研究显示幼儿时期的免疫系统锻炼可能是至关重要的

Microbial Exposure During Early Life Has Persistent Effects on Natural Killer T Cell Function

• Torsten Olszak, 
• Dingding An, 
• Sebastian Zeissig, 
• Miguel Pinilla Vera, 
• Julia Richter,
• Andre Franke, 
• Jonathan N. Glickman, 
• Reiner Siebert, 
• Rebecca M. Baron, 
• Dennis L. Kasper,
• and Richard S. Blumberg

Science 1219328Published online 22 March 2012
Exposure to microbes during early childhood is associated with protection from immune-mediated diseases such as inflammatory bowel disease (IBD) and asthma. Here, we show that, in germ-free (GF) mice, invariant natural killer T (iNKT) cells accumulate in the colonic lamina propria and lung, resulting in increased morbidity in models of IBD and allergic asthma compared to specific pathogen-free (SPF) mice. This was associated with increased intestinal and pulmonary expression of the chemokine ligand CXCL16, which was associated with increased mucosal iNKT cells. Colonization of neonatal—but not adult—GF mice with a conventional microbiota protected the animals from mucosal iNKT accumulation and related pathology. These results indicate that age-sensitive contact with commensal microbes is critical for establishing mucosal iNKT cell tolerance to later environmental exposures.