阻抑骨髓移植受者白血病细胞免疫逃逸的实验研究

目的　了解转染小鼠可溶性Fas(sFas)基因后的骨髓移植 (BMT)能否阻抑白血病细胞的免疫逃逸 ,从而消灭残留白血病细胞、减少白血病复发。方法　经尾静脉向雌性C57BL 6小鼠体内植入EL4细胞 1 0 5个 只 ,建立移植性小鼠T细胞白血病 淋巴瘤模型。用转染sFas基因的腺病毒 (Ads Fas)感染 2 4h的雄性C57BL 6小鼠 (H 2 b)骨髓单个核细胞 ,对60 Co致死量照射的雌性同系小鼠进行BMT(D组 ) ,同时设立 :空白对照组 (A组 ,无骨髓细胞植入 )、常规BMT组 (B组 ,骨髓细胞未感染病毒 )、白血病组 (C组 ,仅输入EL4细胞 ,不进行照射和BMT)和绿色荧光蛋白 (EGFP)移植组 (E组 ,骨髓细胞感染AdEGFP)。观察各组造血重建情况、白血病 淋巴瘤的发生及小鼠生存率。结果　BMT后 1 0天脾指数检查 ,B、D、E三组之间差异无显著性 (P >0 .0 5) ,各组与A组间差异有显著性 (P <0 .0 1 )。移植后 30天外周血检查 ,B和D组恢复正常 ,C和E组白细胞和血小板均低下。 2个月后嵌合体检查存在Y染色体 ,骨髓细胞学检查B、D两组基本正常 ,C、E两组存在大量的瘤细胞。C组与E组死亡小鼠组织病理学显示脾脏等部位存在瘤细胞 ,而存活的B和D组小鼠基本正常。生存率 :A组全部死亡 ,B组 (6只 )和D组 (1 6只 )全部存活 ,C组存活 2只 (1 2 .5 % ) ,E组存活

Experimental study on blocking immune escape of leukemia cells in the recipient after bone marrow transplantation

Objective To investigate whether murine soluble Fas gen e transfected marrow graft could block the immune escape of leukemia cells, so as to eliminate the residual leukemia cells and reduce relapse after bone marrow t ransplantation(BMT).Methods The murine leukemia/lymphoma models were established by inoculating female C57BL/6 mice (H-2b) with 10 5 EL4 cell s/mouse through caudal vein. Donors of BM grafts were C57BL/6 male mice. Bone ma rrow mononuclear cells (BMMCs) wer e transfected with sFas or EGFP by adenovirus(adsFas or adEGFP) 24 hours before BMT(group D or E). The following three groups were set simultaneously: group A, no BMMCs transplanted; group B, BMMCs transplanted with no adenoviruses transfe ction; group C, EL4 cells transfusion only.Hematopoietic reconstitution, genera tion of leukemia/lymphoma and the survival rate were observed in all the groups after BMT.Results The spleen indices examined 11 days after BMT were not obviously different among group B, D and E (P>0.05), but in group A were significantly lower than those in the groups B, D, E( P<0 01). The leukocyte and platelet counts on day 30 after BMT were recovered in group B and D, but were very low in group C and E. The Y-chromosom es appeared 2 mon ths after BMT. Bone marrow pictures in group B and D were almost normal, but in group C and E had plenty of lymphoblast-like tumor cells. Tumors were obviously revealed in the mice of group C and E by histopathology examination, but did no t in group B and D. The survival rate was 0 in group A, 100% in group B and D, 1 2.5% in group C and 6.25% in group E. Compared with that in group E, the surviva l was significantly increased in the sFas group (P<0.01). Conclusions Graft transfected with sFas gene prolonged the post-BMT survival of leukemia/lymphoma mice. The transfection of sFas might block the ef fect of the immune escape of EL4 cells through FasL.