Abstract
The magnitude of lymphocytosis following exercise is directly related to exercise intensity. Infection with cytomegalovirus (CMV) also augments lymphocytosis after exercise. It is not known if the enhanced T-cell response to exercise due to CMV depends on exercise intensity. Furthermore, exercise-induced changes in T-cell expression of type I and type II cytokines are thought to be intensity dependent, but direct comparisons are lacking. The aim of this experiment was to determine if CMV affects the exercise-induced redistribution of T-cell subsets at varying intensities, and determine the effect of exercise intensity on CD8+ T-cell cytokine expression. Seventeen cyclists (nine CMV seropositive; CMV+) completed three 30 min cycling trials at −5, +5, and +15% of blood lactate threshold (LT). T-cell subsets in blood and intracellular expression of type I (IL-2, interferon(IFN)-γ) and type II (IL-4, IL-10) cytokines by CD8+ T cells pre, post, and 1-h post-exercise were assessed by flow cytometry. Independently of CMV, T-cell subset redistribution was greater after +15%LT compared to −5%LT (P < 0.05). Independently of intensity, CMV− mobilized more low- (CD27+ CD28+) and medium- (CD27+ CD28−) differentiated T cells than CMV+, whereas CMV+ mobilized more high (CD27− CD28−) differentiated T cells. The numbers of IL-2+, IFN-γ+, IL-4+, and IL-10+ CD8+ T cells increased after exercise above LT. Only type I cytokine expression was influenced by exercise intensity (P < 0.05). In conclusion, T-cell redeployment by exercise is directly related to exercise intensity, as are changes in the number of CD8+ T-cells expressing type I cytokines. Although CMV+ mobilized more high-differentiated T cells than CMV−, this occurred at all intensities. Therefore, the augmenting effect of CMV on T-cell mobilization is independent of exercise intensity.
Original language | English (US) |
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Article number | e13070 |
Journal | Physiological reports |
Volume | 5 |
Issue number | 1 |
DOIs | |
State | Published - Jan 1 2017 |
Externally published | Yes |
Keywords
- Cytokine
- infection
- inflammation
- lymphocyte
- mobilization
- physical activity
ASJC Scopus subject areas
- Physiology
- Physiology (medical)