高龄老年人外周血树突状细胞亚群及表面标志的分析

Changes in the subgroups and surface markers of dendritic cells from aged people

目的树突状细胞(dendritic cells,DC)在机体免疫应答的启动中起着至关重要的作用。文中主要探讨高龄老年人外周血DC亚群和表面标志的改变。方法应用流式细胞仪直接检测30例高龄老年人(≥80岁)外周血及30例普通老年人(60～70岁)外周血中DC的亚群(DC1和DC2)占白细胞总数的比值,进一步从高龄老年人外周血分离获得单核细胞,用人粒-巨噬细胞集落刺激因子(human granulocyte-macrophage colony-stimulating factor,hGM-CSF)和人白细胞介素-4(humaninterleukin-4,hIL-4)培养1周获得DC,并将普通老年人外周血培养得到的DC设为对照组,观察2组DC表面标志CD1a、HLA-DR、CD80(B7-1)、CD86(B7-2)、CD40、CCR-7和CD209的改变。结果高龄老年人组外周血DC1占白细胞总数的比值及DC1/DC2的比值均低于普通老年人组,前组培养获得的DC的CD1a的细胞阳性率明显较后组低,同样前组DC表达CD40、CD80、CD86、CD209分子的水平均低于后组。结论随着增龄,DC细胞亚群和其表面标志发生了一定的改变,提示这些改变可能参与了老年人免疫衰老的发病机制。

Objective Dendritic cells(DC) play an important role in the initiation of immunologic response.This study aims to investigate the changes in the subgroups and surface markers of DCs derived from the peripheral blood of the aged people. MethodsMononuclear cells were isolated from the peripheral blood of 30 aged people(≥80 yr) and 30 elderly controls(60-70 yr) and cultured with hGM-CSF and hIL-4 for a week to obtain DCs.The percentages of the subgroups of DCs(DC1 and DC2) in the leukocytes were detected by flow cytometry.Changes in the DC surface markers CD1a,HLA-DR,CD80(B7-1),CD86(B7-2),CD40,CCR-7 and CD209 of the aged people were observed and compared with those of the elderly controls.Results Both the percentage of DC1 in the peripheral blood leukocytes and the DC1/DC2 ratio were lower in the aged group than in the elderly controls,and so were the rate of the CD1a positive cells and the expressions of the DC CD40,CD80,CD86 and CD209 molecules.Conclusion The subgroups of DCs and their surface markers undergo changes with aging,which may be involved in the pathogenesis of immune senescence.