Effects of lifelong training on senescence and mobilization of T lymphocytes in response to acute exercise.

Background/purpose: Ageing has profound impact on the immune system, mainly on T-cells. However, it has been suggested that chronic exercise may delay immunosenescence. Master athletes represent an interesting sub-demographic group to test this theory since they maintain a high training frequency and load throughout life. The purpose of this study was to evaluate the effects of lifelong training on the senescence and mobilization of T lymphocytes in response to acute exercise.

Material and methods: Nineteen athletes who regularly participated in training and competitions for more than 20 years throughout their lives and a control group of 10 healthy individuals participated in this study. All subjects performed a progressive test to exhaustion on a cycle ergometer. Blood samples were obtained before (Pre), 10 min after the test (Post) and 1 h after the test (1h). Phenotypic study of peripheral blood T-cells was performed by flow cytometry. Genes of interest expression was done on T-cells purified by cell sorting.

Results: Master athletes had a lower percentage of senescent naïve, central memory and effector memory CD8+ T-cells and senescent naïve and effector memory CD4+ T-cells. Age had a positive effect on SLEC CD8+ T-cells and a negative effect on naïve CD8+ T-cells. VO2max positively correlated with the proportion of naïve CD4+ T-cells and negatively correlated with the percentage of total lymphocytes. No differences were founded for CD4+ and CD8+ T-cells and their subsets between master athletes and the control group at all times of measurement. No differences were observed in the CD45RA expressing effector memory cells (EMRA) for the various study conditions. The mRNA expression of the CCR7 gene for naïve CD8+ T-cells and the Fas-L gene for effector-terminal CD8+ T-cells was not different between masters and controls and did not change in response to the maximal protocol test.

Conclusion: In conclusion, maintaining high levels of aerobic fitness during the natural course of aging may help prevent the accumulation of senescent T-cells.