Introduction: characterization and functions of human T regulatory cells.

The field of human T regulatory (Treg) cells is a rapidly progressing, but still confused field of immunology. The effects of dendritic cell (DC) manipulation in Treg generation and the main features of human "natural" Treg cells, as well as of different populations of adaptive Treg subsets, are still partially unclear. However, it is clear that Treg cells play an important role in human diseases, such as autoimmune disorders, allergy, HIV infection, tumors and graft-versus-host disease.