Abstract
Senescent T-cells accumulate with age, lowering the naïve T-cell repertoire and increasing host infection risk. As this response is likely to be influenced by certain lifestyle factors, we examined the association between aerobic fitness (V̇O2max) and the age-related accumulation of senescent T-cells. Blood lymphocytes from 102 healthy males (18-61. yr) were analyzed for KLRG1, CD57, CD28, CD45RA, CD45RO surface expression on CD4+ and CD8+ T-cells by 4-color flow cytometry. Advancing age (yr) was positively associated with the proportion (%) of senescent (KLRG1+/CD57+; KLRG1+/CD28-) CD4+ (B= 1.00; 1.02) and CD8+ (B= 0.429; 1.02) T-cells and inversely associated with naïve (KLRG1-/CD28+) CD4+ (B= -1.000) and CD8+ (B= -0.993) T-cells. V̇O2max was inversely associated with senescent CD4+ (B= -0.97) and CD8+ (B= -0.240). Strikingly, age was no longer associated with the proportions of senescent or naïve T-cells after adjusting for V̇O2max, while the association between V̇O2max and these T-cell subsets withstood adjustment for age, BMI and percentage body fat. Ranking participants by age-adjusted V̇O2max revealed that the highest tertile had 17% more naïve CD8+ T-cells and 57% and 37% less senescent CD4+ and CD8+ T-cells, respectively, compared to the lowest tertile. V̇O2max was not associated with latent cytomegalovirus (CMV), Epstein-Barr virus (EBV) or herpes simplex virus-1 (HSV-1) infection, indicating that the moderating associations of V̇O2max were not confounded by persistent viral infections. This is the first study to show that aerobic fitness is associated with a lower age-related accumulation of senescent T-cells, highlighting the beneficial effects of maintaining a physically active lifestyle on the aging immune system.
Original language | English (US) |
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Pages (from-to) | 1521-1529 |
Number of pages | 9 |
Journal | Brain, Behavior, and Immunity |
Volume | 25 |
Issue number | 8 |
DOIs | |
State | Published - Nov 2011 |
Externally published | Yes |
Keywords
- Aging
- Exercise immunology
- Immune risk profile
- Immunosenescence
- Latent viral infections
- Physical activity
ASJC Scopus subject areas
- Immunology
- Endocrine and Autonomic Systems
- Behavioral Neuroscience