Burkholderia pseudomallei is a gram-negative opportunistic soil pathogen that causes the life-threatening disease melioidosis. It is endemic in Northern Australia and Southeast Asia but can be found throughout many other regions in the world. Diabetes mellitus is a predisposing risk factor for infection with this organism and it has been demonstrated that diabetic males are particularly susceptible to severe infection. Previous research suggested that monocytes isolated from the whole blood of diabetic males demonstrated a decreased ability to produce the proinflammatory cytokines IL-1β and IL-8. We hypothesized that monocyte-derived macrophages from diabetic males would also secrete lower levels of pro-inflammatory cytokines and that this difference between gender and diabetic state would be more pronounced compared to those seen previously with monocytes. Twenty volunteer with type I diabetes mellitus (ten males and ten females), along with twenty healthy age- and gender-matched controls donated blood for this study. Monocytes were collected from whole blood and allowed to differentiate into macrophages with the use of human recombinant granulocyte-macrophage colony-stimulating factor (GM-CSF). Macrophages were then divided into groups and infected with B. pseudomallei, B. thailandensis (a closely related by non-pathogenic bacterium that inhabits similar niches), and E. coli. An uninfected control was used as well. At six hours post-infection, mRNA was collected from all cells and qPCR was performed to determine cytokine expression levels. All mRNA values collected from cells which had been infected with bacterial agents were normalized against the corresponding concentrations of mRNA from mock-infected cells. Mean log fold increases in both IL-1β and IL-8 were computed and compared. Preliminary testing showed decreased levels of both IL-1β and IL-8 from B. pseudomallei-infected macrophages isolated from a diabetic male compared to the healthy, age-matched male control. Surprisingly, results from all forty donors demonstrated that gender and diabetic state were not significant factors in the proinflammatory responses of macrophages infected with B. pseudomallei, although further testing is needed to determine if these results were influenced by experimental parameters.

Yes / Type 2 diabetes mellitus (T2DM) is increasing worldwide, and it is associated with increased risk of coronary artery disease (CAD). For T2DM patients, the main surgical intervention for CAD is autologous saphenous vein grafting. However, T2DM patients have increased risk of saphenous vein graft failure (SVGF). While the mechanisms underlying increased risk of vascular disease in T2DM are not fully understood, hyperglycaemia, insulin resistance, and hyperinsulinaemia have been shown to contribute to microvascular damage, whereas clinical trials have reported limited effects of intensive glycaemic control in the management of macrovascular complications. This suggests that factors other than glucose exposure may be responsible for the macrovascular complications observed in T2DM. SVGF is characterised by neointimal hyperplasia (NIH) arising from endothelial cell (EC) dysfunction and uncontrolled migration and proliferation of vascular smooth muscle cells (SMCs). This is driven in part by proinflammatory cytokines released from the activated ECs and SMCs, particularly interleukin 6 (IL-6). IL-6 stimulation of the Janus kinase (JAK)/signal transducer and activator of transcription 3 (STAT) pathway is a key mechanism through which EC inflammation, SMC migration, and proliferation are controlled and whose activation might therefore be enhanced in patients with T2DM. In this review, we investigate how proinflammatory cytokines, particularly IL-6, contribute to vascular damage resulting in SVGF and how suppression of proinflammatory cytokine responses via targeting the JAK/STAT pathway could be exploited as a potential therapeutic strategy. These include the targeting of suppressor of cytokine signalling (SOCS3), which appears to play a key role in suppressing unwanted vascular inflammation, SMC migration, and proliferation. / FTM is supported by a University of Botswana PhD scholarship.

A sepse é caracterizada por uma produção excessiva de mediadores inflamatórios, acompanhada de taquicardia e hipotensão. Experimentalmente, a administração de endotoxina (Lipopolissacarídeo, LPS) em doses relativamente elevadas induz choque endotoxêmico, sendo um bom modelo de estudo da sepse. Diversos grupos têm demonstrado ações antiinflamatórias e antitumorais do citral, um composto do óleo essencial de Cymbopogon citratus. Nosso laboratório demonstrou ação antipirética do citral em modelo de febre induzida por LPS, acompanhada de redução nos níveis de citocinas plasmáticas e de prostaglandina E2 (PGE2) no plasma e área pré óptica do hipotálamo (POA), importante região termorregulatória. A hipótese testada neste trabalho foi a de que o citral atenua a hipotensão provocada pela endotoxina, além de amenizar as alterações termoregulatórias. Todos os procedimentos foram executados de acordo com os princípios éticos de experimentação animal, aprovados pelo comitê de ética local (CEUA 2015.1 1214 58-2). Foi realizado o implante de cânulas na artéria e veia femoral para registro da pressão arterial e administração de LPS (1,5 mg/kg) ou salina apirogênica 0,9% além do implante de datalogger na cavidade peritoneal de ratos Wistar, para registro da temperatura corporal. No dia do registro, 30 minutos antes da administração de LPS ou salina, os animais receberam citral (100 mg/kg) ou tween 80 a 1% (veículo) por via oral. Os parâmetros cardiovasculares e temperatura corporal foram registrados por 300 minutos após os respectivos tratamentos. Os valores de pressão arterial média (PAM) e frequência cardíaca (FC) foram coletados a cada 10 minutos após o tratamento e a temperatura corporal foi registrada pelo datalogger em intervalos de 5 minutos. Em outro protocolo foi realizado apenas o implante de cânula na veia femoral dos animais de todos os grupos para administração de LPS ou salina, coleta de sangue para dosagem de interleucina 6, PGE2, nitrito e nitrato e corticosterona e coleta do encéfalo para dosagem de PGE2 e PGD2. As diferenças estatísticas entre os grupos foram analisadas pelo teste ANOVA two-way seguido por pós teste de Newman-Keuls, com o nível de significância adotado de p < 0,05. A administração de LPS provocou queda na PAM eaumento na FC. Tais respostas não foram afetadas pela administração prévia de citral. O LPS também induziu febre e aumento nas concentrações plasmáticas de interleucina - 6 (IL-6), óxido nítrico (NO), PGE2 e corticosterona. Esses parâmetros não foram alterados pela pré- administração de Citral. No entanto, o citral provocou redução na produção de PGD2 naPOA, sem alterar a de PGE2 nesta região. Podemos concluir que o citral não previne as alterações nos parâmetros cardiovasculares no modelo de endotoxemia em ratos, porém reduz a produção de um mediador termorregulatório e inflamatório do sistema nervoso central (a PGD2), sem alterar a produção de outros mediadores inflamatórios a nível periférico (no plasma). Portanto, em um modelo mais agressivo de inflamação sistênica o citral não se mostrou suficiente para proteger o organismo das ações deletérias do LPS. / Sepsis is characterized by the overproduction of inflammatory mediators, accompanied by tachycardia and hypotension. Experimentally, administration of endotoxin (Lipopolysaccharide, LPS) in relatively high doses induces endotoxemic shock, a widely used model of sepsis in rats. Several groups have demonstrated anti-inflammatory and antitumor roles of citral, an essential oil compound of Cymbopogon citratus. Emilio-Silva et al. (2017) have shown an antipyretic role of citral in a model of LPS-induced fever, accompanied by a reduction of cytokines and prostaglandin E2 plasma levels and in the preoptic area of hypothalamus (POA), the hierarchically most important thermoregulatory region. We hypothesized that citral attenuates the LPS-induced hypotension, besides mitigating the thermoregulatory adjustments in rats. All procedures were performed in agreement with ethical guidelines for animal experimentation aproved by the local ethical committee (CEUA 2015.1 1214 58-2). Femoral artery and vein were implanted with cannulas for blood pressure recording and LPS (1.5 mg/kg) or 0.9% apyrogenic saline injection. In a second surgical procedure a datalogger was implanted into the peritoneal cavity for measurements of body temperature. All surgical procedures were performed under Ketamin/xilazin (100/10 mg/kg) anesthesia. One day after arterial catheterization, 30 minutes prior to LPS or saline administration, the animals received either citral (100 mg / kg) or 1% tween 80 (vehicle) oralstarly. The cardiovascular parameters and body temperature were recorded for 300 minutes after the respective treatments. Mean blood pressure (MAP) and heart rate (HR) were collected every 10 minutes after treatments and body temperature was recorded by the datalogger at 5 minute intervals. Blood samples were obtained in another set of rats for interleukin-6, PGE2, nitrite and nitrate and corticosterone analyses. The brain was removed for PGE2 and PGD2 analyses. Statistical differences between groups were analyzed by the two-way or one-way ANOVA test followed by Newman-Keuls post-test, with significance level adopted at p <0.05. As expected, LPS administration caused a decrease in MAP and an increase in HR, and these responses were not affected by citral. LPS also induced fever and increased plasma levels of interleukin - 6 (IL - 6), nitric oxide (NO), prostaglandin E 2 andcorticosterone. These parameters were also not altered by citral. On the other hand, citral caused a reduction in prostaglandin D2 concentration in the POA, but failed to alter PGE2 levels in this region. Our data are consistent with the notion that citral does not affect changes in cardiovascular and thermoregulatory parameters. Consistently, citral also caused no changes in both LPS-induced peripheral inflammatory mediators (in plasma) and in the POA, except PGD2. Therefore, in our model which mimetic a fairly critical situation, citral may not be sufficient to protect the organism from the deleterious actions of LPS. Financial support: FAPESP / CAPES.

The bank vole (Microtus arvalis) develops glucose intolerance both when kept in captivity and in the wild state. Glucose intolerant bank voles kept in captivity exhibited polydipsia, polyuria, hyperglycemia, hyperinsulinemia, islet autoantibodies and a markedly changed islet structure resembling so–called hydropic degeneration. Islets showing hydropic degeneration have reduced β–cell mass. However, the relative islet size to total pancreas area was not changed. Pancreatic islet isolated from glucose intolerant bank voles had an altered islet function showing signs of being exposed to an increased functional demand on their β–cells. Also, islets from male bank voles seem more affected than the islets from females. Islets isolated from glucose tolerant male bank voles cultured for 5 days at 28 mM glucose did not reveal any change in insulin gene expression or insulin biosynthesis rate. However, islets from female bank voles displayed a glucose concentration dependent response. This suggests that there is gender difference in that, islets of female more easily than islets of males adapt to elevated glucose concentration. Furthermore, islets isolated from glucose tolerant males had reduced insulin gene expression after exposure to proinflammatory cytokines for 48 hrs. This effect seemed to be NO-independent since only a minor elevation of nitrite accumulation in the medium was seen, and the use of iNOS inhibitor could not counteract the cytokine effect. The observed response seen in bank vole islets upon exposure to various glucose concentrations or proinflammatory cytokines is similar to those seen in studies of human islets. The bank vole may therefore represent a novel animal model for the study of diabetes. An unresolved issue is the role of the Ljungan virus which is found in the bank vole colony. Bank voles developing glucose intolerance display features of both human type 1 and type 2 diabetes, where environmental factors seems to play an important role as determinant. Our findings suggest that bank voles bred in the laboratory may develop more of a type 2 diabetes. However, bank voles caught in nature instead may rather develop a type 1 form of the disease.

A sepse é caracterizada por uma produção excessiva de mediadores inflamatórios, acompanhada de taquicardia e hipotensão. Experimentalmente, a administração de endotoxina (Lipopolissacarídeo, LPS) em doses relativamente elevadas induz choque endotoxêmico, sendo um bom modelo de estudo da sepse. Diversos grupos têm demonstrado ações antiinflamatórias e antitumorais do citral, um composto do óleo essencial de Cymbopogon citratus. Nosso laboratório demonstrou ação antipirética do citral em modelo de febre induzida por LPS, acompanhada de redução nos níveis de citocinas plasmáticas e de prostaglandina E2 (PGE2) no plasma e área pré óptica do hipotálamo (POA), importante região termorregulatória. A hipótese testada neste trabalho foi a de que o citral atenua a hipotensão provocada pela endotoxina, além de amenizar as alterações termoregulatórias. Todos os procedimentos foram executados de acordo com os princípios éticos de experimentação animal, aprovados pelo comitê de ética local (CEUA 2015.1 1214 58-2). Foi realizado o implante de cânulas na artéria e veia femoral para registro da pressão arterial e administração de LPS (1,5 mg/kg) ou salina apirogênica 0,9% além do implante de datalogger na cavidade peritoneal de ratos Wistar, para registro da temperatura corporal. No dia do registro, 30 minutos antes da administração de LPS ou salina, os animais receberam citral (100 mg/kg) ou tween 80 a 1% (veículo) por via oral. Os parâmetros cardiovasculares e temperatura corporal foram registrados por 300 minutos após os respectivos tratamentos. Os valores de pressão arterial média (PAM) e frequência cardíaca (FC) foram coletados a cada 10 minutos após o tratamento e a temperatura corporal foi registrada pelo datalogger em intervalos de 5 minutos. Em outro protocolo foi realizado apenas o implante de cânula na veia femoral dos animais de todos os grupos para administração de LPS ou salina, coleta de sangue para dosagem de interleucina 6, PGE2, nitrito e nitrato e corticosterona e coleta do encéfalo para dosagem de PGE2 e PGD2. As diferenças estatísticas entre os grupos foram analisadas pelo teste ANOVA two-way seguido por pós teste de Newman-Keuls, com o nível de significância adotado de p < 0,05. A administração de LPS provocou queda na PAM eaumento na FC. Tais respostas não foram afetadas pela administração prévia de citral. O LPS também induziu febre e aumento nas concentrações plasmáticas de interleucina - 6 (IL-6), óxido nítrico (NO), PGE2 e corticosterona. Esses parâmetros não foram alterados pela pré- administração de Citral. No entanto, o citral provocou redução na produção de PGD2 naPOA, sem alterar a de PGE2 nesta região. Podemos concluir que o citral não previne as alterações nos parâmetros cardiovasculares no modelo de endotoxemia em ratos, porém reduz a produção de um mediador termorregulatório e inflamatório do sistema nervoso central (a PGD2), sem alterar a produção de outros mediadores inflamatórios a nível periférico (no plasma). Portanto, em um modelo mais agressivo de inflamação sistênica o citral não se mostrou suficiente para proteger o organismo das ações deletérias do LPS. / Sepsis is characterized by the overproduction of inflammatory mediators, accompanied by tachycardia and hypotension. Experimentally, administration of endotoxin (Lipopolysaccharide, LPS) in relatively high doses induces endotoxemic shock, a widely used model of sepsis in rats. Several groups have demonstrated anti-inflammatory and antitumor roles of citral, an essential oil compound of Cymbopogon citratus. Emilio-Silva et al. (2017) have shown an antipyretic role of citral in a model of LPS-induced fever, accompanied by a reduction of cytokines and prostaglandin E2 plasma levels and in the preoptic area of hypothalamus (POA), the hierarchically most important thermoregulatory region. We hypothesized that citral attenuates the LPS-induced hypotension, besides mitigating the thermoregulatory adjustments in rats. All procedures were performed in agreement with ethical guidelines for animal experimentation aproved by the local ethical committee (CEUA 2015.1 1214 58-2). Femoral artery and vein were implanted with cannulas for blood pressure recording and LPS (1.5 mg/kg) or 0.9% apyrogenic saline injection. In a second surgical procedure a datalogger was implanted into the peritoneal cavity for measurements of body temperature. All surgical procedures were performed under Ketamin/xilazin (100/10 mg/kg) anesthesia. One day after arterial catheterization, 30 minutes prior to LPS or saline administration, the animals received either citral (100 mg / kg) or 1% tween 80 (vehicle) oralstarly. The cardiovascular parameters and body temperature were recorded for 300 minutes after the respective treatments. Mean blood pressure (MAP) and heart rate (HR) were collected every 10 minutes after treatments and body temperature was recorded by the datalogger at 5 minute intervals. Blood samples were obtained in another set of rats for interleukin-6, PGE2, nitrite and nitrate and corticosterone analyses. The brain was removed for PGE2 and PGD2 analyses. Statistical differences between groups were analyzed by the two-way or one-way ANOVA test followed by Newman-Keuls post-test, with significance level adopted at p <0.05. As expected, LPS administration caused a decrease in MAP and an increase in HR, and these responses were not affected by citral. LPS also induced fever and increased plasma levels of interleukin - 6 (IL - 6), nitric oxide (NO), prostaglandin E 2 andcorticosterone. These parameters were also not altered by citral. On the other hand, citral caused a reduction in prostaglandin D2 concentration in the POA, but failed to alter PGE2 levels in this region. Our data are consistent with the notion that citral does not affect changes in cardiovascular and thermoregulatory parameters. Consistently, citral also caused no changes in both LPS-induced peripheral inflammatory mediators (in plasma) and in the POA, except PGD2. Therefore, in our model which mimetic a fairly critical situation, citral may not be sufficient to protect the organism from the deleterious actions of LPS. Financial support: FAPESP / CAPES.

No description available.

Chickens in the poultry industry are reared under intensive conditions where they are often exposed to opportunistic pathogens. Escherichia coli strain O78 is responsible for about half of the cases of avian colisepticemia. Potential therapeutic treatments have been proposed to inhibit the hydrolases that controls the endogenous levels of the endocannabinoid, 2-arachidonoylglycerol (2-AG). 2-AG is the full agonist at the CB2 receptors of the endocannabinoid system expressed among leukocytes and it plays a role in mediating the activation of phagocytic macrophages. It is speculated that elevating 2- AG levels could increase macrophage cytokines and promote the recruitment of immune cells at the infected tissues. The purpose of this study was to investigate the immunomodulating effect of the 2-AG hydrolase inhibitor, JZL184 in chickens. The treatments could potentially up-regulate the innate immune responses in chickens during an E. coli infection by conveying a message from the endocannabinoid system to the immune system.

La mucoviscidose est la maladie génétique récessive la plus fréquente dans les populations caucasiennes. Elle est dûe à des mutations dans le gène CFTR qui code pour une protéine qui a une fonction canal chlorure et qui est exprimée au pôle apical des épithéliums sécrétoires. La mutation la plus fréquente F508del altère le repliement de la protéine, induisant sa dégradation précoce par le protéasome et son absence à la membrane plasmique. La recherche fondamentale se focalise sur la protéine mutée et cherche à découvrir des molécules capables d’adresser celle-ci au pôle apical des cellules épithéliales où elle pourra remplir sa fonction de canal chlorure. Au sein du laboratoire, nous nous intéressons aux interactions de la protéine CFTR/ F508del-CFTR avec d’autres protéines. Nous avons déjà montré l’existence d’une interaction non voulue entre F508del-CFTR et un filament intermédiaire, la cytokératine 8. En combinant une approche in-silico et du criblage haut débit, nous avons identifié des molécules capables d’interrompre ces interactions. Des tests fonctionnels sur des lignées cellulaires ainsi que sur des modèles murins ont montré une restauration de la fonction canal chlorure après traitements avec ces molécules. Au cours de ma thèse, je me suis intéressée à l’une d’entre elles qui est la molécule « c407 ». L’objectif de ma thèse était de comprendre les mécanismes d’action de cette molécule. J’ai également évalué l’efficacité des traitements actuels dans le contexte des allèles complexes de F508del-CFTR. Dans une seconde partie de ma thèse, j’ai étudié l’effet d’une cytokine (TNFα) sur la protéine mutée F508del-CFTR. De façon inattendue, j’ai observé que le TNFα, à des concentrations physiologiques, corrige le défaut de routage de la protéine F508del-CFTR. Cette observation pourrait expliquer une fonction résiduelle de la F508del-CFTR chez certains patients atteints de mucoviscidose. En conclusion, mes travaux ont permis de préciser les mécanismes d’action d’un correcteur et de découvrir un effet inattendu d’une cytokine pro-inflammatoire. Ces travaux permettent de relier la correction d’un défaut de routage au processus inflammatoire ouvrant ainsi un nouveau champ d’investigation. / Cystic fibrosis is due to the loss of epithelial chloride transport caused by mutations in the CFTR gene, the most frequent mutation being F508del. One of the strategies developed to find new treatment for Cystic fibrosis (CF) is to discover compounds that correct the trafficking of F508del-CFTR to the plasma membrane. Using hypothesis-driven approach and combining modeling of NBD1, molecular docking and functional assays, we identified 4 compounds that correct F508del-CFTR function in cells (including human primary bronchial cells in culture) and F508del mice. New correctors probably act by interrupting the interaction between F508del-CFTR with keratin 8 (Odolczyk et al EMBO Mol Med 2013). During my PhD, I focused on one of those molecules, the "c407" molecule. The aim of my thesis was to investigate the mechanisms of action of this molecule. I have also evaluated the effectiveness of current treatments in the context of complex alleles F508del-CFTR. In the second part of my thesis, I studied the effect of a cytokine (TNFα) on the protein F508del-CFTR. Unexpectedly, I observed that the TNFα at physiological concentrations, corrects the trafficking of F508del-CFTR protein. This observation could explain a residual function of F508del-CFTR in some CF patients. In conclusion, my thesis helped to clarify the mechanisms of action of new correctors of F508del-CFTR.

La mucoviscidose est la maladie génétique récessive la plus fréquente dans les populations caucasiennes. Elle est dûe à des mutations dans le gène CFTR qui code pour une protéine qui a une fonction canal chlorure et qui est exprimée au pôle apical des épithéliums sécrétoires. La mutation la plus fréquente F508del altère le repliement de la protéine, induisant sa dégradation précoce par le protéasome et son absence à la membrane plasmique. La recherche fondamentale se focalise sur la protéine mutée et cherche à découvrir des molécules capables d’adresser celle-ci au pôle apical des cellules épithéliales où elle pourra remplir sa fonction de canal chlorure. Au sein du laboratoire, nous nous intéressons aux interactions de la protéine CFTR/ F508del-CFTR avec d’autres protéines. Nous avons déjà montré l’existence d’une interaction non voulue entre F508del-CFTR et un filament intermédiaire, la cytokératine 8. En combinant une approche in-silico et du criblage haut débit, nous avons identifié des molécules capables d’interrompre ces interactions. Des tests fonctionnels sur des lignées cellulaires ainsi que sur des modèles murins ont montré une restauration de la fonction canal chlorure après traitements avec ces molécules. Au cours de ma thèse, je me suis intéressée à l’une d’entre elles qui est la molécule « c407 ». L’objectif de ma thèse était de comprendre les mécanismes d’action de cette molécule. J’ai également évalué l’efficacité des traitements actuels dans le contexte des allèles complexes de F508del-CFTR. Dans une seconde partie de ma thèse, j’ai étudié l’effet d’une cytokine (TNFα) sur la protéine mutée F508del-CFTR. De façon inattendue, j’ai observé que le TNFα, à des concentrations physiologiques, corrige le défaut de routage de la protéine F508del-CFTR. Cette observation pourrait expliquer une fonction résiduelle de la F508del-CFTR chez certains patients atteints de mucoviscidose. En conclusion, mes travaux ont permis de préciser les mécanismes d’action d’un correcteur et de découvrir un effet inattendu d’une cytokine pro-inflammatoire. Ces travaux permettent de relier la correction d’un défaut de routage au processus inflammatoire ouvrant ainsi un nouveau champ d’investigation. / Cystic fibrosis is due to the loss of epithelial chloride transport caused by mutations in the CFTR gene, the most frequent mutation being F508del. One of the strategies developed to find new treatment for Cystic fibrosis (CF) is to discover compounds that correct the trafficking of F508del-CFTR to the plasma membrane. Using hypothesis-driven approach and combining modeling of NBD1, molecular docking and functional assays, we identified 4 compounds that correct F508del-CFTR function in cells (including human primary bronchial cells in culture) and F508del mice. New correctors probably act by interrupting the interaction between F508del-CFTR with keratin 8 (Odolczyk et al EMBO Mol Med 2013). During my PhD, I focused on one of those molecules, the "c407" molecule. The aim of my thesis was to investigate the mechanisms of action of this molecule. I have also evaluated the effectiveness of current treatments in the context of complex alleles F508del-CFTR. In the second part of my thesis, I studied the effect of a cytokine (TNFα) on the protein F508del-CFTR. Unexpectedly, I observed that the TNFα at physiological concentrations, corrects the trafficking of F508del-CFTR protein. This observation could explain a residual function of F508del-CFTR in some CF patients. In conclusion, my thesis helped to clarify the mechanisms of action of new correctors of F508del-CFTR.

La mucoviscidose est la maladie génétique récessive la plus fréquente dans les populations caucasiennes. Elle est dûe à des mutations dans le gène CFTR qui code pour une protéine qui a une fonction canal chlorure et qui est exprimée au pôle apical des épithéliums sécrétoires. La mutation la plus fréquente F508del altère le repliement de la protéine, induisant sa dégradation précoce par le protéasome et son absence à la membrane plasmique. La recherche fondamentale se focalise sur la protéine mutée et cherche à découvrir des molécules capables d’adresser celle-ci au pôle apical des cellules épithéliales où elle pourra remplir sa fonction de canal chlorure. Au sein du laboratoire, nous nous intéressons aux interactions de la protéine CFTR/ F508del-CFTR avec d’autres protéines. Nous avons déjà montré l’existence d’une interaction non voulue entre F508del-CFTR et un filament intermédiaire, la cytokératine 8. En combinant une approche in-silico et du criblage haut débit, nous avons identifié des molécules capables d’interrompre ces interactions. Des tests fonctionnels sur des lignées cellulaires ainsi que sur des modèles murins ont montré une restauration de la fonction canal chlorure après traitements avec ces molécules. Au cours de ma thèse, je me suis intéressée à l’une d’entre elles qui est la molécule « c407 ». L’objectif de ma thèse était de comprendre les mécanismes d’action de cette molécule. J’ai également évalué l’efficacité des traitements actuels dans le contexte des allèles complexes de F508del-CFTR. Dans une seconde partie de ma thèse, j’ai étudié l’effet d’une cytokine (TNFα) sur la protéine mutée F508del-CFTR. De façon inattendue, j’ai observé que le TNFα, à des concentrations physiologiques, corrige le défaut de routage de la protéine F508del-CFTR. Cette observation pourrait expliquer une fonction résiduelle de la F508del-CFTR chez certains patients atteints de mucoviscidose. En conclusion, mes travaux ont permis de préciser les mécanismes d’action d’un correcteur et de découvrir un effet inattendu d’une cytokine pro-inflammatoire. Ces travaux permettent de relier la correction d’un défaut de routage au processus inflammatoire ouvrant ainsi un nouveau champ d’investigation. / Cystic fibrosis is due to the loss of epithelial chloride transport caused by mutations in the CFTR gene, the most frequent mutation being F508del. One of the strategies developed to find new treatment for Cystic fibrosis (CF) is to discover compounds that correct the trafficking of F508del-CFTR to the plasma membrane. Using hypothesis-driven approach and combining modeling of NBD1, molecular docking and functional assays, we identified 4 compounds that correct F508del-CFTR function in cells (including human primary bronchial cells in culture) and F508del mice. New correctors probably act by interrupting the interaction between F508del-CFTR with keratin 8 (Odolczyk et al EMBO Mol Med 2013). During my PhD, I focused on one of those molecules, the "c407" molecule. The aim of my thesis was to investigate the mechanisms of action of this molecule. I have also evaluated the effectiveness of current treatments in the context of complex alleles F508del-CFTR. In the second part of my thesis, I studied the effect of a cytokine (TNFα) on the protein F508del-CFTR. Unexpectedly, I observed that the TNFα at physiological concentrations, corrects the trafficking of F508del-CFTR protein. This observation could explain a residual function of F508del-CFTR in some CF patients. In conclusion, my thesis helped to clarify the mechanisms of action of new correctors of F508del-CFTR.