The CD40 ligand (CD40L) molecule is central to innate and adaptive immunity. CD40L expression is very tightly regulated whereas its CD40 receptor is constitutively expressed by many different cell types. CD40L is expressed transiently on helper T cells (Th) only after activation by specific immune recognition molecules carried by professional antigen presenting cells, in particular, dendritic cells (DC). CD40L subsequently binds to CD40 on DC to enable full Th activation. CD40 ligated DC produce interleukin-12 (IL-12) and contribute both to the development of IFNγ-secreting natural killer cells, a vital component of innate immunity, and of IFNγ-secreting type 1 Th (Th1) cells. CD40 ligated DC also contribute to the development of IL-4- and IL-10-secreting Th2 cells. CD40L on Th cells also binds CD40 on macrophages to enhance their cytotoxic functions. CD40L-expressing Th cells provide the ‘help’ pivotally required to activate other components of adaptive immunity responsible both for clearing invading pathogens and generating the memory cells required to prevent re-infection. Th-supplied CD40L binds (i) B cell CD40 to switch production of antibodies to more potent effector molecules that have higher avidity for antigen, and (ii) DC CD40 to prime then expand antigen-specific cytotoxic T lymphocytes (CTL). Activated NK cells and CTL are required both to eradicate malignant cells and cells infected with viruses or other intracellular pathogens. Genetic CD40L deficiency causes the very rare HyperIgM Syndrome Type 1 (HIGM1), which is realistically modelled by genetically engineered CD40L-deficient mice. Neither CD40L-deficient patients nor mice make effective antibodies or mount cellular immune responses that would defend them against intracellular pathogens such as parasites. Consequently, the only potentially curative therapy is allogeneic stem cell transplantation or CD40L gene replacement. Here, we used a retroviral vector, which constitutively expressed CD40L, to genetically modify CD40L-deficient bone marrow cells, which were used to reconstitute partially the immunity of CD40L-deficient mice. The crucial importance of tight regulation of CD40L expression was revealed when these mice later developed lethal thymic T cell malignancy. Growing tumours escape immune vigilance by genetic alterations that reduce their sensitivity to IFNγ. Using murine tumour models, we incorporated transgenic CD40L expression in therapeutic tumour vaccines to show that CD40L gene transfer augmented the immunogenicity of the host’s tumour thus reducing its tumorigenicity. We translated this finding clinically to safety and immunogenicity testing of a transgenic CD40L- and IL-2- expressing leukaemia vaccine. Finally, the common viral respiratory pathogen, respiratory syncytial virus (RSV) mainly infects young infants and the elderly to cause potentially lethal pneumonia. Both groups have reduced cellular and humoral immunity, which predisposes them to re-infection with RSV. Using a murine model, we showed first that simultaneous adenoviral expression of CD40L augmented primary RSV-specific Th1 responses that were associated with accelerated pulmonary viral clearance. Second, we showed that expression of CD40L in RSV-F and RSV-G subunit DNA vaccines elevated antibody and cellular immune responses to RSV challenge four and eight months after the initial immunisation. These results demonstrate the potent ability of CD40L gene transfer to solve the absolute immune deficiency caused by genetic lesions of CD40L. However, physiological regulation of the transgene is required to prevent serious adverse consequences. In contrast, no adverse effects were observed after transgenic CD40L expression was used to overcome relative immune deficiencies imposed by malignancy and RSV infection. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1298200 / Thesis (Ph.D.) - University of Adelaide, School of Medicine, 2007

Thesis (Ph. D.)--University of Missouri--Columbia, 1997. / "May 1997." Typescript. Vita. Includes bibliographical references (leaves 210-233). Also available on the Internet.

Thesis (Ph. D.)--University of Missouri--Columbia, 1997. / Typescript. Vita. Includes bibliographical references (leaves: 210-233). Also available on the Internet.

Thesis (M. Phil.)--University of Hong Kong, 2009. / Includes bibliographical references (leaves 108-121). Also available in print.

Thesis (M.Med.Sc.)--University of Hong Kong, 2002. / Includes bibliographical references (leaves 42-47). Also available in print.

Respiratory Syncytial Virus (RSV) infection is common among young children. Congenital Heart Disease (CHD) is a risk factor of severe illness and hospitalization. Palivizumab prophylaxis reduces the severity of RSV infection and reduces the risk of hospitalization for children at high risk of severe illness, such as children born premature or with CHD. The aim of this thesis was to evaluate compliance with national guidelines for prophylactic treatment and to study the Relative Risk (RR) of hospitalization due to RSV and unspecified Respiratory Tract Infection (RTI) for children with CHD. In a prospective study, questionnaires were sent to all paediatric cardiology centres in Sweden with questions about prophylactic treatment. Hospitalization rates were retrieved from the national inpatient registry. Heart defects were grouped according to type and the relative risk of hospitalization was calculated for each group and for summer and winter seasons. Half of the patients received prophylactic treatment later than recommended in the guidelines. The risk of hospitalization due to RSV infection was increased (RR=2.06 95% CI 1.6-2.6; p < 0.0001) for children with CHD compared to children without CHD. The RR of hospitalization was also increased for all CHD subgroups, and was further increased during summer for children with the more severe CHD. We conclude that guidelines for prophylactic treatment were not followed and that the risk of hospitalization due to RSV and unspecified RTI was increased for all subgroups of CHD. The risk was increased both during winter and summer and we therefore argue that information to health personnel and parents should include that the risk of severe RTI is present all year round for children with CHD. / Respiratoriskt syncytialvirus (RSV) är det vanligaste förkylningsviruset och de allra flesta barn drabbas före två års ålder. RSV kan leda till allvarlig luftvägsinfektion hos alla barn, men speciellt hos dem med medfött hjärtfel. Någon botande läkemedelsbehandling finns inte för RSV, utan de medicinska insatserna får inriktas mot att mildra sjukdomsförloppet och för svårt sjuka barn krävs sjukhusvård för att exempelvis erhålla syrgasbehandling. Det finns inget vaccin mot RSV, men barn som riskerar att bli svårt sjuka kan behandlas profylaktiskt med en monoklonal antikropp (Palivizumab) som ges som injektion en gång per månad under vintersäsong. Vissa barn med svårt hjärtfel får denna profylaktiska behandling enligt nationella riktlinjer. Vår första studie visade att ungefär hälften av barnen med medfött hjärtfel, aktuella för profylax mot RSV, fick behandlingen senare än vad de nationella riktlinjerna rekommenderade. Denna studie genomfördes via en enkät till alla landets barnkliniker under två vintersäsonger. Vi såg även att något fler barn än förväntat (4.6%) fick RSV-infektion trots profylaktisk behandling och för cirka en tredjedel av dessa barn fördröjdes tiden till hjärtoperation. Behovet av sjukhusvård kan användas som mått på hur svårt ett sjukdomsförlopp är, och baserat på Socialstyrelsens slutenvårdsregister studerade vi alla barn under två års ålder och fann att den relativa risken för sjukhusvård på grund av RSV var högre för barn med hjärtfel än för barn utan hjärtfel (RR=2.06 95% CI 1.6-2.6; p < 0.0001). I vår andra studie, baserad på slutenvårdsregistret, beräknade vi den relativa risken för sjukhusvård på grund av RSV, för barn med olika former av hjärtfel och uppdelat i sommar- och vintersäsong. Risken för sjukhusvård var ökad för alla barn oavsett typ av hjärtfel, och detta gällde såväl under vintern som under sommaren. Barn med de allvarligaste formerna av hjärtfel hade högre risk för sjukhusvård under sommaren jämfört med deras risk under vintern, medan barn med vad som anses vara lättare hjärtfel hade ökad risk för sjukhusvård under hela året, utan någon större skillnad i risk mellan vinter och sommar. Att barn med hjärtfel riskerar att bli svårt sjuka i RSV är väl känt, men våra resultat visar att denna risk även existerar under sommarhalvåret, då det inte är RSV-säsong och då profylax inte ges. Vi fann också att barn med vad som anses vara lättare hjärtfel löper lika stor risk att drabbas av svårare sjukdomsförlopp med sjukhusvård under vintern, som barn med svårare hjärtfel. Att denna information sprids till såväl sjukvårdspersonal som arbetar med denna patientgrupp som till föräldrar med hjärtsjuka barn är viktigt, för att belysa att även dessa barn behöver skyddas, och detta inte bara under vintern och RSV-säsongen.

Made available in DSpace on 2014-06-11T19:32:51Z (GMT). No. of bitstreams: 0 Previous issue date: 2013-10-11Bitstream added on 2014-06-13T18:48:09Z : No. of bitstreams: 1 000735855.pdf: 2456045 bytes, checksum: d4163cc3219978e13e5e6d72726e31c5 (MD5) / O vírus respiratório sincicial bovino (BRSV), agente etiológico relacionado à doença respiratória bovina, causa grandes prejuízos econômicos principalmente na criação de bezerros. O BRSV já foi relatado no Brasil com prevalências sorológicas elevadas, no entanto, ainda não foram determinados os fatores de risco envolvidos na disseminação do vírus nos rebanhos brasileiros e poucas amostras do vírus foram caracterizadas. Assim, o presente estudo teve como objetivo caracterizar a epidemiologia da infecção pelo BRSV em rebanhos bovinos leiteiros do Estado de São Paulo (SP), por meio da análise sorológica e de fatores de risco, e também pelo vírus circulante nesses rebanhos. Foram colhidas 1.243 amostras de sangue e 352 amostras de secreções nasais de bovinos em 26 propriedades rurais, divididas nas regionais de Jaboticabal, São José do Rio Preto e Catanduva, localizadas na região norte do Estado SP. Durante a colheita das amostras, foi aplicado um questionário ao proprietário sobre informações relacionadas como prováveis fatores de risco para a infecção pelo BRSV em cada propriedade. Os soros foram analisados pela técnica de virusneutralização (VN) e as amostras de secreções nasais foram examinadas para detecção do gene das proteínas F e G do BRSV pela RT-nested PCR. Os resultados da VN mostraram elevada prevalência de BRSV nos rebanhos leiteiros, com total de 79,49% de reagentes. Os resultados separados por regionais revelaram prevalências de 76,19%, 83,68% e 69,14% de soropositivos, para Jaboticabal, São José do Rio Preto e Catanduva, respectivamente. Os rebanhos da regional de São José do Rio Preto apresentaram maiores prevalências de BRSV quando comparados aos rebanhos das outras duas regionais. A análise dos fatores de risco permitiu inferir que a idade dos animais e a ocorrência de infecção concomitante pelo herpesvírus bovino tipo 1 e vírus... / Bovine respiratory syncytial virus (BRSV), agent related to bovine respiratory disease, causes large economic losses mainly in calf rearing. BRSV has already been reported in Brazil with high serological prevalence, however, the risk factors related to its dissemination were not yet determined and a few number of virus strains was characterized in Brazilian herds. Thus, the study aimed to characterize the epidemiology of BRSV infection in dairy herds of São Paulo State, using serological and risk factors analysis, and also by virus circulating in these herds. For that, 1.243 blood samples and 352 nasal secretion samples were collected of animals from 26 farms divided into Jaboticabal, São José do Rio Preto and Catanduva regional, located in the northern region of São Paulo State. During the sample collection, a questionnaire was performed to the owner for each property regarding information about possible risk factors for BRSV. Sera were analyzed using virus neutralization test (VNT), and nasal secretions were examined to detect the F and G protein gene of BRSV by RT-nested PCR. VNT results showed high BRSV prevalence in dairy herds, reaching 79.49% of reagents. The separated results by regional revealed prevalence of 76.19%, 83.68% and 69.14% for Jaboticabal, São José do Rio Preto and Catanduva, respectively. The herds in the regional of São José do Rio Preto showed the highest prevalence of BRSV when compared to the other two regional herds. The analysis of risk factors allowed deducing that the age of the animals and the occurrence of concomitant infection by bovine herpesvirus type 1 and bovine viral diarrhea are associated with the high BRSV prevalence, while calving natural lactation was identified as a protective factor. The RT-nested PCR detected a positive sample for the F protein gene, and after its sequencing, the genetic relatedness of the sample to the other ...

Orientador: Samir Issa Samara / Coorientador: Clarice Weis Arns / Banca: Sandra Possebon Gatti / Banca: Fumio Honma Ito / Banca: Fernando Rosado Spilki / Banca: Luís Guilherme de Oliveira / Resumo: O vírus respiratório sincicial bovino (BRSV), agente etiológico relacionado à doença respiratória bovina, causa grandes prejuízos econômicos principalmente na criação de bezerros. O BRSV já foi relatado no Brasil com prevalências sorológicas elevadas, no entanto, ainda não foram determinados os fatores de risco envolvidos na disseminação do vírus nos rebanhos brasileiros e poucas amostras do vírus foram caracterizadas. Assim, o presente estudo teve como objetivo caracterizar a epidemiologia da infecção pelo BRSV em rebanhos bovinos leiteiros do Estado de São Paulo (SP), por meio da análise sorológica e de fatores de risco, e também pelo vírus circulante nesses rebanhos. Foram colhidas 1.243 amostras de sangue e 352 amostras de secreções nasais de bovinos em 26 propriedades rurais, divididas nas regionais de Jaboticabal, São José do Rio Preto e Catanduva, localizadas na região norte do Estado SP. Durante a colheita das amostras, foi aplicado um questionário ao proprietário sobre informações relacionadas como prováveis fatores de risco para a infecção pelo BRSV em cada propriedade. Os soros foram analisados pela técnica de virusneutralização (VN) e as amostras de secreções nasais foram examinadas para detecção do gene das proteínas F e G do BRSV pela RT-nested PCR. Os resultados da VN mostraram elevada prevalência de BRSV nos rebanhos leiteiros, com total de 79,49% de reagentes. Os resultados separados por regionais revelaram prevalências de 76,19%, 83,68% e 69,14% de soropositivos, para Jaboticabal, São José do Rio Preto e Catanduva, respectivamente. Os rebanhos da regional de São José do Rio Preto apresentaram maiores prevalências de BRSV quando comparados aos rebanhos das outras duas regionais. A análise dos fatores de risco permitiu inferir que a idade dos animais e a ocorrência de infecção concomitante pelo herpesvírus bovino tipo 1 e vírus ... / Abstract: Bovine respiratory syncytial virus (BRSV), agent related to bovine respiratory disease, causes large economic losses mainly in calf rearing. BRSV has already been reported in Brazil with high serological prevalence, however, the risk factors related to its dissemination were not yet determined and a few number of virus strains was characterized in Brazilian herds. Thus, the study aimed to characterize the epidemiology of BRSV infection in dairy herds of São Paulo State, using serological and risk factors analysis, and also by virus circulating in these herds. For that, 1.243 blood samples and 352 nasal secretion samples were collected of animals from 26 farms divided into Jaboticabal, São José do Rio Preto and Catanduva regional, located in the northern region of São Paulo State. During the sample collection, a questionnaire was performed to the owner for each property regarding information about possible risk factors for BRSV. Sera were analyzed using virus neutralization test (VNT), and nasal secretions were examined to detect the F and G protein gene of BRSV by RT-nested PCR. VNT results showed high BRSV prevalence in dairy herds, reaching 79.49% of reagents. The separated results by regional revealed prevalence of 76.19%, 83.68% and 69.14% for Jaboticabal, São José do Rio Preto and Catanduva, respectively. The herds in the regional of São José do Rio Preto showed the highest prevalence of BRSV when compared to the other two regional herds. The analysis of risk factors allowed deducing that the age of the animals and the occurrence of concomitant infection by bovine herpesvirus type 1 and bovine viral diarrhea are associated with the high BRSV prevalence, while calving natural lactation was identified as a protective factor. The RT-nested PCR detected a positive sample for the F protein gene, and after its sequencing, the genetic relatedness of the sample to the other ... / Doutor

Made available in DSpace on 2014-06-11T19:22:55Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-01-27Bitstream added on 2014-06-13T20:29:20Z : No. of bitstreams: 1 cravo_hlp_me_sjrp.pdf: 853824 bytes, checksum: 43cbe13f547f1fdf2dfdfbf56e696a9a (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O Vírus Sincicial Respiratório Humano (hRSV) foi identificado em 1957 e mesmo após vários anos de investigação, nenhuma vacina foi desenvolvida. Acredita-se que a chave de inibição da ação viral são suas glicoproteínas de membrana, em especial a proteína de fusão (F), que com auxílio da proteína de ligação (G), é responsável pela instalação do hRSV na célula hospedeira. Há evidências experimentais de que compostos como flavonóides e glicosaminoglicanos podem diminuir a infecção viral, sendo então a proteína F um bom alvo para a ação destes compostos. O presente estudo utilizou de ferramentas de bioinformática para verificar as possíveis regiões de interação da proteína F com a Heparina Sulfatada e Flavonóides. Os programas de bioinformática foram utilizados para: modelagem dos compostos, caracterização e previsão da estrutura secundária da proteína, modelagem da estrutura terciária e docking molecular entre o modelo da proteína F e as estruturas tridimensionais dos Flavonóides e da Heparina Sulfatada. Modelos válidos foram obtidos para as estruturas tridimensionais dos flavonóides e para o modelo completo da proteína F. As características da proteína incluem um alto nível de conservação na seqüência de aminoácidos e, especialmente, em seus sítios de ligação. O docking da proteína com a Heparina, e o virtual screening da biblioteca de Flavonóides e a estrutura da proteína, resultaram em sítios de interação com grande potencial de inibição, uma vez que concordam com evidências experimentais descritos na literatura. A Heparina liga-se ao sítio de clivagem II, importante região para obtenção da atividade de fusão da proteína. Os Flavonóides podem se ligar a região hidrofóbica que desestabiliza... / Human Respiratory Syncytial Virus (hRSV) was identified in 1957 and even after several years of research, no vaccine has been developed yet. It is believed that the key to the inhibition of viral action is its membrane glycoproteins, including the Fusion Protein (F), responsible for the installation of the hRSV in the host cell. There are evidences that compounds such as flavonoids and glycosaminoglycans can decrease the viral infection, and F protein can be a good target for the action of these compounds. The present study checked the possible sites of interaction between F protein and heparin and flavonoids, using computational tools. Bioinformatics programs were used for: modeling compounds, characterization and prediction of protein secondary structure, tertiary structure modeling and the docking between the protein model and the structures of flavonoids and sulfated heparin. Valid models were obtained for flavonoids structures and the complete model of F protein. The characteristics of the protein include a high level of conservation in amino acid sequence and especially in its binding sites. The heparin docking and virtual screening of flavonoids resulted in interaction sites with great potential for inhibition, since they agree with other studies and experimental evidence of F protein inhibition. This study shows that compounds such as sulfated heparin and flavonoids interact in important sites of F protein. Heparin binds to the cleavage site II and flavonoids can bind to the hydrophobic site that destabilizes the formation of the six-helix-bundle region. Both regions are important for conformational changes that F protein undergoes to get its fusion activity. Docking showed that molecular interactions are likely to occur and selected the best candidates for a possible inhibitor. These evidences... (Complete abstract click electronic access below)

Orientador: Fátima Pereira de Souza / Banca: Alessandra Vidotto / Banca: Rogério de Moraes / Banca: Natália Bueno Leite Slade / Banca: Marcio José Tiera / Resumo: O Vírus Sincicial Respiratório Humano (hRSV) é o principal agente causador de doenças respiratórias agudas severas, como pneumonia e bronquiolite. Trata-se de um vírus da família Paramyxoviridae, com simetria helicoidal e envelope lipídico. Possui um genoma de RNA fita simples, não segmentado, com 10 genes codificantes. Um dos fatores que contribuem para o sucesso na replicação viral é a interação da proteína M2-1 com as proteínas P, M e com o RNA. Tal proteína age através da interação com RNA, e assim, participa efetivamente no processo de replicação viral, apresentando atividade anti-parada da replicação sendo ativa quando na forma tetramérica. Deste modo, o ligante que realizar interação com a M2-1 é um potencial candidato a prevenir as interações M2-1 com RNA e demais proteínas, impedindo deste modo o sucesso da replicação viral. Flovonoides são compostos naturais com várias atividades como antioxidante, anticancerígena, cardio protetora, antibacteriana e antiviral. Quercetina é um flavonoide que apresenta atividade antiviral, inibindo o complexo de replicação. Com a finalidade de investigar a interação de um potencial candidato a inibição da atividade da M2-1, clonamos, expressamos e purificamos a proteína M2-1 do hRSV e, determinamos sua característica físico-química de interação com quercetina em diferentes condições de temperatura. Para clonagem e expressão do gene M2-1 foram escolhidos o vetor pGEX-4T-1 e a bactéria Escherichia coli da linhagem BL21 Gold (DE3). A proteína expressa foi purificada em cromatografia de afinidade e cromatografia de exclusão molecular. As análises de composição de estrutura secundária e estabilidade térmica foram realizadas por espectroscopia de dicroísmo circular e, a interação com Quercetina com espectroscopia de fluorescência. Para o mapeamento da interação com a Quercetina foram realizadas docking molecular e dinâmica molecular. A proteína... / Abstract: Human Respiratory Syncytial Virus (hRSV) is the major causative agent of acute respiratory infections such as pneumonia and bronchiolitis. This is a virus of the Paramyxoviridae family with helical symmetry and lipid envelope. It has a single strand RNA genome, not segmented, with 10 coding genes. One of the factors that contribute to success in viral replication is the interaction of M2-1 protein with P, M protein and RNA viral. Such protein acts through the interaction with RNA, hence, participating in the viral replication process, having anti-stop activity in the replication process and, the protein is active only as a tetramer. Thus, a ligand that interacts with M2-1 is a potential candidate to prevent interaction of M2-1 with other proteins, thereby preventing the success of viral replication. The aim of the research is to clone, express and purify the M2-1 protein of hRSV and then determine its physicochemical characteristics of the interaction with Quercetin in different temperatures to investigate the interaction of a potential candidate to inhibit the activity of the M2-1. The M2-1 gene was cloned in vector pGEX-4T-1 and expressed in Escherichia coli strain BL21 Gold (DE3). The expressed protein was purified on affinity chromatography molecular exclusion chromatography, thermal stability and secondary structure were analyzed by circular dicroism and the interaction with Quercetin was analyzed by fluorescence spectroscopy. To understand the interaction mechanism was performed molecular dynamics and molecular docking. The purified protein has 40% α-helix, 10% β-sheet, 19% turns and 31% random coils, being the melting temperature of 55,6°C. The titration of M2- 1 with Quercetin showed that it interacts in two points, on site 1 (the binding affinity is ~1,5x106 M -1 ) and stablishes an ionic interaction and, on site 2 (1,1x105 M -1 ) stablishes a hydrophobic interaction. One Quercetin molecule interacts on site 1 (formed by the ... / Doutor