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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
331

Villitis of Unknown Etiology (VUE) : unravelling placental dysfunction and causes of stillbirth and fetal growth restriction

Derricott, Hayley January 2016 (has links)
Many researchers in the academic and clinical communities theorise that inflammation may underpin the placental dysfunction to which the majority of fetal growth restriction (FGR) and stillbirth cases are attributed. Villitis of unknown etiology (VUE) is an inflammatory condition of the placenta characterised by lesions of macrophages and T cells in the villous stroma. This study addressed the hypothesis that VUE is a maternal-mediated immune reaction that contributes to FGR and stillbirth by detrimentally affecting placental function. The hypothesis was tested by: 1) completing a systematic review of the literature to confirm implied links of VUE to poor pregnancy outcome, 2) performing a detailed characterisation of the cellular phenotype of VUE in stillbirth, 3) developing an in vitro model of VUE and 4) examining the functional effects of VUE using this model. A systematic review of the literature revealed that VUE occurred in 28.6% of placentas from FGR pregnancies compared to 15.6% of placentas from appropriately grown infants (p < 0.0001), confirming the implied association. There were insufficient published studies to be able to corroborate a link with stillbirth. Elevated numbers of macrophages, CD4 and CD8 T cells were quantified in VUE lesions. There were significant increases in pan-placental CD4 and CD8 T cell presence in placentas from stillborn infants with VUE (p < 0.0001). A greater staining area of pro-inflammatory cytokines interleukin (IL)-2 (p < 0.05) and IL-12 (p < 0.0001) was recorded in VUE lesions and a reduction in the anti-inflammatory cytokine IL-4 in the stillbirth with VUE cohort. Dual immunofluorescence of cell markers and cytokines implies that the immune response in VUE is directed towards Th1-type cell-mediated immunity. An in vitro model of VUE was developed that enabled co-culture of explants with fluorescently labelled T cells isolated from matched maternal whole blood samples. Placental tissue and T cells could be maintained in culture for the required duration of the experiment and placental function was not affected by preparation and culture conditions. In vitro co-culture with maternal T cells resulted in a significant reduction in placental function as measured by hCG secretion (p=0.015). There were significant increases in culture supernatant concentrations of IL-1β (p=0.008), IL-10 (p=0.02), interferon-γ (p=0.02) and IL-1Ra (p=0.05) and tissue lysate concentrations of IL-6 (p=0.008) and IL-1β (p=0.02). Culture of explants with a combination of IL-2, IL-12 and anti-IL-4 significantly reduced hCG secretion compared to control (p=0.03).These studies indicate that VUE involves a Th1-type immune response that may affect placental function, the impact of which might be impaired fetal growth that could contribute to stillbirth. The novel in vitro model facilitates future investigations into the pathophysiology of VUE.
332

The Effect of HIV-1 and Accessory Proteins on Monocyte Derived Dendritic Cell Maturation and Function

Fairman, Peter January 2013 (has links)
Dendritic cells (DCs) are specialized members of the innate immune system that are responsible for the initiation of primary adaptive immune responses whose purpose is to resolve infection and inflammation. During most viral infections, mature dendritic cells present critical viral antigens to naïve T-cells within secondary lymphoid organs, resulting in the generation of an antigen-specific adaptive immune response and clearance of the virus. During infection with HIV-1 however, the virus is not cleared and a chronic systemic infection develops characterized by immune dysfunction, CD4+ T-cell depletion, systemic inflammation, and opportunistic infections. A growing body of evidence indicates that HIV-1 subversion of DCs contributes to both HIV-1 pathologies and viral dissemination. A number of similar effects by accessory HIV-1 peptides on DC physiology have also been reported. In vitro studies demonstrate that HIV-1 inhibits DC maturation and function. Ex vivo studies on the other hand describe partially mature, dysfunctional DCs collecting in secondary lymphoid organs. In vitro studies examining the effects of HIV-1-Tat and HIV-1-Vpr have described opposing effects on DC maturation. Therefore we undertook experiments to comprehensively describe the effects of HIV-1 and the Tat and Vpr accessory peptides on DC maturation and function. To understand the contributions of individual viral proteins to DC dysfunction we infected DCs with a dual tropic HIV-1 and examined phenotypic and functional changes after maturation with inflammatory cytokines. Following this we examined the influence of exogenous and endogenous HIV-1-Tat and HIV-1-Vpr on MDDC maturation and function using recombinant proteins and deletion mutant lab adapted HIV-1 strains. Live dual tropic HIV-1 was found to selectively inhibit aspects of phenotypic maturation as well as antigen capture and presentation functions. MDDC MAPK responsiveness to bacterial LPS remained intact however. Exogenous accessory HIV-1 Tat and Vpr did not affect MDDC phenotype but inhibited dextran endocytosis and viral peptide presentation. HIV-1-gp120 increased iMDDC maturation while blunting cytokine induced decreases in MDDC antigen capture abilities. The deletion of HIV-1-Tat did not affect MDDC phenotype, but was found to affect antigen capture decreases by R5 tropic HIV-1BaL. Deletion of HIV-1-Vpr likewise did not affect MDDC phenotype, however it was found to be influential in HIV-1 induced decreases in MDDC antigen presentation to autologous T-cells. These accumulated results indicate that HIV-1 subverts DC maturation and function through whole virus effects and individual accessory peptide influences. Understanding the mechanisms of DC dysfunction in HIV infection may provide some insight into infection prevention strategies and therapies leading to adaptive immune system activation and viral clearance.
333

Development of Vesiculovirus-based Therapeutics for Acute Leukemia

Conrad, David Paul January 2014 (has links)
Outcomes for most patients with acute leukemia remain dismal. In-vitro, vesiculovirus members induced rapid apoptosis of acute leukemia cells. Intravenous injection of lymphoblastic leukemia cells infected ex-vivo with attenuated Vesicular Stomatitis Virus or Maraba Virus followed by gamma-irradiation, controlled leukemic progression in murine recipients. Essential properties of this autologous vaccine [immunotherapy by Leukemia-Oncotropic Virus (iLOV)] and the host’s immune system were characterized. iLOV durability was restricted to the leukemia used to manufacture the vaccine. At administration, virion cell-entry was required but vesiculovirus lifecycle completion was not essential. Apoptotic or necrotic leukemia cells, with/without co-injection of virus, were ineffective vaccines. Similarly ineffective were leukemia cells activated by, or injected with, Toll-like receptor agonists. Naïve recipients of adoptive splenocyte transfer from vaccine-treated immunocompetent donors were protected from leukemic challenge. Efficacy was notably diminished following matched allogeneic bone marrow transplantation; this correlated with isolated depletion of cytotoxic T-cells. iLOV was ineffective in athymic mice. Taken together, iLOV therapy relies on immediate spaciotemporal interactions between infected-dead/dying leukemia cells and the immune system; this promotes adaptive anti-tumor responses. Clinical translation could target patients in remission to control relapse. During the above I discovered that under specific conditions, live vesiculovirus exposed to a precise window of UV fluence reproducibly generates unique “non-replicating rhabdovirus-derived particles” (NRRPs) that maintain cell-entry and cytopathic properties. A gamut of leukemia cells, including multidrug-resistant blasts, underwent rapid NRRPs-induced apoptosis. Normal cell lines and healthy bone marrow mononuclear cells were resistant, in part through interferon-mediated signaling responses. Administering NRRPs intravenously was curative in a murine acute leukemia model, versus uniform disease progression using maximal tolerated dose of replicating virus. Serum levels of an array of immunomodulatory cytokines were significantly elevated after injection of NRRPs. iLOV prepared with NRRPs protected recipients from otherwise lethal leukemia. Intracranial administration of NRRPs proved nonlethal as opposed to neurotoxic live vesiculovirus. Following treatment, neutralizing antibodies were diminished with NRRPs compared to replicating virus. Together, NRRPs exhibit enhanced therapeutic index over replication-competent vesiculovirus. Leukemocidal activity of NRRPs is exerted through a plurality of immune-related and direct cytotoxic effects. This novel approach now extends vesiculovirus-based therapeutics into upfront treatment for acute leukemia.
334

Multiplex immunoassay characterization and species comparison of inflammation in acute and non-acute ischemic infarcts in human and mouse brain tissue

Nguyen, Thuy-Vi V., Frye, Jennifer B., Zbesko, Jacob C., Stepanovic, Kristina, Hayes, Megan, Urzua, Alex, Serrano, Geidy, Beach, Thomas G., Doyle, Kristian P. 06 September 2016 (has links)
This study provides a parallel characterization of the cytokine and chemokine response to stroke in the human and mouse brain at different stages of infarct resolution. The study goal was to address the hypothesis that chronic inflammation may contribute to stroke-related dementia. We used C57BL/6 and BALB/c mice to control for strain related differences in the mouse immune response. Our data indicate that in both mouse strains, and humans, there is increased granulocyte macrophage colony-stimulating factor (GM-CSF), interleukin-6 (IL-6), interleukin-12 p70 (IL-12p70), interferon gamma-induced protein-10 (IP-10), keratinocyte chemoattractant/interleukin-8 (KC/IL-8), monocyte chemoattractant protein-1 (MCP-1), macrophage inflammatory protein-1 alpha (MIP-1 alpha), macrophage inflammatory protein-1 beta (MIP-1 beta), regulated on activation, normal T cell expressed and secreted (RANTES), and Tumor necrosis factor-alpha (TNF-alpha) in the infarct core during the acute time period. Nevertheless, correlation and two-way ANOVA analyses reveal that despite this substantial overlap between species, there are still significant differences, particularly in the regulation of granulocyte colony-stimulating factor (G-CSF), which is increased in mice but not in humans. In the weeks after stroke, during the stage of liquefactive necrosis, there is significant resolution of the inflammatory response to stroke within the infarct. However, CD68+ macrophages remain present, and levels of IL-6 and MCP-1 remain chronically elevated in infarcts from both mice and humans. Furthermore, there is a chronic T cell response within the infarct in both species. This response is differentially polarized towards a T helper 1 (Th1) response in C57BL/6 mice, and a T helper 2 (Th2) response in BALB/c mice, suggesting that the chronic inflammatory response to stroke may follow a different trajectory in different patients. To control for the fact that the average age of the patients used in this study was 80 years, they were of both sexes, and many had suffered from multiple strokes, we also present findings that reveal how the chronic inflammatory response to stroke is impacted by age, sex, and multiple strokes in mice. Our data indicate that the chronic cytokine and chemokine response to stroke is not substantially altered in 18-month old compared to 3-month old C57BL/6 mice, although T cell infiltration is attenuated. We found a significant correlation in the chronic cytokine response to stroke in males and females. However, the chronic cytokine response to stroke was mildly exacerbated by a recurrent stroke in both C57BL/6 and BALB/c mice.
335

Avaliação dos efeitos da leptina em celulas esplenicas de camundongos nod (diabetico não obeso) e balb-c. estudos da influencia da pre estimulação com adjuvante completo de freund

Gontijo, Bruna Aguiar 31 August 2005 (has links)
Orientador: Ricardo de Lima Zollner / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciencias Medicas / Made available in DSpace on 2018-08-07T21:49:59Z (GMT). No. of bitstreams: 1 Gontijo_BrunaAguiar_M.pdf: 901672 bytes, checksum: 6bc049b20d4924d05f816322f4e366f8 (MD5) Previous issue date: 2005 / Resumo: A Leptina é um hormônio produzido principalmente pelo tecido adiposo, estudos sugerem sua relação com o aumento do processo inflamatório observado no diabetes mellitus tipo 1 (DM-1) em camundongos NOD (diabético não obeso), modelo experimental desta doença. Neste estudo, analisou-se o efeito da leptina sobre a viabilidade das células em cultura e na expressão de citocinas pro-inflamatórias (TNFa, IFN?, IL1ß, IL-12 e IL-2) por RT-PCR. Além disso, analisou-se a resposta induzida pela leptina em cultura de células esplênicas, após o estímulo in vivo com adjuvante Completo de Freund (CFA). Os resultados sugerem que a leptina modula a expressão de citocinas pro-inflamatórias, sendo esta modulação específica para cada citocina estudada, sem relação dose dependência, mas de acordo com a resposta imunológica desencadeada pelo efeito do CFA em camundongos NOD e Balb-C / Abstract: Leptin is a hormone produced mainly by the adipocites, studies suggest that can be related with the inflammatory process in type 1 Diabetes (IDDM) observed in NOD mice (diabetic non-obese), a classic experimental model of autoimmune diabetes. In this study, we analyze the leptin effect on cell culture viability and pro-inflammatory cytokines expression in NOD and BALB-C mice spleen cells. The spleen cells were cultivated 24, 48 and 72 hours with different leptin concentrations and the pro-inflammatory cytokines expression (TNFa, IFN?, IL1ß, IL-2, IL-12) were addressed by RT-PCR. Furthermore, we studied the leptin-induced spleen cell response in culture, after in vivo Complete Freund Adjuvant (CFA) stimulation. Our results suggest that leptin can modulates the proinflammatory cytokines expression without relation to dependent on the dose but in accordance with the status of immune response promoted by CFA effect in Balb-C and NOD mice / Mestrado / Ciencias Basicas / Mestre em Clinica Medica
336

Avaliação do efeito de fitocistatinas sobre a expresão génica de catepsinas e citocinas pró-inflamatórias em células raw 264.7 de camundongos e sobre a produção de tnf-a em ratos /

Da Ponte Leguizamón, Natalia January 2017 (has links)
Orientador: Joni Augusto Cirelli / Resumo: As cisteíno-peptidases e as citocinas desempenham um papel importante no inicio e progressão dos processos imuno-inflamatórios, dentre estes, a doença periodontal. As fitocistatinas são cistatinas derivadas das plantas, inibidoras naturais das cisteíno- peptidases. Entre elas a Citrus CPI-2, derivada da laranja e a Cane CPI-4, derivada da cana-de-açúcar tem sido recentemente investigadas. O estudo das mesmas pode levar a novas terapias para o controle da doença periodontal, bem como outras doenças imuno- inflamatórias. O objetivo do presente estudo foi avaliar o efeito inibitório das fitocistatinas (Cane CPI-4 e Citrus CPI-2) sobre mediadores da inflamação. Em estudo in vitro, foi avaliado o efeito da atividade inibitória das fitocistatinas sobre a expressão gênica (RT-PCR em tempo real) das catepsinas B e K e citocinas pró-inflamatórias (IL- 1β, IL-6 e TNF-α) em células de linhagem macrofágica de camundongos (RAW 264.7), após 12 e 24h de estímulo com Porphyromonas gingivalis inativada por calor. Em estudo in vivo, foi avaliada a ação de diferentes concentrações das fitocistatinas sobre a produção de TNF- a por células sanguíneas de ratos submetidos à injeção de LPS de E.coli . Todos os animais foram submetidos à implementação de cânulas na veia femoral para à injeção de LPS de E.coli e na artéria femoral para a extração de sangue em 6 diferentes tempos (de 30 a 180 minutos) após o estimulo com LPS de E.coli (IV, 100 Ug/Kg). A quan... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The cysteine proteinases and the cytokines play an important role in the initiation and progression of immune-inflammatory processes such as periodontal disease. The phytocystatins are cystatins derived from plants and they are natural inhibitors of cysteine proteinases. Among them, the Citrus CPI-2 derived from orange and Cane CPI- 4 derived from sugar cane have been investigated. The study of them may lead to new therapies for the control of periodontal disease and other immune inflammatory diseases. The overall objective of this study was to evaluate the effect of phytocystatins CaneCPI- 4 and CitrusCPI-2 on mediators of inflammation. The aim of the in vitro study was to assess the inhibitory activity of phytocystatins on gene expression (RT-PCR) of cathepsins B and K and pro-inflammatory cytokines (IL- 1β and IL-6 and TNF-α) in murine macrophage cells (RAW 264.7) after 12 and 24 hours of stimulation with heatinactivated bacteria Porphyromonas gingivalis. The aim of the in vivo study was to assess the inhibitory activity of both phytocystatins in the production of TNF-α by blood cells of rats submitted by an injection of lipopolysaccharide (LPS) of E.coli. All animals were subjected to the implementation of cannulas to femoral artery and vein for blood collection at 6 different time points (from 30 to 180 minutes) after LPS stimulus (IV, 100 ug/kg). Quantification of TNF-α was performed by ELISA. According to the results of the in vitro study, Citrus CPI-2 showed a signifi... (Complete abstract click electronic access below) / Mestre
337

The Gut Microbiome and Inflammation in Autism Spectrum Disorder

Parkinson, Sarah M., Beasley, Brooke, Chandley, Michelle 12 April 2019 (has links)
Autism spectrum disorder is a neurodevelopmental disorder marked by social deficits, obsessive behavior, and repetitive actions. It has been shown that there is a communication pathway between the brain and gut called the gut-brain axis. Communication is thought to occur between the bacterial collections known as the microbiota in the gut and the resident immune cells in the brain, microglia. It has been postulated that bacteria in the gut are capable of secreting signaling molecules that can induce increases in pro-inflammatory cytokines. Specific cytokines such as IL-1B and IL-17 will elicit microglia activation and will likely result in alterations in neurotransmission in the brain. The activation or prohibition of maturation of microglia can lead to severe developmental delays. Four animal models will be used for this experiment. C57 will be the control or wildtype model; valproic acid is an anti-seizure medication that will be given to pregnant mice to see effects on offspring. BTBR is the third model, which has been genetically bred to have a thinned corpus callosum. The last model is poly IC, which is a virus that will be injected into mothers. Brain tissue, blood, and fecal samples were collected from animals for each model 21 days after birth. An intense brain developmental procedure known as pruning is occurring at postnatal day 21 that would correlate with the pruning age of a young human child. Pruning is thought to be greatly influenced by immune activation. Immunohistochemistry for the microglial marker IBA-1 (N=4) and peripheral blood analysis for six cytokines (N=5) has been performed in male animals from the four groups. It is hypothesized that there will be an increase in pro-inflammatory cytokines in the blood and microglial activation in the brain. These studies are instrumental in the creation of future mechanistic strategies that may illuminate treatable signaling pathways for ASD.
338

Association between coagulation factor levels, cytokine profiles, clinical manifestations and genotypic features in factor X deficiency

Thwala, Cyprian Mcwayizeni 25 March 2011 (has links)
MSc (Med), Molecular Medicine and Haematology, Faculty of Health Sciences, University of the Witwatersrand / Factor X deficiency is a rare bleeding disorder with an incidence of one in a million in the general population. Patients with the severe form of factor X deficiency suffer from serious bleeds occurring mainly into the joints and the muscle. In the two factor X deficient families currently looked after at the Haemophilia Comprehensive Care Centre, there are definite differences in the bleeding tendencies between and within family members. We hypothesize the differences in genetic mutations and the influence of cytokines to be responsible for these bleeding variabilities. These factors were explored in our study. The study population included a total of fourteen members of the two families with factor X deficiency. Blood for factor X measurement, cytokine studies and genetic studies was collected in the Haemophilia Comprehensive Care Centre of the Charlotte Maxeke Johannesburg Academic Hospital. Each blood was processed according to the test to be performed. Factor X activity levels were measured using the factor X assay, and the information on each patient’s bleeding episodes was obtained from the Haemophiliac Clinic database. Cytokines were analyzed in all patients using the ELISA kits from Biosource. Factor X gene was amplified using PCR and sequenced with Spectrumedix SCE 2410. iv For cytokine studies, high levels of IL-1beta and TNF-alpha were observed in frequent bleeding patients compared to infrequent bleeders. These cytokines are known to be involved in acute inflammatory process leading to cellular infiltrate and joint swelling. This results in synovitis and the creation of massive joint bleeding. The low levels of IL-1beta and TNF-alpha detected in infrequent bleeding patients appear to be related to the high levels of IL-1Ra and IL-10. These anti-inflammatory cytokines are known to inhibit the inflammatory synovitis and lessen the severity of joint bleeding. For genetic studies, differences were observed between the amino acid sequence of the three frequent bleeding patients and the consensus. In addition, a novel mutation Cys350Phe was detected in two of these patients. This mutation is characterized by very low factor X levels which sometimes are not detectable in circulation. The substituted cystine is known to cause defect in the substrate binding, leading to the lost of enzyme activity. From these findings we have concluded that the origin of the heterogeneity of bleeding in factor X deficiency is multifactorial, cytokines and genetic mutations seems to have a role in determining the clinical manifestations of the factor X deficient patients.
339

Immunomodulatory Roles of CTRP3 in Endotoxemia and Metabolic Stress

Petersen, Pia S., Wolf, Risa M., Lei, Xia, Peterson, Jonathan M., Wong, G. William 01 March 2016 (has links)
C1q/TNF-related protein 3 (CTRP3) is a secreted hormone that modulates hepatic glucose and lipid metabolism. Its circulating levels are reduced in human and rodent models of obesity, a metabolic state accompanied by chronic low-grade inflammation. Recent studies have demonstrated an anti-inflammatory role for recombinant CTRP3 in attenuating LPS-induced systemic inflammation, and its deficiency markedly exacerbates inflammation in a mouse model of rheumatoid arthritis. We used genetic mouse models to explore the immunomodulatory function of CTRP3 in response to acute (LPS challenge) and chronic (high-fat diet) inflammatory stimuli. In a sublethal dose of LPS challenge, neither CTRP3 deficiency nor its overexpression in transgenic mice had an impact on IL-1β, IL-6, TNF-α, or MIP-2 induction at the serum protein or mRNA levels, contrary to previous findings based on recombinant CTRP3 administration. In a metabolic context, we measured 71 serum cytokine levels in wild-type and CTRP3 transgenic mice fed a high-fat diet or a matched control low-fat diet. On a low-fat diet, CTRP3 transgenic mice had elevated circulating levels of multiple chemokines (CCL11, CXCL9, CXCL10, CCL17, CX3CL1, CCL22 and sCD30). However, when obesity was induced with a high-fat diet, CTRP3 transgenic mice had lower circulating levels of IL-5, TNF-α, sVEGF2, and sVEGFR3, and a higher level of soluble gp130. Contingent upon the metabolic state, CTRP3 overexpression altered chemokine levels in lean mice, and attenuated systemic inflammation in the setting of obesity and insulin resistance. These results highlight a context-dependent immunomodulatory role for CTRP3.
340

Relationship between Inflammatory Stimulation and Cell Biomechanics in Intervertebral Disc Degeneration

Jacobsen, Timothy January 2022 (has links)
Intervertebral disc (IVD) degeneration (DD) affects over 40% of adults, is a leading cause of disability and costs over $100 billion in economic burden annually. DD is a multifactorial process ultimately leading to tissue breakdown and loss of functionality. DD is associated with increased levels of pro-inflammatory cytokines within the disc and the catabolic effect of inflammatory stimulation on disc cell biology has been well studied. As part of its physiological functioning the disc experiences mechanical, hydrostatic, and osmotic stimuli. Cells within the disc are mechanosensitive to these signals, where hyper physiological and damaging physical signals can perpetuate degenerative effects in the disc. Despite the known contributions of inflammatory stimulation and biomechanics to DD individually, the interaction of inflammation and biomechanics in the IVD is still not well understood. The objective of this thesis is to examine the role of inflammatory stimulation on cellular biophysical properties in the disc, subsequent implications at the tissue level, and its contributions to DD. Here the cell cytoskeleton and actomyosin contractility are identified as key regulators of the response of cellular properties to inflammation. Actomyosin contractility is further identified as a regulator of well-known biological responses to inflammatory stimulation within the disc including ECM catabolism and altered disc tissue mechanics. Altered cellular biophysical properties observed in clinical human DD samples indicate the inflammatory milieu present in DD drive changes in cellular mechanics. Increasing actomyosin contractility is shown to be effective in mitigating the effects of inflammation on cellular biophysical properties and subsequent degenerative effects highlighting its potential as a therapeutic for the treatment of DD.

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