Thesis (Ph.D.) - University of Queensland, 2005. / Includes bibliography.

Thesis (M.Sc.)--York University, 2005. Graduate Programme in Biology. / Typescript. Includes bibliographical references (leaves 83-93). Also available on the Internet. MODE OF ACCESS via web browser by entering the following URL: http://gateway.proquest.com/openurl?url%5Fver=Z39.88-2004&res%5Fdat=xri:pqdiss &rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&rft_dat=xri:pqdiss:MR11803

Thesis (Ph. D.)--University of California, San Diego and San Diego State University, 2009. / Title from first page of PDF file (viewed July 22, 2009). Available via ProQuest Digital Dissertations. Vita. Includes bibliographical references (p. 115-137).

Τα φυσικά φονικά κύτταρα (NK) αποτελούν περίπου το 10% των κυκλοφορούντων λεμφοκυττάρων και παίζουν σημαντικό ρόλο στην πρώτη γραμμή άμυνας του ανοσοποιητικού συστήματος. Έχουν την ικανότητα να αναγνωρίζουν καρκινικά και μολυσμένα κύτταρα, τα οποία μπορούν να θανατώνουν απελευθερώνοντας κυτταροτοξικά κοκκία και κυτταροκίνες. Σκοπός της παρούσας εργασίας ήταν η μελέτη της έκκριση IFN-γ και TNF-α, από τα περιφερικά μονοπύρηνα (PBMCs) και ΝΚ κύτταρα, έπειτα από διέγερση με Gram θετικά και Gram αρνητικά βακτήρια (αναλογία ΝΚ κύτταρα προς βακτήρια 10:1), παρουσία ή απουσία εξωγενούς IL-2. Μικρή παραγωγή IFN-γ παρατηρήθηκε μόνο στα PBMCs, με μεγαλύτερη συγκέντρωση στις 20 ώρες έπειτα από διέγερση με L.monocytogenes, ενώ δεν παρατηρήθηκε παραγωγή TNF-α. Ο λόγος ΝΚ κύτταρα: βακτήρια (10:1) που χρησιμοποιήθηκε, η έλλειψη βοηθητικών κυττάρων και ο μικρός χρόνος διέγερσης, πιθανώς να ήταν και οι αιτίες που δεν παρήχθησαν καθόλου κυτταροκίνες από τα ΝΚ κύτταρα, ενώ η χαμηλή παραγωγή IFN-γ από τα PBMCs, πιθανώς να οφείλεται, είτε στην παραγωγή IL-10 από τα μακροφάγα είτε στο ότι το ερέθισμα διέγερσης δεν ήταν αρκετό, ώστε να ενεργοποιηθούν πλήρως. Περαιτέρω μελέτες χρειάζονται για την πλήρη κατανόηση της έκκρισης των κυτταροκινών από τα ΝΚ κύτταρα, παρουσία παθογόνων και δυνητικά παθογόνων μικροοργανισμών. / Natural killer (NK) cells comprise about 10% of all circulating lymphocytes and play crucial role to innate immune responses. NK cells can recognize tumor or infected cells and kill them by the release of cytotoxic molecules and cytokines. The aim of the study was to identify IFN-γ and TNF-α production from peripheral blood mononuclear cells (PBMCs) and purified ΝΚ cells, after stimulation with Gram positive and Gram negative bacteria (in ratio 10 NK:1 bacteria), in the presence or the absence of exogenous IL-2. Only PBMCs produced IFN-γ, with greater amounts after 20 hours stimulation with L.monocytogenes, while no production of TNF-α was observed. The low ratio, the absence of accessory cells and the short time of stimulation, probably, were responsible for the fact that no cytokine were produced from NK cells, whereas the low production of IFN-γ from PBMCs was, probably, due to the production of IL-10 from macrophages Alternatively, it is possible that the ratio and the time points were not enough for the full stimulation of PBMCs. Additional studies are needed to demonstrate the NK cytokine profile pattern, in the presence of pathogens and potential pathogen microorganisms.

Made available in DSpace on 2014-08-13T14:50:43Z (GMT). No. of bitstreams: 0 Previous issue date: 2013-02-21Bitstream added on 2014-08-13T18:00:54Z : No. of bitstreams: 1 000750733.pdf: 1281894 bytes, checksum: dc49e77c506e8c2dbd261f5086ca51f7 (MD5) / A pré-eclâmpsia (PE) é uma síndrome específica da gestação humana, caracterizada por uma resposta inflamatória sistêmica, de maior intensidade do que a observada na gestação normal. Nessa patologia, células do sistema imune inato como monócitos e granulócitos encontram-se ativadas endogenamente e secretam níveis elevados de radicais livres e citocinas inflamatórias. 1) Determinar o estado de ativação endógena de monócitos pela expressão de receptores TLR2 e TLR4, bem como a ativação do fator de transcrição nuclear NF-κB nessas células em gestantes portadoras de PE distribuídas quanto à idade gestacional de aparecimento das manifestações clínicas (precoce ou tardia) da doença; 2) Correlacionar a expressão de TLR2 e TLR4 com a produção de fator de necrose tumoral alfa (TNF-), interleucina-10 (IL-10) e IL-12 por monócitos estimulados com lipopolissacáride de Escherichia coli (LPS) e peptidoglicano (PGN) de bactéria Gram-positiva em gestantes com PE precoce ou tardia; 3) Verificar se os parâmetros estudados diferenciam PE precoce e tardia. Foram estudadas 92 gestantes, sendo 32 normotensas e 60 portadoras de PE, pareadas pela idade gestacional. As gestantes pré-eclâmpticas foram classificadas de acordo com o aparecimento das manifestações clínicas em PE precoce (<34 semanas de gestação, n=30) e PE tardia (≥34 semanas de gestação, n=30). Monócitos de sangue periférico obtidos de gestantes normotensas ou com PE foram cultivados por 18 h na ausência ou presença de LPS ou de PGN. A expressão de receptores TLR2 e TLR4, presentes na superfície de monócitos, foi detectada por citometria de fluxo, empregando-se anticorpos monoclonais específicos, marcados com fluorocromos. Para análise da ativação do fator de transcrição nuclear NF-κB os monócitos foram incubados na presença ou ausência de LPS ou PGN por 30 min e o extrato nuclear obtido foi empregado para dosagem de NF-κB. Monócitos ... / Preeclampsia (PE) is a pregnancy-specific human syndrome characterized by a systemic inflammatory response, with higher intensity than the one observed in normal pregnancy. In this pathology, innate immune cells such as monocytes and granulocytes are activated endogenously and secrete high levels of inflammatory cytokines and free radicals. 1) to determine the activation state of monocytes by endogenous expression of TLR2 and TLR4 receptors as well as the nuclear transcription factor (NF-κB) activation in these cells in pregnant women with PE, distributed according to the gestational age of clinical manifestations (early or late-onset) of the disease; 2) to correlate TLR2 and TLR4 expression with TNF-α, IL-10 and IL-12 by monocytes stimulated with lipopolysaccharide (LPS) of Escherichia coli and peptidoglycan (PGN) of Gram-positive bacteria in pregnant women with early-onset or late-onset PE; 3) to verify if the parameters studied may differentiate early-onset or late-onset PE. We studied 92 pregnant women, 32 normotensive and 60 women with PE, paired for gestational age. Preeclamptic pregnant women were classified according to onset of clinical manifestations in early-onset PE (<34 weeks gestation, n=30) and late-onset PE (≥ 34 weeks gestation, n=30). Monocytes from peripheral blood obtained from preeclamptic and normotensive pregnant women were incubated for 18h in the absence or presence of LPS or PGN. Expression of TLR2 and TLR4 receptors present on the surface of monocytes, was detected by flow cytometry, using specific monoclonal antibodies labeled with fluorochromes. To analyze NF-κB, monocytes were incubated with or without LPS or PGN for 30 min and the nuclear extract obtained was employed for NF-κB determination. Monocytes were further cultured in the presence or absence of LPS and PGN and the supernatant obtained after 18h cultivation was aspirated and used for TNF-α, IL-10, IL-12p40 and IL-12p70 determination by ...

Cytokines are important mediators of immune functions in humans and animals, interleukin (IL)-15 is a proinflammatory cytokine, which is mainly produced by monocytes. It shares many of its functions with IL-2, which is partly due to the shared use of receptor subunits on target cells, and serves as a growth and survival factor for T lymphocytes. The type IIL-15 receptor is composed of the IL-2R β and γ subunits, which form a trimeric complex with the high affinity IL-15Rα chain. The expression of IL-15 is tightly regulated both at the transcriptional and translational level. The production of IL-15 is associated with immune responses against bacterial and parasitic pathogens but has also been associated with the pathology of human autoimmune diseases, in particular Rheumatoid Arthritis (RA). RA is characterized by chronic inflammation within the synovial membrane accompanied by infiltration of lymphocytes leading to progressive, erosive destruction of cartilage and underlying bone. The severity of RA is associated with the overexpression of proinflammatory cytokines within the synovial tissue, in particular tumor necrosis factor alpha (TNF α) which is thought to play a central role in maintaining the inflammatory processes within the arthritic joint. So far, little is known about the processes that initiate and perpetuate RA. IL-15 was found in the synovial tissue of RA patients where it stimulated the production of TNFα, placing IL-15 in a central position orchestrating the cytokine cascade that causes inflammation and pathology in RA. Antagonists to IL-15 may therefore have an important therapeutic potential for the treatment of RA in humans. A major aim of this project has been to clone and express a recombinant IL-15 antagonist to use as a therapeutic agent in a murine model of RA closely related to the human disease, collagen-induced arthritis (CIA). A soluble IL-15Rα was cloned from a murine macrophage cell line and expressed in a bacterial expression system. The resulting protein has a molecular weight of 26kD and bound to IL-15 specifically. It also had a neutralizing effect on IL-15-induced proliferation of T cell lines. Administration of soluble IL-15Rα to mice prevented the onset of CIA and had a suppressive effect on disease severity and incidence. Mice treated with the recombinant IL-15Rα also showed reduced serum cytokine production and altered humoral responses against collagen. These results consolidate the therapeutic potential of IL-15 antagonists for the treatment of inflammatory diseases. To further enhance the therapeutic properties of recombinant IL-15Rα, a second expression construct has been cloned fusing the extracellular region of native IL-15Rα to the constant region of the murine immunoglobulin heavy chain. This construct was expressed in a mammalian expression system and results in a product of 66kD, which also bound to IL-15. The generation of knockout mice by gene targeting is a powerful tool to study the function of gene products in vivo. The Cre/lox system provides a novel strategy to generate inducible and tissue specific genomic alterations that allow the detailed analysis of gene function. The second part of this project was concerned with the generation of a mouse model lacking IL-15Rα in a tissue specific way by conditional mutagenesis in embryonic stem (ES) cells. Using cDNA encoding the extracellular domain of IL-15Rα as a radiolabeled probe, a murine genomic library was screened. Two clones containing part of the gene encoding IL-15Rα were characterized. A DNA construct was cloned to target the IL-15Rα gene in murine ES cells. Homologous recombination of the construct with the target locus resulted in the flanking of the critical regions of the IL-15Rα-gene by loxP sites. Cre-mediated recombination in vitro caused the deletion of loxP site flanked sequences within the genome of the targeted clone. Using this technique, two ES cell clones have been generated that allow the generation of mice that either lack IL-15Rα in all tissues or are suitable for conditional mutagenesis mediated by Cre recombinase. The resulting model may provide a useful tool to study the effects of IL-15 in inflammatory processes in vivo.

Diverse species of RNA can be post-transcriptionally uridylated on 3’ termini to modulate their biological function. Key cellular enzymes involved in the catalysis of RNA uridylation have been identified as two closely related terminal uridyltransferase (TUT) family members known as Zcchc6 and Zcchc11. To date, most reports on the function of TUTs have been gleaned from reductionist in vitro systems, however the biological function of these enzymes in integrated animal models remains unknown. The goal of this work was to investigate physiological roles for the TUT proteins during normal homeostasis and during infectious stress. To achieve this, we generated two constitutive, animal models of TUT-deficiency for both Zcchc6 and Zcchc11. The first knockout animal of the two TUTs to be examined was Zcchc11. Given previous reports that Zcchc11 played essential roles in stem cell biology, it was anticipated that Zcchc11-null mice would be result in embryonic lethality. We observed decreased survival and organismal growth following birth. The hepatic small RNA transcriptome revealed reduced sequence lengths and terminal uridylation across mature microRNAs and the expression of IGF-1 was enhanced by Zcchc11 expression in vitro. MiRNA silencing of IGF-1 was alleviated by the uridylation of IGF-targeting miRNA. We concluded that the Zcchc11-mediated terminal uridylation of mature microRNAs is pervasive and physiologically significant. In the second model examined, we observed that Zcchc6 deficiency did not impact perinatal mortality or litter size, but in contrast to Zcchc11-null mice, Zcchc6-null animals exhibited enhanced organismal growth following birth. A survey of tissue Zcchc6 mRNA expression showed enrichment in the lungs and upon further analysis we observed Zcchc6 to be uniquely and highly expressed in mouse and human primary alveolar and bone marrow derived macrophages, increased during monocyte-to-macrophage differentiation and regulated the expression of select cytokines including IL-6 and CXCL1 during inflammation. These studies indicated that Zcchc6 was required for the development of immunocompetent macrophages and calibrated macrophage-mediated innate immune responses in the airspaces. Taken together, these data provide evidence of independent and overlapping roles for TUT proteins in diverse physiological systems in living animal models.

O objetivo do presente estudo foi avaliar os níveis das metaloproteinases da matriz MMP-9, MMP-3 e MMP-13, e das quimiocinas MCP-1, MIP-1&#946; e RANTES, no fluido gengival de dentes sob força ortodôntica. Foram recrutados 14 pacientes (3 homens e 11 mulheres) que foram submetidos à movimentação ortodôntica dos caninos superiores. Amostras do fluido gengival foram coletadas com tiras de Periopaper em diferentes tempos. O volume do FG foi determinado com o uso do Periotron e os niveis das MMPs e das quimiocinas quantificados usando-se uma multianálise imunoenzimática com microesferas. Os resultados mostraram que existe um aumento significativo no volume do FG na área de pressão em quase todos os tempos analisados, quando comparados às áreas de tensão. Os níveis da MMP-9 foram muito superiores aos das MMP-13 e MMP-3. Na análise da evolução do tempo pode ser observada uma alteração significativa nos níveis da quantidade total de MMP-9, MMP-13 e MMP-3 e na concentração de MMP-13 e MMP-3 durante o período de movimentação dentária no lado de pressão. A elevação dos níveis de expressão destas MMPs 1 hora após a aplicação da força ortodôntica sugere que estas enzimas estejam envolvidas na remodelação periodontal induzida. As quimiocinas MCP-1, MIP-1&#946; e RANTES foram detectadas no sulco gengival em todos os diferentes intervalos de tempo analisados, nas áreas de tensão e de pressão. Porém, diversas amostras estavam abaixo do nível de detecção do ensaio e, os níveis dessas quimiocinas no fluido gengival não parecem ser alterados pelas forças ortodônticas. / The goal of the present study was to evaluate the levels of the matrix metalloproteinases MMP-9, MMP-3 and MMP-13 and of the chemokines MCP-1, MIP-1&#946; and RANTES in the gingival crevicular fluid of teeth under orthodontic forces. Fourteen subjects (3 males and 11 females) were enrolled and subjected to orthodontic tooth movement of their maxillary canines. Samples of gingival crevicular fluid were collected from both tension and pressure sides using Periopaper strips at different time points. The volume of GCF was determined using a Periotron and the levels of MMPs and chemokines quantified using a multiplex microbead immunoassay. The results demonstrated that the levels of MMP-9 were higher than the levels of MMP-13 and MMP-3. Statistically significant fluctuations during the orthodontic tooth movement could be detected for the total amount of MMP-9, MMP-13 and MMP-3 and for the concentration of MMP-13 and MMP-3 at the pressure side. The elevation in the levels of these MMPs, 1 hour after the application of the orthodontic force, suggests that these enzymes are involved in the induced periodontal remodeling. The chemokines MCP-1, MIP-1&#946; and RANTES were detected in the GCF in both tension and pressure sides at different time points. However, several samples were below the level of detection of the assay and the levels of theses mediators in GCF did not seem to be altered by the orthodontic forces.

Made available in DSpace on 2016-04-01T17:55:12Z (GMT). No. of bitstreams: 0 Previous issue date: 2015-12-01. Added 1 bitstream(s) on 2016-04-01T18:01:07Z : No. of bitstreams: 1 000860846.pdf: 837516 bytes, checksum: 02cdd507d97224a5f320a426addd6cc9 (MD5) / Hamamelis virginiana L. é uma planta nativa dos Estados Unidos da América que foi inserida no Brasil por conta de suas vastas atividades biológicas, como ação antimicrobiana e anti-inflamatória. As pesquisas com extratos desse vegetal são vastas, embora não haja estudos com extrato glicólico da mesma. O objetivo do presente trabalho foi avaliar a atividade antimicrobiana e anti-inflamatória do extrato glicólico de Hamamelis virginiana L. sobre cepas padrão de leveduras do gênero Candida (Candida albicans, C. dubliniensis, C. glabrata, C. guilliermondii, C. krusei e C. tropicalis), espécies de bactérias Gram-positivas (Enterococcus faecalis Staphylococcus aureus e Streptococcus mutans) e Gram-negativas (Acinetobacter baumanii, Escherichia coli, Klebsiella pneumoniae), nas fases planctônica e biofilme; além de avaliar a citotoxicidade e atividade anti-inflamatória. A atividade antimicrobiana foi realizada por teste de microdiluição em caldo para a determinação da Concentração Inibitória Mínima (CIM) e Concentração Microbicida Mínima (CMM), sendo os resultados utilizados como parâmetro para análise em biofilmes monotípicos. A atividade citotóxica foi analisada pelo teste MTT e quantificação da produção das citocinas interleucina-1β (IL-1β) e fator de necrose tumoral alfa (TNF-α) por ELISA, sendo a avaliação da atividade anti-inflamatória realizada por meio de exposição da cultura de macrófagos de camundongo (RAW 264.7) a lipopolissacarídeo (LPS) de E. coli seguido por tratamento com o extrato de H. virginiana L. Os resultados que apresentaram distribuição normal foram analisados por ANOVA e teste Tukey (p≤ 0,05); já os sem distribuição normal foram analisados por Kruskal-Wallis e pós teste Dunns. Os resultados obtidos revelam que o extrato glicólico de Hamamelis virginiana L. proporcionou atividade antimicrobiana sobre os micro-organismos testados no presente estudo e o teste de citoxicidade.... / Hamamelis virginiana L. is a North American plant that was insert in Brasil because their biological activities, like antimicrobial and anti-inflamatory activities. Large researchs are development with H. virginiana L. extracts, although there are no studies with glycolic extract from it. The objective of this work was to evaluate the antimicrobial and anti-inflammatory activity of glycolic extract of Hamamelis virginiana L. over standard strains of genus Candida yeast (C. albicans, C. dubliniensis, C. glabrata, C. guilliermondii, C. krusei e C. tropicalis), species of Gram-positive bacteria (Enterococcus faecalis, Staphylococcus aureus e Streptococcus mutans) and Gram-negative (Acinetobacter baumanii, Escherichia coli, Klebsiella pneumoniae), in plankton communities and biofilm; besides the cytotoxicity and anti-inflammatory. The antimicrobial activity was performed by microdiluition test in broth for determining the Minimum Inhibitory Concentration (MIC) e Minimum Microbicide Concentration (MMC), and the results used for antimicrobial analysis in biofilms monotypic. The cytotoxic activity was analyzed by the MTT test and quantification of production of the cytokines IL-β 1 and TNF-α by ELISA., being that the anti-inflamatory activity was performed with exposition of macrophages mouse culture to E. coli lipopolissacaride (LPS) and extract post-treatment. The results were analyzed by ANOVA and Tukey Test (p ≤ 0.05) if the results present normal distribuition; and Kruskal Wallis and post-test Dunn if the results don't presente normal distribuition (p ≤ 0.05). Results shows that the H. virginiana L. glycolic extract have antimicrobial activity about test micro-organisms and the cytotoxicity test shows high cellular viability or equal the control, except for the 100 mg/mL for 24 h contact time. Cytokines weren't produced by macrophages. Nitric oxide was produced by cells in a con...

Made available in DSpace on 2014-06-11T19:31:28Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-07-30Bitstream added on 2014-06-13T19:41:20Z : No. of bitstreams: 1 peresi_e_dr_botfm.pdf: 1052630 bytes, checksum: e59a57f6f635bf2f461011c84b7d7f71 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Universidade Estadual Paulista (UNESP) / It is estimated that one-third of the total world population is latently infected with M. tuberculosis and only 5-10% of the infected individuals will develop active TB disease during their life-time. The reason why some infected individuals develop active disease, while others do not is not yet entirely understood. Given the central role of TLR-2 in the incitement of inflammation, polymorphisms in its gene might be involved in both infectious and inflammatory diseases. The aim of this study was to evaluate the influence of TLR2 - 16934A/T and GT repeat polymorphisms on the immune response of PTB patients undergoing anti-TB treatment at different time points of anti-tuberculosis treatment: T1 (beginning), T2 (3 months) and T3 (end). For this we genotyped TLR2 -16934 and (GT)n repeats polymorphisms and evaluated the immune response of pulmonary tuberculosis patients during the time of anti-tuberculosis treatment. The present study suggests that TLR2 - 16934A/T and GT repeats polymorphisms can influence differential TLR-2, NF-κB and cytokine levels during anti-TB treatment. We also suggest that PTB patients with TLR2 - 16934 AA genotype may have a worst outcome of the disease, since they have a lower IFN-γ, cytokine essential to initiate the protective immunity to active TB. This association could not be made in our study due to the low number of patients evaluated. Since TLR-2 play a major role in initiating immune response against M. tuberculosis other polymorphisms in TLR2 would be crucial to better understand protective immune responses and may serve as biomarkers of protection or susceptibility to TB