• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 87
  • 68
  • 23
  • 10
  • 10
  • 10
  • 7
  • 5
  • 3
  • 3
  • 3
  • 3
  • 3
  • 3
  • 3
  • Tagged with
  • 241
  • 241
  • 152
  • 71
  • 68
  • 62
  • 57
  • 54
  • 46
  • 39
  • 32
  • 30
  • 30
  • 29
  • 28
  • 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.
191

Studie av celltillväxt hos kondrocyter och mesenkymala stromaceller från benmärg- en utvärdering av optimala odlingsförhållanden / Study of cell growth in chondrocytes and mesenchymal stroma cells from bone marrow - an evaluation of optimal culture conditions

Emilsson, Sara January 2023 (has links)
Introduktion: Hyalint brosk består av kondrocyter inbäddade i ett extracellulärt matrix som täcker alla kroppens synoviala leder. I dag är skador på hyalint brosk ett folkhälsoproblem med begränsade behandlingsmöjligheter. Mesenkymala stamceller har i flertalet studier visat sig vara en lovande kandidat för framtida behandling av broskskador, eftersom dessa kan differentiera till broskproducerande kondrocyter. Modern behandling av broskskador innefattar odling av patientens egna kondrocyter eller stamceller för att sedan återföra dem till broskskadan. För att göra detta effektivt behöver optimering av odlingsförhållanden för aktuella celler utföras. Syfte: Att undersöka tillväxt hos kondrocyter samt mesenkymala stromaceller från benmärg i varierande odlingsförhållanden, detta med avseende att utvärdera vilka tillsatser som mest gynnar cellernas viabilitet och proliferation. Material & Metod: Framtagning av kondrocyter och mesenkymala stromaceller från benmärg i denna studie utfördes på överblivet ortopediskt material från en individ. Cellerna kollagenasbehandlades innan de odlades ut i ett standardmedium under tre veckor. Därefter odlades de i närvaro av olika tillsatser under sex dagar. Cellernas viabilitet mättes genom relativ fluorescens med CellTiter-Blue® reagens medan proliferationen mättes genom cellräkning med flödescytometri. Resultat: Det fanns en signifikant skillnad (ANOVA, p<0,05) mellan minst två tillsatser inom grupperna för viabilitetsanalys samt cellräkning för både kondrocyter och benmärgderiverade mesenkymala stromaceller (BMMSC). Kondrocyterna som odlades i närvaro av fetalt bovint serum (FBS) hade högre proliferation och viabilitet än de celler som odlades i frånvaro av FBS. FBS i kombination med insulin-transferrin-selen (ITS) och kondrocytfaktorerna (KF) dexametason, prolin, insulin samt transforming growth factor beta hade störst positiv effekt på proliferationen. Vidare visade Minimum Essential Medium α med tillsats av FBS 10 % ha störst effekt, av den panel som undersöktes, på både viabilitet och proliferation hos BMMSC. Slutsats: FBS i kombination med ITS och KF hade störst stimulerande effekt på proliferation hos kondrocyter. Val av standardmedium hade större betydelse än tillsats av faktorer vid odling av BMMSC in vitro. / Introduction: Articular cartilage consists of chondrocytes and covers all the synovial joints in the body. Articular cartilage injuries are today a public health issue with limited orthopedic treatments. Mesenchymal stem cells have shown to be a promising candidate for future treatment of articular cartilage injuries due to their many abilities. Modern treatment of cartilage damage involves cultivation of the patient´s own chondrocytes and stem cells. To make this treatment as effective as possible the culture conditions for chondrocytes and stem cells must be optimized. Aim: To study cell growth in chondrocytes and mesenchymal stromal cells from bone marrow in varying culture conditions, this regarding to evaluate the most optimal culture conditions for cell viability and proliferation. Method: Cell extraction in this study was performed on leftover orthopedic material. The cells were treated with collagenase and then cultured in a standard medium for three weeks before they were cultured in presence of various factors for six days. Cell viability was measured by relative fluorescence while proliferation was measured by cell counting. Result: There was a statistically significant difference (ANOVA, p<0,05) between at least two additives within the groups for viability analysis and cell count for both chondrocytes and bone marrow-derived mesenchymal stromal cells (BMMSC). The chondrocytes cultured in presence of fetal bovine serum (FBS) had a higher proliferation and viability compared to the cells cultured in the absence of FBS. FBS in combination with insulin-transferrin-selenium (ITS) and the chondrocyte factors (CF) dexamethasone, proline, insulin and transforming growth factor beta had the biggest impact on proliferation. Minimum Essential Medium α with FBS 10% additive showed positive effects on both viability and proliferation of BMMSCs. Conclusion: FBS in combination with ITS and CF had a good effect on the proliferation of chondrocytes. The choice of standard medium seems to have a more important role than growth factor additive when studying BMMSCs expansion in vitro.
192

Bone marrow mesenchymal stromal cell-derived extracellular matrix displays altered glycosaminoglycan structure and impaired functionality in Myelodysplastic Syndromes

Kaur Bains, Amanpreet, Behrens Wu, Lena, Rivière, Jennifer, Rother, Sandra, Magno, Valentina, Friedrich, Jens, Werner, Carsten, Bornhäuser, Martin, Götze, Katharina S., Cross, Michael, Platzbecker, Uwe, Wobus, Manja 22 February 2024 (has links)
Myelodysplastic syndromes (MDS) comprise a heterogeneous group of hematologic malignancies characterized by clonal hematopoiesis, one or more cytopenias such as anemia, neutropenia, or thrombocytopenia, abnormal cellular maturation, and a high risk of progression to acute myeloid leukemia. The bone marrow microenvironment (BMME) in general and mesenchymal stromal cells (MSCs) in particular contribute to both the initiation and progression of MDS. However, little is known about the role of MSC-derived extracellular matrix (ECM) in this context. Therefore, we performed a comparative analysis of in vitro deposited MSC-derived ECM of different MDS subtypes and healthy controls. Atomic force microscopy analyses demonstrated that MDS ECM was significantly thicker and more compliant than those from healthy MSCs. Scanning electron microscopy showed a dense meshwork of fibrillar bundles connected by numerous smaller structures that span the distance between fibers in MDS ECM. Glycosaminoglycan (GAG) structures were detectable at high abundance in MDS ECM as white, sponge-like arrays on top of the fibrillar network. Quantification by Blyscan assay confirmed these observations, with higher concentrations of sulfated GAGs in MDS ECM. Fluorescent lectin staining with wheat germ agglutinin and peanut agglutinin demonstrated increased deposition of N-acetyl-glucosamine GAGs (hyaluronan (HA) and heparan sulfate) in low risk (LR) MDS ECM. Differential expression of N-acetyl-galactosamine GAGs (chondroitin sulfate, dermatan sulfate) was observed between LR- and high risk (HR)-MDS. Moreover, increased amounts of HA in the matrix of MSCs from LR-MDS patients were found to correlate with enhanced HA synthase 1 mRNA expression in these cells. Stimulation of mononuclear cells from healthy donors with low molecular weight HA resulted in an increased expression of various pro-inflammatory cytokines suggesting a contribution of the ECM to the inflammatory BMME typical of LR-MDS. CD34+ hematopoietic stem and progenitor cells (HSPCs) displayed an impaired differentiation potential after cultivation on MDS ECM and modified morphology accompanied by decreased integrin expression which mediate cell-matrix interaction. In summary, we provide evidence for structural alterations of the MSC-derived ECM in both LR- and HR-MDS. GAGs may play an important role in this remodeling processes during the malignant transformation which leads to the observed disturbance in the support of normal hematopoiesis.
193

Transforming Growth Factor Beta 3-Loaded Decellularized Equine Tendon Matrix for Orthopedic Tissue Engineering

Roth, Susanne Pauline, Brehm, Walter, Groß, Claudia, Scheibe, Patrick, Schubert, Susanna, Burk, Janina 09 February 2024 (has links)
Transforming growth factor beta 3 (TGF3) promotes tenogenic differentiation and may enhance tendon regeneration in vivo. This study aimed to apply TGF3 absorbed in decellularized equine superficial digital flexor tendon scaffolds, and to investigate the bioactivity of scaffold-associated TGF3 in an in vitro model. TGF3 could effectively be loaded onto tendon scaffolds so that at least 88% of the applied TGF3 were not detected in the rinsing fluid of the TGF3-loaded scaffolds. Equine adipose tissue-derived multipotent mesenchymal stromal cells (MSC) were then seeded on scaffolds loaded with 300 ng TGF3 to assess its bioactivity. Both scaffold-associated TGF3 and TGF3 dissolved in the cell culture medium, the latter serving as control group, promoted elongation of cell shapes and scaffold contraction (p < 0.05). Furthermore, scaffold-associated and dissolved TGF3 affected MSC musculoskeletal gene expression in a similar manner, with an upregulation of tenascin c and downregulation of other matrix molecules, most markedly decorin (p < 0.05). These results demonstrate that the bioactivity of scaold-associated TGF3 is preserved, thus TGF3 application via absorption in decellularized tendon scaffolds is a feasible approach.
194

A1-reprogrammed mesenchymal stromal cells as a therapeutic vaccine against solid tumors

Pereira Gonçalves, Marina 09 1900 (has links)
L'efficacité de la réponse antitumorale repose sur l'activité des cellules T cytotoxiques, qui peut être stimulée par des vaccins contenant des antigènes spécifiques aux tumeurs. Malgré le fait d'être les principales cellules présentatrices d'antigènes (CPA) responsables de l'activation des cellules TCD8, les cellules dendritiques (CD) ont rencontré des défis dans le développement de vaccins contre le cancer, notamment en ce qui concerne leur fabrication et efficacité. Pour combler ces problèmes, cette étude propose d’utiliser des cellules stromales mésenchymateuses (CSM) comme plateforme de vaccination alternative, en exploitant les avantages des CSMs en matière de fabrication, de sécurité et de plasticité. La plasticité remarquable des CSMs leur permet d'acquérir une capacité de présentation croisée sous des stimuli spécifiques. Étant donné que la présentation croisée est essentielle pour induire l'activation des cellules T contre les antigènes tumoraux, cette étude vise à convertir les CSMs en cellules présentatrice d‘antigènes en améliorant l'exportation des antigènes des endosomes vers le cytosol - une étape critique du processus. Dans cette démarche, nous avons examiné une librairie de molécules dérivés de l’Accum, une molécule initialement conçue pour favoriser la destruction de la membrane endosomale. Après avoir évalué leur potentiel à induire la présentation croisée, nous avons sélectionné la molécule A1 pour des investigations subséquentes. Les études mécanistiques ont démontré qu'A1 déclenchait des processus cellulaires essentiels favorisant une présentation croisée efficace, notamment une augmentation de la capture, dégradation et évasion des antigènes des endosomes ainsi que la production de d’espèces oxygénés réactifs. L'efficacité thérapeutique des CSMs reprogrammées par A1 (ARM) en tant que vaccin anticancéreux a été évaluée chez des souris ayant des tumeurs, en monothérapie et en combinaison avec l’anti-PD-1. La thérapie combinée ARM a induit une régression tumorale et a augmenté les taux de survie dans les modèles de tumeurs solides. En conclusion, cette étude présente une stratégie innovante pour transformer les CSM en cellules à présentation croisée en déclenchant l'échappement endosomal de l'antigène. Les cellules ARMs en association avec des inhibiteurs des points de contrôle immunitaire présentent un potentiel en tant que plateforme de vaccination contre les tumeurs solides. De plus, ces résultats soulignent l'importance de l'évasion des endosomes dans la présentation croisée d‘antigènes et ouvrent la voie à de nouvelles plateformes de vaccins contre le cancer. / The effectiveness of antitumoral response relies on cytotoxic T-cell activity, which can be stimulated through vaccines carrying tumor-specific antigens. Despite being the primary antigen-presenting cells (APCs) responsible for CD8 T-cell activation, dendritic cells (DCs) have encountered challenges in cancer vaccine development, particularly in manufacturing and efficiency. To address this gap, this study proposes mesenchymal stromal cells (MSCs) as an alternative vaccine platform, leveraging the advantages in manufacturing, safety profile, and plasticity of MSCs. The remarkable plasticity of MSCs enables them to acquire cross-presentation capacity under specific stimuli. Given that cross-presentation is pivotal for inducing T-cell activation against tumor antigens, this study aims to convert MSCs into antigen cross-presenting cells by enhancing the export of antigens from endosomes to the cytosol—a critical step in the process. In this pursuit, we screened a library of Accum and variant molecules designed to promote endosomal disruption. After evaluating their potential to induce cross-presentation, we selected the molecule A1 for further investigation. Mechanistic studies demonstrated that A1 triggers essential cellular processes supporting efficient cross-presentation, including enhanced antigen uptake, processing, endosomal escape, and reactive oxygen species production. The therapeutic efficacy of A1-reprogrammed MSCs (ARMs) as an anticancer vaccine was evaluated in tumor-bearing mice, as monotherapy and combined with anti-PD-1. In solid tumor models, ARMs combination therapy induced tumor regression and increased survival rates. In conclusion, this study presents an innovative strategy to transform MSCs into cross-presenting cells by triggering antigen endosomal escape. ARM cells in combination with immune checkpoint inhibitors hold potential as a vaccination platform against solid tumors. These findings underscore the importance of endosomal escape on antigen cross-presentation and pave the way for new cancer vaccine platforms.
195

Papel de Notch e NF-kB na regulação de fatores de transcrição durante a diferenciação in vitro de células T a partir de células progenitoras hematopoéticas CD34+ / Role of Notch and NF-kB in the regulation of transcription factors during in vitro differentiation of T cells from CD34+

Schiavinato, Josiane Lilian dos Santos 01 April 2011 (has links)
Em estudos anteriores desenvolvidos por este grupo de pesquisa uma expressão mais elevada de alvos transcricionais e componentes da via NF-kB, bem como altos níveis de NOTCH1, foi identificada em células-tronco hematopoéticas (CTH) CD34+ de sangue de cordão umbilical (SCU) quando comparadas às CTH CD34+ de medula óssea (MO). Este grupo verificou ainda, por comparação das células CD34+ com as CD133+ (mais primitivas) que diversos fatores de transcrição (FT) envolvidos com o potencial de hemangioblasto, com a autorenovação das CTH, e com a diferenciação linfóide; como: RUNX1/AML1, GATA3, USF1, TAL1/SCL, HOXA9 e HOXB4 apresentaram-se mais expressos em células mais primitivas. A potencial participação das vias Notch e NF-kB na regulação destes FT tem importância conceitual e prática no entendimento da biologia das CTH, e dos processos envolvidos na diferenciação destas células. Com isto em vista, este projeto teve como objetivo, estudar o papel da via NF-kB e da via Notch na regulação destes FT. Para isso, um modelo experimental in vitro, de diferenciação de CTH CD34+ em linfócitos T, foi utilizado e a influência de fatores agonistas e inibidores farmacológicos destas vias, foram avaliados por citometria de fluxo e PCR em tempo real. Nossos resultados evidenciam o papel da via Notch na regulação transcricional de HOXB4 e GATA3 em células-tronco hematopoéticas CD34+ humanas, o que foi confirmado com base na expressão dos alvos diretos de Notch (HEY1 e HES1). Notamos ainda, que a expressão dos transcritos HES1, GATA3 e HOXB4 é prejudicada pela síntese protéica das CTH, uma vez que quando empregamos o prétratamento com a droga CHX há aumento da transcrição dos mesmos. Também podemos inferir que a ação do TNF- é positiva sobre esses transcritos, já que quando o utilizamos há elevação do nível de expressão desses transcritos, com exceção a HES1. Em relação ao cocultivo das CTH com as células estromais de camundongos, verificamos que apenas a linhagem OP9-DL1 detém a capacidade de promover a diferenciação celular T, e isso foi comprovado pelo surgimento de células comprometidas com a linhagem linfocítica T, através da presença dos marcadores de superfície específico CD7+ e CD1a+. Esses resultados auxiliarão na compreensão dos mecanismos moleculares de regulação transcricional envolvidos não apenas na diferenciação de linfócitos T, mas também na manutenção de um estado mais primitivo das CTH. Este conhecimento pode vir a contribuir com o desenvolvimento ou otimização de protocolos laboratoriais visando à expansão de CTH ou geração de células T para usos terapêuticos. / In previous studies by this research group a higher expression of transcriptional targets and components via NF-kB, as well as high levels of NOTCH1, was identified in hematopoietic stem cells (HSC) CD34 + cells from umbilical cord blood (UCB) compared to CD34 + hematopoietic stem cells from bone marrow (BM). This group also found, by comparing the CD34 + cells with CD133 + (more primitive) that several transcription factors (TF) involved in the potential of hemangioblast, with self-renewal of hematopoietic stem cells and to differentiated lymphocytic; as Runx1 / AML1, GATA3, USF1, TAL1/SCL, HOXB4 and HOXA9 were more expressed in more primitive cells. The potential involvement of Notch signaling pathways and NF-kB in the regulation of FT has conceptual and practical importance in understanding the biology of HSC, and the processes involved in differentiation of these cells. With this in mind, this project aimed to study the role of NF-kB pathway and Notch signaling in the regulation of FT. For this, an experimental model in vitro differentiation of CD34 + hematopoietic stem cells into T lymphocytes, was used and the influence of pharmacological agonists and inhibitors of these pathways were evaluated by flow cytometry and real-time PCR. Our results highlight the role of Notch signaling in the transcriptional regulation of GATA3 and HOXB4 in hematopoietic stem cells CD34 + human, which was confirmed based on the expression of direct targets of Notch (HES1 and HEY1). We also note that the expression of transcripts HES1, GATA3 and HOXB4 protein synthesis is hampered by the HSC, since when we use the pre-treatment with the drug there CHX increased transcription thereof. We can also infer that the action of TNF- is positive about these transcripts, since when we use it for raising the level of expression of these transcripts, except the HES1. In relation to the HSC coculture with stromal cells of mice, we found that only the line-DL1 Op9 has the ability to promote T cell differentiation, and this was evidenced by the appearance of cells committed to the T lymphocyte lineage, through the presence of specific surface markers CD7 + and CD1a +. These results will help understand the molecular mechanisms of transcriptional regulation involved not only in the differentiation of T lymphocytes, but also in maintaining a more primitive state of HSC. This knowledge may contribute to the development or optimization of laboratory protocols aimed at the expansion of HSC or generation of T cells for therapeutic use.
196

Expressão gênica diferencial das células estromais obtidas de medula óssea na presença ou ausência de célula tumoral oculta em pacientes com câncer de mama / Differential gene expression of bone marrow stromal cells from breast cancer patients in the presence or abscence of occult tumor cells

Milani, Cintia 21 September 2006 (has links)
A célula estromal pode influenciar o desenvolvimento do tumor no sítio primário e secundário, mas pouco é conhecido sobre as características moleculares das células estromais presentes na medula óssea de pacientes com câncer de mama. Nosso objetivo foi avaliar a expressão gênica diferencial entre as células estromais oriundas de medula óssea na presença ou ausência de célula tumoral oculta. Coletamos dez aspirados de medula óssea das pacientes com câncer de mama. A classificação do comprometimento da medula por células tumorais ocultas foi realizada pela detecção da expressão de CK19 por Nested-RT-PCR e quatro entre dez pacientes apresentaram presença de célula tumoral na medula óssea. Estabelecemos culturas primárias de células estromais de todas as amostras e, selecionamos amostras originárias de duas pacientes contendo linfonodos comprometidos e presença de célula tumoral oculta em medula e também de duas pacientes que não apresentavam linfonodos comprometidos e nem célula tumoral oculta na medula. As pacientes selecionadas eram pós-menopausadas com diagnóstico de carcinoma ductal invasor e expressão imunohistoquímica positiva para receptor de estrógeno e progesterona. Realizamos avaliação do perfil de expressão gênica entre estes dois grupos, o que nos revelou 21 genes diferencialmente expressos dentre os 4.608 genes imobilizados em lâmina de cDNA microarray; nove genes hiperexpressos em célula estromal de medula comprometida (PTHLH, TLOC1, NCOA6, C17orf57, ANAPC11, MAST4, POLR3E, CPNE1 e B4GALT5) e doze genes hipoexpressos em célula estromal de medula comprometida (MRPL2, NAT10, DAP, RNF2, FLOT2, FKBP10, SLIT3, EBNA1BP2, SLC35B2, MICAL2, GPR3, TSPAN17). Nossos dados sugerem que apesar da expressão gênica de células estromais oriundas de medula óssea comprometida ou não por micrometástases ser semelhante, algumas diferenças podem ser identificadas. / Stromal cells may influence tumor development in primary and secundary sites, however, molecular characteristics of bone marrow stromal cells from breast cancer patients are almost unknown. Our aim was to evaluate the differential gene expression of bone marrow stromal cells from breast cancer patients in the presence or abscence of occult tumor cells. Bone marrow (BM) aspirates were obtained from 10 breast cancer patients. The presence of occult bone marrow disseminated tumor cells was detected by CK19 expression quantified by reverse transcriptase polymerase chain reaction (RT-PCR). Presence of tumoral cell was detected in four of ten BM samples. Stromal cells primary cultures were established and samples from two patients with positive lymph nodes and presence of occult tumor cells in bone marrow and samples from two patients with negative lymph nodes and abscence of occult tumor cells in bone marrow were selected. All the included patients were postmenopausal with invasive ductal carcinoma and positive estrogen and progesterone receptors detected by immunohistochemical analysis. Gene profile evaluated in cDNA microarray slides containing 4.608 spotted genes revealed 21 differencially expressed genes, nine upregulated (PTHLH, TLOC1, NCOA6, C17orf57, ANAPC11, MAST4, POLR3E, CPNE1 e B4GALT5) and twelve downregulated (MRPL2, NAT10, DAP, RNF2, FLOT2, FKBP10, SLIT3, EBNA1BP2, SLC35B2, MICAL2, GPR3, TSPAN17) in stromal cell derived from bone marrow in the presence of tumor breast cancer cell. Our data suggest that gene expression from bone marrow derived stromall cells in the presence or abscence of occult tumor cells seems similar, however small differences may be identified.
197

Impact of IL-7 signaling on adoptive T cell therapy

Deiser, Katrin 18 January 2016 (has links)
Das Zytokin Interleukin-7 (IL-7) ist für die Entstehung und das Überleben reifer T Zellen von zentraler Bedeutung. Die Gabe von IL-7 führt sowohl in der Maus als auch im Menschen zu erhöhten T Zellzahlen und einem veränderten T Zellphänotyp. Folglich könnte sich die therapeutische Gabe von IL-7 bei Patienten mit geschwächtem Immunsystem positiv auswirken. Diese Hypothese wird derzeit in mehreren klinischen Studien untersucht. Bisher wurde allerdings nur die Wirkung von IL-7 auf T-Zellen studiert. Zu dessen Wirkung auf andere Immun- oder Stromazellen sowie deren IL-7-abhängigen Beitrag zur Regulation der T-Zellhomöostase ist nur wenig bekannt. Daher war es Ziel der Arbeit, den Einfluss einer therapeutischen Gabe von IL-7 auf adoptiv-transferierte T-Zellen in IL-7-Rezeptor (IL-7R)-kompetenten und defizienten lymphopenischen Mäusen zu studieren. Die Untersuchungen bestätigen, dass die Gabe von IL-7 T-Zellantworten unterstützt, zeigen jedoch auch, daß viele dieser Effekte von IL-7R-exprimierenden Wirtszellen abhängig sind. Dies weist darauf hin, dass IL-7R-vermittelte Signale in Wirtszellen indirekt T-Zellantworten beeinflussen. Zudem zeigte sich, dass effiziente anti-Tumor-T Zellantworten von IL 7R-vermittelten Signalen in Wirtszellen abhängen. Vor allem nicht-hämatopoetische Wirtszellen fungieren hier als Regulatoren der IL-7-Therapie-vermittelten T Zelldifferenzierung. Unsere Ergebnisse bestätigen außerdem, dass Stromazellen in verschiedenen Organen il-7 exprimieren und zeigen darüber hinaus, dass diese Zellen durch die Gabe von IL-7 beeinflusst werden. Wir folgern daraus, dass die Effekte der IL-7-Therapie auf T Zellhomöostase teilweise indirekt über il-7-exprimierende Stromazellen vermittelt werden. Um diese Zellen genauer identifizieren und untersuchen zu können, haben wir ein neues transgenes Mausmodell charakterisiert, was es erleichtern wird, die beteiligten molekularen Signalwege zu analysieren und den Erfolg der adoptiven T Zelltherapie zu verbessern. / Interleukin-7 (IL-7) is an essential cytokine required for the development and maintenance of mature T cell. Its availability is limited under normal conditions, but rises during lymphopenia, leading to increased T cell proliferation. The administration of recombinant IL-7 to normal or lymphopenic mice and humans results in increased T cell numbers and altered T cell phenotype. Hence, IL-7 administration could mediate therapeutic benefits in immunocompromised patients and is currently tested in several clinical trials. However, besides its well-studied effects on T cells little is known about the effect of IL-7 on other immune and non-immune cells and their influence on T cell homeostasis. Therefore, we evaluated the effect of IL-7 therapy on adoptively transferred T cells in IL-7 receptor (IL-7R)-competent and IL-7R-deficient lymphopenic mice. We confirm the benefits of IL-7 therapy on T cell responses but additionally show that many of these effects are dependent on IL-7R expression by host cells, indicating that IL-7R signaling in host cells modulates T cell responses. We show that efficient T cell responses against cancer are dependent on host IL-7R signaling. Based on studies in bone-marrow chimeric mice, we identify non-hematopoietic host cells as main regulators of IL-7 therapy-modulated T cell differentiation. We conclude from these data that IL-7 therapy affects non-hematopoietic stromal cells that modulate the success of adoptive T cell therapy. Our results confirm that stromal cells in various organs express il-7 and show that these cells are targeted by IL-7 therapy in vivo. Hence, we propose that il-7-expressing cells regulate IL-7 therapy-modulated T cell homeostasis. To identify and study these il-7 expressing stromal cells in more detail, we characterized a new transgenic mouse model that will facilitate determining the molecular pathways to improve the success of adoptive T cell therapy.
198

Avaliação dos efeitos da sinvastatina via Inibidor do Ativador do Plasminogênio 1 (PAI-1) sobre a terapia celular com células estromais mesenquimais / Evaluation of the effects of simvastatin in mesenchymal stromal cell therapy through Plasminogen Activator inhibitor 1 (PAI-1)

Faria, Carolina Arruda de 08 August 2016 (has links)
A Doença Pulmonar Obstrutiva Crônica (DPOC) é caracterizada pela limitação persistente de trocas gasosas, usualmente progressiva e associada a uma resposta inflamatória crônica exacerbada das vias aéreas a partículas e gases nocivos. Apesar de prevenível e tratável, não se logrou até o presente uma terapêutica eficaz, que resulte na cura da doença. Neste cenário, a terapia celular apresenta-se como uma alternativa terapêutica potencialmente promissora em DPOC, bem como em outras doenças pulmonares degenerativas e de caráter inflamatório. Porém, vários aspectos da terapia celular carecem de um melhor entendimento. Um dos principais desafios ao sucesso da terapia celular são as baixas taxas de sobrevivência das células transplantadas. O Inibidor do Ativador de Plasminogênio 1 (Plasminogen Activator Inhibitor 1 - PAI-1) pode representar um potencial mediador da sobrevivência de células estromais mesenquimais (CTM) pós-transplante, pois tem sido proposto que anticorpos neutralizadores do PAI-1 auxiliam no aumento da sobrevivência de CTM no tecido-alvo da terapia celular. Desta forma, a diminuição dos níveis de PAI-1 possui um potencial terapêutico interessante, ao modular os principais processos envolvidos na criação de um ambiente pouco propício ao \"homing\" celular durante o processo de injúria. A diminuição dos níveis de PAI-1 é promovida, pela sinvastatina, fármaco da família das estatinas. Desta forma, objetivou-se com este trabalho analisar os efeitos da sinvastatina sobre a expressão do PAI-1, bem como sua influência na sobrevivência das células infundidas para terapia celular de enfisema pulmonar em modelo murino. Camundongos da linhagem FVB foram submetidos à instilação intranasal de elastase para indução de enfisema pulmonar e, posteriormente, tratados com CTM do tecido adiposo e sinvastatina. Os resultados mostraram que, quanto aos aspectos morfológicos e funcionais, considerando-se a análise conjunta de ambos os pulmões, não houve diferença estatisticamente significativa entre os grupos submetidos à instilação intranasal de elastase e submetidos à terapia celular com CTM tratados ou não com sinvastatina. Quando porém os pulmões foram analisados individualmente constatou-se que não houve diferença estatisticamente significativa entre os grupos controle e os resultados referentes ao lado direito do pulmão dos animais tratados com elastase e que receberam sinvastatina e infusão de CTM. Diferenças anatômicas entre os lados direito e esquerdo do pulmão, levaram a uma maior deposição de células no lado direito, como evidenciado pelos resultados obtidos nos ensaios de bioluminescência. Pode-se, portanto, inferir que a recuperação morfológica no lado direito do pulmão de animais com DPOC/enfisema poderia ser decorrente de um efeito regenerativo parácrino das CTM associadas à sinvastatina. / Chronic Obstructive Pulmonary Disease - COPD is characterized by the persistent limitation of gas exchange, is usually progressive, and associated to a chronic augmented inflammatory response of the airways to particles and noxious gases. Despite preventable e treatable, an effective, curative therapeutic approach is yet to be achieved. In this context, cell therapy presents itself as a promising therapeutic approach for COPD and other pulmonary inflammatory and degenerative diseases. However, many aspects of cell therapy with stem cells remain unclear. One of the major challenges to the success of cell therapy are the low survival rates of transplanted cells. The Plasminogen Activator Inhibitor 1 (PAI-1) is a potential mediator of the survival of mesenchymal stromal cells (MSC) after transplantation, since PAI-1 neutralizing antibodies have been shown to increase the survival rate of MSC in the target tissue of cell therapy. Thus, the decreased levels of PAI-1 has an interesting therapeutic potential to modulate key processes involved in creating an inhospitable environment, during the process of injury, to the homing of transplanted cells. Decreased levels of PAI-1 are promoted by simvastatin, a drug of the statins family. Thus, the goal of this work was to evaluate the effect of simvastatin in vivo on the expression of PAI-1, as well as its influence on the survival rate of infused cells in mice model of cell therapy for pulmonary COPD/emphysema. FVB mice were submitted pulmonary emphysema induction by means of intranasal instillation of elastase and than treated with adipose-derived mesenchymal stem cells and simvastatin. The results regarding morphological and functional aspects, when considering the analisys of both lungs, presented no statistically significant difference among the groups submitted to intranasal instillation of elastase and cell therapy with MSC, treated or not with simvastatin. However, when the lungs where analyzed individually, it was found that there was no statistically significant difference between the control group and the results regarding the right lung of animals treated with elastase and that received simvastatin and MSC infusion. Anatomical differences between the right and left sides of the lung lead to a higher deposition of cells in the right side, as observed in the bioluminescence assays. Thus, it is possible to infer that the morphological recovery in the right side of the lung of animals with DPOC/emphysema could be due to a regenerative paracrine effect of mesenchymal stem cells associated with simvastatin.
199

Influência do microambiente no prognóstico do câncer da mama / Influence of the microenvironment on breast cancer prognosis

Makdissi, Fabiana Baroni Alves 19 February 2014 (has links)
Introdução: Os cânceres de mama subtipos Luminal A e B (HER2 negativo) podem apresentar prognóstico variável, a depender do índice de proliferação, avaliado pelo Ki67. As células malignas e as células estromais adjacentes (fibroblastos e células de resposta imune ) podem interagir tanto pelo contato célula a célula como por fatores secretados por elas, ambas influenciando no comportamento tumoral. Já foi demonstrado que as células estromais podem aumentar a proliferação das células do câncer da mama. Objetivo: Nosso objetivo foi avaliar o perfil de expressão gênica de células do estroma em câncer de mama luminal A e luminal B e analisar se este se correlaciona com o prognóstico da doença. Pacientes e Métodos/ Resultados: Amostras de tumores de 11 pacientes na pós menopausa foram analisadas, todas elas HER2 negativas. A expressão de Ki67 foi <= 10 % em 5 pacientes (luminal A) e >= 30 % em outras 6 amostras(Luminal B ). Células estromais foram microdissecadas para a extração de RNA, que posteriormente foi hibridizado na plataforma de microarray Agilent G485 -1A GE 8x60K. Após a normalização, 50 % dos genes com a maior variância foram selecionados para análise por SAM duas classes desemparelhado (software TMEV ) e aceitando FDR 14.1%, 35 sequências foram identificadas como diferencialmente expressas, incluindo 16 genes conhecidos, entre as células estromais das amostras de Luminal A versos Luminal B, todos mais expressos nas amostras B. Dentre as funções biológicas enriquecidas em genes diferencialmente expressos encontram-se regulação positiva do sistema imune, incluindo genes como ZAP70 (proteína quinase 70kDa associada a cadeia zeta (TCR)), CD38 (molécula CD38); UBASH3A (ubiquitina associada e SH3 domínio que contém A); PLA2G7 (fosfolipase A2, grupo VII (fator acetil ativador de plaquetas no plasma)); NCR3 (citotoxicidade natural, provocando receptor 3). Nosso próximo passo foi avaliar se a expressão de alguns genes selecionados estava associada com prognóstico de tumores luminais. Para tal selecionamos amostras de outro grupo de 89 pacientes com seguimento de pelo menos 5 anos, cujos tumores eram ER(+), HER2(-), para análise de expressão proteica em Tissue microarray. Caracterizamos os fibroblastos destas amostras com 3 marcadores de fibroblastos: actina de músculo liso (AML), S100A4 e caveolina-1 (CAV1) e analisamos a marcação da proteína ZAP70. Correlacionamos a expressão proteica de todos os marcadores com as características anatomopatológicas da amostra. Observamos que fibroblastos de todas as amostras de tumor de mama expressam AML, S100A4 e CAV1, em diferentes proporções, entretanto não detectamos diferença entre os tumores luminais A e B. Também não obsevamos diferença de expressão de AML, S100A4 e CAV1 em relação a grau histológico, comprometimento linfonodal e estadiamento clínico. Nestas amostras não detectamos expressão proteica de ZAP70 em fibroblastos tumorais. Conclusão: Houve expressão diferencial de 16 genes relacionados a processos imunes, todos eles mais expressos em células estromais de tumores Luminal B em relação a luminal A / Introduction: Luminal breast cancer subtypes A and B (HER2 negative) may present a variable prognosis, depending on tumor proliferation index, evaluated by Ki67 expression. Malignant cells and adjacent stromal cells (fibroblasts and immune response cells) may interact by both cell contact and secreted factors and influence tumor behavior. It was shown that stromal cells may enhance breast cancer cells proliferation. Objective: Our aim was to evaluate stromal cells gene expression profile in luminal A and luminal B tumors and to evaluate whether selected transcripts expressed in stromal cells may be associated with prognosis in breast cancer. Material/ Methods and Results: Hormone receptor positive tumor samples from 11 post menopausal patients were analyzed, all of them Her2 negative. Ki67 expression <= 10% (luminal A) was observed in five and Ki67 >= 30% (luminal B) in six samples. Stromal cells were microdissected for RNA extraction, which was hybridized in Agilent G485-1A GE 8x60K microarray platform. After normalization, 50% of the genes with the highest variance were selected for further analysis by two class unpaired SAM (TMEV software) and accepting FDR 14,1%, 35 sequences, including 16 known genes, were found differentially expressed between stromal cells from luminal A vs luminal B breast cancer samples, all of them more expressed in luminal B. Among biological functions enriched in genes found differentially expressed were positive regulation of immune system process, including genes as: ZAP70 (zeta-chain (TCR) associated protein kinase 70kDa); CD38 (CD38 molecule); UBASH3A (ubiquitin associated and SH3 domain containing A); PLA2G7 (phospholipase A2, group VII (platelet-activating factor acetylhydrolase, plasma); NCR3 (natural cytotoxicity triggering receptor 3). Our next step was evaluate whether expression of selected genes was associated with prognosis in another group of patients. Tumor samples from 89 patients with at least 5 years of follow up, all of them estrogen receptor positive and HER2 negative, were selected. Tissue microarray was prepared with stromal tumor compartment from paraffin embedded tumor samples. Fibroblasts were characterized for the expression of 3 fibroblasts markers (alfa-SMA, alpha smooth muscel actin; S100A4 and CAV1, caveolin 1), and ZAP70. Correlation of expression of these markers with prognostic variables was determined. Expression of alfa-SMA, S100A4 and CAV1 was detected in fibroblasts from all tumor samples in different proportions, however no differential expression was observed between luminal A and B tumors. Neither difference was detected on the expression of these proteins in relation with histological grade, lymph node involvement and clinical stage. Conclusion: A differential expression of 16 genes involved in immune process was found, all of them more expressed in fibroblasts from luminal B as compared with luminal A tumors
200

Phenotypic and molecular characterization of mice deficient in protein kinase A regulatory subunit type 1A (prkar1a) and catalytic subunit A (prkaca). / CUHK electronic theses & dissertations collection

January 2010 (has links)
A population of stromal cells that retains osteogenic capacity in adult bone (adult bone stromal cells or aBSCs) exists and is under intense investigation in relation to osteogenesis and relevant pathology. aBSCs may be different from their embryonic or neonatal counterparts, and are influenced by species-/age-specific and other factors. Mice heterozygous for a null allele of prkar1a (Prkar1a+/-, a gene encoding for cyclic adenosine mono-phosphate (cAMP)-dependent regulatory subunit of protein kinase A (PKA), developed bone lesions that resembled fibrous dysplasia (FD) originated from cAMP-responsive osteogenic cells. Prkar1a +/- mice were crossed with mice heterozygous for catalytic subunit Calpha (Prkaca+/-), the main PKA activity-mediating molecule and generated mouse model with double heterozygosity for prkar1a and prkaca (Prkar1a +/-Prkaca+/-). Unexpectedly, Prkar1a+/-Prkaca+/- mice developed a large number of osseous lesions starting at 2--3 months of age that varied from the rare chondromas in the long bones and the ubiquitous osteochondrodysplasia of tail vertebral bodies to the occasional sarcoma in older animals. Cells from these lesions were fibroblast- and FD-like, and almost always originated from an area proximal to the growth plate and adjacent to endosteal surface of the periosteum; they expanded gradually in the bone marrow space. These cells expressed osteogenic cell markers, showed higher PKA activity that was mostly type II (PKA-II) and display an alternate pattern of catalytic subunit expression, and surprisingly possessed higher cAMP levels. In addition, markers of bone synthesis and lysis were increased. Gene expression profiling not only confirmed an early (progenitor) osteoblastic nature for these cells but also showed a signature that was indicative of mesenchymal-to-epithelial (MET) transition and increased Wnt signaling, particularly the brachyury expression. These studies show that a specific subpopulation of aBSCs can be stimulated in adult bone by PKA-II and altered Calpha activity, generating the only available germline mutant mouse model of a disorder that has similarities to human FD. Along with previous data, these studies also suggest that the effects of cAMP signaling on osteogenesis and stromal cell maintenance and proliferation in mice are age-, bone-, site- but also PKA-type and catalytic subunit-specific. / Parts of the work have been published in Proceedings of the National Academy of Sciences of the United States of America 2010; 107(19):8683--8. / Tsang, Kit Man. / Advisers: Constantine A. Stratakas; Kwak-Pui Fung. / Source: Dissertation Abstracts International, Volume: 72-04, Section: B, page: . / Thesis (Ph.D.)--Chinese University of Hong Kong, 2010. / Includes bibliographical references (leaves 144-183). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. Ann Arbor, MI : ProQuest Information and Learning Company, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.

Page generated in 0.0632 seconds