间充质干细胞联合NK细胞输注抑制DC减轻aGVHD

Alleviation of Graft-versus-host Disease after Infusion of Mesenchymal Stem Cells Combined with Natural Killer Cells by Reducing Dendritic Cells in Mice

【目的】观察骨髓MSC联合NK细胞输注对小鼠异基因骨髓移植后aGVHD的影响,初步探讨其作用机制。【方法】分离C57BL/6小鼠骨髓细胞,体外培养MSC;取C57BL/6小鼠脾脏细胞,磁珠分选NK细胞;建立C57BL/6→BALB/c小鼠异基因骨髓移植模型,接受移植小鼠随机分为4组,每组10只小鼠,MSC和NK细胞移植组,MSC移植组,NK细胞移植组和培养基对照组。根据aGVHD分值,肝、脾、小肠aGVHD病理损害和平均存活时间,评价aGVHD的程度。ELISA法检测小鼠血清中IFNγ和IL-12的含量。流式细胞术检测受鼠脾脏细胞CD11c和CD86的表达情况。【结果】根据GVHD分值,肝、脾、小肠aGVHD病理损害和平均存活时间综合评价,与培养基对照组比较,MSC联合NK细胞移植组,MSC移植组和NK细胞移植组,发生aGVHD的程度均减轻,以MSC联合NK细胞移植组减轻最为明显。IFNγ的含量,NK细胞组明显高于MSC联合NK细胞移植组,MSC移植组和培养基对照组。IL-12的含量,MSC联合NK细胞移植组低于NK细胞移植组和培养基对照组,MSC移植组低于培养基对照组。脾脏DC细胞的含量,MSC联合NK细胞移植组未成熟DC(CD11c+CD86-)和成熟DC(CD11c+CD86+)均低于MSC移植组,NK细胞组和培养基对照组。【结论】MSC联合NK细胞输注降低DC细胞数量,减轻aGVHD,延长小鼠生存时间。

[Objective] To observe the effect of infusion of bone marrow mesenchymal stem ceils （MSC） combined with natural killer cells （NK） on acute graft versus host disease （aGVHD） after allogeneic bone marrow transplantation （allo-BMT） in mice and investigate the preliminary mechanism. [ Methods ] Bone marrow cells isolated from C57BL/6 mice were cultured to MSC in vitro. NK cells were separated from spleen cells in C57BL/6 mice through magnetic beads. Allogeneic bone marrow transplantation models were established with BALB/c mice as recipients and C57BL/6 mice as donors. Forty BALB/c mice were divided into 4 groups at randoms i.e. ： MSC combined with NK group, MSC group, NK group and medium control group. According to GVHD scores, GVHD pathological changes in the liver, spleen and gut, and average survival time, aGVHD were valued. The concentrations of IFNγ and IL-12 in the serum were detected through ELISA assay. The expression rates of CD11c and CD86 on the surface of spleen cells were detected through flow cytometry. [Results] According to GVHD scores, GVHD pathological changes in the liver, spleen and gut, andaverage survival time, compared to blank control group, the aGVHD manifestations of MSC combined with NK group, MSC group and NK group were alleviated, especially in MSC combined with NK group. The IFNγ concentration of NK group was higher than that of MSC combined with NK group, MSC group and medium control group. The IL-12 concentration of MSC combined with NK group was lower than that of NK group and medium control group respectively, and MSC group was lower than medium control group. The numbers of both immature dendritc cells （CD11c＋CD86-） and mature dendritic ceils （CD11c＋ CD86＋） of spleen in MSC combined with NK group were lower than those of MSC group, NK group and medium control group. [Conclusion] Infusion of bone marrow mesenchymal stem cells combined with natural killer cells decreased the number of dendritic cells, alleviated acute graft versus host disease and prolonged survival time in mice.