title: Active suppression of the allogeneic histocompatibility reactions during the metamorphosis of the clawed toad Xenopus.
abstract: Metamorphosis is a privileged period for the induction of tolerance to allografts. Transfer of lymphocytes from metamorphosing Xenopus into isogenic adults prevented the rejection of a skin graft differing from the adult host by minor histocompatibility antigens. This implies that active suppression is involved at one step of the induction of tolerance to the self-antigens that differentiate at the time of metamorphosis. The reciprocal experiments of preventing tolerance induction by transfer of normal adult cells into metamorphosing animals failed. However, passive transfer of anti-graft immunity in tolerant animals was partially observed, provided that a transfer of primed cells was done simultaneously with the challenging graft. Thus, memory cells are not as sensitive to the suppression as are the cells that respond in a first set reaction.
mesh_terms: D000818:Animals; D006649:Histocompatibility Antigens / Q000235:genetics; D007108:Immune Tolerance; D007165:Immunosuppression Therapy; D007814:Larva / Q000276:immunology; D017710:Lymphocyte Transfusion; D008675:Metamorphosis, Biological; D013154:Spleen / Q000637:transplantation; D014184:Transplantation, Homologous; D014981:Xenopus / Q000276:immunology* / Q000502:physiology
chemical_list: D006649:Histocompatibility Antigens