人外周血单核细胞人白细胞抗原-DR表达和细胞因子水平的增龄性改变

摘要

目的 研究人外周血单核细胞(PBMC)人白细胞抗原DR的表达和单核细胞体外分泌细胞因子水平的增龄性改变.方法 352例不同年龄的体检者按年龄分为A组120例(20～69岁)、B组85例(70～79岁)、C组98例(80～89岁)、D组49例(90～102岁).用流式细胞仪检测PBMC表面人白细胞抗原(HLA)-DR的表达；每组随机抽取10人,用ELISA方法检测经内毒素(LPS)刺激前后PBMC分泌肿瘤坏死因子-α(TNF-o)、白细胞介素(IL)-6、IL-10等细胞因子的水平,并比较各年龄组PBMC表面HLA-DR表达的变化以及分泌TNF-α、IL-6、IL-10等细胞因子水平的变化.结果 A,B,C,D各组之间PBMC表面HLA-DR的表达有显著性差异(F=159.712,P=0.000),且不同年龄组人群PBMC表面HLA-DR的表达呈随龄性增加(r=0.744,P=0.000)；LPS刺激前各年龄组人群PBMC分泌TNF-α,IL-6,IL-10细胞因子的水平无显著性差异(P＞ 0.05);LPS刺激后各年龄组人群PBMC分泌TNF-α,IL-6,IL-10细胞因子的水平较LPS刺激前均有明显增高(P＜0.05)；将LPS刺激后各组PBMC分泌细胞因子的水平进一步行组内比较发现,与A组相比,B,C,D各组分泌TNF-o、IL-6的水平明显减低(P＜0.05),分泌IL-10的水平明显增高(P＜0.05).结论 人PBMC细胞免疫功能呈随龄性改变,其表面HLA-DR的表达呈随龄性增加；LPS刺激前各年龄组人群PBMC分泌TNF-α、,IL-6,IL-10细胞因子的水平无显著性差异；而LPS刺激后,70岁以上老年人PBMC分泌TNF-α和IL-6的水平明显减低,分泌IL-10的水平明显增高.%Objective To investigate age-related changes in the expression of human leukocyte antigen-DR (HLA-DR) in peripheral blood mononuclear cells (PBMCs) and levels of cytokines secreted by PBMCs. Methods A total of 352 individuals who underwent physical examinations in our hospital were stratified into four groups based on age: group A, n=120, age 20-69 years; group B, n=85, age 70-79 years; group C, n=98, age 80-89 years; group D, n=49, age 90-102 years. Expression of HLA-DR in PBMCs was detected with flow cytometry. In addition, 10 individuals from each group were randomly selected, and their PBMCs were isolated and subsequently used for determining the levels of TNF-a, IL-6 and IL-10 by ELISA before and after LPS stimulation. HLA-DR expression and cytokine levels were compared between the different age groups. Results HLA-DR expression was significantly different between A, B, C, and D groups(F= 159.712, P=0.000), and it increased in an age dependent manner(r = 0.744, P = 0.000). No significant difference was found in TNF-a, IL-6 and IL-10 levels in PBMCs before LPS stimulation between group A, B, C and D (P > 0.05), while, their levels increased significantly after LPS stimulation(P < 0.05). Compared with group A, TNF-a and IL-6 levels decreased, and the IL-10 level increased significantly(P < 0.05)in group B, C and D after LPS stimulation. Conclusion Expression of HLA-DR increases in an age-dependent manner in human PBMCs, indicating an age-related change of immunological function. There is no significant difference in the levels of TNF-a, IL-6 and IL-10 secreted by PBMCs before LPS stimulation, while after LPS stimulation, the TNF-a and IL-6 levels decrease and IL-10 level increases significantly in individuals more than 70 years old.