Prenatal maternal infection promotes tissue-specific immunity and inflammation in offspring

Mom’s IL-6 rewires baby’s gut immunity Most infections that occur during pregnancy are mild and transient. However, whether such pathogen encounters can shape the long-term trajectory of the offspring’s immune system remains unclear. Lim et al . infected pregnant mice with the common food-borne pathogen Yersinia pseudotuberculosis (YopM) (see the Perspective by Amir and Zeng). Although the infection was maternally restricted and short-lived, the offspring harbored greater numbers of intestinal T helper 17 cells into adulthood. Interleukin-6 (IL-6) mediated this tissue-restricted effect by acting on fetal intestinal epithelium during development. Although offspring from mothers infected with YopM or injected with IL-6 showed enhanced resistance to oral infection with Salmonella Typhimurium, they also exhibited higher susceptibility toward enteric inflammatory disease. —STS