13 research outputs found

    TRIZ: A Theory of Inventive Problem Solving

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    People usually face two kinds of problems: those with generally known solutions and those with unknown solutions. Those with known solution can usually be solved by information found in books, technical journals, or other subject matter. The other type of problems is the one with no known solution. It is called an inventive problem. "TRIZ" is the acronym in Russian (Теория решения изобретательских задач) for "Theory of Inventive Problem Solving" created by Genrikh Altshuller who was a patent investigator in Russian Navy in 1946 looking for inventive cross-disciplinary analogous solutions to various engineering problems (through the law of increasing ideality and engineering parameters' contradictions and the corresponding conflict resolution strategies). This is an INSE6240 project presentation discussing TRIZ

    Exploration des cytokines pro-inflammatoires et de l’inflammasome NLRP3 dans les infections intracellulaires : cas de H. pylori et des virus à ARN

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    Helicobacter pylori (H. pylori) is a bacteria that infects the stomach and induces inflammatory gastritis, which can be chronic and progress to gastric cancer. The severity of the infection and its clinical course are associated with various factors including the immune status of the host. The initial inflammatory response to H. pylori infection results in the secretion of a wide range of cytokines, including interleukin-1β (IL-1β), IL-8 and IL-17A. which appear to play a key role in the initiation and progression of gastric cancer. Among these cytokines, IL-1β is a key cytokine during H. pylori infection whose expression is associated with gastric inflammation and carcinogenesis. The production of this cytokine depends on the activation of the inflammasome, in particular the NLRP3 inflammasome. The latter, responsible of the activation of inflammatory processes, is essential for the maintenance of homeostasis against various pathogenic infections such as bacterial and viral infections.The general objective of this work is i) to study the expression and polymorphism of genes for cytokines such as IL-1β, IL-17 and IL-8 in Moroccan patients infected with H. pylori. ii) explore the activation of the NLRP3 inflammasome by H. pylori and determine the mechanisms involved in the activation of this complex by RNA viruses; known as defined activators of NLRP3.Our results underlined a high prevalence of H. pylori and demonstrated a cytokine signature: it can predict metaplasia during the progression of H. pylori infection involving a decrease in IL17A expression in the antrum and increased expression of IL-1β in the fundus. In particular, the genetic polymorphisms of IL-1β (IL-1β -31 and -511) do not appear to influence IL-1β expression significantly.In view of the difficulties encountered in isolating and culturing H. pylori, we used LPS from H. pylori to stimulate the inflammasome. Our results show that the transfection of cells in vitro with bacterial LPS induces the production of IL-1β which appears to be modulated by caspase 4, NOD1 and NOD2. Furthermore, while it is clearly established that RNA viruses induce activation of the NLRP3 inflammasome, the mechanisms by which these viruses induce IL-1β production are not well understood and remain to be confirmed. The results of this part of the work showed that the replication of cytopathogenic RNA viruses such as vesicular stomatitis virus (VSV) or encephalomyocarditis virus (EMCV) induces lytic cell death leading to an efflux of potassium which triggers activation of the NLRP3 inflammasome. Thus, viruses with a high replication capacity and which have a cytopathic effect are capable of inducing the activation of caspase-1 leading to the production of IL-1β. Conversely, viruses which induce type I IFN response are very poor inducers of the NLRP3 inflammasome.A better understanding of the activation of the inflammasome could help in the development of targeted therapeutic strategies for use in the fight against bacterial and viral infections.Key words: Helicobacter pylori, inflammation, NLRP3 inflammasome, IL-1β, RNA virus.Helicobacter pylori (H. pylori) est une bactérie qui infecte l’estomac et induit une gastrite inflammatoire, qui peut être chronique et évoluer vers un cancer gastrique. La sévérité de l’infection et son évolution clinique sont associées aux différents facteurs notamment le statut immunitaire de l’hôte. La réponse inflammatoire initiale à l'infection à H. pylori entraîne la sécrétion d'un large panel de cytokines, notamment l'interleukine-1β (IL-1β), l'IL-8 et l'IL-17A. qui semblent jouer un rôle clé dans l'initiation et la progression du cancer gastrique. Parmi ces cytokines, l'IL-1β est une cytokine clé au cours de l’infection à H. pylori dont l’expression est étroitement associée à l'inflammation gastrique et à la carcinogenèse. La production de cette cytokine dépend de l'activation de l'inflammasome, en particulier l'inflammasome NLRP3. Ce dernier, responsable de l’activation des processus inflammatoires, est essentiel pour le maintien de l'homéostasie contre diverses infections pathogènes telles les infections bactérienne et virale.L’objectif général de ce travail est i) d’étudier l’expression et le polymorphisme des gènes de cytokines comme IL-1β, IL-17 et IL-8 chez des patients marocains infectés par H. pylori. ii) explorer l’activation de l'inflammasome NLRP3 par H. pylori et déterminer les mécanismes impliqués dans l'activation de ce complexe par des virus à ARN ; connus comme des activateurs définis de NLRP3.Nos résultats ont souligné une prévalence élevée de H. pylori et ont mis en évidence une signature cytokinique : elle peut prédire la métaplasie au cours de la progression de l'infection à H. pylori impliquant une diminution de l’expression de l'IL17A dans l’antre et une augmentation de l’expression de l'IL-1β dans le fundus. Plus particulièrement, les polymorphismes génétiques de l’IL-1β (IL-1β -31 et -511) ne semblent pas influencer l’expression de l’IL-1β de manière significative.Au regard des difficultés rencontrés pour l’isolement et la culture de H. pylori, nous avons utilisé le LPS de H. pylori pour stimuler l’inflammasome. Nos résultats montrent que la transfection des cellules in vitro par le LPS bactérien induit la production de l’IL-1β qui semble être modulée par la caspase 4, NOD1 et NOD2. Par ailleurs, bien qu’il soit clairement établi que les virus à ARN induisent l’activation de l’inflammasome NLRP3, les mécanismes par lesquels ces virus induisent la production d'IL-1β ne sont pas bien compris et restent à confirmer. Les résultats de cette partie du travail ont montré que la réplication des virus à ARN cytopathogènes tels que le virus de la stomatite vésiculaire (VSV) ou le virus de l'encéphalomyocardite (EMCV) induit une mort cellulaire lytique conduisant à un efflux de potassium qui déclenche l'activation de l'inflammasome NLRP3. Ainsi, les virus à forte capacité de réplication et qui ont un effet cytopathique sont capables d'induire l'activation de la caspase-1 conduisant à la production d'IL-1β. A l'inverse, les virus qui induisent une très bonne réponse IFN de type I sont de très mauvais inducteurs de l'inflammasome NLRP3.Une meilleure compréhension de l’activation de l’inflammasome pourrait aider dans la mise au point de stratégies thérapeutiques ciblées utilisables dans la lutte contre les infections bactérienne et virale.Mots clés : Helicobacter pylori, inflammation, inflammasome NLRP3, IL-1β, virus à ARN

    The Role of Optineurin in Antiviral Type I Interferon Production

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    After a viral infection and the stimulation of some pattern-recognition receptors as the toll-like receptor 3 in the endosomes or the RIG-I-like receptors in the cytosol, activation of the IKK-related kinase TBK1 leads to the production of type I interferons (IFNs) after phosphorylation of the transcription factors IRF3 and IRF7. Recent findings indicate an involvement of K63-linked polyubiquitination and of the Golgi-localized protein optineurin (OPTN) in the activation of this crucial kinase involved in innate antiviral immunity. This review summarizes the sensing of viruses and the signaling leading to type I IFN production following TBK1 activation through its ubiquitination and the sensing of ubiquitin chains by OPTN at the Golgi apparatus

    Exploration of Pro-Inflammatory Cytokines and NLRP3 Inflammasome in Intracellular Infections : Cases of H. pylori and RNA Viruses

    No full text
    Helicobacter pylori (H. pylori) est une bactérie qui infecte l’estomac et induit une gastrite inflammatoire, qui peut être chronique et évoluer vers un cancer gastrique. La sévérité de l’infection et son évolution clinique sont associées aux différents facteurs notamment le statut immunitaire de l’hôte. La réponse inflammatoire initiale à l'infection à H. pylori entraîne la sécrétion d'un large panel de cytokines, notamment l'interleukine-1β (IL-1β), l'IL-8 et l'IL-17A. qui semblent jouer un rôle clé dans l'initiation et la progression du cancer gastrique. Parmi ces cytokines, l'IL-1β est une cytokine clé au cours de l’infection à H. pylori dont l’expression est étroitement associée à l'inflammation gastrique et à la carcinogenèse. La production de cette cytokine dépend de l'activation de l'inflammasome, en particulier l'inflammasome NLRP3. Ce dernier, responsable de l’activation des processus inflammatoires, est essentiel pour le maintien de l'homéostasie contre diverses infections pathogènes telles les infections bactérienne et virale.L’objectif général de ce travail est i) d’étudier l’expression et le polymorphisme des gènes de cytokines comme IL-1β, IL-17 et IL-8 chez des patients marocains infectés par H. pylori. ii) explorer l’activation de l'inflammasome NLRP3 par H. pylori et déterminer les mécanismes impliqués dans l'activation de ce complexe par des virus à ARN ; connus comme des activateurs définis de NLRP3.Nos résultats ont souligné une prévalence élevée de H. pylori et ont mis en évidence une signature cytokinique : elle peut prédire la métaplasie au cours de la progression de l'infection à H. pylori impliquant une diminution de l’expression de l'IL17A dans l’antre et une augmentation de l’expression de l'IL-1β dans le fundus. Plus particulièrement, les polymorphismes génétiques de l’IL-1β (IL-1β -31 et -511) ne semblent pas influencer l’expression de l’IL-1β de manière significative.Au regard des difficultés rencontrés pour l’isolement et la culture de H. pylori, nous avons utilisé le LPS de H. pylori pour stimuler l’inflammasome. Nos résultats montrent que la transfection des cellules in vitro par le LPS bactérien induit la production de l’IL-1β qui semble être modulée par la caspase 4, NOD1 et NOD2. Par ailleurs, bien qu’il soit clairement établi que les virus à ARN induisent l’activation de l’inflammasome NLRP3, les mécanismes par lesquels ces virus induisent la production d'IL-1β ne sont pas bien compris et restent à confirmer. Les résultats de cette partie du travail ont montré que la réplication des virus à ARN cytopathogènes tels que le virus de la stomatite vésiculaire (VSV) ou le virus de l'encéphalomyocardite (EMCV) induit une mort cellulaire lytique conduisant à un efflux de potassium qui déclenche l'activation de l'inflammasome NLRP3. Ainsi, les virus à forte capacité de réplication et qui ont un effet cytopathique sont capables d'induire l'activation de la caspase-1 conduisant à la production d'IL-1β. A l'inverse, les virus qui induisent une très bonne réponse IFN de type I sont de très mauvais inducteurs de l'inflammasome NLRP3.Une meilleure compréhension de l’activation de l’inflammasome pourrait aider dans la mise au point de stratégies thérapeutiques ciblées utilisables dans la lutte contre les infections bactérienne et virale.Mots clés : Helicobacter pylori, inflammation, inflammasome NLRP3, IL-1β, virus à ARN.Helicobacter pylori (H. pylori) is a bacteria that infects the stomach and induces inflammatory gastritis, which can be chronic and progress to gastric cancer. The severity of the infection and its clinical course are associated with various factors including the immune status of the host. The initial inflammatory response to H. pylori infection results in the secretion of a wide range of cytokines, including interleukin-1β (IL-1β), IL-8 and IL-17A. which appear to play a key role in the initiation and progression of gastric cancer. Among these cytokines, IL-1β is a key cytokine during H. pylori infection whose expression is associated with gastric inflammation and carcinogenesis. The production of this cytokine depends on the activation of the inflammasome, in particular the NLRP3 inflammasome. The latter, responsible of the activation of inflammatory processes, is essential for the maintenance of homeostasis against various pathogenic infections such as bacterial and viral infections.The general objective of this work is i) to study the expression and polymorphism of genes for cytokines such as IL-1β, IL-17 and IL-8 in Moroccan patients infected with H. pylori. ii) explore the activation of the NLRP3 inflammasome by H. pylori and determine the mechanisms involved in the activation of this complex by RNA viruses; known as defined activators of NLRP3.Our results underlined a high prevalence of H. pylori and demonstrated a cytokine signature: it can predict metaplasia during the progression of H. pylori infection involving a decrease in IL17A expression in the antrum and increased expression of IL-1β in the fundus. In particular, the genetic polymorphisms of IL-1β (IL-1β -31 and -511) do not appear to influence IL-1β expression significantly.In view of the difficulties encountered in isolating and culturing H. pylori, we used LPS from H. pylori to stimulate the inflammasome. Our results show that the transfection of cells in vitro with bacterial LPS induces the production of IL-1β which appears to be modulated by caspase 4, NOD1 and NOD2. Furthermore, while it is clearly established that RNA viruses induce activation of the NLRP3 inflammasome, the mechanisms by which these viruses induce IL-1β production are not well understood and remain to be confirmed. The results of this part of the work showed that the replication of cytopathogenic RNA viruses such as vesicular stomatitis virus (VSV) or encephalomyocarditis virus (EMCV) induces lytic cell death leading to an efflux of potassium which triggers activation of the NLRP3 inflammasome. Thus, viruses with a high replication capacity and which have a cytopathic effect are capable of inducing the activation of caspase-1 leading to the production of IL-1β. Conversely, viruses which induce type I IFN response are very poor inducers of the NLRP3 inflammasome.A better understanding of the activation of the inflammasome could help in the development of targeted therapeutic strategies for use in the fight against bacterial and viral infections.Key words: Helicobacter pylori, inflammation, NLRP3 inflammasome, IL-1β, RNA virus

    The role of optineurin in antiviral type I interferon production

    No full text
    After a viral infection and the stimulation of some pattern-recognition receptors as the toll-like receptor 3 in the endosomes or the RIG-I-like receptors in the cytosol, activation of the IKK-related kinase TBK1 leads to the production of type I interferons (IFNs) after phosphorylation of the transcription factors IRF3 and IRF7. Recent findings indicate an involvement of K63-linked polyubiquitination and of the Golgi-localized protein optineurin (OPTN) in the activation of this crucial kinase involved in innate antiviral immunity. This review summarizes the sensing of viruses and the signaling leading to type I IFN production following TBK1 activation through its ubiquitination and the sensing of ubiquitin chains by OPTN at the Golgi apparatus

    The role of optineurin in antiviral type I interferon production

    No full text
    International audienceAfter a viral infection and the stimulation of some pattern-recognition receptors as the toll-like receptor 3 in the endosomes or the RIG-I-like receptors in the cytosol, activation of the IKK-related kinase TBK1 leads to the production of type I interferons (IFNs) after phosphorylation of the transcription factors IRF3 and IRF7. Recent findings indicate an involvement of K63-linked polyubiquitination and of the Golgi-localized protein optineurin (OPTN) in the activation of this crucial kinase involved in innate antiviral immunity. This review summarizes the sensing of viruses and the signaling leading to type I IFN production following TBK1 activation through its ubiquitination and the sensing of ubiquitin chains by OPTN at the Golgi apparatus

    Leptospira interrogans Prevents Macrophage Cell Death and Pyroptotic IL-1β Release through Its Atypical Lipopolysaccharide

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    International audienceLeptospira interrogans are bacteria that can infect all vertebrates and are responsible for leptospirosis, a neglected zoonosis. Some hosts, such as humans, are susceptible to the disease, whereas mice are resistant and get chronically colonized. Although leptospires escape recognition by some immune receptors, they activate the NOD-like receptor pyrin 3–inflammasome and trigger IL-1β secretion. Classically, IL-1β secretion is associated with lytic inflammatory cell death called pyroptosis, resulting from cytosolic LPS binding to inflammatory caspases, such as caspase 11. Interestingly, we showed that L. interrogans and Leptospira biflexa do not trigger cell death in either murine, human, hamster, or bovine macrophages, escaping both pyroptosis and apoptosis. We showed, in murine cells, that the mild IL-1β secretion induced by leptospires occurred through nonlytic caspase 8–dependent gasdermin D pore formation and not through activation of caspase 11/noncanonical inflammasome. Strikingly, we demonstrated a potent antagonistic effect of pathogenic L. interrogans and their atypical LPS on spontaneous and Escherichia coli LPS-induced cell death. Indeed, LPS of L. interrogans efficiently prevents caspase 11 dimerization and subsequent massive gasdermin D cleavage. Finally, we showed that pyroptosis escape by leptospires prevents massive IL-1β release, and we consistently found no major role of IL-1R in controlling experimental leptospirosis in vivo. Overall, to our knowledge, our findings described a novel mechanism by which leptospires dampen inflammation, thus potentially contributing to their stealthiness

    IL-1 Polymorphism and <i>Helicobacter pylori</i> Infection Features: Highlighting VNTR’s Potential in Predicting the Susceptibility to Infection-Associated Disease Development

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    Genetic polymorphisms at the IL-1 cluster are associated with increased Helicobacter pylori (H. pylori)-associated disease risk in an ethnically dependent manner. Due to the corroborated role of IL-1β in H. pylori infection progression, our aim is to depict the impact of IL1B rs1143627 and rs16944 as well as the IL1RN variable number of identical tandem repeats (VNTR) on the clinical and biological features of Moroccan H. pylori-infected patients. A total of 58 patients with epigastralgic pain were referred to the gastroenterology department for histopathological and clinical analysis. DNA extraction from antrum and fundus biopsies and PCR–RFLP were performed to detect polymorphisms. As a result, VNTR was significantly associated with IL-1β antrum levels (p-value = 0.029), where the *1/*4 genotype showed a positive association with upregulated cytokine levels in the antrum and was clustered with H. pylori-infected patients’ features and higher levels of IL-1β in the antrum and fundus. Likewise, *1/*1 genotype carriers clustered with severe gastritis activity and H. pylori density scores along with low levels of IL-1β in the antrum and fundus, while the *1/*2 genotype was clustered with non-infected-patient features and normal IL-1β levels. In conclusion, VNTR might be an interesting predictor to identify patients at risk of developing H. pylori-associated pathologies
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