甲泼尼龙对移植物细胞构成的影响及其在H-2半相合小鼠造血干细胞移植中的作用

Influence of methylprednisolone on cell component of donor graft and on H-2 haploidentical hematopoiefic stem cell transplantation in mice

目的研究甲泼尼龙对移植物细胞构成的影响及其对H-2半相合小鼠造血干细胞移植的作用。方法以C57BL／6J（H-2b）雄性小鼠为供鼠，C57BL／6J（H-2b）×BALB／c（H-2d）F1代雌性小鼠为受鼠，以常规动员方案（单用G—CSF）为对照，在此基础上加用3d剂量分别为2mg／kg（小剂量组）、10mg／kg（中剂量组）及50mg／kg（大剂量组）的甲泼尼龙动员造血干细胞，流式细胞术检测移植物中T细胞亚群、DC1（HLA—DR^＋CD11c^＋细胞）及CD34^＋细胞，干细胞回输后观察移植后的排斥、急性移植物抗宿主病（aGVHD）的发生及生存情况。结果与对照组比较，动员方案中加用不同剂量甲泼尼龙的各实验组移植物中CD3^＋T细胞比例均有显著下降（P〈0．05），其中CD4^＋T细胞比CD8^＋T细胞下降更为明显，CD4^＋／CD8^＋比值显著下降，而CD4^＋CD25^＋T细胞比例则显著上升，DC1比例下降，CD34^＋细胞比例上升。CD3^＋T细胞、CD3^＋CIM^＋T细胞和CD34^＋细胞百分比在小剂量、中剂量和大剂量组问差异有统计学意义（P值均〈0．05）。对照组、小剂量组、中剂量组和大剂量组植活率分别为90％、100％、100％、80％。与对照组比较，各实验组HLA半相合移植受鼠aGVHD严重程度均明显下降（P〈0．05），不同剂量的实验组间差异有统计学意义（P〈0．05）；移植后小鼠生存期均较对照组明显延长（P〈0．05），中剂量组较小剂量组延长（P〈0．05），但大剂量组反而较中剂量组缩短（P〈0．05）。结论动员方案中加用甲泼尼龙可选择性去除供鼠移植物中的T细胞，同时下调其中DC1比例，提升CD34^＋细胞比例，使H-2半相合小鼠移植后GVHD明显减轻，生存期延长。一定剂量的甲泼尼龙不会增加移植排斥风险。

Objective To explore the influence of methylprednisolone （MP） on cellular component in donor graft and on H-2 haploidentical hematopoietic stem cell transplantation（HSCT） in mice. Methods A murine model of H-2 haploidentical HSCT was established by using of c57BL/6J male mouse as donor and （c57BL/6J× LB/C）F1 female mouse as recipient. The donor mouse received peripheral-blood（PB） progenitor cells mobilization regimens consisted of recombinant human granulocyte colony-stimulating factor （rhG- CSF） alone （ control group） or combined with MP in dose of 2 mg/kg daily [ small-dose（SD） group], 10 mg/kg daily [ middle-dose（MD） group], and 50 mg/kg daily [ large-dose（LD） groupl respectively. Percentage of T cell subsets,DC1 （ HLA-DR^＋ CDllc＋ ） and CD34^＋ cell in the grafts were detected by flow cytometry. Transplant rejection, severity of GVHD and survival time were observed. Results The percentages of CD3 ^＋ T cell in donor grafts in the three groups were significantly lower than that in control group （ P 〈 0.05 ）. The percentage of CD3 ^＋ CD4 ^＋ T cells decreased more significantly than that of CD3 ^＋ CD8^ ＋ T cells, and CIM/CD8 ratios decreased significantly. The percentage of CIM ^＋ CD25^ ＋T cells increased significantly, the percentage of DC1 （ HLA-DR ^＋ CD11 c ^＋） decreased and the percentage of CD34^ ＋ cells increased in all the three groups than in control group. There were significant differences in the percentage of CD3^ ＋ T cells , CD3 ^＋ CIM ^＋ T cells and CD34^ ＋ cells in donor grafts among SD group, MD group and LD group （ P 〈 0.05 ）.The engraftment rates in control, SD, MD and LD groups were 90% , 100% , 100% and 80% respectively. Severity of aGVHD in each study group decreased significantly compared with that in control group （P 〈 0.05 ）. There were statistical diferences among different dosage groups （P 〈 0.05 ）. Survival time after transplantation in all study groups were significantly longer than that in control group （P 〈 0.05） , and in MD group was significantly longer than in SD group and LD groups （P 〈 0.05）. Conclusions Addition of methylprednisolone to routine donor mice HSC mobilization regimen has a definite effect in alleviating aGVHD and prolonging survival time of mouse after H-2 haploidentical HSCT. With a suitable dosage addition of methylprednisolone to donor mice HSC mobilization regimen could avoid the increasing risk of graft rejection