目的:证实骨髓细胞(BM)来源的髓源性抑制细胞(MDSC)可以趋化外周调节性T细胞(Treg)聚集于小鼠移植心脏，并发挥免疫调节功能。方法:体外应用曲古霉素A(TSA)联合单核巨噬细胞集落刺激因子(GM-CSF)诱导C57BL/6供体小鼠BM分化为CD11b＋Gr-1＋MDSC,将C57BL/6小鼠心脏移植至BALB/c小鼠腹腔，心脏移植成功的小鼠分为四组(每组n＝12)，M组：经受体小鼠尾静脉注入5×10n 6供鼠骨髓来源MDSC细胞；C组：经尾静脉注入同剂量生理盐水；M＋T组：经尾静脉注入5×10n 6供鼠MDSC细胞及口服TAK-778(100 mg/kg，每周3次)；H组：同系小鼠心脏移植。移植术后7 d对移植心脏进行Treg荧光标记，Elisa检测心肌组织及外周CCL5含量，监测各组小鼠移植心脏存活状况。n 结果:TSA联合GM-CSF诱导的骨髓细胞经磁珠分选可获得纯度为93.8%的CD11b＋Gr-1＋MDSC，过继输入MDSC的小鼠移植心脏部位Treg数量为对照组4倍，过继输入MDSC后拮抗CCR5可明显抑制Treg向移植心脏迁徙(n P＝0.017)，M组和M＋T组在移植物和外周血浆中CCL5含量差异有统计学意义(n P<0.05)，M组小鼠移植心脏存活时间较其他组长，并且差异有统计学意义(n P＝0.014)。n 结论:供体小鼠骨髓来源MDSC可以在体内通过CCL5趋化Treg至移植器官，延长移植心脏存活时间。“,”Objective:To confirm that myeloid-derived suppressor cells(MDSC)derived from bone marrow cells (BM) can accumulate and home peripheral regulatory T cells(Treg)to the transplanted heart of mouse, and exert immunoregulatory functions.Methods:Trichomycin A(TSA)combined with mononuclear macrophage colony stimulating factor(GM-CSF)were used in vitro to induce BM of C57BL/6 donor mice differentiate into CD11b+ Gr-1+ MDSC, and C57BL/6 mice Hearts were transplanted into the abdominal cavity of BALB/c mice. The mice with successful heart transplantation were divided into four groups (n=12 in each group). Group M: 5 × 106 bone marrow-derived MDSC cells were injected via the tail vein of recipient mice; group C: the same dose of normal saline was injected through the tail vein; group M + T: 5 × 106 donor MDSC cells and oral administration of TAK-778 (100 mg/kg, 3 times a week) were injected via tail vein of recipient mice; group H: heart transplantation of homologous mice.After transplantation, the tregs in transplanted heart were fluorescently labeled on the 7th day after transplantation. The myocardial tissue and peripheral CCL5 were detected by ELISA, the survival of the transplanted heart in each group were monitored.Results:The bone marrow cells induced by TSA combined with GM-CSF were sorted by magnetic beads, and can obtain CD11b+ Gr-1+ MDSC with a purity of 93.8%. The number of Tregs in the transplanted heart of mice that received MDSC was 4 times that of the control group, antagonism of CCR5 can significantly inhibit the migration of Treg to the transplanted heart(n P=0.017), There was a significant difference in CCL5 content between group M and group M + T(n P<0.05), The survival time of heart transplantation in group M was longer than that in other groups, and the difference was statistically significant (n P=0.014).n Conclusions:MDSC from donor mouse bone marrow can chemoattract Treg to transplanted organs through CCL5 in vivo, and prolong the survival time of transplanted heart.