Preface.- Selection of CD4+CD25+ Regulatory T Cells by Self-Peptides.- The Role of TCR Specificity in Naturally Arising CD25+ CD4+ Regulatory T Cell Biology.- Thymic Commitment of Regulatory T Cells Is a Pathway of TCR-Dependent Selection That 'Isolates' Repertoires Undergoing Positive or Negative Selection.- Selection and Behaviour of CD4+CD25+ T Cells in vivo: Lessons from T Cell Receptor Transgenic Models.- Migration Matters: Functional Properties of Naïve- and Effector/Memory-Like Regulatory T Cell Subsets.- Peripheral Generation and Function of CD4+CD25+ Regulatory T Cells.- Dendritic Cells, Key Cells for the Induction of Regulatory T Cells?.- Autoimmune Gastritis Is a Well-Defined Autoimmune Disease Model for the Study or CD4+CD25+ T Cell-Mediated Suppresion.- Regulatory T Cells in Experimental Colitis.- Autoimmune Ovarian Disease in Day 3-Thymectomized Mice: the Neonatal Time Window, Antigen Specificity of Disease Suppression, and Genetic Control.- Regulatory T Cells in Transplantation Tolerance. Infectious Tolerance.- CD4+CD25+ Regulatory T Cells in Hematopoietic Stem Cell Transplantation.- ..................- Phenotypic and Functional Differences Between Human CD4+CD25+ and Type 1 Regulatory T Cells.- Subject Index.

yetwehopethatitwillofferinspirationandorientationtothescientistwho wouldliketoenterthis?eld. To date, many different cells have been described that can suppress + + other cells of the immune system: CD4 CD25 regulatory T cells (Treg), + ? CD4 CD25 regulatory T cells, T regulatory 1 cells (Tr1), T-helper 3 cells + ? (Th3),CD8 CD28 Tcells,NKTcells,aswellastolerogenicdendriticcells. Suppressive CD4 T cells fall at least into two categories. So called natural VI Preface + + CD4 CD25 Tregformpartoftheintra-thymicallyselectedTcellrepertoire andapparentlyconstituteadistinctlineage. Incontrast,"adaptive"regulatory Tcellsareinstructedintheperipherytobecomesuppressivecells,theyform + + amoreheterogeneousgroupincludingCD4 CD25 Treg,Tr1,andTh3cells. As natural Treg are so far the best characterized entity, the ?rst three contributionsofthisvolume(C. Cozzoetal. ,C. -S. Hsiehetal. ,andL.