骨髓间充质干细胞调节心脏移植大鼠的免疫功能

Immune function regulation by bone marrow mesenchymal stem cells in rats undergoing heart transplantation

BACKGROUND:Heart transplantation is an effective method for treatment of end-stage heart failure, but immune rejection that seriously impact therapeutic effacicy is easy to occur after transplantation.OBJECTIVE:To investigate the regulatory effect of bone marrow mesenchymal stem cells on the immune function of rats undergoiong heart transplantation. METHODS:Twenty Lewis rats were enrolled as donors, and 20 Wistar rats as recipients. Heart transplantation models were established in the Wistar rats. These 20 model rats were randomized into cell transplantation and control group with 10 rats in each group. Forty-eight hours after heart transplantation, rats in the cell transplantation group were given bone marrow mesenchymal stem cell suspension (1 mL, 2×10⁸ cells/L) via the tail vein, while rats in the control group were given normal saline in the same dose. Then, the expression levels of serum interleukin-2, interleukin-10 and percentage of CD4⁺, CD8⁺, CD4⁺/CD8⁺, CD4⁺CD25^high, CD4⁺CD25^high Foxp3⁺ T cells in the venous blood were detected in the two groups at 7 days after cell transplantation. Additionally, rat myocardial tissues were taken and observed pathologically. RESULTS AND CONCLUSION:The survival time of the cell transplantation group was significantly longer than that of the control group (P < 0.05). The expression level of interleukin-2 showed no significant difference between the two groups (P > 0.05), but the level of interleukin-10 in the cell transplantation group was significantly higher than that in the control group (P < 0.05). Compared with the control group, the percentage of CD4⁺/CD8⁺, CD4⁺CD25^high, CD4⁺CD25^high Foxp3⁺ and CD4⁺ T cells was significantly higher, and the percentage of CD8⁺ T cells was significantly lower in the cell transplantation group (P < 0.05). Histopathological findings showed that there were a small amount of infiltrated lymphocytes in the cell transplantation group with the presence of slight bleeding and edema, and these inflammatory reactions were milder than those in the control group. These findings indicate that bone marrow mesenchymal stem cell transplantation can effectively reduce the rejection in rats undergoing heart transplantation.