Induction of peripheral CD4+ T-cell tolerance and CD8+ T-cell cross-tolerance by dendritic cells.

DC can present and cross-present self-antigens to autoreactive CD4(+) and CD8(+) T cells, respectively, and incapacitate them by inducing anergy, deletion or converting them into Treg. In this review, we summarize the recent progress in immune tolerance research, which has been achieved by employing antigen- and TCR-transgenic mice. We cover the numerous discoveries that have furthered our knowledge of the DC subsets and maturation pathways involved in tolerance; the signals, such as CD70, TGF-beta, B7-H1/PD-L1, which dictate the decision between immunity and tolerance; and the in vivo role of DC in the maintenance of CD4(+) T-cell tolerance and CD8(+) T-cell cross-tolerance.