221 |
Immunisation active à base de peptides, dérivés de l’IL-6 et de l’IL-1β, dans les maladies inflammatoires chroniques / Peptide-based active immunization against IL-6 and IL-1β in chronic inflammatory diseasesDesallais, Lucille 13 May 2013 (has links)
Les anticorps monoclonaux anti-cytokine ont constitué une révolution dans le traitement des maladies inflammatoires chroniques, mais leur utilisation présente des inconvénients (non réponse, résistance, effets secondaires, coûts élevés).Notre équipe développe une stratégie alternative originale, l’immunisation active à base de peptides de cytokines. Elle a pour but de faire synthétiser, par l’organisme même du patient, des anticorps neutralisant les effets pathogènes dus à l’excès de cytokines.Durant ma thèse, j’ai montré que l’immunisation active contre un peptide dérivé de l’IL-6 murine est protectrice dans un modèle murin de sclérodermie systémique. L’immunisation de singes avec l’équivalent humain entraîne une réduction significative des réactions inflammatoires locales suite à l’induction d’une réaction d’HSR. De plus, l’immunisation active contre deux peptides dérivés de l’IL-1β et de l’IL-23 conduit à la réduction de la sévérité de l’EAE.Ces résultats confortent l’intérêt de cibler les cytokines par l’approche d’immunisation active à base de peptides, qui pourra permettre de diversifier l’offre thérapeutique actuellement disponible. / Monoclonal antibodies have been a revolution for the treatment of chronic inflammatory diseases, but their use shows major drawbacks (non-response, resistance, side effects and prohibitive costs).Our team develops an original alternative strategy: anti-cytokine peptide-based active immunization.The aim of the approach is to make the patient’s own organism produce antibodies capable of neutralizing the pathogenic effects of cytokine overproduction.During my PhD, I have demonstrated that active immunization against an IL-6 murine peptide confers clinical protection in a murine model of systemic sclerosis. Monkeys immunized against the human peptide also showed a significant decrease of local inflammatory reactions following a delayed-type hypersensitivity reaction. Moreover, active immunization against an IL-1β and an IL-23 murinepeptide led to a reduction of the severity of the EAE in mice.These results comfort the interest of anti-cytokine peptide-based active immunization, which should eventually widen the choice of therapeutics available for the patients.
|
222 |
Rétrocontrôle des réponses Th2 par l'interleukine-6 et identification d'un nouveau facteur de transcription exprimé par les lymphocytes T helper folliculaires / Restriction of Th2 responses by interleukin-6 and identification of a new transcription factor expressed in follicular helper T cellsDebuisson, Delphine 05 December 2014 (has links)
L’objectif de notre travail a été de caractériser le rôle de l’IL-6 dans la différenciation des lymphocytes Tfh et des lymphocytes Th2. Les lymphocytes Tfh ont pour fonction d’aider les lymphocytes B à produire des anticorps indispensables pour nous protéger contre divers pathogènes. Les lymphocytes Th2, quant à eux, sont spécialisés dans l’élimination de parasites extracellulaires tels que les helminthes.<p>Dans un premier temps, nous avons voulu identifier les gènes dont l’expression est induite par l’IL-6, avec comme objectif une meilleure compréhension des mécanismes permettant aux lymphocytes T de se différencier en cellules Tfh.<p>Au cours de notre travail, nous avons identifié le facteur de transcription, MyoR (Myogenic Repressor) comme étant exprimé au sein des lymphocytes T helper et dont l’expression est induite par l’IL-6. Nos observations expérimentales ont démontré que le facteur MyoR n’est pas indispensable pour la différenciation des lymphocytes Tfh, ni pour leur fonction. Cependant, l’expression de l’ARNm codant pour MyoR pourrait être utilisée comme un biomarqueur des cellules Tfh in vitro ou in vivo.<p>Nous avons ensuite caractérisé la réponse immune induite in vivo par des cellules présentatrices d’antigènes issues de souris déficientes pour l’IL-6. Cette approche nous a permis de mettre en évidence le rôle immunosuppresseur de l’IL-6 sur le développement des réponses de type Th2. En effet, nous avons montré que l’injection de BMDCs (Bone Marrow derived dendritic cells) IL-6-/- dans des souris receveuses de type sauvage induisent une réponse Th2 augmentée in vivo.<p>Nos résultats suggèrent que l’inhibition de la réponse Th2 par l’IL-6 in vivo et in vitro pourrait impliquer la présence d’un ou de plusieurs miRNAs.<p>Cette inhibition pourrait être un mécanisme de rétrocontrôle afin d’éviter une exacerbation de la réponse immune Th2. / Doctorat en Sciences / info:eu-repo/semantics/nonPublished
|
223 |
Metabolismo do ferro em hamsters infectados experimentalmente com leptospira interrogans sorovar pomona: influência na patogênese da doença / Iron metabolism in hamsters experimentally infected with Leptospira interrogans sorovar pomona: influence on disease pathogenesisSobroza, ânderson Oliveira 22 November 2013 (has links)
Anemia in Leptospira interrogans infected individuals is one of the most common
complications found in the severe form of the disease. Iron plays an important role in the
hematopoietic processes; however, its precise metabolism on individuals with leptospirosis is
still unknown. Therefore, the aim of this study was to analyze the classic iron markers
associated to the storage process in hamsters experimentally infected by L. interrogans
serovar Pomona (virulent strain LPF). Four groups with six hamsters each were used; two
groups were controls (C7 and C14) and two were experimental groups with infected animals
(T7 and T14). Blood samples were collected on the seventh (C7 and T7) and fourteenth days
(C14 and T14) post-inoculation (PI). Iron availability was determined in sera samples by the
assessment of iron, ferritin, transferrin, and iron binding capacity, whereas the bone marrow
was also evaluated for the deposition of this metal by Pearl s reaction. Additionally, the total
antioxidant capacity (TAC) and total oxidant status (TOS) were assessed, along with hepcidin
and IL-6 levels to be involved in iron metabolism. Based on the results, it was possible to
observe the onset of an acute condition with crisis hemolytic and regenerative response. The
other parameters showed an increase in seric iron, ferritin, as well as a positive Pearl s
reaction in animals from the groups T7 and T14 compared with the control groups.
Transferrin levels decreased in animals from the group T14 with saturation index, but without
statistical difference among all tested groups. TAC was increased in both periods, while TOS
was increased only on day 14 PI. Hepcidin and IL-6 were statistically increased on days 7 and
14 PI. Therefore, it was observed that the serum profile from infected animals showed a
strong hemolytic pattern, with some demonstration of ferric tissue sequestration. The results
show that iron metabolism is activated in hamsters infected by L. interrogans sorovar
Pomona, and therefore has participation in the pathogenesis of the disease. / A ocorrência de anemia em indivíduos infectados por Leptospira interrogans é uma
das complicações decorrentes à doença em sua forma mais severa. O ferro tem um papel
importante nos processos hematopoiéticos, no entanto, o seu metabolismo preciso em
indivíduos com leptospirose ainda é desconhecido. Portanto, o objetivo deste trabalho foi
analisar os marcadores clássicos relativos à reserva de ferro no organismo de hamsters
experimentalmente infectados com L. interrogans sorovar Pomona, estirpe virulenta LPF.
Para isto, foram utilizados 24 hamsters machos, distribuídos em quatro grupos, sendo dois
grupos Controles (C7 e C14) e dois Testes (T7 e T14), com 6 animais em cada grupo.
Amostras de sangue foram coletadas no sétimo (Grupos C7 e T7) e no décimo quarto dias
pós-inoculação (Grupos C14 e T14). A disponibilidade de ferro foi determinada no soro, pela
dosagem de ferro sérico, ferritina, transferrina e capacidade de ligação do ferro, ao passo que
a medula óssea também foi quantificada quanto à deposição de ferro, através da reação de
Pearls. Além disso, a capacidade antioxidante total (CAT) e status total de oxidantes (TOS)
foram avaliados, em conjunto com hepcidina e os níveis de IL-6, por serem variáveis
envolvidas no metabolismo do ferro. Com os resultados, foi possível observar a instalação de
um quadro agudo com crise hemolítico-regenerativa. Nos demais parâmetros, encontrou-se
uma elevação do ferro sérico, ferritina, e da positividade na Reação de Pearls, nos dois grupos
teste em relação aos controles. A transferrina apresentou uma redução no grupo T14, com
índices de saturação, no entanto, sem diferença estatística entre os grupos. Capacidade
antioxidante total foi aumentada em ambos os períodos , enquanto TOS foi aumentada apenas
no dia 14 PI . Hepcidina e IL-6 foram significativamente elevados nos dias 7 e 14 de PI .
Portanto , observou-se que o perfil sérico de animais infectados apresentam um forte padrão
hemolítico, com alguma demonstração de sequestro tecidual férrico. Os resultados mostram
que o metabolismo do ferro é alterado em hamsters infectados por L. interrogans sorovar
Pomona, e que, portanto, tem participação na patogenia da doença.
|
224 |
Toll-like receptor 4 and interleukin 6 gene polymorphisms in Helicobacter pylori related diseasesPohjanen, V.-M. (Vesa-Matti) 31 May 2016 (has links)
Abstract
Helicobacter pylori is a Gram-negative bacterium, which infects the stomach of more than 50% of the population worldwide. In addition to being the most important risk factor for gastric cancer and peptic ulcers, H. pylori infection is a risk factor for several extra-digestive diseases including dyslipidemia. The consequences of having an H. pylori infection are significantly influenced by the inflammatory response of the host. The pattern recognition receptor Toll-like receptor 4 (TLR4) and the cytokine interleukin 6 (IL6) are important mediators of inflammation in H. pylori related diseases.
We have analyzed a series of control subjects and patients with dyspepsia, peptic ulcers or gastric cancer for frequent genetic polymorphisms of the TLR4 and IL6 genes. The prevalence of H. pylori infection, the histologic features of gastritis and cancer and serum endocrine markers and lipid concentrations were also analyzed. Furthermore, the expression of TLR4 was analyzed in specific cell types of gastric mucosa by immunohistochemistry.
The TLR4 wild type genotypes of polymorphisms +896 and +1196 were associated with an increased risk of peptic ulcers. The same genotypes also associated with higher serum gastrin levels, but not with atrophy or other features of gastritis. The TLR4 expression was seen in the gastrin and somatostatin secreting cells of gastric mucosa. These results suggest a regulatory link between TLR4 and gastrin secretion. Such a link indicates the presence of a novel effector mechanism for innate immunity in modifying the host endocrine function. The IL6 -174 polymorphism associated significantly with a risk of the diffuse type of gastric carcinoma but not with the intestinal type or its precursor conditions. Finally, we demonstrated that H. pylori infections modify HDL serum levels significantly only in IL6 -174 CC genotype patients, which suggests that the detrimental effects of H. pylori infections on HDL levels are transmitted through IL6. These results clarify the mechanisms of H. pylori related diseases and open new possibilities for research on peptic ulcer disease, gastric cancer and dyslipidemia. / Tiivistelmä
Helicobacter pylori on yleinen ihmisen mahalaukussa esiintyvä Gram-negatiivinen bakteeri. Helikobakteeri on tärkein mahasyövän ja maha- ja pohjukaissuolihaavan riskitekijä ja se on myös muun muassa rasva-aineenvaihdunnan häiriöiden riskitekijä. Ihmisen tulehdusvaste vaikuttaa merkittävästi helikobakteeri-infektion seurauksiin. Tollin kaltainen reseptori 4 (TLR4), joka on hahmontunnistusreseptori ja tulehduksenvälittäjäaine interleukiini 6 (IL6) ovat tärkeitä ihmisen tulehdusvasteeseen osallistuvia proteiineja.
Olemme tutkineet dyspepsiaa, maha- ja pohjukaissuolihaavaa ja mahasyöpää sairastavilta potilailta sekä kontrollihenkilöiltä TLR4:n ja IL6:n geenien yleisiä emäsjärjestyksen polymorfioita. Tutkimme myös helikobakteeri-infektion yleisyyttä ja histologisia piirteitä, mahasyövän histologisia piirteitä ja seerumin merkkiaineita ja lipidipitoisuuksia. Lisäksi tutkimme TLR4:n ilmenemistä mahan limakalvolla immunohistokemiallisesti.
TLR4:n polymorfismien +896 ja +1196 villin tyypin genotyypit liittyivät kohonneeseen maha- ja pohjukaissuolihaavan riskiin. Samat genotyypit liittyivät myös korkeampiin gastriinitasoihin. TLR4:ä esiintyi mahalaukun limakalvolla gastriinia tai somatostatiinia ilmentävissä soluissa. Täten TLR4:n ja maha- pohjukaissuolihaavariskin yhteys näyttää välittyvän gastriinin erityksen kautta, mikä viittaa uuteen säätely-yhteyteen luontaisen immuniteetin ja mahalaukun umpieritysjärjestelmän välillä. IL6 -174 -polymorfismi yhdistyi diffuusin tyypin mahakarsinooman riskiin mutta ei intestinaalisen tyypin karsinooman riskiin. Helikobakteeri-infektio yhdistyi pienentyneisiin HDL-kolesterolipitoisuuksiin vain potilailla, joilla oli IL6 -174 CC genotyyppi, mikä viittaa helikobakteerin kolesterolitasoille haitallisen vaikutuksen välittyvän IL6:n kautta. Nämä tulokset antavat lisätietoa helikobakteerin aiheuttamien sairauksien mekanismeista ja avaavat uusia tutkimuspolkuja myös mahahaavan, mahasyövän ja rasva-aineenvaihdunnan häiriöiden kliiniseen tutkimukseen.
|
225 |
The role of human cytomegalovirus encoded viral G protein-coupled receptors in onco-modulatory signallingSubramoney, Preya 22 June 2011 (has links)
Human cytomegalovirus (HCMV) is a ubiquitous virus of the herpes type that infects a high percentage of some populations. One of the most researched genes expressed by HCMV with close homology to human chemokine receptors is the US28 G protein-coupled receptor. Study design: This study was initiated to elucidate the intracellular signalling pathways of an inflammatory factor (IL-6) and an angiogenic factor (STAT3) triggered by the viral US28 oncogene and the presence of US28 in the HCMV viral particle. These pathways were observed by introducing the US28 gene into two human cell lines by infection with a HCMV strain that expresses the US28 gene (wild type), and two HCMV strains where the US28 gene was deleted (ÄUS28 and ÄUS28/UL33). Special attention was directed at the expression of IL-6 after promotion of the US28 gene and subsequent phosphorolation of STAT3. A new US28 antibody was validated and a method developed in an attempt to determine US28 on the viral particle. The following techniques were applied: Cell culture work, two mammalian cell lines were used, HFF’s and U373 MG. Virus stock titre determination to determine the multiplicity of infection. Protein quantitation to determine very small quantities of protein for Western blot analysis. ELISA for the quantitative determination of IL-6. Western blotting for phospho- STAT3 determination and validation of the US28 antibody. Immunocytochemistry was used for back titrations of virally infected cells. Immunofluorescence assay and use of confocal microscopic techniques was used for the location of the US28 gene in the virion and for tSTAT3 translocation to the nucleus. Conclusion: A clear increase in IL-6 secretion (495% ± 1%) was seen, and this was after only an hour in HCMV WT infected cells. From the increase in IL-6 secretion a subsequent increase in STAT3 phosphorylation was detected in the same samples. A clear link has been established between IL-6 and STAT3. A method to determine whether US28 was present in the HCMV viral particle was designed and preliminary results obtained. The results were inclusive. / Dissertation (MSc)--University of Pretoria, 2011. / Pharmacology / unrestricted
|
226 |
A importância da interação entre estresse oxidativo, biogênese de mitocôndrias e mitofagia na resposta de células estreladas hepáticas ao resveratrolMartins, Leo Anderson Meira January 2014 (has links)
A fibrose hepática é uma patologia que acompanha outras doenças crônicas do fígado como a cirrose e o hepatocarcinoma. As células estreladas hepáticas (HSC, do inglês hepatic stellate cells) compõem uma população celular heterogênea que se caracteriza por transitar entre dois fenótipos. As células com fenótipo quiescente possuem a capacidade de armazenar vitamina A em gotas lipídicas. Os insultos ao fígado desencadeiam uma resposta inflamatória que gera estímulos parácrinos e autócrinos mediados por citocinas e espécies reativas. Neste contexto, as HSC assumem um fenótipo ativado fibrogênico e tornam-se responsáveis pela cicatrização hepática. Danos crônicos ao fígado levam a uma deposição de matriz extracelular exagerada que configura o estado patológico da fibrose. O resveratrol (RSV – 3,4’,5-tri-hidroxi-trans-estilbeno) é uma fitoalexina produzida por algumas espécies de plantas. Inúmeros efeitos benéficos à saúde são atribuídos ao RSV por causa do seu potencial antioxidante, antiinflamatório e pró-apoptótico. Estudos anteriores mostraram que tratamento da GRX, uma linhagem murina de HSC ativadas, com concentrações de RSV próximas as biodisponíveis (0,1 a 1 μM) resultou em parada do ciclo na fase S com consequente inibição de proliferação celular, um efeito associado à citotoxicidade e que pode favorecer a resolução da fibrose hepática. Neste estudo, por técnicas espectrofotométricas, foi demonstrado que tratamento da GRX por 24 horas com concentrações entre 0,1 a 50 μM de RSV promoveu um efeito pró-oxidante que causa uma citotoxicidade dependente da dose, bastante aumentada no grupo tratado com a concentração mais alta. Os efeitos citotóxicos atenuados encontrados nas células tratadas por 120 horas sugerem que a GRX pode se tornar resistente a estes efeitos. O potencial pró-oxidante do RSV foi o ponto de partida para investigar a possibilidade de que esta fitoalexina provocasse uma alteração no metabolismo mitocondrial da GRX. Para isso, os efeitos do RSV (1 a 50 μM) na função mitocondrial, na indução de morte mediada por estas organelas e na autofagia/mitofagia foram investigados por técnicas de espectrofotometria, de imunocitoquímica, de citometria de fluxo, de microscopia confocal e de microscopia eletrônica de transmissão em GRX tratadas por 24 e 120 horas. Foi demonstrado que todas as concentrações de RSV promovem apoptose por meio da ativação de caspases, alteram a dinâmica/função mitocondrial e induzem o aumento de autofagia/mitofagia na GRX. No entanto, o RSV provocou biogênese de mitocôndrias nos grupos tratados com 1 e 10 μM, enquanto que o tratamento com 50 μM causou dano celular evidente na GRX, sem induzir biogênese de mitocôndrias. Desta forma, é possível que a citotoxicidade “dose-dependente” do RSV, que causa a morte celular e dano oxidativo em 24 horas de tratamento, esteja relacionada com o desequilíbrio entre a indução concomitante de apoptose mediada por dano mitocondrial, autofagia/mitofagia e biogênese de mitocôndrias. Por fim, foi investigada a liberação de TNF-α, Interleucina-6 e Interleucina-10 pela GRX tratada por 24 e 120 horas com RSV (0,1 a 50 μM), considerando o papel antiinflamatório do RSV e o papel das HSC ativadas na sinalização autócrina que contribui para a modulação fenotípica destas células. Foi demonstrado que o tratamento da GRX com RSV por 24 e 120 horas induziu a redução da liberação de Interleucina-6; enquanto que a liberação de TNF-α e Interleucina-10 foi aumentada. Estes resultados confirmam um efeito antiinflamatório do RSV que deve contribuir na prevenção da ativação ou da perpetuação do estado ativado das HSC por meio de sinalização autócrina. Ainda que a concentração do RSV seja importante para efetivamente induzir a morte das HSC ativadas, o tratamento com esta fitoalexina pode ser promissor para a resolução da fibrose hepática por diminuir a população de células ativadas e, possivelmente, prevenir a perpetuação do estado fenotípico ativado. Estudos avaliando indicadores de quiescência em células tratadas são ainda necessários para desvendar completamente os efeitos do RSV quanto às possibilidades de inibição da perpetuação ou reversão fenotípica das HSC ativadas. / Liver fibrosis is a disease that accompanies other hepatic chronic diseases such as cirrhosis and hepatocellular carcinoma. Hepatic stellate cells (HSC) are a heterogeneous cell population characterized by transiting between two phenotypes. Cells with a quiescent phenotype are able to store vitamin A into lipid droplets. Damage to the liver trigger an inflammatory response that generates paracrine and autocrine stimulation mediated by cytokines and reactive species. In this context, HSC assume an activated and fibrogenic phenotype responsive for hepatic wound-healing. Chronic insults to the liver lead to an excessive deposition of extracellular matrix that configures the pathological state of fibrosis. Resveratrol (RSV – 3,4’,5-tri-hidroxi-trans-stilbeno) is a phytoalexin produced by some species of plants. Several beneficial effects are attributed to this molecule due to its antioxidant, antiproliferative and pro-apoptotic potential. Previous studies showed that treatment with bioavailable concentrations of RSV (0.1 to 1 μM) promoted an arrest cycle at the S phase in GRX, a murine activated HSC model, leading to cell proliferation inhibition, a cytotoxic effect that contributes to the liver fibrosis resolution. In this study, it was shown by spectrophotometric techniques that GRX treatment for 24 hours at concentrations between 0.1 to 50 μM of RSV promoted a fairly clear pro-oxidant effect that causes a dose-dependent cytotoxicity that was higher in the group treated with 50 μM. The attenuated cytotoxicity found after 120 hours of GRX treatment suggest that these cells became resistant to this effect. The pro-oxidant potential of RSV was the starting point for investigating the possibility that this phytoalexin would cause a change in the GRX mitochondrial metabolism. Thus, the effects of RSV (1 to 50 μM) on altering the mitochondrial function, on inducing mitochondrial-mediated cell death, and autophagy/mitofagia were investigated in GRX treated for 24 and 120 hours by spectrophotometric techniques, immunocytochemistry, flow cytometry, confocal microscopy, and transmission electron microscopy. All the RSV concentrations promote cell apoptosis through caspases activation, alter the mitochondrial dynamics and function, and induce an increase of autophagy/mitofagia. Curiously, only 1 and 10 μM of RSV induced mitochondrial biogenesis in GRX, while the highest concentration caused an evident cell damage without inducing mitochondrial biogenesis. Thus, it is possible that the "dose-dependent" cytotoxicity of RSV, which causes cell death and oxidative damage in 24 hours of treatment, is related to an imbalance between the concomitant induction of mitochondrial-mediated apoptosis, autophagy/mitofagia, and mitochondrial biogenesis. Finally, it was investigated the release of TNF-α, Interleukin-6 and Interleukin-10 by GRX treated for 24 and 120 hours with RSV (0.1 to 50 μM), considering the anti-inflammatory role of RSV and the autocrine signalling role of HSC that contributes to the perpetuation of its activated phenotype. It was demonstrated that GRX treatment with RSV for 24 and 120 hours reduced the release of Interleukin-6 in the culture medium; whereas the release of TNF-α and Interleukin-10 was increased. These results confirm the anti-inflammatory properties of RSV and may contribute to the prevention of HSC activation through autocrine signalling. Although RSV concentration is important to effectively induce activated HSC death, cells treatment with this phytoalexin may be promising for liver fibrosis resolution through decreasing the population of activated cells or through preventing the perpetuation of activated state of HSC. Future studies evaluating the quiescence indicators of GRX under RSV treatment are still needed to fully unravel the effects of this phytoalexin on inhibiting the perpetuation of activated HSC or reversing its activated phenotype.
|
227 |
Inflammation bei chronischen Lebererkrankungen – neue Biomarker zur MortalitätsabschätzungSchneider, Christoph 15 February 2021 (has links)
No description available.
|
228 |
The Characterization of Iron and Zinc Redistribution in Pancreatic Beta-Cells Under Conditions of Low-Grade InflammationCounts, Grace P. 28 April 2022 (has links)
No description available.
|
229 |
IL-6 tronquée, un antagoniste naturel de l’IL-6 ? : sélection d’un système d’expression : établissement de preuves de concept in vitro : dans les hémopathies malignes et dans les adénocarcinomes du rein / Truncated IL-6 , a natural IL-6 antagonist ? : selection of an expression system and establishment of in vitro proof of concept on haematological malignancies and on renal adenocarcinoma cellsMansuy, Adeline 17 December 2009 (has links)
L'interleukine-6 (IL-6) exerce des propriétés biologiques multiples telles que l'activation des cellules immunocompétentes, l'activation de la réponse inflammatoire et l'hématopoïèse. Produite également par les cellules tumorales, l'IL-6 impacte la prolifération, la différenciation et la survie de ces dernières. L'IL-6 représente donc depuis plusieurs années une cible thérapeutique pertinente. Dans la première partie de ce travail, nous avons exploré une nouvelle piste potentielle pour bloquer l'activité biologique de l'IL-6, en utilisant un antagoniste naturel que notre équipe a identifié dans plusieurs lignées d'adénocarcinomes du rein, à savoir la molécule tronquée tIL-6. Suite à l'évaluation comparée de deux systèmes d'expression (E. coli versus CHO), nous avons retenu les cellules CHO comme source de production de fractions enrichies en tIL-6 par chromatographie de gel d'exclusion. Disposant d'un panel d'adénocarcinomes de rein (ACHN, Caki1, CLB CHA, CLB VER) et d'une lignée érythroleucémique (TF1), l'activité fonctionnelle de tIL-6 in vitro a été étudiée sur (1) la signalisation IL-6 induite, (2) la prolifération cellulaire IL-6 induite, la survie cellulaire et (4) la modulation de l'expression de protéines relevantes de l'apoptose. La molécule tIL-6 bloque la phosphorylation de la tyrosine Tyr705 de STAT3, qui est un des éléments clés de la voie de signalisation de l'IL-6. Nous rapportons également une autre observation nouvelle indiquant que tIL-6 exerce un effet pro-apoptotique sur certaines lignées RCC. Dans la seconde partie de notre étude, l'impact d'un Ac Mo anti IL-6 dans la réversion de la résistance aux cytotoxiques ou à la radiothérapie a été étudié. Nos résultats démontrent que la voie IL-6 ne constituerait pas un mécanisme majeur de résistance / Interleukin-6 (IL-6) plays numerous physiological roles including haematopoiesis, immune response and inflammation, but also plays a role in modulating cell growth, differentiation and survival of tumors cells. The first goal of the present study was to investigate on the potential role of the truncated protein IL-6 (tIL-6) encoded by the spliced IL-6 mRNA discovered in renal carcinoma cells (RCC). The R&D program was designed based on an industrial approach, aiming at reaching the decision stage to enter or not into preclinical development. Firstly two different expression systems were investigated (E. coli versus CHO cell line). The mammalian expression system was selected as the protein source since a recombinant glycosylated tIL-6 with a molecular weight similar to the predicted natural molecule was obtained from enriched fractions following size exclusion chromatography. Secondly by using a cell line panel including renal carcinoma cells (ACHN, Caki-1, CLB CHA, CLB-VER ) and an erythroleucemic cell line (TF1), in vitro tIL-6 functional activity were analyzed on (1) IL-6 induced signaling, (2) IL-6 induced cell proliferation, (3) on cell survival and also (4) on expression of specific set of proteins involved in apoptosis pathways. The truncated IL-6 was found inhibit IL-6 induced STAT3 Tyr705 and to induce apoptosis in some RCC cell lines which could be depending on IL-6 expression. Understanding more precisely the role of natural truncated IL-6 and its impact in cell tumour growth control will be a major issue in the development of innovative approach to antagonize directly or not IL6. The second goal of the present study was to investigate on reversing resistance of cancer cell lines to cytotoxics or ionizing radiations through the use of a monoclonal antibody directed against IL-6. Our data support the fact that IL-6 is not the preponderant actor of cell resistance to cytotoxics and ionizing radiations, which seems to be regulated by a complex network of proteins
|
230 |
Aberrant Biomolecular Expression and Activity as a Target for Novel Diagnostics and TherapeuticsNoori, Mahboubeh Sadat January 2019 (has links)
No description available.
|
Page generated in 0.0334 seconds