Effect of T suppressor cells on the maintenance phase of tolerance to cardiac allografts in the rats / 中华外科杂志

ABSTRACT

<p><b>OBJECTIVE</b>To study the role of T suppressor cells in immune tolerance to cardiac allografts in the rats.</p><p><b>METHODS</b>Male DA rat hearts were transplanted to male Lewis rats using Ono's model and randomly divided into five groups group 1 untreated, group 2 portal venous injection of 3 x 10(8) DA splenocytes to Lewis rat, group 3 intraperitoneal injection of cyclophosphamide (80 mg/kg) to Lewis rat, group 4 portal venous injection of 3 x 10(8) DA splenocytes combined with intraperitoneal injection of cyclophosphamide (80 mg/kg) to Lewis rat, 15 days later heart transplantation was performed. Group 5 intravenous injection 3 (108 splenocytes of group 4 to normal recipient, and then heart transplantation was performed. Mean survival time (MST), histological changes, mixed lymphocyte reaction (MLR) were measured after operation.</p><p><b>RESULTS</b>The survival time of heart allografts in the group 4 [MST (71.5 +/- 29.1) d, t = -14.063, -13.915, -13.777; P < 0.01] was significantly longer than in the groups of 1 [MST (7.3 +/- 1.0) d], 2 [MST (7.8 +/- 0.8) d], 3 [MST (8.2 +/- 1.1) d ]. Only a few inflammatory cells infiltrated in cardiac allografts in the groups of 4 and 5. MLR in the groups of 4 and 5 were significantly decreased compared with those of normal control (t = 29.902, 23.047; P < 0.01).</p><p><b>CONCLUSIONS</b>Portal venous injection of donor splenocytes combined with intraperitoneal injection of cyclophosphamide could induce immune tolerance to cardiac allografts. The immune tolerance could be transferred through splenocytes. T suppressor cells play an important role in the immune tolerance.</p>