Tolerogenic dendritic cells and induction of T suppressor cells in transplant recipients.

Tolerogenic antigen presenting cells (APC), primarily dendritic cells (DC), are essential to the induction and maintenance of immunologic tolerance in clinical transplantation. They induce the differentiation of CD8+ T suppressor (Ts) and CD4+ T regulatory (Treg) or anergic cells, which prevent transplant rejection maintaining a state of quiescence. Tolerogenic APC express high levels of inhibitory receptors such as Immunoglobulin-like transcript (ILT)3 and 4 which inhibit the effector function of T cells that recognize HLA-peptide complexes on APC. Here, we describe the methods for detection of tolerogenic APC induced by allospecific Ts/Treg cells.