Abstract
CD4+CD25+ regulatory lymphocytes (Treg) are recognized as the most important regulatory cells of the immune system and are involved in immune tolerance, autoimmunity, inflammation, transplantation, cancer and HIV infection. Tregs can be naturally occurring (nTregs), derived from the thymus or induced in the periphery from naive cells (iTregs). Both lymphocytes (nTregs and iTregs) have sim…