【摘要】 目的探讨新生儿脐带血(CB)和母亲外周血(PB)中调节性T (Treg)细胞比率及T细胞上程序性死亡受体1(PD-1的表达差异。方法收集新生儿脐带血24例,母亲外周血20例。血常规检测白细胞计数及分类;流式细胞术检测新鲜血液中CD34+造血干细胞的含量、Treg细胞的比率及T细胞上PD-1的百分比;植物血凝素(PHA-L)体外刺激CB和PB后,检测T细胞上PD-1表达的变化。结果新鲜CB组中Treg细胞的比率高于新鲜PB组(P<0.05)。新鲜CB组中CD4~+T细胞上PD-1的表达水平明显低于PB组(P<0.001)。PHA-L体外刺激CB发现,PD-1在CD3~+CD4~+T细胞和CD3~+CD8~+T细胞上表达均升高(P均<0.05);PHA-L体外刺激PB发现,PD-1在CD3~+CD4~+T细胞上表达升高(P<0.05),在CD3~+CD8~+T细胞上表达升高无统计学意义(P>0.05)。结论新生儿脐带血Treg细胞比率较母亲外周血高,而脐带血T细胞上PD-1表达量较低,但活化后表达升高更明显,可能是脐带血作为移植物能够降低移植物抗宿主病(GVHD)发病率和严重程度的原因。更多还原

【Abstract】 This study was designed to investigate the difference in regulatory T(Treg) cells ratio and programmed cell death protein 1(PD-1) expression between neonatal cord blood(CB) and maternal peripheral blood(PB). A total of 24 healthy neonatal CB samples and 20 healthy maternal PB samples were collected, and blood routine test was performed for white blood cell counting and classification; flow cytometry was used to detect the content of CD34+hematopoietic stem cells, Treg cells and PD-1+T cells in fresh CB and PB samples; the expression of PD-1 on T cells with or without phytohemagglutinin(PHA-L) stimulation was analyzed by flow cytometry. Data showed that the proportion of Treg cells in the fresh CB cells was significantly higher than that in the fresh PB cells(P<0.05). Furthermore, the expression level of PD-1 on CD4~+T cells in fresh CB group was significantly lower than that in PB group(P<0.001). After PHA-L stimulation, PD-1 expression on CD3~+CD4~+T cells and CD3~+CD8~+T cells was significantly upregalated(P<0.05) in CB group. While in PB group, PD-1 expression significantly increased on CD3~+CD4~+T cells but not on CD3~+CD8~+T cells. In conclusion, the Treg cells proportion in CB cells is higher than that in PB cells; the proportion of T cells expressing PD-1 is lower in CB, but the increase of PD-1 after stimulation is higher than that in PB. Our study provides a possible explanation to the low incidence and severity of graft-versus-host disease(GVHD)when CB is used as a graft.更多还原