Antibody-induced transplantation tolerance: the role of dominant regulation.

A short-treatment with nondepleting antibodies, such as those targeting CD4 or CD154 (CD40 ligand), allows long-term graft survival without the need for continuous immunosuppression. This state of immune tolerance is maintained by regulatory CD4+ T cells present within both the lymphoid tissue and the tolerated graft. The nature of such regulatory T cells, their relationship to CD4+CD25+ T cells, and their mode of action have all been the subjects of much attention recently. Here, we review recent progress on understanding the nature, specificity, and mechanisms of action of T cells mediating dominant tolerance brought about by antibody therapy.