芽孢杆菌影响NLRP6介导的沙门菌免疫逃逸与激发猪肠上皮细胞自噬的作用机理

Salmonella are pathogens that seriously threaten human public health, and also cause enteric infectious diseases in swine. The host regulates the balance of intestinal microflora via NLRP6 pathway, while exploits the autophagy for clearance of the pathogens. Salmonella escape the host’s immune surveillance by the mechanism which suppresses the non-canonical NF-κB pathway regulated by NLRP6. In the present work, a porcine model of Salmonella infection in vivo will be established, and the in vitro model, combined with the CRISPR/Cas9 gene knockout technology in order to build the target gene deletion porcine intestinal epithelial cells line, are also constructed. The aims of the present work are to test the hypotheses: (1) a selected mixture of Bacillus prevents NLRP6-mediated Salmonella escape via promoting the activation of NF-κB and MAPK signal pathway; (2) Bacillus promotes the transformation of autophagy-related protein LC3-I to LC3-II and exploits the autophagy for Salmonella clearance and replication; and (3) Bacillus affects RORγt+ ILC3s and CD4+ T cell subset (TH1, TH17 and Treg cells) population. The present work will reveal the mechanism of Bacillus prevents NLRP6-mediated immune escape of Salmonella and exploits the autophagy in porcine intestinal epithelial cells. Select probiotics may allow for tailoring strategies to control and prevent Salmonella disease.

沙门菌严重威胁人类公共卫生与健康，也是引起猪肠道感染的重要致病菌。机体通过NLRP6途径调节肠道微生态区系平衡，同时经宿主自噬加速对病原菌的清除。沙门菌可利用NLRP6抑制非经典NF-κB途径以逃逸宿主的免疫监控。本项目拟建立仔猪沙门菌感染模型，结合运用CRISPR/Cas9基因敲除技术构建目的基因缺失的猪肠上皮细胞系，旨在通过研究：（1）优选芽孢杆菌混合制剂可通过促进NF-κB活化和激活MAPK信号转导途径，从而阻止NLRP6介导的沙门菌免疫逃逸；（2）芽孢杆菌诱导自噬体相关蛋白LC3-I向LC3-II转化与宿主自噬在沙门菌清除和复制过程中的作用；和（3）芽孢杆菌对肠黏膜RORγt+ILC3s和CD4+ T细胞亚群（TH1、TH17 及Treg细胞）分布规律的影响，揭示芽孢杆菌阻止NLRP6介导的沙门菌免疫逃逸与激发猪肠上皮细胞自噬的作用机理，为合理运用益生菌防控沙门菌病提供科学依据。

沙门菌严重威胁人类公共卫生与健康，也是引起猪肠道感染的重要致病菌。机体通过NLRP6途径调节肠道微生态区系平衡，同时经宿主自噬加速对病原菌的清除。沙门菌可利用NLRP6抑制非经典NF-κB途径以逃逸宿主的免疫监控。本项目拟建立仔猪沙门菌感染模型，结合运用CRISPR/Cas9基因敲除技术构建目的基因缺失的猪肠上皮细胞系，旨在通过研究：（1）优选芽孢杆菌混合制剂可通过促进NF-κB活化和激活MAPK信号转导途径，从而阻止NLRP6介导的沙门菌免疫逃逸；（2）芽孢杆菌诱导自噬体相关蛋白LC3-I向LC3-II转化与宿主自噬在沙门菌清除和复制过程中的作用；和（3）芽孢杆菌对肠黏膜RORγt+ILC3s和CD4+ T细胞亚群（TH1、TH17 及Treg细胞）分布规律的影响，揭示芽孢杆菌阻止NLRP6介导的沙门菌免疫逃逸与激发猪肠上皮细胞自噬的作用机理，为合理运用益生菌防控沙门菌病提供科学依据。