No description available.

In many tumors, persistently-active signal transducer and activator of transcription 3 (STAT3) imparts several oncogenic features such as survival, proliferation, angiogenesis, and immune escape. Therefore, STAT3 targeting in cancer and cancer-exposed dendritic cells (DCs) is important for cancer therapy. Our objective is developing delivery modalities of STAT3-targeting small interfering RNA (siRNA) using lipid-modified polyethylenimine (PEI) polyplexes and poly(D,L lactic-co-glycolic) acid (PLGA) nanoparticles (NPs), and evaluating the therapeutic outcomes in vitro and in vivo. Significant increase in siRNA condensation, protection, and cellular uptake by B16.F10 melanoma was seen by stearic-acid-modified PEI (PEI-StA) compared to unmodified PEI. Moreover, PEI-StA increased the STAT3 silencing potency of siRNA compared to PEI. STAT3 knockdown was accompanied with significant induction of interleukin-6 (IL-6) secretion and reduction of vascular endothelial growth factor (VEGF) production and cytotoxicity evidenced by increased Caspase 3 activity in vitro and in vivo, and significant inhibition in tumor growth. Analysis of tumor microenvironment showed CD3+ cells infiltration corresponding to STAT3 knockdown. The levels of CD4+ helper cells, CD8+ cytotoxic cells, and NKT cells significantly increased. DC infiltration and activation significantly increased in tumor mass following STAT3 knockdown as evidenced by high expression of CD86 and CD40. Moreover, IFN-, IL-12, and TNF- significantly increased following STAT3 knockdown by PEI-StA compared to PEI, suggesting Th1-type immunity. Allogenic capacity of DCs isolated from siRNA-treated mice was evidenced by the high T cell proliferation and IL-2 production in mixed lymphocytes reaction (MLR). Then, we explored STAT3 knockdown in DCs exposed to tumor derived factors (TDFs). We investigated encapsulation of siRNA complexes (PEI or PEI-StA) into PLGA NPs (PLGA-P and PLGA-PS). PLGA-P and PLGA-PS had an average diameter of ~ 370 nm and zeta potential of ~ -16 mV. Uptake and endosomal localization was confirmed. After TDFs exposure, DCs showed high STAT3 and low CD86 expression. STAT3 silencing by PLGA-P and PLGA-PS restored DC functionality as evidenced by upregulation of CD86, IL-12, and TNF- and MLR activity. PLGA significantly reduced PEI-associated toxicity. Therefore, STAT3 targeting in B16 cells by siRNA polyplexes of PEI and PEI-StA, or in DCs by PLGA-P and PLGA-PS provide potential strategies for cancer therapy. / Pharmaceutical Sciences

No description available.

Large granular lymphocyte leukemia (LGLL) represents a rare group of diseases with considerable difficulties in their correct diagnostic workup and therapy. The major challenges lie in their distinction from reactive (including autoimmune) lymphoproliferations. Moreover, monoclonal LGL proliferative diseases are in fact a heterogeneous group of disorders, as recognized by the three subtypes in the current WHO classification. It distinguishes two chronic forms (the focus of this case series), namely T-LGLL and chronic lymphoproliferative disorders of Natural Killer cells (CLPD-NK) as well as aggressive NK-cell leukemia. In the clinical routine, the variable presentations and phenotypes of T-LGLL and CLPD-NK are underappreciated. The relevant differential diagnoses range from benign reactive T-cell expansions to other mature T-cell leukemias to highly aggressive gd-lymphomas. T-LGLL or CLPD-NK patients suffer from a wide variety of symptoms often including, but not limited to, cytopenias or classical autoimmune phenomena. They receive treatments ranging from mere supportive measures (e.g. antibiotics, growth factors, transfusions) over strategies of immunosuppression up to anti-leukemic therapies. The diagnostic pitfalls range from recognition of the subtle T-cell proliferation, repeated establishment of monoclonality, assignment to a descript immunophenotypic pattern, and interpretations of molecular aberrancies. Here, we report a series of selected cases to represent the spectrum of LGLL. The purpose is to raise awareness among the scientifically or practically interested readers of the wide variety of clinical, immunological, and phenotypic features of the various forms of LGLL, e.g. of T-cell type, including its gd forms or those of NK-lineage. We highlight the characteristics and courses of four unique cases from two academic centers, including those from a prospective nationwide LGLL registry. Each case of this instructive catalogue serves to transport a key message from the areas of (chronic inflammatory) contexts in which LGLL can arise as well as from the fields of differential diagnostics and of various treatment options. Implications for optimization in these areas are discussed.

Submitted by PPG Pediatria e Sa?de da Crian?a (pediatria-pg@pucrs.br) on 2018-01-02T16:42:12Z No. of bitstreams: 1 Tese Lidiane.pdf: 1449534 bytes, checksum: 483272938ee77a60ad54caa8f898d243 (MD5) / Approved for entry into archive by Caroline Xavier (caroline.xavier@pucrs.br) on 2018-01-24T12:15:04Z (GMT) No. of bitstreams: 1 Tese Lidiane.pdf: 1449534 bytes, checksum: 483272938ee77a60ad54caa8f898d243 (MD5) / Made available in DSpace on 2018-01-24T12:17:42Z (GMT). No. of bitstreams: 1 Tese Lidiane.pdf: 1449534 bytes, checksum: 483272938ee77a60ad54caa8f898d243 (MD5) Previous issue date: 2017-08-31 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / Introduction: acute bronchiolitis (AB) is an inflammatory disease of the airways considered the most common pathology of the lower respiratory tract in childhood. Responsible for a large number of hospitalizations in infants is one of the leading respiratory diseases worldwide, raising the costs of health care in infants. According to epidemiological data, between 75,000 and 125,000 children are hospitalized in the United States each year with infections caused by respiratory syncytial virus (RSV), accounting for approximately 25% of pediatric pneumonia and up to 70% of hospitalizations for acute bronchiolitis. Children with deficiencies in cell-mediated immunity can develop more severe and prolonged infections. Activation of the mTOR, STAT-3 and STAT-6 signaling pathways have been identified as key regulators in different functions of the immune system. The aim of this study was to investigate the relationship between the gene expression of mTOR, STAT-3, STAT-6 and AB severity. Methods: it is a cohort study that included a group of infants less than 12 months old with AB admitted to a tertiary hospital in Porto Alegre, Brazil. Nasopharyngeal lavage was collected from all patients and stored in Trizol solution at -80?C at the Biomedical Research Institute (IPB) of PUCRS for subsequent extraction of RNA and cDNA synthesis. Specific primers were used to verify the relative expression of mTOR, STAT-3 and STAT-6 by means of real-time PCR. The results obtained were correlated with AB severity markers such as hospitalization time and wheezing time. Results: for the analysis of expression of the mTOR signaling protein and transcription factors STAT-3 and STAT-6, 23 patients hospitalized with AB were included. A general correlation was made between clinical markers (days of hospitalization and days of wheezing) and expression of signaling pathways. Data were stratified according to severity markers and showed a trend towards decreased mTOR expression in patients with a wheezing time equal to or greater than 5 days (r = -0.702 and p = 0.024). However, the STAT-3 and STAT-6 signaling pathways were not correlated with AB severity factors when applied in this group of patients. Conclusion: transcription factors are essential for generating effective immune responses. mTOR, STAT-3 and STAT-6 participate in the expression of a variety of genes in response to cellular stimuli and may play a key role in the manifestation of the disease. Our data demonstrate the decrease in mTOR expression, with improvement in clinical markers of severity, but other studies are needed to reinforce this finding. / Introdu??o: a bronquiolite aguda (BA) ? uma doen?a inflamat?ria das vias a?reas considerada a patologia mais comum do trato respirat?rio inferior na inf?ncia. Respons?vel por um grande n?mero de hospitaliza??es em lactentes ? uma das principais doen?as respirat?rias em todo o mundo, elevando os custos de cuidados de sa?de em lactentes. Segundo dados epidemiol?gicos, entre 75.000 e 125.000 crian?as s?o hospitalizadas nos Estados Unidos anualmente com infec??es causadas pelo v?rus sincicial respirat?rio (VSR), respondendo por aproximadamente 25% das pneumonias pedi?tricas e at? 70% das interna??es por bronquiolite aguda (BA). As crian?as com defici?ncia na imunidade mediada por c?lulas podem desenvolver infec??es mais graves e prolongadas. A ativa??o das vias de sinaliza??o mTOR, STAT-3 e STAT-6 t?m sido identificadas como reguladores-chave em diferentes fun??es do sistema imune. O objetivo deste estudo foi investigar a rela??o entre a express?o g?nica de mTOR, STAT-3, STAT-6 e a gravidade da BA. M?todos: trata-se de um estudo de coorte onde foi inclu?do um grupo de lactentes de idade inferior a 12 meses, com BA, internados em um hospital terci?rio de Porto Alegre, Brasil. Foi coletado lavado nasofar?ngeo de todos os pacientes e armazenados em solu??o de Trizol ? temperatura de -80?C no Instituto de Pesquisas Biom?dicas (IPB) da PUCRS para posterior extra??o de RNA e s?ntese de cDNA. Foram utilizados os iniciadores espec?ficos para verificar a express?o relativa de mTOR, STAT-3 e STAT-6 por meio de PCR em tempo real. Os resultados obtidos foram correlacionados com marcadores de gravidade da BA como tempo de interna??o e tempo de sibil?ncia. Resultados: para a an?lise da express?o da prote?na de sinaliza??o mTOR e fatores de transcri??o STAT-3 e STAT-6, foram inclu?dos 23 pacientes hospitalizados com BA. Foi realizada uma correla??o geral entre os marcadores cl?nicos (dias de interna??o e dias de sibil?ncia) e a express?o das vias de sinaliza??o. Os dados foram estratificados de acordo com os marcadores de severidade e mostraram uma tend?ncia para a diminui??o da express?o de mTOR em pacientes com tempo de sibil?ncia igual ou superior a 5 dias (r = -0,702 e p = 0,024). No entanto, as vias de sinaliza??o STAT-3 e STAT-6 n?o foram correlacionadas com fatores de gravidade da BA quando aplicadas neste grupo de pacientes. Conclus?o: os fatores de transcri??o s?o essenciais para gerar respostas imunes eficazes. O mTOR, STAT-3 e STAT-6 participam na express?o de uma variedade de genes em resposta a est?mulos celulares e podem desempenhar um papel-chave na manifesta??o da doen?a. Nossos dados demonstram a diminui??o da express?o de mTOR, com melhora dos marcadores cl?nicos de gravidade, por?m outros estudos s?o necess?rios para refor?ar este achado.

[Truncated abstract] Fibrosis is a feature of many pulmonary conditions, including idiopathic pulmonary fibrosis (IPF), which is characterised by the accumulation of fibroblasts/myofibroblasts and excessive deposition of collagen. IPF is a disease of unknown aetiology that is unresponsive to current therapy and is typically fatal. The inflammatory cytokine interleukin (IL)-6 is elevated in patients with IPF and recent studies have shown that IL-6-induced signalling is altered in lung fibroblasts from patients with IPF. IL-6 belongs to the gp130 cytokine family, which is a group of ten structurally related cytokines, that all require the membrane bound glycoprotein gp130 to activate intracellular signalling pathways. Gp130 activates intracellular signalling through the Shp2-ERK1/2 and STAT1/3 pathways to mediate cellular activities. This thesis tests the hypothesis that gp130-mediated signalling is dysregulated in the development and progression of pulmonary fibrosis. To address this hypothesis, I assessed the role of gp130-mediated signalling in a mouse model of bleomycin-induced lung fibrosis. This thesis utilised two novel gp130 mutant mice strains with directed and enhanced gp130-mediated Shp2-ERK1/2 (gp130¿STAT/¿STAT) or STAT1/3 (gp130757F/757F) signalling. I observed complete protection from fibrosis in gp130¿STAT/¿STAT mice up to 60 days after bleomycin treatment and profound fibrosis in gp130757F/757F mice compared to wt controls. The enhanced fibrosis observed in gp130757F/757F mice was diminished by monoallelic deletion of STAT3 (gp130757F/757F;STAT3+/-), identifying gp130-STAT3 signalling as a novel promoter of lung fibrosis. ... In addition, IL-6/11 activation of gp130-mediated signalling modulated transforming growth factor (TGF)-ß-induced effects on adult fibroblast proliferation and myofibroblast differentiation. Interaction between IL-6/11 and TGF-ß1 on fibroblast proliferation was dependent on both the gp130-ERK1/2 and gp130-STAT1/3 pathways. Loss of either pathway abrogated the effects of IL-6 and IL-11 on TGF-ß1- 4 induced fibroblast proliferation. However, it was clear that gp130-STAT3 signalling inhibited TGF-ß1-induced myofibroblast differentiation of primary lung fibroblasts. The inhibition of myofibroblast differentiation was associated with gp130-STAT3 dependent inhibition of TGF-ß1-induced Smad3 phosphorylation. These results indicate that IL-6 and IL-11 promote myofibroblastic differentiation of lung fibroblasts, while gp130-STAT3 signalling inhibits TGF-ß1-induced Smad3 phosphorylation and myofibroblastic differentiation of lung fibroblasts While the pathogenesis of IPF is unknown, it is believed that excessive collagen deposition, aberrant fibroblast behaviour and an inflammatory response are critical to the progression of this disease. It has been shown here that IL-6 family cytokines mediate the development and progression of bleomycin-induced lung fibrosis by increasing collagen synthesis, fibroblast proliferation, myofibroblast differentiation and inflammation through gp130-STAT3 signalling. This thesis has demonstrated that differential activation of cytoplasmic signalling pathways by a membrane bound receptor can have a profound effect on pulmonary responses to injury. Furthermore, this thesis is the first study to identify the gp130-STAT3 pathway as a therapeutic target in the treatment of IPF.

Das Lipopolysaccharid Bindende Protein (LBP) ist ein überwiegend in der Leber synthetisiertes Akutphaseprotein. Es bindet den Zellwandbestandteil Lipopolysaccharid (LPS) Gram-negativer Bakterien und transportiert es zu zellulären Rezeptoren, wodurch das angeborene Immunsystem aktiviert wird. In dieser Arbeit wird die Regulation der LBP-Expression in Interleukin (IL)-1, IL-6 und Dexamethason (Dex) stimulierten humanen Hepatomzelllinien HuH-7 und HepG2 untersucht. Der wichtigste Stimulator ist dabei IL-6, dessen Wirkung über die Transkriptionsfaktoren (TF) Stat-3, C/EBP-beta und AP-1 vermittelt wird. Für alle 3 TF konnten aktive Bindungsstellen auf dem LBP-Promotor nachgewiesen werden. Für IL-1-Effekte die u. a. über den TF NF-kappaB vermittelt werden, konnten ebenfalls aktive Bindungsstellen nachgewiesen werden. Die Wirkung von Dex wird über Glucocorticoid Responsive Elements (GREs) vermittelt. Auf dem LBP-Promotor befinden, sich wie gezeigt werden konnte, mehrere aktive GREs, wobei einige verstärkend und einige hemmend wirken. Eine zu beobachtende Synergiewirkung von Dex und IL-6 wird durch die Aufregulation des IL-6-Rezeptors durch Dex verursacht. Die LBP-Expression kann durch TGF (Transforming Growth Factor)-beta gehemmt werden. Der TGF-beta-Signalweg über Smads ist in den Hepatomzellen aktiv, vermittelt aber nicht den TGF-beta-Hemmeffekt, sondern eine geringe stimulierende Wirkung, die bei alleiniger TGF-beta-Inkubation auftritt. Die inhibierende Wirkung von TGF-beta wird durch Gfi-1- und AP-1-Bindungsstellen vermittelt. Die Gfi-1-Bindungsstelle nimmt dabei, wie hier erstmals gezeigt werden konnte, eine herausragende Stellung ein. Die Aufklärung der LBP-Regulation und dabei besonders die Hemmung der LBP-Expression kann mittelfristig dazu beitragen, den klinischen Verlauf von inflammatorischen und infektiösen Erkrankungen zu beeinflussen und bietet daher Potenzial für neue Therapieansätze. / Lipopolysaccharide (LPS) binding protein (LBP) is an acute phase protein with the ability to bind and transfer LPS of Gram-negative bacteria. This soluble pattern recognition molecule represents an important defense principle of the host. Regulation of the hepatic acute phase response and its termination are important mechanisms for limiting systemic inflammatory activity of the host. Here were analyze the cooperation of Interleukin (IL)-1, IL-6, and Dexamethasone (Dex) at LBP expression in the hepatoma cell lines HuH-7 and Hep G2. The major inducer of LBP expression is IL-6. Within the LBP promoter numerously highly consensus binding sites such as AP-1, C/EBP-beta? and STAT3 are present, that confer transcriptional activity as shown by truncation and mutation experiments. Additionally, activate NF-kappaB sites activated by IL-1 were detected at the LBP promoter. By mutation experiments of the promoter furthermore were found differentially active glucocorticoid response elements (GREs). The promoter contains GREs enhancing the activity as well as inhibitory ones. The enhancing effect towards LBP expression by Dex was mediated by IL-6. Dex stimulated the expression of the IL-6 receptor and therefore upregulated the IL-6 pathway. Transforming Growth Factor (TGF)-beta is able to inhibit LBP expression in stimulated cells. An AP-1 binding site was identified mediating inhibitory TGF-beta effects towards LBP promoter activity. Furthermore it was shown that a growth factor independence (Gfi)-1 binding site localized near the AP-1 site is essential for mediating the TGF-beta inhibitory effect. The relevancy of the Gfi-1 site fore mediating TGF-beta effects indicates a novel mechanism for understanding inhibitory TGF-beta effects at the transcriptional level. In summary the complex regulation of LBP were elucidate which may help to eventually develop novel intervention strategies for acute phase, sepsis, and septic shock.