异基因造血干细胞移植后外周血NK细胞S1PR5表达变化对移植物抗宿主病的影响

异基因造血干细胞移植(allo-HSCT)后,供者来源的自然杀伤细胞(NK)可在保留移植物抗白血病(GVL)效应的同时发挥控制移植物抗宿主病(GVHD)作用。NK细胞表面的1磷酸鞘氨醇受体5(S1PR5)通过与胞外的第一信使1磷酸鞘氨醇(S1P)相互作用,调节NK细胞的迁移和在外周血、脾、淋巴结等器官中的分布。本研究旨在探讨allo-HSCT后外周血NK细胞S1PR5表达变化及对GVHD的影响。分离纯化17例供者及相应受者移植后1个月外周血NK细胞,通过荧光探针实时定量PCR技术检测S1PR5 mRNA的表达情况,并结合患者临床资料和随访结果进行分析。结果表明,供者与allo-HSCT后患者外周血中NK细胞S1PR5表达变化(0.235±0.191 vs0.330±0.261,P>0.05)不具有统计学意义;急性GVHD(aGVHD)患者组移植后外周血NK细胞S1PR5表达水平较无aGVHD的患者组明显下降(0.973±0.834 vs 6.166±5.32,P<0.05);移植后患者与相应供者相比,外周血NK细胞S1PR5表达水平下降超过10%时易发生aGVHD;NK细胞S1PR5表达变化与慢性GVHD发生率无明显相关性(3.401±2.324 vs 2.762±1.972,P>0.05)。结论:NK细胞S1PR5表达水平下调与aGVHD发生有关,可能机制是由于S1PR5的低表达影响了NK细胞在体内的分布,从而影响到调控aGVHD的作用。

Influence of NK cell S1PR5 expression on graft versus host disease in allogenetic hematopoietic stem cell transplantation

Natural killer (NK) cells can suppress the development of graft verse host disease (GVHD) while retaining antitumor response in allogenetic hematopoietic stem cell transplantation (allo-HSCT). Sphingosine-1-phosphase receptor 5 (S1PR5) can regulate NK cell migration and distribution in vivo by interacting with sphingosine-1-phosphase (S1P). This study was aimed to investigate S1PR5 expression change of NK cells in allo-HSCT and to explore the relationship between S1PR5 change and frequency of acute/chronic graft-versus-host disease (aGVHD/cGVHD). The S1PR5 expression was detected by real time quantitative PCR in the RNA extracted from blood NK cells of 17 couples of donor and recipient one month after allo-HSCT. The results showed that S1PR5 mRNA level variations in NK cells of donors and recipients post-allo-HSCT were not statistically significant (0.235 ± 0.191 vs 0.330 ± 0.261, P > 0.05). S1PR5 expression of NK cells was significantly lower in patients with aGVHD than those in patient without aGVHD (0.973 ± 0.834 vs 6.166 ± 5.32, P < 0.05). Compared with the corresponding donor, S1PR5 expression levels of patient declined by more than 10 that caused the high incidence of aGVHD. No significant correlation was found between S1PR5 expression of NK cells and cGVHD (3.401 ± 2.324 vs 2.762 ± 1.972, P > 0.05). It is concluded that the decreased expression level of NK cells S1PR5 is associated with aGVHD occurrence. Possible mechanism is due to S1PR5 low expression affecting distribution of NK cells in vivo, so affecting the regulation of NK cells for aGVHD.