title: Studies on the mechanism of chronic graft rejection in mice.
abstract: Acute and chronic types of rejection after transplantation are distinguished. The exact mechanism, however, by which the different types of rejections have been brought about are not clarified. In this study, experimental data are presented on some characteristics of the chronic type of graft rejection. Allografting was performed between isogeneic mouse strains differing at their strong histocompatibility antigens. Recipients were treated with antithymocyte serum (ATS). Those recipients which showed a chronic type of graft rejection were selected and regrafted with a second-set or a third party allograft. It was found that, in most cases, the chronic rejection of first-set allografts did not results in a sensitization (= accelerated rejection), but rather in a partial specific tolerance (= prolonged graft survival) to a second-set allograft. Furthermore, transfer of spleen cells from mice of chronic rejection into normal, adult, ATS-treated, allografted mice did not result in any significant change of the mean graft survival as compared to mice not receiving spleen cell transfer. On the other hand, transfer of spleen cells from mice with acutely rejected grafts resulted in a shortened graft survival. It is supposed that the partial specific tolerance observed after chronic graft rejection may be maintained rather by a specific suppressor mechanism than clonal deletion.
mesh_terms: D000818:Animals; D000961:Antilymphocyte Serum / Q000627:therapeutic use; D002908:Chronic Disease; D006084:Graft Rejection; D006085:Graft Survival; D006649:Histocompatibility Antigens; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008808:Mice, Inbred CBA; D011817:Rabbits; D016038:Skin Transplantation; D013154:Spleen / Q000637:transplantation; D013997:Time Factors
chemical_list: D000961:Antilymphocyte Serum; D006649:Histocompatibility Antigens