白细胞介素-22在猪螺杆菌感染的肥胖小鼠胃黏膜相关淋巴组织中的表达及意义

Expression and significance of IL-22 in the gastric mucosa associated lymphoid tissue of Helicobacter suit infected obese mice

目的探讨白细胞介素-22(IL-22)在猪螺杆菌(Helicobacter suis,H.suis)感染的肥胖小鼠胃黏膜相关淋巴组织(mucosa associated lymphoid tissue,MALT)中的表达及意义。方法 40只雌性C57BL/6小鼠随机分为4组,每组10只,即正常对照组(NC组)、高脂饮食组(HFD组)、感染组(HS组)与感染+高脂饮食组(HS+HFD组)。NC组与HS组给予普通饮食,HFD组与HS+HFD组自感染后第3周开始给予高脂饮食;差异性饮食24周后处死小鼠(实验过程中无小鼠死亡),取其胃组织行HE染色检测各组小鼠胃黏膜淋巴滤泡的数量与大小;Real-time PCR检测各组小鼠胃黏膜IL-22及其受体IL-22R1与B细胞趋化因子CXCL13 mRNA表达水平。结果 H.suis感染可诱导小鼠胃黏膜淋巴滤泡的形成;与HS组相比,HS+HFD组小鼠胃黏膜淋巴滤泡的数量与大小明显增加,胃黏膜IL-22、CXCL13 mRNA表达水平也明显增加。结论高脂饮食诱导的肥胖可促进H.suis感染后胃MALT的形成,其机制可能与肥胖时胃黏膜中IL-22的表达上调有关。

Objective To investigate the expression and significance of IL-22 in the gastric mucosa associated lymphoid tissue(MALT)of Helicobacter suis(H.suis)infected obese mice.Methods Forty female C57BL/6 mice were randomly divided into four groups(10 mice per group),which were named as normal control(NC)group,high fat diet(HFD)group,H.suis infection(HS)group and H.suis infection+high fat diet(HS+HFD)group.The mice in NC group and HS group were given ordinary diet,and the mice in HFD group and HS+HFD group were given high fat diet from the third week postinfection.At 24 weeks after different diets,all of the mice were sacrificed to collect gastric tissues.The number and size of gastric lymphoid follicles were detected by HE staining and the expressions of IL-22 and its receptor IL-22R1,chemokines CXCL13 mRNA in the gastric mucosa of mice were detected by Real-time PCR.Results H.suis infection induced the formation of lymphoid follicles in the gastric mucosa.The number and size of gastric lymphoid follicles and the expressions of IL-22 and CXCL13 mRNA in the gastric mucosa of HS+HFD group were significantly increased compared with HS group.Conclusion High fat diet induced obesity can promote the formation of gastric MALT after H.suis infection.The mechanism may be associated with the upregulation of IL-22.