TRAIL和TRAIL-R2在重型再生障碍性贫血患者外周血CD8^+T细胞的表达变化

Expressions of TRAIL and TRAIL-R2 in the peripheral blood CD8^+T cells of patients with severe aplastic anemia

目的:研究肿瘤坏死因子相关凋亡诱导配体(TRAIL)和TRAIL受体2(TRAIL-R2)在重型再生障碍性贫血(SAA)患者外周血CD8^+T细胞的表达变化。方法:将初诊为SAA的47例患者作为初诊组,同期免疫抑制治疗的41例SAA患者作为缓解组,34例健康者作为对照组。采用流式细胞术检测3组外周血CD8^+T细胞中TRAIL和TRAIL-R2表达,采用RT-PCR和Western Blot检测3组外周血CD8^+T细胞中TRAIL、TRAILR2mRNA和蛋白表达水平,分析TRAIL和TRAIL-R2表达水平与SAA患者临床指标的关系。结果:初诊组CD8^+T细胞中TRAIL、TRAIL-R2阳性表达率均显著低于对照组和缓解组(P<0.05);3组CD8^+T细胞中TRAIL、TRAIL-R2mRNA相对表达量比较差异均无统计学意义(P>0.05);初诊组和缓解组CD8^+T细胞中TRAIL和TRAIL-R2蛋白表达量显著低于对照组(P<0.05);SAA患者CD8^+T细胞中TRAIL表达水平与中性粒细胞计数、网织红细胞百分比分别呈显著正相关关系(r=0.615、0.703,P=0.000、0.000)。结论:SAA患者外周血CD8^+T细胞中TRAIL和TRAIL-R2表达降低,可能与自身免疫性T细胞过度激活有关,在骨髓造血功能损伤及全血细胞减少过程中发挥重要调控作用。

Objective:To study the expressions of tumor necrosis factor related apoptosis inducing ligand(TRAIL)and TRAIL receptor 2(TRAIL-R2)in the peripheral blood CD8^+T cells of patients with severe aplastic anemia(SAA).Method:Forty-seven patients diagnosed with SAA were used as newly diagnosed group,at the same time,41 patients with SAA treated with immunosuppressive therapy were used as remission group and 34 healthy subjects were used as control group.Flow cytometry was used to detect the expressions of TRAIL and TRAIL-R2 in peripheral blood CD8^+T cells of three groups,the expression levels of TRAIL,TRAIL-R2 mRNA and protein in peripheral blood CD8^+T cells of three groups were detected by RT-PCR and Western Blot,the relationships between the expression levels of TRAIL and TRAIL-R2 with clinical indexes of SAA patients were analyzed.Result:The positive expression rates of TRAIL and TRAIL-R2 in CD8^+T cells of the newly diagnosed group were significantly lower than those in the control group and the remission group(P<0.05);there was no significant difference in the mRNA relative expressions of TRAIL and TRAIL-R2 in CD8^+T cells between the three groups(P>0.05);the protein expression levels of TRAIL and TRAIL-R2 in CD8^+T cells in the newly diagnosed group and the remission group were significantly lower than those in the control group(P<0.05);the expression level of TRAIL in CD8^+T cells of SAA patients was significantly positively correlated with absolute neutrophil count and reticulocyte percentage(r=0.615,0.703,P=0.000,0.000).Conclusion:The expressions of TRAIL and TRAIL-R2 in peripheral blood CD8^+T cells of SAA patients decreased,which may be related to over activation of autoimmune T cells and plays an important regulatory role in injury of hematopoietic function in bone marrow and the process of pancytopenia.