Dietary antigens limit mucosal immunity by inducing regulatory T cells in the small intestine

Abstract

Keeping immune cells quiet on a diet Over thousands of years, our immune systems has evolved to distinguish self from foreign, perpetrating attacks on microbes but not ourselves. Given this, why do we fail to mount an immune response against most of the food we eat? Kim et al. compared normal mice, mice lacking microbes, and mice lacking microbes that were fed an elemental diet devoid of dietary antigens (see the Perspective by Kuhn and Weiner). Dietary antigens normally induced a population of suppressive immune cells called regulatory T cells in the small intestine. The cells were distinct from regulatory T cells induced by microbial antigens and prevented strong reactions against food. Science , this issue p. 858 ; see also p. 810