[Mechanisms in the induction and maintenance of transplantation tolerance: an overview].

Transplantation tolerance is used as model for investigation of mechanisms in recognition of "self" and "non-self". The clonal deletion of specific lymphocytes as reason transplantation tolerance is called more and more in question. Active mechanims, as for instance induction and maintenance by suppressor cells are more possible. Suppressor cells may be active not only in inhibition of inductor phase but also in blocking of effector cells. A synergistic effect of blocking factors is supposed too. The thymus plays an important role in induction of transplantation tolerance. Different methods for induction of tolerance are described.