L’objectif consistant à élaborer des «aimants par conception» peut être atteint en adaptant les structures moléculaires des complexes de coordination. Les molécules conçues devraient présenter les caractéristiques requises pour des applications spécifiques, qui résultent de leur riche diversité structurale. Des complexes mononucléaires à base de Ni avec une grande anisotropie magnétique et des molécules polynucléaires à base de Ni et de Co sont préparés et étudiés dans cette thèse. Les synthèses, les études magnétiques et les propriétés électrochimiques des complexes contenant un ligand pontant non innocent sont étudiées. Les complexes mononucléaires Ni(II) à géométrie bipyramide trigonale sont préparés avec des ligands axiaux et les contre-anions différents. L'effet de la nature des ligands axiaux et du changement structural induit par les contre-anions sur l'anisotropie magnétique est étudié expérimentalement et analysé à l'aide de calculs théoriques. Des molécules organiques sont utilisées pour concevoir des complexes trinucléaires à grande anisotropie magnétique et à couplage d'échange faible. Plusieurs complexes polynucléaires à base de Ni et de Co où le TTC³⁻ agit comme un ligand pontant innocent et le HHTP³⁻ comme un ligand non innocent typique sont cristallisés avec diverses structures (TTC = Trithiocyanurate; HHTP = Hexahydroxytriphénylène). Pour les complexes contenant le ligand non innocent (HHTP), les anions radicalaires sont produits par électrochimie. La combinaison de la spectro-électrochimie et de la spectroscopie à résonance paramagnétique électronique couplée à des études d'électrochimie permet d'étudier la délocalisation des électrons sur les radicaux organiques générés et le couplage d'échange entre les ions métalliques. / The objective of elaborating “magnets by design” can be achieved by tailoring the molecular structures of coordination complexes. The designed molecules are expected to exhibit the characteristics required for specific applications, virtually resulting from their rich structural diversity. Mononuclear Ni-based complexes with large magnetic anisotropy and polynuclear Ni- and Co-based molecules are designed in this dissertation. The syntheses, magnetic studies, and electrochemical properties of the complexes containing non-innocent bridge ligand are investigated. The Ni(II) mononuclear complexes with trigonal bipyramid geometry are prepared by tuning the axial ligands and the counter anions. The effect of the nature of the axial ligands and the structural change induces by the counter anions on magnetic anisotropy is studied experimentally and analyzed with the help of theoretical calculations. Large organic molecules are used to design trinuclear complexes with large magnetic anisotropy and weak exchange coupling. Several polynuclear Ni- and Co-based complexes with TTC³⁻ acting as an innocent bridging ligand and HHTP as a typical non-innocent ligand, are crystallized with various structures (TTC = Trithiocyanurate; HHTP = Hexahydroxytriphenylene). For the complexes containing the non-innocent ligand (HHTP), radical anions are produced by electrochemistry. The combination of spectroelectrochemical and Electron Paramagnetic Spectroscopy coupled to electrochemistry studies allow investigating the delocalization of the electrons on the generated organic radicals and the exchange coupling among the metal ions.

Transmissible spongiform encephalopathies (TSEs), or prion diseases, are fatal neurodegenerative diseases that affect several species, such as scrapie in sheep or goats and CJD in humans. In several species, neurological disease is preceded by TSE agent accumulation in lymphoid tissues prior to neuroinvasion. While oral transmission is considered the most common route for scrapie, transmission can also occur through lesions to the skin or mucosa, for example in the mouth or gastrointestinal tract due to rough feed, or birth associated skin damage. Scrapie has also been experimentally transmitted through skin scarification in mice. Following scrapie infection via skin scarification, PrPSc accumulates in the draining lymph node (LN) before spreading to other organs in the lymphoreticular system. It is not yet known by what means the scrapie agent is transported from the skin to the draining LN. Dendritic cells (DCs) in the skin have been found to transport viruses, such as HIV or Dengue, from the skin, thereby raising the question whether DCs or Langerhans cells (LCs), located within the epidermis, play a role in the uptake and transport of the TSE agent from the skin to the draining LN. CD11c is a cell surface marker traditionally used to identify or isolate DCs from other cell types. Mice and rats are naturally resistant to Diphtheria toxin (DTX). A transgenic mouse line was created where the Diphtheria toxin receptor (DTR) was expressed on CD11c+ cells. The presence of this receptor on CD11c+ cells allowed for the temporary conditional depletion of CD11c+ cells following a single injection of DTX. The cells repopulate the tissues within a time frame specific to the tissues the cells are located in. These mice were used to determine whether the absence of CD11c+ cells at the time of scrapie infection via the skin had an effect on the early accumulation of PrPSc within the lymphoid tissues and on disease progression. Immunohistochemical analysis demonstrated that early PrPSc accumulation in the draining LNs was delayed following depletion of CD11c+ cells, indicating that their potential role in the transport of the scrapie agent from the skin. Scrapie incubation period was not affected by the absence of the CD11c+ cells at the time of infection. Recent findings show that CD11c is not exclusive to DCs and is also expressed on macrophage populations. Following DTX-mediated depletion, DCs repopulate the tissues much faster than CD11c+ macrophages. Scrapie infection was carried out in the skin in DTX treated mice after DCs had repopulated the tissues but before macrophage numbers had returned, to determine whether macrophages rather than DCs played a role in the early accumulation of PrPSc in the draining LNs. No differences in PrPSc accumulation were observed in mice depleted of macrophages compared to controls and there was no effect on disease incubation period. Another transgenic mouse line was used, where DTX expression on langerin+ cells (LCs and langerin+ DCs in the dermis), allowed for their temporary depletion through DTX treatment. Following langerin+ cell depletion, increased PrPSc accumulation was observed in the draining LNs 7 weeks post infection, but did not affect the incubation period of disease. These results indicate that the absence of LCs somehow accelerated PrPSc accumulation, and that LCs might play a preventative role in early stages after infection. Histopathological analysis was used to complement microarray studies aimed to determine what immune responses were associated with scarification and DTXmediated depletion of cells within the skin and whether these responses might be linked to disease transmission. DCs and LCs in the skin appear to play different roles in the early stages following scrapie infection via the skin, but the lack of effect on incubation period does not rule out the involvement of other cell types or cell-free mechanisms of scrapie agent spread from the skin.

Esta pesquisa avaliou o efeito da transferência passiva dos leucócitos do colostro na imunidade específica de bezerras recém-nascidas. Foram acompanhadas 20 bezerras Holandesas durante o período neonatal, distribuídas em dois grupos experimentais: grupo COL+ recebeu colostro fresco (4L) proveniente de suas respectivas mães; e grupo COL- recebeu colostro congelado e acelular (4L), oriundo de vacas doadoras de colostro. As avaliações foram realizadas antes da mamada do colostro (M0), 1-2 (M1), 7 (M2), 14 (M3), 21 (M4) e 28 dias pós-nascimento (M5). As bezerras foram submetidas ao exame clínico, seguido da colheita das amostras sanguíneas para realização de hemograma, imunofenotipagem e cultivo celular. Os dois grupos foram colostrados com colostro de igual qualidade com relação à concentração de imunoglobulinas (70-120 g/L). A concentração de células do colostro fresco fornecido ao grupo COL+ foi de 1.895.849 células/mL. Não foi possível encontrar diferenças para as funções vitais em relação aos grupos experimentais. O exame específico dos sistemas revelou um caso de broncopneumonia, três de inflamação umbilical e maior frequência de escore de fezes 3 no COL-. As alterações clínicas foram refletidas no eritrograma das bezerras, sendo encontrado menor valor médio para a taxa de hemoglobina (HGB) no COL- em M3. Em relação à idade, observou-se redução gradativa dos valores médios para He (hemácias), HGB, HCT (hematócrito) e índices hematimétricos no primeiro mês de vida. A frequência de bezerras anêmicas foi maior no grupo COL- nos momentos M4 e M5. Em relação ao leucograma, observou-se diferença entre os grupos para linfócitos no M0 e M2 com valores superiores no COL-. Em relação aos momentos foi possível detectar leucocitose por neutrofilia no M0 e M1, observando-se inversão da relação neutrófilo:linfócito a partir desses momentos. Os valores de CD45+CD45RO- foram maiores em M0 no COL-, além disso, observou-se aumento da expressão do marcador de memória celular CD45RO+ do M0 ao M1 nos dois grupos experimentais. O CD3+gamma-delta- aumentou no decorrer do estudo, em contrapartida as células CD3+gamma-delta+ foram menores em M5 com relação ao M0-M3. Foi detectado também aumento dos valores de CD14+MHCII+ no primeiro mês de vida indicando maturação das células apresentadoras de antígeno. Em relação à produção de citocinas pelas células mononucleares sanguíneas, foi possível identificar maior concentração de IFN-gamma em M4, quando as células do COL- foram estimuladas com S. aureus (1 mononuclear:10 bactérias inativadas). A concentração de IL-17 detectada a partir das células do COL+ foi maior em M3, quando as células foram estimuladas com ConA. Com base nos resultados obtidos, pode-se concluir que: a) bezerras COL- apresentaram maior frequência e intensidade de doenças que evoluíram para anemia da inflamação; b) bezerras COL- apresentaram maior número absoluto de linfócitos, representadas especialmente pela subpopulação CD3+gamma-delta+ nos episódios de maior frequência de diarreias; c) Linfócitos de memória CD45RO+ aumentaram após a colostragem em ambos os grupos, sugerindo que outros componentes acelulares do colostro podem apresentar papel fundamental no desenvolvimento da resposta imunológica de bezerras recém-nascidas; d) a subpopulação CD3+gamma-delta- e as células CD14+MHCII- e CD14+MHCII+ aumentaram durante o primeiro mês de vida, indicando maturação imunológica; e) as células mononucleares das bezerras não responderam ao Herpesvírus Bovino tipo 1, porém responderam aos estímulos bacterianos, especialmente para a Escherichia coli; a interpretação do leucograma em conjunto com a análise das variações apresentadas para as citocinas inflamatórias IFN-gamma e IL-17 permitem afirmar que as bezerras apresentaram resposta inflamatória retardada e de menor magnitude no COL-. / This study evaluated the effect of leukocytes passive transference from bovine colostrum in specific immunity of newborn calves. During neonatal period, 20 Holstein calves were followed. Animals were distributed in two experimental groups: COL+ which received fresh colostrum (4L) from their mothers, and COL- which received frozen and acellular colostrum (4L) that came from donor cows. The evaluations were performed in the following moments: before colostrum intake (M0), 1-2 (M1), 7 (M2), 14 (M3), 21 (M4) and 28 days after birth (M5). Heifers were submitted to clinical examination. Then, blood samples were harvested for hemogram, immunophenotyping and cell culture. Both groups were fed with the same quality of colostrum (immunoglobulin concentration 70-120 g/L). The cell concentration of fresh colostrum that was provided to COL+ group was 1.895.849 cells/mL. It was not possible to detect differences in vital functions concerning the experimental groups. The system specific examination reveled one case of bronchopneumonia, three cases of umbilical inflammation and major rates of diarrhea score 3 in group COL-. Clinical alterations were reflected in calves erythrogram. It was found lower mean value for hemoglobin (HGB) in M3 for COL-. Regarding age, a gradual reduction in mean values for erythrocytes, HGB, HCT (hematocrit) and hematimetric rates were observed in the first month of life. The frequency of anemic heifers was higher in COL- group at moments M4 and M5. Regarding leukogram, it was observed difference between groups for lymphocytes in M0 and M2 with higher values in COL-. Concerning moments, it was possible to detect leukocytosis by neutrophilia from M0 up to M1 and inversion of neutrophil:lymphocyte relation from this moment. Values of CD45+CD45RO- was higher in M0 for COL-, furthermore, increase of cellular memory marker expression CD45RO+ was observed from M0 to M1 in both groups. The CD3+gamma-delta- increased during the study. On the other hand, CD3+gamma-delta+ were lower in M5 in relation to M0-M3. Increase of CD14+MHCII+ values were also detected in the first month of life, indicating maturation of antigen presenting cells. Regarding cytokine production by mononuclear cells of heifers blood, it was possible to identify higher concentration of IFN-gamma in M4 when cells of COL- were stimulated with S. aureus (1 mononuclear: 10 inactivated bacteria). The concentration of IL-17 detected from COL+ cells was higher in M3, when cells were stimulated with ConA. Based on these results, it can be concluded that: a) COL- heifers presented higher frequency and intensity of diseases that evolved to anemia of inflammation; b) COL- heifers presented higher lymphocyte absolute number, represented specially by CD3+gamma-delta+ subsets in episodes of higher frequency of diarrhea; c) memory lymphocytes CD45RO+ increased after colostrum intake in both groups, suggesting that other acellular colostrum components can present fundamental role in development of immunological response in newborn heifers; d) the subset of CD3+gamma-delta- and the cells CD14+MHCII- and CD14+MHCII+ increased during the first month of life, indicating immunological maturation; e) heifers mononuclear cells did not respond for herpes virus bovine type 1, however, responded for bacterial stimulus, specially Escherichia coli. The interpretation of leukogram with the variation of presented analyses for inflammatory cytokines IFN-gamma and IL-17, allow to state that heifers presented delayed inflammatory response and of lesser magnitude in COL-.

Made available in DSpace on 2016-08-10T10:55:55Z (GMT). No. of bitstreams: 1 AISLAN SENA STIVAL.pdf: 587198 bytes, checksum: e198d94f5ca28a047840fd9b7bf9147c (MD5) Previous issue date: 2011-02-28 / Introduction: Today, Brazil has the second position among the countries with more richness of reptiles in their territory. The Bothrops moojeni is a poisonous snake found abundantly in the Midwest region of Brazil. Neurotoxins are complex mixtures containing neurotoxins, cytotoxins, myotoxins, proteases and nucleases. The venom of Bothrops moojeni and composed a great number of bioactive components that may eventually be a potential therapeutic use in scientific research focused on health. Objectives: The objective of this project was to evaluate the activity of noncytotoxic venom Bothrops moojeni in peripheral blood mononuclear cells (CMN). Methodology: In this work were obtained CMN donations from healthy individuals, MNCs were separated in the density gradient. After activation of CMN with phytohemagglutinin (PHA) and interleukin (IL2) was added different concentrations of cobra venom B. moojeni to evaluate its activity is not cytotoxic. Results: The levels of 0.5 and 0.05 mg / mL crude venom of Bothrops moojeni showed no cytotoxic activity on human peripheral blood CMN. Conclusion: The crude venom of Bothrops moojeni by not showing cytotoxicity at levels of 0.5 and 0.05 mg / mL, is potentially useful for evaluating potential therapeutic effects on these cells infected with microorganisms such as HIV - 1. / Introdução: O Brasil possui hoje a segunda colocação dentre os países com maior riqueza de répteis em seu território. A Bothrops moojeni é uma serpente venenosa encontrada abundantemente na região Centro Oeste do Brasil. O veneno das serpentes são misturas complexas contendo neurotoxinas, citotoxinas, miotoxinas, proteases e nucleases. O veneno da Bothrops moojeni e composto de um grande numero componentes bioativos que poderá ser no futuro um potencial uso terapêutico nas pesquisas científicas voltadas para a área da saúde. Objetivos: O objetivo deste projeto foi o de avaliar a atividade não citotóxica do veneno bruto Bothrops moojeni em células mononucleares de sangue periférico (CMN). Metodologia: Neste trabalho foram obtidas CMN de doações de pessoas sadias, as CMN foram separadas em meio de gradiente de densidade. Após ativação das CMN com fitohemaglutinina (PHA) e interleucina (IL2) foram adicionadas diferentes concentrações do veneno da cobra Bothrops moojeni para avaliar sua atividade não citotóxica. Resultados: As concentrações 0,5 e 0,05 μg/mL do veneno bruto da serpente Bothrops moojeni não apresentou atividade citotóxica sobre CMN do sangue periférico humano. Conclusão: O veneno bruto da serpente Bothrops moojeni por não apresentar citotoxicidade nas concentrações 0,5 e 0,05 μg/mL, é potencialmente útil para verificar possível efeito terapêutico sobre estas células infectadas por microorganismos como por exemplo o HIV - 1.

A inflamação associada à obesidade é caracterizada por uma ativação crônica e de baixa intensidade do sistema imune. Diversos autores demonstraram mudanças em parâmetros inflamatórios após perda de peso. A cirurgia bariátrica é um método para tratar obesidade com alta eficiência e menor risco de recidiva. Os mononucleares de sangue periférico (MNSP) constituem um material biológico interessante para pesquisa, visto a capacidade de refletir alterações de expressão gênica de diferentes tecidos e o fácil acesso para análise. O presente estudo teve por objetivo avaliar os efeitos da obesidade e da perda de peso induzida por cirurgia bariátrica sobre a atividade imunológica, por meio de cultura primária de MNSP de pacientes com obesidade grau III (IMC >= 40 kg/m2). Foram coletadas amostras de sangue de veia periférica de 10 voluntários com peso normal (grupo controle) e antes e após a cirurgia de 20 voluntários com obesidade grau III. Após a separação dos mononucleares pelo gradiente de Ficoll-HyPaque, as células foram estimuladas por lipopolissacarídeo (LPS) ou concanavalina A (Con-A) e os sobrenadantes das culturas coletados para dosagem de IL-1?, IL-6, TNF-?, IFN-?, IL-10 e IL-17 por teste ELISA. As amostras de sangue também foram utilizadas para exames bioquímicos, dosagens de adiponectina, leptina e citocinas séricas. Os resultados evidenciaram maiores concentrações de IL-6, TNF-?, IL-1? e IL-10 nos sobrenadantes das culturas de MNSP do grupo com obesidade em relação ao grupo controle. Na comparação entre dosagens de citocinas do grupo com obesidade, observamos redução de TNF-?, IL-1? e IL-10 após 6 meses da cirurgia, a qual não foi observada após 1 ano, e aumento de IL-17 após 1 ano de tratamento. Não houve diferença significativa nas concentrações de citocinas séricas na comparação entre os grupos com obesidade e controle ou pré e pós-operatório. Observamos correlações das citocinas de sobrenadante das culturas de MNSP e séricas com resultados laboratoriais relacionados à homeostase glicêmica em pacientes com obesidade antes e após a cirurgia bariátrica, além da correlação entre citocinas do sobrenadante e o estado de adiposidade no pós-operatório. Concluímos que a obesidade grau III está associada a modificações da produção de citocinas por MNSP e a perda de peso induzida por cirurgia bariátrica influencia esta produção no primeiro ano de tratamento. / The obesity-associated inflammation is characterized by a chronic and low intensity activation of the immune system. Several authors have shown changes in inflammatory parameters after weight loss. Bariatric surgery is a method for treating obesity with high efficiency and less risk of recurrence. Peripheral blood mononuclear cells (PBMC) are an interesting biological material for research, due to the ability to reflect changes in gene expression in different tissues and easy access to analysis. This study aimed to evaluate the effects of obesity and weight loss induced by bariatric surgery on immune activity through PBMC culture of morbidly obese patients (BMI >= 40 kg/m2). Peripheral vein blood samples were collected from 10 volunteers with normal weight (control group) and before and after the surgery in 20 volunteers with morbid obesity. After separation of the mononuclear cells by Ficoll-Hypaque gradient centrifugation, cells were stimulated with lipopolysaccharide (LPS) and concanavalin A (Con-A) and culture supernatants collected for IL-1?, IL-6, TNF-?, IFN-?, IL-10 and IL-17 dosage by ELISA. Blood samples were also used for biochemical examinations and adiponectin, leptin and serum cytokine dosage. The results showed higher concentrations of IL-6, TNF-?, IL-1? and IL-10 in the supernatants of the MNSP cultures of the obesity group in relation to the control group. In the comparison between cytokine dosages of the obesity group, we observed reduction of TNF-?, IL-1? and IL-10 after 6 months of surgery, which was not observed after 1 year, and IL-17 increased after 1 year of treatment. There was no significant difference in serum cytokine concentrations in the comparison between obesity and control groups or operated group. We observed correlations of cytokines obtained in PBMC culture supernatant and serum with laboratory results related to glucose homeostasis in patients with obesity before and after bariatric surgery, as well as correlation between cytokines of the supernatant and the state of adiposity postoperatively. We conclude that morbid obesity is associated with changes in cytokine production by PMNC and weight loss induced by bariatric surgery influences cytokine production in the first year of treatment.

Orientador: Flávio Henrique Caetano / Banca: Ana Maria Costa Leonardo / Banca: Maeli Dal Pai Silva / Banca: Maria Tercilia Vilela de Azeredo Oliveira / Banca: Carmem Silvia Fontanetti Christofoletti / Resumo: O presente estudo teve como objetivo analisar os leucócitos circulantes em microscopia de luz e eletrônica e sua distribuição sazonal, além de procurar estabelecer o período de renovação celular desses leucócitos, e principalmente de caracterizar os fagócitos mononucleares do sangue de tartaruga, e sua capacidade de fagocitose frente a material inerte. Neste trabalho utilizou-se seis tartarugas Phrynops hilarii, originárias de ilhas do estuário do rio Guaíba Porto Alegre (RS), que estavam ambientadas em nosso biotério. A coleta de sangue foi realizada em todos os períodos sazonais, por punção de vasos laterais do pescoço e coletados em tubos de ensaio heparinizados. Foram realizados esfregaços sanguíneos, corados com Leishmann e Giemsa, contando-se quinhentas células de cada animal e após a obtenção dos dados, foi aplicado o teste estatístico de Bonferroni. Para a análise autorradiográfica foi injetado 1000μCi / kg de thymidine-H A. Para microscopia eletrônica processamos a nata leucocitária obtida por meio de centrifugação do sangue, para a analise citoquímica incubamos com citidina-5'-monofosfato, betaglicerofosfato de sódio, Trimetafosfatase, para averiguar a resposta fagocitária utilizamos 0,01% de carvão coloidal.Os resultados mostram que os leucócitos de Phrynops hilarii tem descrição de leucócitos semelhantes às outras espécies, somente os basófilos e linfócitos não sofreram alterações em sua distribuição sazonal. Todos os leucócitos com exceção dos basófilos apresentaram renovação celular após sete dias. Caracterizamos monoblasto, promonócito, monócitos e macrófago no sangue circulante bem como a capacidade dos fagócitos mononucleares de fagocitar células mortas e materiais inerte. / Abstract: The aim of this study was to analyze the leukocytes in the blood using electronic and light microscopy and their seasonal distribution, also to characterize the leukocyte cells replacement and mainly to characterize the mononuclear phagocytes in the blood and their phagocytic capacity. In this study, it was used six turtles (Phrynops hilarii), caught at the Guaíba river estuary, Porto Alegre, Rio Grande do Sul, Brazil and lodged for 1 week at the Central Animal House, University of São Paulo, Ribeirão Preto, São Paulo, Brazil. Blood was obtained during the seasonal periods by puncturing the lateral vessels of the neck. The blood samples were stained by Leishmann and Giemsa, counting five hundred cells in each animal. After the obtained data, it was applied the Bonferroni test as statistical method. For the autoradiographic analysis, it was injected in the circulating blood 1000 μCi/kg of 3Hthymidine. For electronic microscopy, it was processed the leukocyte substrate by circulating blood centrifugation. For cytochemical analyses, blood smears were air dried, post-fixed in 4% formalin and submitted to the determination of the following enzyme activities: acid phosphatases (β-g1ycerophosphatase and citidine-5′-sodium monophosphatase), and trimetaphosphatase. The results showed that the leukocytes of Phrynops hilarii have the leukocytes description similar to the other species, only the basophiles and lymphocytes did not suffer alterations in their seasonal distribution. All the leukocytes, in exception of the basophiles showed cells replacement after seven days. It was characterized the monocytes and macrophages in the circulating blood as well as the phagocytes capacity. / Doutor

Terminally differentiated B cells are responsible for antibody generation, a key component of adaptive immunity. IgG antibodies play an important role in defence against infection but can be pathogenic in some autoimmune diseases and in solid organ transplantation. In addition to antibody generation, there is increasing interest in the antibody-independent functions of B cells, including their ability to regulate immune responses via the production of IL10. In this thesis I firstly explored the therapeutic potential of belimumab, an anti-BLyS antibody, in an experimental medicine study in kidney transplant recipients. The rationale for this study was based on published studies showing that B cells activate alloreactive T cells and secrete human leukocyte antigen (HLA) and non-HLA antibodies that negatively affect graft function and survival, but may also play a protective role by regulating alloimmune responses promoting transplant tolerance. B-Lymphocyte Stimulator (BLyS) is a cytokine that promotes B cell activation and survival. We performed the first randomized controlled trial using belimumab as early maintenance immunosuppression in kidney transplantation. In belimumab-treated subjects, we demonstrate a reduction in naïve and activated memory B cells, plasmablasts, IgG transcripts in peripheral blood and new antibody formation as well as evidence of reduced CD4 T cell activation and of a skewing of the residual B cell compartment towards an IL10-producing regulatory phenotype. This experimental medicine study highlights the potential of belimumab as a novel therapeutic agent in transplantation. In the second part of my project I performed a preclinical study investigating the potential efficacy of bromodomain inhibitors in reducing antibody-mediated immune cell activation. Immune complexed antigen can activate mononuclear phagocytes (MNP), comprising macrophages and dendritic cells (DCs), via ligation of Fc gamma receptors (FcγR), that bind the Fc region of IgG. FcγR-dependent MNP activation results in profound changes in gene expression that mediate antibody effector function in these cells. The resulting inflammatory response can be pathological in the setting of autoimmune diseases, such as systemic lupus erythematosus and in antibody-mediated rejection in transplantation. BET proteins are a family of histone modification 'readers' that bind acetylated lysine residues within histones and function as a scaffold for the assembly of complexes that regulate gene transcription. Bromodomain inhibitors (I-BET) selectively inhibit the transcription of a subset of inflammatory genes in macrophages following toll-like receptor stimulation. Since MNPs make a key contribution to antibody-mediated pathology, we sought to determine the extent to which I-BET inhibits macrophage and DC activation by IgG. We show that I-BET delays phagolysosome maturation associated with build-up of immune complex (IC) whilst selectively inhibiting IC induced cytokine production. I-BET changed MNP morphology, resulting in a less adherent phenotype, prompting an assessment of its impact on DC migration. In vitro, in a three-dimensional collagen matrix, IgG-IC induced augmentation of DC chemotaxis to chemokine (C-C motif) ligand 19 (CCL19) was abrogated by the addition of I-BET. In vivo, two photon imaging showed that systemic I-BET treatment reduced IC-induced dermal DC mobilisation. Tissue DCs and transferred DC also had reduced migration to draining lymph nodes following I-BET treatment. These observations provide mechanistic insight into the potential therapeutic benefit of I-BET in the setting of antibody-associated inflammation.

A necessidade de tratamentos mais eficazes e menos invasivos para os pacientes, em adição à capacidade de diferenciação celular da medula óssea sugere que o transplante de células mononucleares totais poderia ser uma das melhores formas de tratamento para as diversas patologias existentes. Entretanto, vários fatores implicam sobre a viabilidade das células da medula óssea dos quais destacamos a ausência de padronização de protocolo de criopreservação que permita a manutenção da viabilidade celular, sendo altamente necessário o desenvolvimento de estudos nesta área. Deste modo, neste estudo, após a anestesia de um grupo de animais foi realizada punção da medula óssea, separação das células mononucleares e avaliação da viabilidade. Foram testados oito meios diferentes para criopreservação das células. O meio de congelamento A é composto por 20% dimetilsulfóxido (DMSO), 40% Dulbecco´s Modified Eagle´s Médium (DMEM) e 40% de Plasma Autólogo, o meio de congelamento B contém 20% dimetilsulfóxido (DMSO), 40% Roswell Park Memorial Institute (RPMI) e 40% de Plasma Autólogo, o meio de congelamento C tem em sua composição 20% dimetilsulfóxido (DMSO), 40% soro fetal bovino (SFB) e 40% plasma autólogo, o meio de congelamento D é composto de 20% dimetilsulfóxido (DMSO) e 80% de plasma autólogo, o meio E constitui-se de 5% dimetilsulfóxido (DMSO), 47,5% de Dulbecco\'s Modified Eagle\'s Médium (DMEM) e 47,5% de plasma autólogo, o meio F contém 5% dimetilsulfóxido (DMSO), 47,5% de Roswell Park Memorial Institute (RPMI) e 47,5% de plasma autólogo, o meio G contém 5% dimetilsulfóxido (DMSO), 47,5% de soro fetal bovino (SFB) e 47,5% de plasma autólogo e o meio H constitui-se de 5% dimetilsulfóxido (DMSO) e 95% de plasma autólogo. Após as análises realizadas pela técnica de citometria de fluxo, o meio mais eficiente na criopreservação das células mononucleares de suínos foi o protocolo D por possuir maior concentração de plasma autólogo e crioprotetor. / The necessity of the most efficient and less invasive treatments for the patients, in addition to the capacity of cellular differentiation of the bone marrow suggests that the transplant of mononuclear total cells might be one of the best treatment for several pathologies. Meantime, several factors influence on the viability of the cells of the bone marrow as the absence of standardization of criopreservação protocol which could allow the maintenance of the cellular viability, being an important issue of investigation. In this study, after the anaesthesia of a group of animals, samples of bone marrow were collected, following the separation of the mononuclear cells and evaluation of the viability. Eight different protocols were tested for cells criopreservation. The protocol A by 20% dimetilsulfóxido (DMSO), 40% Dulbecco\'s Modified Eagle\'s Médium (DMEM) and 40% autologus plasma, B protocol conatained 20% dimetilsulfóxido (DMSO), 40% Roswell Park Memorial Institute (RPMI) and 40% autologus plasma, the C protocol was composed 20 % dimetilsulfóxido (DMSO), 40% bovine fetal serum (SFB) e 40% autologus plasma, D protocol was made using 20% dimetilsulfóxido (DMSO) and 80% autologus plasma, E protocol was constituted by 5% dimetilsulfóxido (DMSO), 47,5% de Dulbecco\'s Modified Eagle\'s Médium (DMEM) and 47,5% autólogo plasma, the F contains 5% dimetilsulfóxido (DMSO), 47,5% de Roswell Park Memorial Institute (RPMI) and 47,5% autologo plasma, the protocol G was compoed by 5% dimetilsulfóxido (DMSO), 47,5% de bovine feta serum (SFB) and 47,5% autologus plasma and the H protocol was 5% dimetilsulfóxido (DMSO) and 95% autologus plasma. After flux citometer analyses, the most efficient protocol in criopreservation of the mononuclear cells of pigs was the protocol D which was composed the by the most amount of autologus plasma and crioprotectant.

Spectroscopic studies have been used to describe the mechanism of the decomposition of hydrogen peroxide by solutions of a dimeric Cu(II) complex of a dissymetric Schiff base, [CuSALAD]2.H2O, and imidazole or methyl substituted imidazoles, B, which form monomeric CuSALAD.B2 complexes, in aqueous ethanol solvent. Freezing point depression and vapor pressure lowering studies were carried out to confirm the dimeric nature of the [CuSALAD]2.H2O complex that had been previously reported. The stoichiometry of the [CuSALAD]2.H2O-imidazole equilibrium was extensively studied pointing to a 1:4 stoichiometry. The CuSALAD.B2 adducts exhibited certain catalytic properties that mimic those of catalase enzymes. The different imidazoles were buffered to acidic, neutral and basic pH media in order to investigate the pH effects of this reaction. Two charge transfer (CT) bands were observed near 420 and 450 nm upon addition of hydrogen peroxide to CuSALADB2 solutions, and were associated with two proposed intermediates (CuBOOH and CuBOOCu). A mechanism consistent with these results has been developed. First order dependence of the rate on CuSALAD.B2 was observed in the presence of excess CuSALAD.B2 over hydrogen peroxide, whereas second order dependence was observed with the latter in excess. The CuBOOCu intermediate was unstable in the presence of EDTA, and a first order dependence of rate of formation of intermediate on both CuSALAD.B2, and hydrogen peroxide was observed.

In cardiovascular disease the repair response is insufficient to restore blood flow, leading to the death of muscle and loss of tissue function. Therefore, strategies to augment the endogenous cell response and its effects may help improve tissue recovery and function. In this study we explored the use of tissue-engineered collagen matrices for augmenting endogenous regenerative processes after myocardial infarction. Treatment with the sLeX-collagen matrix reduced inflammation and apoptosis and had a positive regenerative effect on the infarcted mouse heart, through improved vascular density and possibly enhanced cardiomyogenesis. Additionally, we investigated the effects of cryopreservation on generating circulating angiogenic cells (CACs) from peripheral blood mononuclear cells (PBMCs), as a potential source of stem cells that could be used in combination with our collagen scaffold. Our findings show that despite PBMCs experiencing phenotypic changes after cryopreservation, they may still be used to generate the same therapeutic CACs as freshly procured PBMCs.