MRC-Arthritis Research UK Centre for Musculoskeletal Ageing Research, Institute of Inflammation and Ageing, University of Birmingham, Birmingham, UK.
Centre of Human and Aerospace Physiological Sciences, King's College London, London, UK.
Aging Cell. 2018 Apr;17(2). doi: 10.1111/acel.12750. Epub 2018 Mar 8.
It is widely accepted that aging is accompanied by remodelling of the immune system including thymic atrophy and increased frequency of senescent T cells, leading to immune compromise. However, physical activity, which influences immunity but declines dramatically with age, is not considered in this literature. We assessed immune profiles in 125 adults (55-79 years) who had maintained a high level of physical activity (cycling) for much of their adult lives, 75 age-matched older adults and 55 young adults not involved in regular exercise. The frequency of naïve T cells and recent thymic emigrants (RTE) were both higher in cyclists compared with inactive elders, and RTE frequency in cyclists was no different to young adults. Compared with their less active counterparts, the cyclists had significantly higher serum levels of the thymoprotective cytokine IL-7 and lower IL-6, which promotes thymic atrophy. Cyclists also showed additional evidence of reduced immunesenescence, namely lower Th17 polarization and higher B regulatory cell frequency than inactive elders. Physical activity did not protect against all aspects of immunesenescence: CD28 CD57 senescent CD8 T-cell frequency did not differ between cyclists and inactive elders. We conclude that many features of immunesenescence may be driven by reduced physical activity with age.
人们普遍认为，衰老伴随着免疫系统的重塑，包括胸腺萎缩和衰老 T 细胞频率的增加，导致免疫功能受损。然而，在这一文献中并没有考虑到体力活动，体力活动会影响免疫力，但随着年龄的增长会急剧下降。我们评估了 125 名成年人（55-79 岁）的免疫特征，这些成年人在成年后的大部分时间里都保持着高水平的体力活动（骑自行车），他们与 75 名年龄匹配的老年人和 55 名不经常锻炼的年轻人进行了比较。与不活动的老年人相比，骑自行车者的幼稚 T 细胞和近期胸腺移民（RTE）的频率都更高，而骑自行车者的 RTE 频率与年轻人没有差异。与不那么活跃的同龄人相比，骑自行车者的血清中具有胸腺保护作用的细胞因子 IL-7 水平明显更高，而促进胸腺萎缩的 IL-6 水平则更低。骑自行车者还表现出免疫衰老程度降低的其他证据，即 Th17 极化程度较低，B 调节细胞频率较高，而不活动的老年人则没有这些特征。体力活动并不能完全预防免疫衰老的所有方面：与不活动的老年人相比，骑自行车者的 CD28 CD57 衰老 CD8 T 细胞频率没有差异。我们的结论是，随着年龄的增长，体力活动的减少可能是导致许多免疫衰老特征的原因。
