[Regulatory T cells - a possible promising target in the treatment of autoimmune diseases].

Regulatory T-cells play a key-role in maintaining immunological tolerance to self and may have a key role in the development of new therapeutic principles. We present an overview of the current concepts of regulatory T-cells. A proportion of these cells develops during normal T-cell maturation in the thymus, while other subtypes are induced in the periphery. They have similar functional properties: they proliferate poorly, inhibit the activation of other T-cells and are protective in models of autoimmunity. The underlying mechanisms are not completely understood, probably cell-cell-contact dependent mechanisms and cytokines such as IL-10 and TGF beta play a role. Besides CD25 several other surface markers are known to identify regulatory T-cells, however, none of these markers seems to be exclusive for regulatory T-cells. Finally, we give an outlook over possible therapeutic applications of these cells.