A 'natural' way to provide innate mucosal immunity

The mucosal barrier comprises a layered defense system including physio-chemical and immunological strategies to contain commensal microflora while protecting the host against potential pathogens. In contrast to the clearly established and well-characterized role for the adaptive immune system in intestinal defense, our knowledge on innate immune mechanisms that operate in the gut is much less defined. The recent identification of novel innate lymphoid cells (ILC), including 'NK-like' cells that naturally produce IL-22 and appear to play a role in intestinal defense, demonstrates an unexpected and increasing complexity in mucosal innate immunity.