异基因NK细胞在白血病小鼠单倍体相合骨髓移植中的作用

本研究观察异基因NK细胞在白血病小鼠单倍体相舍骨髓移植中的作用。建立荷EL9611（H-2^d）红白血病细胞的CB6F1^H-2b/d小鼠动物模型，5天后将其随机分为7组，每组10只。CB6F1^2b/d受鼠为移植组，9Gy（^60Co）照射后以C57BL／6^h-2b为供鼠，进行骨髓移植。对照组分为5组：对照1组为未治疗组；对照2组为单纯照射组；对照3组为阿糖胞苷治疗组：小鼠腹腔注射阿糖胞苷50mg／kg×6d；对照4组为单纯骨髓细胞移植组：小鼠照射后4小时移植C57BL／6^h-2b小鼠骨髓细胞；对照5组为GVHD对照组：小鼠照射后4小时移植C57BL／6^H-2b小鼠骨髓细胞和脾细胞。实验组分为2组：实验A组，照射后输注C57BL／6^H-2b小鼠NK细胞1×10^6／只，4小时后移植C57BL／6^H-2b。小鼠骨髓细胞；实验B组：照射后同实验1组，4小时后移植C57BL／6^H-2b小鼠骨髓细胞和脾细胞。以血象、体重、生存期和病理组织学变化为观察指标并作组间比较。结果表明，对照1、2、3、5组小鼠生存期分别为（10．10±0．88）天、（9．80±0．92）天、（22．70±3．23）天、（20．10±1．73）天，对照4组生存期为（30．10±15．95）天，其中2只小鼠超过30天；实验A、B组小鼠生存期分别为（39．10±18．11）天、（49．30±17．24）天，实验1组4只小鼠生存期超过30天，实验2组7只生存期超过30天，其中实验1组与对照1、2、3、5组比较均有显著性差异（P〈0．01），实验2组同其他组比较均有显著性差异（P〈0．05）。因白血病死亡的小鼠，可见肝脾明显肿大，结构破坏，有大量白血病细胞浸润。实验组长期存活的小鼠出现Y染色体（嵌合率80％-90％）。结论：在荷EL9611（H-2^d）红白血病细胞CB6F1^H-2b小鼠模型的单倍体相合骨髓移植中供者NK细胞具有杀灭白血病细胞并降低GVHD的双重作用。

Effectiveness of Allogeneic NK Cells in Haploidentical Bone Marrow Transplantation for Leukemic Mice

The aim of study was to investigate the effectiveness of allogeneic natural killer (NK) ceils in haploidentical bone marrow transplantation (BMT) for leukemia mice. CB6F1H-2b/d murine model of EL9611 (H-2d) erythroleukemia was established by intravenous injection of EL9611 (H-2d) cells. CB6F1H-2b/d mice were transplanted with bone marrow (BM) cells from C57BL/6H-2b mice. Seventy CB6F1H-2b/d mice were randomly divided into 7 groups with 10 mice per group. 5 control groups were: group 1, in which no treatment was performed; group 2, in which mice were lethally irradi-ated (9 Gy) ; group 3, in which mice were treated with cytarabine with dose of 50 mg/kg for6 days followed by the infu-sion of EL9611 (H-2d) ; group 4, in which mice were transplanted with BMT and group 5-the GVHD-control group, in which mice were transplanted with BM and spleen cells from C57BL/6H-2b mice 4 hours after irradiation. Experimental groups were divided into 2 groups: group A, in which mice were injected with C57BL/6H-2b NK cells (1 × 106) after irra-diation and were transplanted with BM from C57BL/6H-2b 4 hours later, and group B, in which mice were transplanted with BM ceils and spleen cells from C57BL/6H-2b 4 hours after irradiation. The effect was assessed and compared by blood pic-rare, survival time, body weight, and histopathology in the recipients. The results showed that the survival times in control group 1,2, 3 and5 were (10. 10±0.88) , (9.80±0.92), (22.70±3.23) and (20.10±1.73) days respectively. The survival time of control group 4 was (30. 10±15.95) days and was over 30 days in 2 mice. The survival times in experi-mental group A and B were (39. 10±18.11) and (49.30±17.24) days respectively. 4 mice in experimental group 1 and 7 mice in group 2 survived over 30 days. The survival time of experimental group 1 was significantly longer than that of control group 1,2, 3 and 5 (p<0.01). The survival time of experimental group 2 was significantly longer than that of other groups (p<0.05). Histopathologic examination showed that splenohepatomegalia and disorganization of liver and spleen with infiltration of a large amount of leukemia cells in mice dead of leukemia. Chimerism of Y chromosome was shown in mice of experimental groups with long survival time. It is concluded that the injection with donor-derived NK cells can both eliminate leukemia cells and decrease the severity of GVHD after haploidential BMT.