Regulatory T cells for immunotherapy of autoimmune diseases: from the bench to the bedside

The induction of antigen-specific unresponsiveness or tolerance is critical for the prevention of autoimmunity and maintenance of immune homeostasis. The presence of regulatory T cells (Treg cells) has been recently demonstrated in animals and in humans. Interestingly, Treg cells may be either quantitatively or qualitatively altered in human autoimmune diseases, for example, multiple sclerosis, psoriasis, Type 1 diabetes and inflammatory bowel disease (IBD), suggesting a role in disease pathophysiology. The present review summarises the emerging literature on the developmental origin and function of human Treg cells. The potential clinical application of Treg cells to human autoimmune diseases and to post-transplantation graft-versus-host disease is discussed.