Immune tolerance induced by combined heart-thymus transplantation for heart allograft in rats / 中南大学学报(医学版)

ABSTRACT

OBJECTIVE@#To explore the role of combined heart-thymus transplantation for heart allograft in rats.@*METHODS@#Vascularized heart-thymus combined transplantation was performed with microsurgical technique. Graft survival, histopathology, infiltration of CD4+, CD8+ T cells, level and mRNA expressions of IL-2 and IL-4 in the serum and cardiac grafts were investigated.@*RESULTS@#Heart allograft in the controls had a survival time of (6.0+/-0.76) d. heart-thymus combined transplantation in non-thymectomized rats had a survival time of (6.88+/-0.64)d (P<0.05). Heart-thymus combined transplantation in thymectomized rats led to an evident survival time of (14.13+/-5.82)d (P<0.01) for cardiac graft, which further obtained long term survival after short course of treatment with cyclosporine. Pathologic lesion and infiltration of CD4+ and CD8+ T cells in cardiac grafts showed mitigated in the long term survival group. IL-2 level in the serum and cardiac grafts maintained low level in the long term survival group, whereas IL-4 maintained high level.@*CONCLUSION@#Whether thymectomized or not in recipient rats, heart-thymus combined transplantation has a positive effect to protect cardiac graft. Furthermore, in thymectomized rats heart-thymus combined transplantation may lead to evident survival prolongation of the heart grafts, which induces immune tolerance in short course of treatment with cyclosporine.