Uchakin Peter N, Stowe Raymond P, Paddon-Jones Douglas, Tobin Brian W, Ferrando Arny A, Wolfe Robert R
Department of Internal Medicine, Mercer University School of Medicine, 1550 College Street, Macon, GA, USA.
Aviat Space Environ Med. 2007 Jun;78(6):608-12.
Hypokinesia is associated with spaceflight and prolonged illnesses and may lead to secondary immune deficiency.
The distribution of immunocytes in whole blood, mitogen-induced cytokine secretion in vitro, Epstein-Barr virus (EBV) reactivation, and plasma cortisol levels were studied in 13 healthy volunteers subjected to a horizontal bed rest (BR) regime for 28 d. Samples were collected before the study, weekly during BR, and then 3-5 d after the regime ended. Additionally, subjects were treated with hydrocortisone on the 1st and 27th d of BR to simulate the hypercortisolemia that occurs during stress.
The factors of 28-d BR regime accompanied by acute hypercortisolemia significantly decreased the relative and absolute number of total lymphocytes, CD3+ T-cells, T-helper subset, and monocytes, but increased the percentage of the CD8+ T-cells, and NK cells at the 4th wk compared with the baseline. A significant decrease in mitogen-activated secretion of IL-2, IFN-gamma, TNF-beta, IL-6, and IL-10 was registered at the same interval. Also, secretion of IL-2 and IFN-gamma declined at the 2nd week of the BR regime. Secretion of IL-4 was significantly higher at the 2nd and 3rd weeks compared with the baseline. A significant increase in the shedding of EBV DNA in saliva was observed as early as the 3rd wk of BR.
Stress factors associated with BR significantly alter immune responsiveness in vitro and in vivo. Changes in the cytokine secretion and cytokine imbalance precede latent EBV reactivation. PHA/LPS-activated cytokine secretion in whole blood can be used as a test system for predicting latent virus activation.
运动功能减退与太空飞行及长期患病有关，可能导致继发性免疫缺陷。
对13名健康志愿者进行为期28天的水平卧床休息（BR），研究全血中免疫细胞的分布、体外丝裂原诱导的细胞因子分泌、爱泼斯坦-巴尔病毒（EBV）再激活及血浆皮质醇水平。在研究前、BR期间每周以及BR结束后3 - 5天采集样本。此外，在BR的第1天和第27天对受试者使用氢化可的松，以模拟应激期间发生的高皮质醇血症。
伴随急性高皮质醇血症的28天BR方案的因素显著降低了总淋巴细胞、CD3 + T细胞、辅助性T细胞亚群和单核细胞的相对和绝对数量，但与基线相比，在第4周时CD8 + T细胞和NK细胞的百分比增加。在同一时间段内，丝裂原激活的IL - 2、IFN - γ、TNF - β、IL - 6和IL - 10分泌显著减少。此外，在BR方案的第2周，IL - 2和IFN - γ的分泌下降。与基线相比，IL - 4的分泌在第2周和第3周显著更高。早在BR的第3周就观察到唾液中EBV DNA脱落显著增加。
与BR相关的应激因素在体外和体内显著改变免疫反应性。细胞因子分泌的变化和细胞因子失衡先于潜伏性EBV再激活。全血中PHA/LPS激活的细胞因子分泌可作为预测潜伏病毒激活的测试系统。
