| Objective This study was designed to investigate the effect of intrathymic inoculation with xenogeneic antigens on the delayed xenograft rejection (DXR) in the model of pig to monkey Heart Xenotransplantation, to inquire the possibility of inducing the recipient's tolerance to the grafted heart and to find the better inducer.Materials and methods Donor(meishan pig) and recipient (rhesus monkey) were divided randomly into four groups. Group A (Control group):without pretreatment; Group B (WBI group):the recipients received 2.5Gy Co60 y-ray whole body irradiation(WBI); Group C (WBI plus intrathymic inoculation with pig SCs group):after WBI, the recipient thymus was injected with the pig SCs(spleen cells) 5 X 107 7days later ,and Group D (WBI plus intrathymic inoculation with the pig VECs group):after WBI, the recipient thymus was injected with the pig VECs(vascular endothelial cells) 5 X 107 7days later. After different pretreatments to the recipients, the abdominal heterotopic heart transplantation from pig to monkey were performed. The grafted heart mean survival time (MST), the percentage of pig-VECs-lysed and the results of MLR (mixed lymphocyte reaction) before transplantation were observed. The change of antibody IgG of the recipient before and after transplantation was detected by the flow cytometry(FCM).Results (1)MST: Group D (124.3 ± 12.0h)>Group C (91.1±22.8h) >Group B (65.2±5.6h)>Group A (36.2±5.9h). Group D and Group Cwere prolonged significantly (P<0.05), and Group D was longer than Group C (P<0.05).(2)The percentage of the pig-VECs-lysed with monkey serums: Group D and Group C were apparently lower than the others (P<0.05), and Group D was lower than Group C (P<0.05).(3)The results of MLR: The proliferation of the recipient T cells in Group D and Group C was particularly inhibited (P<0.05). There was no difference between Group D and Group C (P>0.05).(4)The change of antibody IgG of the recipient: The level of IgG in Group D and Group C ascended slower significantly after transplantation (P<0.05). There was no difference between Group D and Group C (P>0.05).Conclusion (1)lntrathymic inoculation with donor SCs or VECs can delay DXR process and can prolong survival time of the grafted heart, but can't overcome DXR completely in the heart xenotransplantation. (2) Donor VECs was the better inducer than donor SCs in the heart xenotransplantation. |
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