title: Acute aerobic exercise in humans increases cytokine expression in CD27(-) but not CD27(+) CD8(+) T-cells.
abstract: Exercise alters the percentage of CD8(+) T-cells in the bloodstream expressing type I and type II cytokines. It is unknown if this reflects a change in cytokine expression within individual cells, or whether these observations result from the exercise-induced shift in the proportions of early/intermediate (CD27(+)) and late (CD27(-)) differentiated cells, which have vastly different cytokine profiles. 16 males cycled for 60 min at 95% maximal steady state. Mononuclear cells isolated from blood collected before, immediately after, and 1 h after exercise were cultured overnight with and without phytohaemagglutinin stimulation. CD8(+) T-cells were assessed for differentiation markers and intracellular cytokine expression by flow cytometry. The numbers and percentage of CD27(-)CD8(+) T-cells increased immediately after exercise and fell below pre-exercise values 1 h later. At 1 h after exercise, an increased number and percentage of CD8(+) T-cells expressing IL-2, IFN-γ, TNF-α, IL-6, IL-4, and IL-10 was observed in both stimulated and unstimulated cells. The cytokine response to exercise was confined to CD27(-)CD8(+) T-cells, although cytokine expression among CD8(+) T-cells was highest when the proportion of CD27(-)CD8(+) T-cells was lowest. Moreover, the cytokine response to exercise could be predicted by the number of late cells in resting blood: cytokine expression was highest among those with low resting proportions of late cells. We conclude that exercise-induced changes in the percentage of CD8(+) T-cells expressing cytokines are not due to proportional shifts in early/intermediate and late differentiated T-cells. Exercise may prime late-differentiated blood CD8(+) T-cells to initiate effector functions in preparation for their extravasation into the tissues.
authors.affiliation: Laboratory of Integrated Physiology, Department of Health and Human Performance, University of Houston, Houston, TX 77204, USA.
authors.forename: Emily C
authors.initials: EC
authors.lastname: LaVoy
authors.forename: Jos A
authors.initials: JA
authors.lastname: Bosch
authors.forename: Thomas W
authors.initials: TW
authors.lastname: Lowder
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Simpson
mesh_terms: D000328:Adult; D018414:CD8-Positive T-Lymphocytes / Q000166:cytology / Q000378:metabolism; D002454:Cell Differentiation / Q000502:physiology; D016207:Cytokines / Q000378:metabolism*; D015444:Exercise / Q000502:physiology*; D005434:Flow Cytometry; D006801:Humans; D007371:Interferon-gamma / Q000378:metabolism; D016753:Interleukin-10 / Q000378:metabolism; D007376:Interleukin-2 / Q000378:metabolism; D015847:Interleukin-4 / Q000378:metabolism; D015850:Interleukin-6 / Q000378:metabolism; D008297:Male; D013601:T-Lymphocytes / Q000166:cytology / Q000378:metabolism*; D018127:Tumor Necrosis Factor Receptor Superfamily, Member 7 / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
chemical_list: D016207:Cytokines; C573415:IFNG protein, human; C508609:IL10 protein, human; C508594:IL2 protein, human; C508598:IL4 protein, human; C508600:IL6 protein, human; D007376:Interleukin-2; D015850:Interleukin-6; D018127:Tumor Necrosis Factor Receptor Superfamily, Member 7; D014409:Tumor Necrosis Factor-alpha; D016753:Interleukin-10; D015847:Interleukin-4; D007371:Interferon-gamma