剔除CCR5基因供者小鼠细胞加重急性移植物抗宿主疾病

目的评价供者CCR5在经过强化预处理的骨髓移植动物模型受者体内的作用,为异基因造血干细胞移植的临床应用提供科学依据。方法经过致死剂量照射的BALB/C小鼠接受异基因C57BL/6小鼠骨髓移植。根据回输的细胞不同分为4组:1)B6 CCR5 KO组,受者接受C57BL/6 CCR5-/-小鼠骨髓和脾脏细胞;2)B6 WT组,受者接受野生型C57BL/6小鼠骨髓和脾脏细胞;3)B6 CCR5 KO BMC组,受者只接受C57BL/6 CCR5-/-小鼠骨髓细胞;4)B6 WT BMC组,受者只接受野生型C57BL/6小鼠骨髓细胞。结果与B6 WT组比较,B6 CCR5 KO组小鼠以更快的速度死于急性移植物抗宿主疾病(GVHD);其受者体内的CD8+T细胞大量增生;T细胞恢复后产生更多的干扰素-γ(INF-γ)和肿瘤坏死因子-α(TNF-α),T细胞有丝分裂原刀豆素水平处于较高水平,进一步促进T细胞增生。组织学检测提示移植剔除CCR5基因受者细胞的小鼠肾脏出现病理损伤,肝脏存在更为严重的病理变化。结论剔除CCR5基因的异基因骨髓移植使GVHD发病率增加,供者CD8+T细胞在受者体内增生加重肝肾损害。提示CCR5在异基因骨髓移植中起着重要作用。

An Absence of Gene CCR5 on Donor Cells Results in Acceleration of Acute Graft-anti-host Disease

Objective To evaluate the role of gene CCR5 on donor cells in models where intensive preconditioning of the recipient occurs,thus provide the scientific evidence for clinical experience of allo-HSCT.Methods Lethally irradiated BALB/C mice received C57BL/6 mice is allogeneic bone marrow transplants.We divided mice into 4 groups according to receiving variant donor cells: B6 CCR5 KO group,receiving C57BL/6 CCR5(^-/-)mice bone marrow cells and splenocytes;B6 WT BMC group,receiving C57BL/6 mice bone marrow cells and splenocytes;B6 CCR5 KO BMC group,receiving C57BL/6 CCR5(^-/-) bone marrow cells alone;B6 WT BMC group,receiving C57BL/6 mice bone marrow cells alone.Results Compared to B6 WT group,B6 CCR5 KO group succumbed to acute GVHD at an accelerated rate.Donor CD8⁺ T cells expanded to a significantly greater extent in recipients of CCR5 KO vs WT control cells.T cells recovered from recipients of CCR5 KO cells roduced more IFN-γ and TNF-Αand proliferated to a T-cell mitogen at a significantly greater level than T cells from recipients of WT cells,indicating that CCR5 plays a role in downregualting donor alloreative CD8⁺ T-cells expansion.Histological assessment of the mice indicated pathological lesions in the kidney and a greater degree of liver pathological changes in mice that received CCR5 KO donor grafts.Conclusion The absence of gene CCR5 on donor cells results in increased GVHD and donor CD8⁺ T cells as well as hepatic and renal lesions in allo-HSCT,which indicated gene CCR5 is very important in allo-BMT.