白细胞介素-7受体α联合细菌鞭毛蛋白对异基因骨髓移植小鼠急性移植物抗宿主病作用的初步探讨

Preliminary study on IL-7 receptor α combined with bacterial flagellin intervening acute graft-versus-host disease of mice after allogeneic bone marrow transplantation

目的 分析白细胞介素（IL）-7受体α（IL-7Rα）、细菌鞭毛蛋白单用及联合作用于小鼠异基因骨髓移植后急性移植物抗宿主病（aGVHD）模型的疗效,探讨其可能机制.方法 以BALB/C（H-2d）雌性小鼠为受鼠,均接受9 Gy 60Co全身照射,取C57BL/6（H-2b）供鼠骨髓细胞1×107个和脾细胞2×107个经尾静脉输注给受鼠.将受鼠分为单纯照射移植组（A组）、IL-7Rα干预组（B组）、细菌鞭毛蛋白干预组（C组）、IL-7Rα联合细菌鞭毛蛋白干预组（D组）,每组6只,观察受鼠的症状、体征、生存时间及造血功能恢复情况.结果 A组小鼠生存期为（22.5±2.30）d,30d生存率为50.0％（3/6）, 、且出现明显的倦怠、食欲缺乏、脱毛、弓背等aGVHD表现；B组小鼠生存期为（25.83±3.49）d,30 d生存率为33.3％（2/6）,aGVHD表现较A组轻；C组小鼠生存期为（26.33±3.52）d,30 d生存率为33.3％（2/6）,亦出现aGVHD表现,程度同B组；D组小鼠生存期为（30.17±2.86）d,30 d生存率为66.7％（4/6）,aGVHD表现较前3组轻.4组小鼠外周血白细胞计数均于移植后第7天降至最低,后逐渐恢复,A组较3组干预组恢复慢,B、C两组移植后第14、21、28、30天外周血恢复比较,差异均无统计学意义（均P＞ 0.05）；D组小鼠外周血较B、C组恢复快,差异均有统计学意义（均P＜ 0.05）.4组小鼠移植后第2周CD3＋T细胞比例均明显下降,第3周开始逐渐上升,与A组比较,B、C、D3组小鼠CD3＋T细胞比例上升明显,B、C两组移植后第2、3、4周比较,差异均无统计学意义（均P＞ 0.05）；D组小鼠较B、C组小鼠T细胞亚群CD3＋T细胞恢复快（均P＜0.05）.结论 通过全身照射能成功建立aGVHD小鼠模型；外源性IL-7Rα、细菌鞭毛蛋白均可减轻aGVHD的发生,两者单用无明显差异,二者联合干预aGVHD小鼠模型与单一干预比较,aGVHD发生更轻,造血恢复会更快.

Objective To compare the effects between the impact of IL-7Rα,bacterial flagellin alone to the acute graft-versus-host disease and the combination of both,and to explore its possible mechanism.Methods The BALB/C （H-2d） female mice as recipients were divided into alone irradiation transplantation group （group A）,IL-7Rα intervention group （group B）,bacterial flagellin intervention group （group C）,IL-7Rα combined with bacterial flagellin intervention group （group D）,and 6 mice in each group.All mice were accepted 9 Gy 60Co total body irradiation,and 1×107 bone marrow cells and 2× 107 spleen cells of donors C57BL/6 （H-2b） mice were infused via the tail vein to recipient mice.The symptoms,signs,survival time and hematopoietic function recovery of the recipient mice were observed.Results Mice survival of group A was （22.5±2.30） d,30 d survival rate was 50.0 % （3/6）,and aGVHD performances inculding the fatigue,anorexia,hair removal,arched,and so on appeared obviously.Survival of group B was （25.83±3.49） d,30 d survival rate was 33.3 % （2/6）,aGVHD performances compared with group A was lighter.Survival of group C was （26.33±3.52） d,30 d survival rate was 33.3 % （2/6）,also appeared aGVHD performance,which degree was same to the group B.survival of group D was （30.17±2.86） d,30 d survival rate was 66.7 % （4/6）,aGVHD performances compared to the other three groups was lightest.The white blood cell count of four groups were reduced to minimum at ＋7 d,then the three intervention groups gradually recovered.The WBC recovery at 14,21,28,30 day after the transplant of group A compared with slowly was the intervention groups （P 〉 0.05）,WBC recovery of B was roughly equal to group C （P 〉 0.05）,while the WBC recovery of group D was faster than group B or C （P 〈 0.05）.At 2nd week after transplantation,CD3＋ T cells was significantly decreased in 4 groups,and at 3rd week began gradually rised.Compared with group A,the proportion of CD3＋ cells of other three groups were increased significantly,there was no statistical signifiance of CD3＋ cell proportion between group B and group C at 2nd,3rd,4th week after transplantation （P 〉 0.05）,while the CD3＋ T cell recovery in group D was faster than group B or C （P 〈 0.05）.Conclusions The stable aGVHD mouse model was established.Exogenous IL-7Rα and bacterial flagellin may reduce the incidence of aGVHD.There was no significant difference for aGVHD when they was used alone,but when combination of them,aGVHD is slighter and the hematopoietic recorery is faster.