Shimizu Kazuhiro, Kimura Fuminori, Akimoto Takayuki, Akama Takao, Tanabe Kai, Nishijima Takahiko, Kuno Shinya, Kono Ichiro
Graduate School of Comprehensive Human Sciences, University of Tsukuba, Ibaraki, Japan.
Exerc Immunol Rev. 2008;14:24-37.
CD28 molecule expression on the surface of T cells plays a critical role in upregulation of various cytokines synthesis and T-helper (Th) cell proliferation and differentiation. However aging induces a decrease in CD28 expression and unbalance of Th1/Th2, leading to impairment of Th-cell mediated immune function. The purpose of this study was to assess the effects of moderate exercise training on CD28 expression and the balance of Th1/Th2 cells in elderly people. Forty-eight elderly subjects were assigned to an exercise training group (EXC: 13 males, 15 females; aged 61-76) or a non-exercise control group (CON: 7 males, 13 females; aged 62-79). Subjects in EXC participated in exercise sessions 5-days a week for 6 months. Meanwhile, subjects in CON maintained their normal physical activity levels during the study period. Blood samples were collected before and after the training period. Samples were measured for the number of leukocytes and lymphocytes, as well as for CD3+, CD4+, CD28+CD4+, IFN-gamma+CD4+, IL-4+CD4+ cells. The number of leukocytes, lymphocytes, and CD3+ cells did not change after 6 months in both EXC and CON. The number of CD4+ and CD28+CD4+ cells significantly increased after the training in EXC (P < 0.05), while CON did not show significant changes. In the EXC group, IFN-gamma+CD4+ cell numbers were significantly higher following the training (P < 0.05), but the number of IL-4+CD4+ cells was not changed. In the CON group, there were no significant alterations in IFN-gamma+CD4+ and IL-4+CD4+ cell numbers. In conclusion, moderate exercise training in the elderly is associated with improvement of expression of CD28 on Th cells and Th1/Th2 balances. Therefore, exercise training could up-regulate Th cell-mediated immune functions and be helpful for a decrease in the risk of infections and autoimmune diseases in elderly people.
T细胞表面CD28分子的表达在多种细胞因子合成的上调以及辅助性T（Th）细胞的增殖和分化中起着关键作用。然而，衰老会导致CD28表达下降以及Th1/Th2失衡，从而导致Th细胞介导的免疫功能受损。本研究的目的是评估适度运动训练对老年人CD28表达及Th1/Th2细胞平衡的影响。48名老年受试者被分为运动训练组（EXC：男性13名，女性15名；年龄61 - 76岁）或非运动对照组（CON：男性7名，女性13名；年龄62 - 79岁）。EXC组的受试者每周进行5天的运动训练，持续6个月。同时，CON组的受试者在研究期间保持其正常的身体活动水平。在训练期前后采集血样。检测样本中的白细胞和淋巴细胞数量，以及CD3 +、CD4 +、CD28 + CD4 +、IFN - γ + CD4 +、IL - 4 + CD4 +细胞数量。6个月后，EXC组和CON组的白细胞、淋巴细胞及CD3 +细胞数量均未发生变化。训练后，EXC组的CD4 +和CD28 + CD4 +细胞数量显著增加（P < 0.05），而CON组未显示出显著变化。在EXC组中，训练后IFN - γ + CD4 +细胞数量显著升高（P < 0.05），但IL - 4 + CD4 +细胞数量未改变。在CON组中，IFN - γ + CD4 +和IL - 4 + CD4 +细胞数量均无显著变化。总之，老年人进行适度运动训练与Th细胞上CD28表达的改善及Th1/Th2平衡有关。因此，运动训练可上调Th细胞介导的免疫功能，有助于降低老年人感染和自身免疫性疾病的风险。
