Licensing microbes for symbiosis

Abstract

Mucosal Immunology Gut microbiota have several important functions, including aiding host metabolism and limiting pathogen invasion by competing for essential nutrients. To establish and sustain this symbiotic relationship, it is vital that the host develops tolerance to gut microbial antigens early in life. Knoop et al. found that mouse gut tolerance to symbionts develops between 10 and 20 days after birth and is perfectly synchronized with the formation of goblet cell-associated antigen passages (GAPs) in the colon. These GAPs facilitate transport of bacterial antigens from the gut lumen to the lamina propria. Thus, gut microbial tolerance is restricted to microbes that colonize the colon early in life. Sci. Immunol. 2 , eaao1314 (2017).