -- University of Texas Southwestern Medical Center at Dallas, 2003. / Vita. Bibliography: 45-48.

Thesis (Ph. D.)--Miami University, Dept. of Microbiology, 2007. / Title from second page of PDF document. Includes bibliographical references (p. 91-102).

Introdução: Cistite Hemorrágica (CH) é uma grave complicação do Transplante de Células-Tronco Hematopoiéticas (TCTH) Alogênico. Sua incidência varia de 12 a 25,5%. A forma precoce desenvolve-se devido aos efeitos tóxicos de certos quimioterápicos usados no regime de condicionamento, especialmente Ciclofosfamida. Já a CH tardia ocorre a partir do terceiro dia após o TCTH e sua etiologia é multifatorial. Vários fatores de risco para o desenvolvimento de CH tardia foram descritos, incluindo Doença do Enxerto Contra o Hospedeiro (DECH) aguda, doador não relacionado, infecções por vírus urotrópicos, sexo masculino e condicionamento mieloablativo. Materiais e Métodos: O presente estudo tem como objetivos descrever a incidência de CH em pacientes adultos e pediátricos submetidos a TCTH alogênico e identificar fatores de risco associados ao desenvolvimento de CH nesta população. Foram analisados dados de prontuário de 347 pacientes submetidos a TCTH Alogênico no Hospital de Clínicas de Porto Alegre no período de Janeiro de 2001 a Dezembro de 2014. Resultados: CH ocorreu em 42 pacientes (12,1%, IC: 8,9 - 16%), em uma média de 53.4 dias após o procedimento (desvio padrão: 28.1 dias). Apenas 1 paciente (2,4%) desenvolveu CH precoce, com início dos sintomas no D+1. Entre os 41 pacientes que desenvolveram CH tardia, BK vírus foi o principal agente viral identificado. CH ocorreu em 12.8% dos pacientes que receberam condicionamento mieloablativo e em 10.5% dos restantes (P = 0,704). Dos 197 pacientes que apresentaram DECH aguda, 35 (17,8%) desenvolveram CH e somente 7 (4,9%) apresentaram CH na ausência de DECH aguda (P < 0,001). CH foi mais frequente também em pacientes do sexo masculino (P = 0,027). Conclusão: A incidência de CH em nossa amostra foi semelhante à encontrada em outros trabalhos. DECH aguda e sexo masculino estiveram associados a um maior risco de desenvolvimento de CH. / Introduction: Hemorrhagic cystitis (HC) is a serious complication of Allogeneic Hematopoietic Stem Cell Transplantation (HSCT) afecting 12 to 25.5% of the patients. The early-onset form of HC develops during or until 72 hours after the conditioning regimen containing high doses of certain chemotherapy drugs such as Busulfan and especially Cyclophosphamide. Late-onset HC occurs from the third day on after HSCT and its etiology is multifactorial. Several risk factors for the late-onset form have been reported including graft-versus-host disease (GVHD), unrelated donor, urotropic infections, male gender and myeloblative conditioning regimen. Methods: This study aims to evaluate the incidence of HC in adult and pediatric patients undergoing Allogeneic HSCT and to identify risk factors associated with the development of HC in this population. Medical records of 347 patients who underwent Allogeneic HSCT at Hospital de Clínicas, Porto Alegre, Brazil, from January 2001 to December 2014 were analyzed. Results: HC occurred in 42 patients (12.1% CI: 8.9 - 16%) at an average of 53.4 days after the procedure (standard deviation: 28.1 days). Only one of them developed early-onset HC, with onset of symptoms on D+1. Among the 41 patients who developed late-onset HC, BKV was the main identified viral agent. HC developed in 12.8% of the patients treated with myeloablative conditioning and in 10.5% of the remaining patients (P = 0.704). Of the 197 patients with acute GVHD, 35 (17.8%) developed HC and only 7 (4.9%) showed HC in the absence of GVHD (P<0.001). HC was also more frequent in males than females (P = 0.027). Conclusion: The incidence of HC in our sample was similar to that found in other studies. In our cohort of patients being male and having acute GVHD increased the risk of developing HC.

Introdução: Cistite Hemorrágica (CH) é uma grave complicação do Transplante de Células-Tronco Hematopoiéticas (TCTH) Alogênico. Sua incidência varia de 12 a 25,5%. A forma precoce desenvolve-se devido aos efeitos tóxicos de certos quimioterápicos usados no regime de condicionamento, especialmente Ciclofosfamida. Já a CH tardia ocorre a partir do terceiro dia após o TCTH e sua etiologia é multifatorial. Vários fatores de risco para o desenvolvimento de CH tardia foram descritos, incluindo Doença do Enxerto Contra o Hospedeiro (DECH) aguda, doador não relacionado, infecções por vírus urotrópicos, sexo masculino e condicionamento mieloablativo. Materiais e Métodos: O presente estudo tem como objetivos descrever a incidência de CH em pacientes adultos e pediátricos submetidos a TCTH alogênico e identificar fatores de risco associados ao desenvolvimento de CH nesta população. Foram analisados dados de prontuário de 347 pacientes submetidos a TCTH Alogênico no Hospital de Clínicas de Porto Alegre no período de Janeiro de 2001 a Dezembro de 2014. Resultados: CH ocorreu em 42 pacientes (12,1%, IC: 8,9 - 16%), em uma média de 53.4 dias após o procedimento (desvio padrão: 28.1 dias). Apenas 1 paciente (2,4%) desenvolveu CH precoce, com início dos sintomas no D+1. Entre os 41 pacientes que desenvolveram CH tardia, BK vírus foi o principal agente viral identificado. CH ocorreu em 12.8% dos pacientes que receberam condicionamento mieloablativo e em 10.5% dos restantes (P = 0,704). Dos 197 pacientes que apresentaram DECH aguda, 35 (17,8%) desenvolveram CH e somente 7 (4,9%) apresentaram CH na ausência de DECH aguda (P < 0,001). CH foi mais frequente também em pacientes do sexo masculino (P = 0,027). Conclusão: A incidência de CH em nossa amostra foi semelhante à encontrada em outros trabalhos. DECH aguda e sexo masculino estiveram associados a um maior risco de desenvolvimento de CH. / Introduction: Hemorrhagic cystitis (HC) is a serious complication of Allogeneic Hematopoietic Stem Cell Transplantation (HSCT) afecting 12 to 25.5% of the patients. The early-onset form of HC develops during or until 72 hours after the conditioning regimen containing high doses of certain chemotherapy drugs such as Busulfan and especially Cyclophosphamide. Late-onset HC occurs from the third day on after HSCT and its etiology is multifactorial. Several risk factors for the late-onset form have been reported including graft-versus-host disease (GVHD), unrelated donor, urotropic infections, male gender and myeloblative conditioning regimen. Methods: This study aims to evaluate the incidence of HC in adult and pediatric patients undergoing Allogeneic HSCT and to identify risk factors associated with the development of HC in this population. Medical records of 347 patients who underwent Allogeneic HSCT at Hospital de Clínicas, Porto Alegre, Brazil, from January 2001 to December 2014 were analyzed. Results: HC occurred in 42 patients (12.1% CI: 8.9 - 16%) at an average of 53.4 days after the procedure (standard deviation: 28.1 days). Only one of them developed early-onset HC, with onset of symptoms on D+1. Among the 41 patients who developed late-onset HC, BKV was the main identified viral agent. HC developed in 12.8% of the patients treated with myeloablative conditioning and in 10.5% of the remaining patients (P = 0.704). Of the 197 patients with acute GVHD, 35 (17.8%) developed HC and only 7 (4.9%) showed HC in the absence of GVHD (P<0.001). HC was also more frequent in males than females (P = 0.027). Conclusion: The incidence of HC in our sample was similar to that found in other studies. In our cohort of patients being male and having acute GVHD increased the risk of developing HC.

Submitted by Luciana Ferreira (lucgeral@gmail.com) on 2015-10-29T11:10:52Z No. of bitstreams: 2 Dissertação - Hugo César Pereira Santos - 2015.pdf: 3535564 bytes, checksum: 4fc7d88b1da6008bc42c01f46e4f8d7a (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2015-10-29T11:20:29Z (GMT) No. of bitstreams: 2 Dissertação - Hugo César Pereira Santos - 2015.pdf: 3535564 bytes, checksum: 4fc7d88b1da6008bc42c01f46e4f8d7a (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2015-10-29T11:20:29Z (GMT). No. of bitstreams: 2 Dissertação - Hugo César Pereira Santos - 2015.pdf: 3535564 bytes, checksum: 4fc7d88b1da6008bc42c01f46e4f8d7a (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2015-03-19 / Fundação de Amparo à Pesquisa do Estado de Goiás - FAPEG / The human adenoviruses (HAdV) infect people of all ages worldwide, causing a wide range of clinical syndromes, depending on the viral type. In immunocompromised hosts, as transplanted patients, HAdV infection can result in a bad prognosis. Some aspects of viral pathogenesis, such as the association between viremia and/or viral load with disseminated disease and the optimal moment to start the therapy, are still not well established in adult patients that have undergone allogeneic hematopoietic stem cell transplantation (ASCT). Therefore, the main objective of this study was to monitor ASCT recipients for HAdV occurrence, and also correlate viral positivity, viral load and molecular variant with clinical symptoms and patients’ prognosis. For this, stool and serum from 21 patients were monitored in a 2 years period (from October/2012 to October/2014). Serum and fecal samples were screened by Nested-PCR, using primers targeting a partial region of the hexon gene (143bp). Fecal samples were further screened by a commercial enzyme immunoassay (EIA). In total, 57% of the patients had at least one positive sample (serum or stool) for HAdV. Patients presented high viral load (varying from 7,7x103 to 2x108 copies/mL), with a higher viral load in stool when compared to serum. Positive samples were submitted to genomic sequencing, revealing the occurrence of HAdV from C, D and F species. The main clinical symptom presented by infected patients was diarrhea, and graft-versus-host disease was the main intercurrence; however it was not possible to directly associate viral positivity to cause of death. We hope to contribute for a better understanding of the HAdV infection pattern in patients submitted to ASCT. Our data highlights the importance of the inclusion of HAdV testing in the routine laboratory exams of this group of patients. / Os adenovírus humanos (HAdV) podem infectar pessoas de todas as idades, causando uma ampla gama de quadros clínicos. Em pacientes imunocomprometidos, como os indivíduos que receberam transplante, a infecção por esses vírus pode resultar em pior prognóstico para o paciente. Determinados aspectos da patogenia viral, como a associação entre viremia e/ou carga viral com a doença disseminada, bem como o melhor momento para o início da terapia, não estão ainda bem esclarecidos em pacientes que foram submetidos ao transplante de células progenitoras hematopoiéticas (TACPH), principalmente em indivíduos adultos. Dessa forma, o principal objetivo deste estudo foi realizar o monitoramento da infecção por HAdV e a caracterização molecular das variantes virais em pacientes submetidos ao TACPH, bem como determinar a carga viral e correlacionar a infecção com o quadro clínico e prognóstico dos pacientes. Foram analisadas amostras de soro e fezes de 21 pacientes submetidos ao TACPH no período de dois anos (de outubro/2012 a outubro/2014). As amostras de fezes foram triadas por ensaio imunoenzimático e por Nested-PCR, enquanto as amostras de soro foram triadas somente por Nested-PCR de uma região parcial do gene hexon (produto esperado de 143 pb). Foram detectadas amostras positivas de soro e/ou fezes de 57% dos pacientes. De forma geral, os pacientes do presente estudo apresentaram elevadas cargas virais (variando de 7,7x103 à 2x108 CG/mL), que foram mais elevadas nas fezes. As amostras positivas foram submetidas ao sequenciamento genômico e resultados revelaram a ocorrência de adenovírus das espécies C, D e F. O principal quadro clínico apresentado pelos pacientes foi a diarreia e a principal intercorrência observada, a doença do enxerto contra o hospedeiro (DECH). Dez pacientes foram a óbito durante o período de estudo, entretanto, não foi possível associar a infecção por HAdV diretamente à causa mortis. Esperamos que os dados obtidos possam auxiliar no melhor entendimento do padrão da infecção dos HAdVs em pacientes submetidos ao TACPH, de forma a contribuir para que a pesquisa de adenovírus seja incluída na rotina de exames desses pacientes.

O melanoma representa menos de 5% de todos os cânceres de pele, porém, quando em estádio metastático possui prognóstico ruim. Entretanto, o genótipo dos melanomas pode prover uma oportunidade para intervenção terapêutica pelo fato de 90% dos casos de melanoma possuem p53 selvagem e grande parte destes possuem deleção na região cromossômica codificadora de interferon beta. Em prévios estudos, desenvolvemos o vetor adenoviral AdRGD-PG que fornece expressão do transgene em resposta à p53 através do promotor PG e ainda o tripeptídeo RGD, que possibilita que o adenovírus transduza uma maior gama de células pela alteração de seu mecanismo de entrada. Temos utilizado este vetor para entrega da versão murina de interferon beta em modelos de terapia gênica e imunoterapia de melanoma murino, revelando uma significativa habilidade do interferon beta em inibir a proliferação celular in vitro e in vivo e promover resposta imune antitumoral. No presente trabalho, os esforços se aplicam em adaptar essa estratégia em modelo de melanoma humano para observar se a mesma interação é encontrada. O vetor AdRGD-PGhIbeta, portador do cDNA de interferon beta humano (hIbeta) foi construído e expressão do transgene observada após transdução das linhagens estabelecidas de melanoma humano SK-MEL-05 e SK-MEL-147 (ambas p53 selvagem). Foi observado um robusto efeito antitumoral in vitro onde transferência de hIbeta promoveu acumulo de células hipodiploides (mais que 80% da população celular 96 horas após transdução) e evidências de morte por apoptose (exposição de fosfatidilserina e atividade de caspases 3/7) em ambas as linhagens. Nas duas linhagens, o efeito bystander foi demonstrado quando a presença de poucas células transduzidas (ex., 10%) foi suficiente para promover o acumulo significativo de células hipodiploides (mais que 40% neste exemplo). Em modelo de terapia gênica in situ utilizando células SK-MEL-147, também foi observado forte efeito antitumoral da hIbeta com total remissão do tumor de todos os animais tratados sem recidiva durante noventa dias. A presença de hIbeta na circulação dos animais foi confirmada 48h após o tratamento com AdRGD-PG hbeta mas presente em somente dois de sete animais 90 dias após o tratamento, sugerindo que o tratamento inicial e não um efeito off target foi responsável pela resposta. Com a finalidade de investigar efeitos colaterais do sequestro do vetor adenoviral pelo fígado, observamos a concentração circulante das enzimas aminotransferase de aspartate e aminotransferase de alanine (AST e ALT, respectivamente), que se mostrou não alterada quando comparadas entre animais que receberam injeção do vetor tratamento, vetor controle e solução salina. Com nossos resultados concluímos que vetores adenovirais carreando interferon-beta humano são capazes de transduzir a linhagem de melanoma SK-MEL-147 in vitro e in vivo, promovendo efeito bystander e remissão tumoral sem indução de efeitos adversos / Melanoma represents less than 5% of all cases of skin cancer, although, when metastatic, prognosis is dire. However, the genotype of melanomas might provide an opportunity for therapeutic intervention since 90% of melanoma cases possess wild-type p53 and a great portion of these possess deletion of the chromosomal region encoding interferon beta. In previous studies, we developed the adenoviral vector AdRGD-PG that supplies expression of the transgene in response to p53 through the PG promoter and that utilizes the RGD tripeptide, allowing the adenovirus to transduce a wider range of cells due to the alterated mechanism of entrance. We have used this vector to deliver the murine version of interferon beta in murine models of melanoma gene therapy and immunotherapy, revealing a significant ability of interferon beta to inhibit cellular proliferation in vitro and in vivo and promote an anti-tumor immune response. In the present project, we aimed to adapt this strategy for a human melanoma model in order to reveal if the same impact will be observed. The AdRGD-PGhIbeta vector encoding the human interferon beta (hIbeta) cDNA was constructed and expression of the transgene confirmed after transduction of the established human melanoma cell lines SK-MEL-05 and SK-MEL-147 (both wild-type p53). A striking anti-tumor effect was observed in vitro where the transfer of hIbeta promoted an accumulation of hypodiploid cells (over 80% of the cellular population 96 hours after transduction) and evidence of death by apoptosis (exposure of phosphatidylserine and activity of caspases 3/7) in both cell lines. In these cell lines, a bystander effect was demonstrated when the presence of few transduced cells (ex., 10%) was enough to promote significant accumulation of hypodiploid cells (over 40% in this example). In a model of in situ gene therapy using SK-MEL-147 cells, hIbeta induced a strong anti-tumor effect including total tumor remission in all treated animals without relapse during ninety days. The presence of hIbeta in the circulation of the animals was confirmed 48h after treatment with AdRGD-PGhIbeta, but was present in only two of the seven animals 90 days post-treatment, suggesting that the initial treatment, not off target effects, was responsible for the response. With the goal of investigating collateral effects of adenoviral sequestration by the liver, we assayed the circulating concentration of aspartate aminotransferase and alanine aminotransferase (AST and ALT, respectively), which showed no alteration when compared with animals that received the treatment with a control vector or saline solution. We conclude that our adenoviral vector carrying human interferon-beta is capable of transducing the human melanoma cell line SK-MEL-147 in vitro and in vivo, promoting a bystander effect and tumor remission without inducing adverse effects

Objetivos: Os objetivos deste estudo foram: 1) determinar a eficácia da transferência gênica do vetor de adenovírus sorotipo 5, carreando o gene do receptor do fator de crescimento endotelial vascular (VEGF) solúvel humano (sVEGFR1) para a glândula lacrimal (GL); 2) investigar se a expressão de sVEGFR1 interfere na neovascularização da córnea (NVC), induzida por queimadura alcalina; 3) avaliar a segurança do procedimento. Métodos: Trinta e dois ratos Wistar foram submetidos à queimadura central da córnea direita com solução de hidróxido de sódio (NaOH) 1 M. Os animais foram divididos em três grupos e injetados diretamente em sua GL direita 25 ?l de vetores virais AdVEGFR1 (1x1010 pfu) (12 animais), 25 ?l do vetor AdNull (1x1010pfu) (10 animais), ou 25 ?l de solução salina (Controle). Após sete dias, a NVC foi observada e fotografada na lâmpada de fenda. A secreção lacrimal foi medida com fenol. A presença do sVEGFR1 na GL foi testada por qPCR (quantitative polymerase chain reaction) e a coloração, por imunofluorescência. O qPCR foi também utilizado para comparar o RNA mensageiro (RNAm) de ilterleucina-1beta (IL-1?), ilterleucina-6 (IL-6) e fator de necrose tumoral alfa (TNF-?) na GL e no gânglio do trigêmeo (GT). Resultados: O vetor AdVEGFR1 transfectou 83% dos ratos. O sVEGFR1 estava presente nas células acinares da GL. A NVC foi prevenida em nove de doze animais do grupo AdVEGFR1, em comparação com o grupo Ad-Null (3:10) e o grupo Controle (1:10) (p=0,0317). A secreção lacrimal e o RNAm das citocinas na GL e no GT foram semelhantes nos três grupos (p>0,05). Conclusões: A transferência gênica do vetor adenoviral para a GL demonstrou expressão local do sVEGFR1 humano, e evitou a NVC na maioria dos olhos expostos a queimaduras alcalinas, se mostrando seguro para a estrutura e função da GL. / Purpose: The aims of this study were: 1) to determine the efficacy of adenovirus vector serotype 5 (Ad) encoding human soluble VEGF receptor 1 (sVEGFR1) gene transfer to the lacrimal gland (LG); 2) to investigate whether expression of sVEGFR1 acts in corneal neovascularization (CNV), induced by alkali burn and; 3) to evaluate the safety of the procedure. Methods: AdVEGFR1viral vectors (25 ?l, 1x1010pfu) were injected in the right LG of rats and compared with AdNull vector (25 ?l, 1x1010pfu) or 25?l saline (Control) before cornea alkali burn with 1 M NaOH. After seven days, CNV was observed and photographed in the slit lamp. Tear secretion was measured with phenol red thread. The animals were tested for human VEGFR1 mRNA and protein in the LG by qPCR and immunofluorescence staining, respectively. qPCR was also used to compare the mRNA of IL-1?, IL-6, and TNF-? in LG and ipsilateral trigeminal ganglion (TG). Results: Ad-VEGFR1 transfected 83% of the rats. VEGFR1 was present in LG acinar cells. CNV was prevented in 9 of 12 animals of Ad-VEGFR1 group, compared to Ad-Null (3:10) and Control (1:10) (p=0.0317). The tear secretion and the cytokines mRNA in LG and TG were similar all three groups (p>0.05). Conclusion: Adenoviral vector gene transfer to LG as the has shown local expression of human sVEGFR1, as It prevented CNV in most of the eyes exposed to alkali burn and was safe for LG structure and function.

Viruses are etiologic agents of a great number of diseases of human beings and animals. However, there are only a little amount antiviral medicines available that is almost exclusively used in human health. Several studies have demonstrated that propolis has biological activities against virus, bacteria and fungi. Its chemical composition is diverse varying according to season, plants available and collection. The antiviral activity of ethanolic extracts of propolis have already been described for some human viruses. The aim of this study was to evaluate the antiviral activity of propolis ethanolic extracts against two viruses causing respiratory disease in small animals, the feline calicivirus (FCV) and canine adenovirus 2 (CAV-2), and also the bovine diarrheal disease virus (BVDV).Two samples of ethanolic extracts of propolis were used; one obtained in the lab and another obtained commercially. In order to perform the experiments the MTT test ((3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) was used to determine the 50% cytotoxic concentration (CC50), the 50% inhibitory concentration (IC50) and, the terapeuthic index (TI=IC50/CC50). The propolis extracts were added to the cell cultures in different moments of the viral infection. They were included before virus inoculation, after virus inoculation, and before and after virus inoculation. The two propolis samples showed similarities in the qualitative analysis but they had small differences in the quantitative analysis. The CC50 of the extracts varied among 251 and 343μg/ml and the commercial extract showed less toxicity. Both extracts demonstrated better antiviral activity when added before virus inoculation and the ITs varied from 6 to 13. The best results were obtained with the propolis extracted in the lab. The BVD was the virus showing the greater sensitivity to the ethanolic extracts in the conditions applied. Taken all the data together, it can be concluded that the ethanolic extract of propolis has a potential for future use as a medicine in the therapy of respiratory disease caused by CAV-2, and, also, that the action mechanisms on BVDV should be better evaluated in detail regarding the hepatitis C virus (HCV). / Os vírus são os agentes etiológicos de um grande número de enfermidades em seres humanos e animais, no entanto, há um pequeno número de fármacos antivirais disponíveis para o uso que é feito quase exclusivamente na medicina humana. Estudos demonstram que a própolis apresenta variada atividade biológica frente a vírus, bactérias e fungos. Sua composição química é bastante diversa, podendo variar conforme a época, vegetação e área de coleta. A atividade antiviral de extratos aquosos e etanólicos de própolis já foi descrita para alguns vírus humanos. O presente trabalho tem como objetivo avaliar a atividade antiviral do extrato de própolis frente a dois vírus causadores de doença respiratória em pequenos animais, o calicivírus felino (FCV) e o adenovírus canino tipo 2 (CAV-2), e também ao vírus da diarréia viral bovina (BVDV). Foram testadas neste experimento duas amostras de extrato etanólico de própolis, uma delas obtida comercialmente e a outra extraída no laboratório. Para realizar este estudo utilizou-se o método colorimétrico do MTT (3-(4,5 dimetiltiazol-2yl)-2-5-difenil-2H tetrazolato de bromo), através do qual determinou-se a concentração citotóxica a 50% (CC50), concentração inibitória a 50% (IC50) e o índice terapêutico (IT=IC50/CC50). Os extratos de própolis foram adicionados ao cultivo celular em diferentes momentos da infecção viral. Estes foram incluídos antes da inoculação viral, depois da inoculação viral, e antes e depois da inoculação viral. As duas amostras de própolis apresentaram similaridades na análise qualitativa e pequenas diferenças na análise quantitativa. A CC50 destes extratos variou de 251 a 343μg/ml sendo que o extrato comercial apresentou-se ligeiramente menos tóxico. Ambos os extratos demonstraram melhor atividade antiviral quando adicionados anteriormente à inoculação viral apresentando ITs que variaram de 6 a 13. Os melhores resultados foram obtidos com o própolis extraído no laboratório. O BVDV foi o vírus que demonstrou maior sensibilidade ao extrato etanólico de própolis nas condições experimentais aplicadas. Levando-se em consideração os resultados obtidos, pode-se concluir que o extrato etanólico de própolis apresenta potencial para futura utilização como fármaco no tratamento de doenças respiratórias causadas pelo CAV2 e que o mecanismo de ação sobre o BVDV deve ser avaliado com maiores detalhes com vistas ao vírus da hepatite C (HCV).

All challenges associated with influenza A viruses including antigenic variation in hemagglutinin (HA) and neuraminidase (NA), the evolving drug resistance and the drawbacks of current vaccines hinder our ability to control this constant threat. Furthermore, gene reassortment as well as the direct transmission of highly pathogenic avian viruses to humans can result in an occasional emergence of novel influenza strains with devastating pandemic potential. Therefore, it is crucial to investigate alternative approaches to better control these viruses and to develop new prophylactic and treatment options. Targeting highly conserved epitopes or antigens among the different subtypes of influenza A virus could offer protection against broad range of influenza viruses, including emerging strains. In my research, I have investigated the potential of broadly neutralizing antibodies against HA and conducted mechanistic study of a prototype vaccine based on the highly conserved nucleoprotein (NP). We recently found that the 14 amino acids of the amino-terminus of the fusion peptide of influenza HA2 subunit is the only universally conserved sequence in all HA subtypes of influenza A and the two lineages of influenza B viruses. Here, I show that universal antibodies targeting this linear sequence in the viral HA (Uni-1 antibodies) can cross-neutralize multiple subtypes of influenza A virus by inhibiting the pH-dependant fusion of viral and cellular membranes. It is noted that the influenza NP is a highly conserved antigen and has the potential to induce heterosubtypic immunity against divergent subtypes of influenza A virus. However, NP-based vaccination only affords weak protective immunity compared to HA. This is mostly due to the non-sterilizing immunity induced by NP. Using CD40 ligand (CD40L), a key regulator of the immune system, as both a targeting ligand and a molecular adjuvant, I show that single immunization with recombinant adenovirus carrying a fused gene encoding the secreted NP-CD40L fusion protein provided robust and long-lasting protection against influenza in normal mice. It enhanced both B-cell and T-cell responses and augmented the role of both NP-specific antibodies and CTLs in protection. Importantly, it afforded effective protection in CD40L and CD4 deficient mice, confirming that the induced protection is CD40L-mediated and CD4+ T cell-independent. The rapid evolution of the influenza A viruses necessitates the development of new alternatives to contain this medically important pathogen. The results of these studies could significantly contribute to future vaccine development and avert the necessity of yearly vaccine updates.

La fièvre aphteuse (FMD pour Foot-and-mouth disease en anglais) est une maladie très contagieuse touchant les animaux biongulés. Elle provoque des dégâts économiques considérables sur toute la surface du globe. La fièvre aphteuse est provoquée par un virus, le FMDV. Il s'agit d'un virus à ARN simple brin, de polarité positive appartenant au genre Aphtovirus dans la famille Picornaviridae. Ce virus se réplique et se propage dans l'hôte très rapidement. Dans les zones infectées, les deux principales stratégies de contrôle utilisées sont l'abattage systématique des animaux infectés et la vaccination. A l'inverse, les vaccins ne sont pas utilisés dans les zones sans FMDV, mais l'apparition d'une épidémie nécessite des stratégies pour arrêter ou au moins limiter la diffusion du virus. Actuellement, les vaccins inactivés sont les vaccins les plus utilisés pour prévenir la maladie. Cependant, ils requièrent une production à grande échelle du virus, et malgré les mesures mises en place (laboratoire sécurisé, etc), des épidémies ont été provoquées par le passé du fait de la fuite de virus FMDV. De plus, il est difficile de distinguer les animaux infectés des vaccinés (DIVA). Il est donc nécessaire de développer de nouveaux vaccins. Au cours de l'infection, la polyprotéine du virus est clivée par des protéases virales en précurseurs structural (P1) et non structuraux (P2 et P3). La protéase 3C est responsable de la majorité des clivages ; ainsi, le précurseur P1 est clivé par la 3C en trois protéines structurales, VP1, VP3 et VP0, formant le protomère de FMDV, l'unité de base de la capside virale. La protéine VP1 joue des rôles importants dans l'attachement, la protection et le sérotypage. Du fait de la présence d'un site antigénique linéaire suffisant à la protection par production d'anticorps neutralisants, VP1 est considérée comme la protéine la plus immunogénique du virus. Dans cette étude, nous avons développé un nouveau vaccin contre la FMD, basé sur l'adénovirus canin de type 2 (Cav2). L'évaluation du transfert de gène médié par Cav2 chez le porc et le bétail in vitro montre des résultats prometteurs pour le développement de vaccins pour ces espèces, notamment l'expression des antigènes de FMDV par les candidats vaccins Cav2-FMDV. L'immunogénicité de ces candidats vaccins a été montrée chez les modèles murins et cobayes. De plus, des résultats encourageants ont été observés chez le cobaye, suggérant que la réponse immunitaire élicitée par les vecteurs recombinants pouvait conduire à une protection partielle des animaux après épreuve. Cependant, une optimisation de l'immunisation doit être faite dans le but de confirmer ces résultats. Ce type de vaccin peut de plus être utilisé comme vaccin marqueur, car il ne contient aucune protéine non structurale. / Foot-and-mouth disease (FMD) is a highly contagious and economically devastating disease affecting cloven-hoofed livestock worldwide. Foot-and-mouth disease virus (FMDV) is the causative agent of FMD and one of the most infectious known animal viruses. FMDV is a positive-sense, single-stranded RNA virus belonging to the Aphthovirus genus in the Picornaviridae family. FMDV replicates and spreads in the host extremely rapidly. Slaughter and vaccination are the two major strategies used to control FMD in infected countries. In FMDV-free countries, vaccines are not used, and once the disease breaks out in these areas, strategies are required to stop or at least slow the spread of the virus. Currently, inactivated vaccines are by far the most commonly used vaccines to prevent FMD. Such vaccines, however, require large-scale production of virus, and despite the use of bio-safety facilities, vaccine production has led to inadvertent virus release and FMDV outbreak. Another limitation of inactivated vaccines is the difficulty in distinguishing between infected and vaccinated animals (DIVA). Therefore, improved vaccines need to be developed.During infection, the FMDV polyprotein is cleaved into structural (P1) and non-structural (P2 and P3) precursors by a viral protease. The non-structural 3C protein is the protease that is responsible for most of the maturation events. The P1 precursor is processed by 3C protease into three structural proteins, VP1, VP3 and VP0, forming the FMDV protomer. The VP1 protein plays important roles in attachment, protective immunity and serotype specificity. VP1 is considered to be the major immunogenic protein, as it contains a linear antigenic site that is able to induce neutralizing antibodies that suffice to protect animals against the disease.In this project, we developed a novel vaccine against FMD, based on canine adenovirus type 2 (Cav2). In vitro evaluation of Cav2 mediated gene transfer in pigs and cattle showed that the Cav2 vector holds promise for the development of vaccines for pigs and cattle. Study of these recombinant viruses indicated that Cav2-FMDV supported expression of FMDV capsid proteins in vitro. The immunogenicity of these recombinant viruses was evidenced in mouse and guinea pig models, and encouraging results in guinea pigs suggested that the immune response elicited against FMD by recombinant virus could afford partial protection against FMDV challenge. In the future, immunization with Cav2-derived vector should be optimized to confirm these preliminary results. This type of vaccine, when designed to express capsid but not non-structural proteins of FMDV, can serve as a marker vaccine against FMD.