中文摘要：

为了探讨肠道固有层NK细胞在抵抗肠道胞内菌感染中作用,我们建立了鼠伤寒沙门氏菌肠道感染模型,发现在用抗体清除NK1.1＋NK细胞后,小鼠体重明显下降,肠系膜淋巴结和肝脾等部位的载菌量显著增多;继而应用流式细胞技术检测到感染后小肠固有层中NK细胞数量明显增加,发生明显活化,且IFN-γ的表达量增多;最后我们观察到,清除NK细胞明显削弱小鼠肠道固有层巨噬细胞的杀菌能力。结果表明,肠道NK细胞在抵抗肠道病原微生物入侵时发挥关键的作用,并且可通过促进肠道固有层巨噬细胞的活化增强巨噬细胞对病原菌的清除作用。

英文摘要：

To explore the role of intestinal NK cells in the defense against intracelllular bacteria infection,an intestinal Salmonella infection model was established with S.typhimuriumstrain.In vivo depletion of NK cells with anti-NK1.1antibody resulted in severe loss of weight and a significant increase of bacteria load in the mesentery lymphoid nodes（MLN）,liver and spleen.The number of NK cells and the frequency of activated NK cells in the small intestine augmented and the production of IFN-γincreased after S.typhimuriuminfection.Moreover,depletion of NK cells led to significant attenuation of macrophage activation and production of bactericidal substances,such as ROS and IL-1βby macrophages.These results showed that intestinal NK cells are necessary for reducing pathogen burden and contribute to protection against the Salmonella typhimurium through promoting the activation and function of macrophages.