Exercise-induced change in type 1 cytokine-producing CD8+ T cells is related to a decrease in memory T cells.
In response to exercise, both CD4(+) and CD8(+) T cells are mobilized to the blood, but the levels of these cells decline below preexercise values in the postexercise period. T cells are functionally polarized, depending on the cytokines they produce. Type 1 cells produce, e.g., interferon (INF)-gamma, whereas type 2 produce, e.g., interleukin (IL)-4. It was recently demonstrated that exercise induces a decrease in the percentage of type 1 T cells. The present study further investigated the mechanisms underlying the exercise-induced shift in the balance between type 1 and type 2 cytokine-producing cells. Seven healthy men performed 1.5 h of treadmill running with blood samples drawn before exercise, at the end of exercise, and 2 h after exercise. Intracellular expression of IFN-gamma, IL-2, and IL-4 was detected in CD4(+) and CD8(+) T cells after stimulation with phorbol 12-myristate 13-acetate and ionomycin. Intracellular expression of IFN-gamma within CD8(+) cells was decreased in the postexercise period compared with values obtained immediately after exercise, whereas the expression of IL-2 and IL-4 did not change within the CD4(+) and CD8(+) cell populations. The decrease in IFN-gamma-producing CD8(+) T cells postexercise was negatively correlated with a decrease in percentage of memory T cells within the CD8(+) cells (r = -0.94; P < or = 0.002). In conclusion, this study demonstrates that the exercise-induced change in type 1 cytokine-producing T cells is related to a decline in memory cells.
Ibfelt
Tobias
T
Department of Infectious Diseases, Rigshospitalet, University of Copenhagen, DK-2200 Copenhagen, Denmark.
Petersen
Emil Wolsk
EW
Bruunsgaard
Helle
H
Sandmand
Marie
M
Pedersen
Bente Klarlund
BK
D000328:Adult; D016516:CD4-CD8 Ratio; D018414:CD8-Positive T-Lymphocytes / Q000166:cytology* / Q000276:immunology* / Q000378:metabolism; D015444:Exercise / Q000502:physiology*; D005434:Flow Cytometry; D006801:Humans; D007156:Immunologic Memory / Q000502:physiology*; D007371:Interferon-gamma / Q000378:metabolism; D017493:Leukocyte Common Antigens / Q000378:metabolism; D008297:Male; D009504:Neutrophils / Q000166:cytology / Q000276:immunology; D054562:Protein Tyrosine Phosphatase, Non-Receptor Type 1; D012420:Running / Q000502:physiology
D007371:Interferon-gamma; D017493:Leukocyte Common Antigens; D054562:Protein Tyrosine Phosphatase, Non-Receptor Type 1