Institute for Medical Microbiology and Hygiene, University Hospital Tübingen, Tübingen, Germany ; German Centre for Infection Research, University of Tübingen, Tübingen, Germany.
PLoS One. 2013 Aug 20;8(8):e71338. doi: 10.1371/journal.pone.0071338. eCollection 2013.
In industrialized countries bacterial intestinal infections are commonly caused by enteropathogenic Enterobacteriaceae. The interaction of the microbiota with the host immune system determines the adequacy of an appropriate response against pathogens. In this study we addressed whether the probiotic Bifidobacterium adolescentis is protective during intestinal Yersinia enterocolitica infection. Female C57BL/6 mice were fed with B. adolescentis, infected with Yersinia enterocolitica, or B. adolescentis fed and subsequently infected with Yersinia enterocolitica. B. adolescentis fed and Yersinia infected mice were protected from Yersinia infection as indicated by a significantly reduced weight loss and splenic Yersinia load when compared to Yersinia infected mice. Moreover, protection from infection was associated with increased intestinal plasmacytoid dendritic cell and regulatory T-cell frequencies. Plasmacytoid dendritic cell function was investigated using depletion experiments by injecting B. adolescentis fed, Yersinia infected C57BL/6 mice with anti-mouse PDCA-1 antibody, to deplete plasmacytoid dendritic cells, or respective isotype control. The B. adolescentis-mediated protection from Yersinia dissemination to the spleen was abrogated after plasmacytoid dendritic cell depletion indicating a crucial function for pDC in control of intestinal Yersinia infection. We suggest that feeding of B. adolescentis modulates the intestinal immune system in terms of increased plasmacytoid dendritic cell and regulatory T-cell frequencies, which might account for the B. adolescentis-mediated protection from Yersinia enterocolitica infection.
在工业化国家，细菌性肠道感染通常是由肠致病性肠杆菌科引起的。微生物群与宿主免疫系统的相互作用决定了对病原体的适当反应的充分性。在这项研究中，我们研究了双歧杆菌是否在肠道耶尔森菌感染中具有保护作用。雌性 C57BL/6 小鼠用双歧杆菌喂养，感染耶尔森菌，或用双歧杆菌喂养，然后感染耶尔森菌。与感染耶尔森菌的小鼠相比，用双歧杆菌喂养和感染耶尔森菌的小鼠体重减轻和脾脏耶尔森菌负荷明显减少，表明它们免受耶尔森菌感染。此外，这种保护作用与肠道浆细胞样树突状细胞和调节性 T 细胞频率的增加有关。通过用抗小鼠 PDCA-1 抗体注射用双歧杆菌喂养、感染耶尔森菌的 C57BL/6 小鼠，以耗尽浆细胞样树突状细胞，或相应的同种型对照，进行耗尽实验来研究浆细胞样树突状细胞的功能。在用抗 PDCA-1 抗体耗尽浆细胞样树突状细胞后，双歧杆菌介导的对耶尔森菌向脾脏扩散的保护作用被消除，这表明浆细胞样树突状细胞在控制肠道耶尔森菌感染方面具有至关重要的作用。我们认为，双歧杆菌的喂养调节了肠道免疫系统，增加了浆细胞样树突状细胞和调节性 T 细胞的频率，这可能是双歧杆菌介导的对耶尔森菌感染的保护作用的原因。
