大小鼠之间造血干细胞嵌合体抗异种移植物抗宿主病

Mixed hematopoietic chimerism for preventing graft-versus-host disease in mice receiving rat bone marrow transplantation

目的探讨克服异种骨髓移植间强烈的移植物抗宿主病(GVHD)的措施。方法(1)将12只SD大鼠经5.0 Gy亚致死剂量全身照射后,4 h内每只经尾静脉输入28只正常BALB/c小鼠骨髓细胞8×107个。2 d后从腹腔注射环磷酰胺(Cy)100 mg/kg·b.w.,诱导形成对BALB/c小鼠产生特异性免疫耐受的嵌合体大鼠10只。(2)24只BALB/c小鼠接受9.0 Gy致死剂量全身照射后随机均分为3组,照射后4 h内经尾静脉注射骨髓细胞进行移植。A组输注正常SD大鼠的骨髓细胞4×107个;B组输注正常SD大鼠的骨髓细胞4×107个和脾细胞2×107个;C组输注嵌合体SD大鼠的骨髓细胞4×107个和脾细胞2×107个;观察GVHD的发生情况。结果A组有2只小鼠死于感染和放射损伤,所有对象均未观察到明显GVHD表现。B组平均累积存活时间为10 d[95%可信区间为(8,12)],死前均出现不同程度的典型GVHD表现。而C组除2只小鼠分别于移植后18、31 d死亡外,其余的均存活超过150 d。三组间比较有统计差异(P<0.002)。结论对有受者嵌合体的供者进行异种骨髓移植,有助于克服异种移植物抗宿主病。

Objective To find a method for preventing graft-versus-host disease (GVHD) in BALB/c mice receiving rat bone marrow transplantation. Methods Firstly 12 SD rats were conditioned with 5.0 Gy sublethal total body irradiation(TBI), fol-lowed by infusion of 8×10 7 bone marrow cells from 28 BALB/c mice within 4 h and intraperitoneal administration of 100 mg/kg cyclophosphamide (Cy) 2 d later, for the purpose of inducing chimeric SD rats with specific immunological tolerance. Secondly, 24 BALB/c mice were exposed to 9.0 Gy lethal TBI and divided randomly into 3 equal groups designated respec-tively as groups A, B and C. Mice in group A were injected with 4×10 7 bone marrow cells from 4 normal rats, and mice in group B were injected with 4×10 7 bone marrow cells and 2×10 7 spleen cells from 4 normal rats, while those in group C were given 4×10 7 bone marrow cells and 2×10 7 spleen cells from 6 chimeric rats. The mice were then observed for 150 d for GVHD. Results In the second procedure, 2 mice in group A failed to survive due to infection and radiation injury respective-ly, and none of the rest mice presented signs of GVHD. The mice in group B all developed GVHD of varied degrees with symptoms as wasting, diarrhea, fur loss, arched body posture, and even bloody stool, and all died within 5 to 15 d with an av-erage survival of 10.0 d (95% confidence intervial 8,12). Pathological examination of the liver and intestinal tissues revealed inflammatory lymphocyte infiltration and necrosis. The majority of the mice in group C, in contrast, survived for more than 150 d with only two died on the postoperative days 18 and 31 respectively. The survival time of group B was significantly shorter than that of the other two groups. Conclusion Donor/recipient chimerism may help prevent GVHD in xenogeneic bone marrow transplantation.