Exploration of Pro-Inflammatory Cytokines and NLRP3 Inflammasome in Intracellular Infections : Cases of H. pylori and RNA Viruses ; Exploration des cytokines pro-inflammatoires et de l’inflammasome NLRP3 dans les infections intracellulaires : cas de H. pylori et des 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 ...