增龄对人体外周血CD4+CD25+Foxp3+调节T细胞、CD4+T细胞及细胞因子表达的影响

目的探讨增龄对人体外周血CD4⁺CD25⁺Foxp3⁺调节T细胞(CD4⁺CD25⁺Foxp3⁺Treg)、CD4⁺T细胞及细胞因子表达的影响。方法选择青年人(20~45岁)、中老年人(50~75岁)及高龄老年人(≥80岁)各40例,分别检测3组外周血CD4⁺T、CD4⁺CD25⁺Foxp3⁺Treg的绝对计数,并计算后者占前者的百分比,同时检测并比较3组人群外周血IL-2、干扰素-γ(IFN-γ)、TNF-α、IL-10和IL-17水平。结果高龄老年组CD4⁺T细胞绝对计数较中老年组与青年组显著下降(P<0.05);高龄老年组和中老年组外周血CD4⁺CD25⁺Foxp3⁺Treg绝对计数均明显高于青年组(P<0.05);中老年组CD4⁺CD25⁺Foxp3⁺Treg占CD4⁺T细胞百分比明显高于青年组,高龄老年组明显高于中老年组,差异均有统计学意义(P<0.05)。高龄老年组IL-2、IFN-γ和IL-17水平明显低于青年组和中老年组(P<0.05),中老年组IL-2明显低于青年组(P<0.05),高龄老年组IL-10水平明显高于青年组和中老年组(P<0.05),3组TNF-α水平差异无统计学意义(P>0.05)。结论中老年以后人体外周血CD4⁺CD25⁺Foxp3⁺Treg绝对计数明显增高,随着增龄,其占CD4⁺T细胞百分比逐渐升高。高龄老年人外周血CD4⁺T细胞绝对计数、IL-2、IFN-γ和IL-17水平明显下降,IL-10水平明显增高,说明老年人免疫功能进一步下降,衰老的微环境发生了改变。

Effect of aging on the expression ofCD4+CD25+Foxp3+regulatory T cells,CD4+T cells and cytokines in peripheral blood

Objective To investigate the effects of aging on the expression of CD4⁺CD25⁺Foxp3⁺regulatory T cells(Treg),CD4⁺T cells in human peripheral blood and the levels of cytokines.Methods The absolute counts of CD4⁺T cells and CD4⁺CD25⁺Foxp3⁺Treg,and the levels of interleukin-2(IL-2),interferon-γ(IFN-γ),tumor necrosis factor-α(TNF-α),IL-10 and IL-17 were measured respectively in peripheral blood of 40 young persons(20-45 years old),40 middle-aged persons(50-75 years old)and 40 elderly persons(above 80 years old),and also the percentage of CD4⁺CD25⁺Foxp3⁺Treg in CD4⁺T cells in peripheral blood of the three groups was calculated.The differences among the three groups were compared.Results The absolute count of CD4⁺T cells in peripheral blood decreased significantly in the elderly group than those in the young group and the middle-aged group(P<0.05).The absolute count of CD4⁺CD25⁺Foxp3⁺Treg was significantly higher in peripheral blood in the elderly group and the middle-aged group than that in the young group(P<0.05).The percentage of CD4⁺CD25⁺Foxp3⁺Treg in CD4⁺T cells was the highest in the elderly group,followed by the middle-aged group and the young group(P<0.05).The levels of IL-2,IFN-γand IL-17 in the elderly group were significantly lower than those in the young group and the middle-aged group(P<0.05),and the level of IL-2 in the middle-aged group was significantly lower than that in the young group(P<0.05).The level of IL-10 in the elderly group was significantly higher than that in the young group and the middle-aged group(P<0.05),and the level of TNF-αamong the three groups showed no significant difference(P>0.05).Conclusions The absolute count of CD4⁺CD25⁺Foxp3⁺Treg in peripheral blood increases significantly after middle-age.With the increase of age,the ratio of CD4⁺CD25⁺Foxp3⁺Treg/CD4⁺T cells increases significantly.In the elderly,the absolute count of CD4⁺T cells and the levels of IL-2,IFN-γ,IL-17 decrease significantly,while the level of IL-10 significantly increases,indicating that the immune function of the elderly further decreases and the microenvironment is changed.