ABSTRACT
PURPOSE: Investigate training status and sex effects on the redistribution of senescent and naïve T-lymphocytes following acute exercise. METHODS: Sixteen (8 male, 8 female) trained (18.3±1.7yr) soccer players (Tr) and sixteen (8 male, 8 female) untrained (19.3±2.0yr) controls (UTr) performed a treadmill running test to volitional exhaustion. Blood lymphocytes were isolated before (Pre), immediately post, and 1-h post-exercise for assessment of cell surface expression of CD28 and CD57 on CD4(+) and CD8(+) T-lymphocyte subsets. Plasma was used to determine cytomegalovirus (CMV) serostatus. RESULTS: Exercise elicited a redistribution of T-lymphocyte subsets. Senescent CD4(+) and CD8(+) T-lymphocytes increased by 42.4% and 45.9% respectively, while naïve CD4(+) and CD8(+) T-lymphocytes decreased by 8.7% and 22.5% respectively in response to exercise. A main effect (P<0.05) of training status was observed for senescent CD4(+), CD8(+) and naïve CD8(+) T-lymphocytes: UTr had a higher proportion of senescent and a lower proportion of naïve CD8(+) T-lymphocytes than Tr. A main effect (P<0.05) of sex was observed in senescent CD4(+), CD8(+) and naïve CD4(+), CD8(+) T-lymphocytes. Males had a higher proportion of senescent and lower proportion of naïve T-lymphocytes than females. A sex-by-training status interaction (P<0.05) was observed for the senescent and naïve CD4(+) T-lymphocytes (but not CD8(+)) with the highest percentage of senescent and lowest percentage of naïve T-lymphocytes observed in UTr males. CMV exerted a significant main covariate effect (P<0.05) in the senescent and naïve (P<0.05) CD8(+) T-lymphocytes but not in the senescent and naïve CD4(+) T-lymphocytes. CONCLUSION: This study highlights important sex and training status differences in the senescent and naïve T-lymphocyte redistribution in response to exercise that warrants further investigation.
