Preliminary study on tolerance induction by combined xenotransplantation of rat thymus and metanephros anlagen / 中华微生物学和免疫学杂志

ABSTRACT

ObjectiveTo investigate whether the cellular immune function of athymia nude mice can be reestablished and whether the recipients' specific immune tolerance can be induced by the combined xenotransplantation of embryonic thymus and metanephros anlagen from rats to athymia nude mice.Methods Male and female rats were mated overnight.The presence of vaginal plaques was marked as the embryonic day 0(E0).The whole embryos from Lewis rats on embryonic day 15(E15) were taken for the present experiment.The Lewis E15 metanephros and thymus anlagen were taken out from the embryos and immediately preserved in normal saline at 4℃,and then were implanted into the omentum and renal capsule of nude mice.10 weeks post-implantation,the peritoneotomy was carried out on some recipients,metanephros and thymus transplants were removed for histopathological examination.The concentrations of urea nitrogen and creatinine in cyst fluid from the metanephros transplants were measured.The survival time of the recipients was observed after nephrectomy.The blood of the recipients was obtained to detect the re-establishment of T lymphocyte with flow cytometry(FCM).The lymphocyte suspension extracted from recipients were mixed respectively with the spleen cells suspension of Lewis rats,BN rats or C57BL/6 mice to perform mixed lymphocyte reaction(MLR) test.The skins of Lewis rats,BN rats,C57BL/6 and nude mice were transplanted in the chest-back of the recipients to observe the reject reaction.Results10 weeks post-implantation,both E15 metanephros and thymus transplants were enlarged,and showed well-developed structure under optical microscope and electronic microscope.Metanephros displayed partial excreting function.The concentrations of urea nitrogen and creatinine in cyst fluid from the metanephros transplants were close to the concentrations in the bladder urine.The combined transplant recipients survived longer than the others after nephrectomy(P ＜0.05).The re-establishment of T lymphocyte from the blood of recipients was certified by FCM.MLR indicated that the lymphocyte of the combined transplant recipients had normal reaction to the spleen cells of the BN rats and C57BL/6 mice,but had under-reaction to the donor Lewis's( P＜0.01 ).Survival time of the skin from donor Lewis is longer than that of the BN rats' and the C 5 7 BL/6 mice' s ( P ＜ 0.01 ).Conclusion E15 Lewis metanephros and thymus anlagen heterografted into the athymia nude mice will grow and function well.The nude mice with combined transplantation of E15 Lewis thymus and metanephros anlagen can reestablish immunologic function and may induce tolerance to the metanephros and skin graft from donor Lewis