CD103 spurs on suppressors

An integrin expressed by gut dendritic cells (DCs) gives regulatory T (T reg) cells the green light for suppression, according to a study on page 1051. Annacker and colleagues show that DCs expressing the integrin CD103 are required for T reg cells to subdue gut-attacking effector T cells in a mouse model of inflammatory bowel disease (IBD).Naturally occurring T reg cells help protect against autoimmunity and excessive inflammation by suppressing the activity of effector T cells. This group had previously shown that transferring T reg cells protects against T cell–induced IBD in mice. The suppression of IBD requires the cytokine TGF-β and possibly the high levels of CD103 that are seen in a subset of T reg cells.

Annacker et al. now show, however, that CD103 is not...