Control of immune pathology by regulatory T cells

There is now compelling evidence that immune responses for both foreign and self antigens are downregulated by T cells that are specialised for this function; these are known as regulatory T (T reg) cells. This review describes progress in the characterisation of the T reg cells that mediate both mucosal tolerance and tolerance to self antigens. The recent work on the antigen specificity, generation and mode of action of T reg cells is also reviewed.