title: T-cell redeployment and intracellular cytokine expression following exercise: effects of exercise intensity and cytomegalovirus infection.
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.
authors.affiliation: Department of Health & Human Performance, University of Houston, Houston, Texas eclavoy@uh.edu.
authors.forename: Emily C
authors.initials: EC
authors.lastname: LaVoy
authors.affiliation: Department of Arts & Sciences, University of Delaware, Newark, Delaware.
authors.forename: Maryam
authors.initials: M
authors.lastname: Hussain
authors.affiliation: Department of Health & Human Performance, University of Houston, Houston, Texas.
authors.forename: Justin
authors.initials: J
authors.lastname: Reed
authors.affiliation: Department of Health & Human Performance, University of Houston, Houston, Texas.
authors.forename: Hawley
authors.initials: H
authors.lastname: Kunz
authors.affiliation: Department of Health & Human Performance, University of Houston, Houston, Texas.
authors.forename: Mira
authors.initials: M
authors.lastname: Pistillo
authors.affiliation: Department of Health & Human Performance, University of Houston, Houston, Texas.
authors.forename: Austin B
authors.initials: AB
authors.lastname: Bigley
authors.affiliation: Department of Health & Human Performance, University of Houston, Houston, Texas.
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Simpson
mesh_terms: D000328:Adult; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology; D016207:Cytokines / Q000378:metabolism*; D003587:Cytomegalovirus / Q000276:immunology*; D003586:Cytomegalovirus Infections / Q000276:immunology* / Q000821:virology; D015444:Exercise / Q000502:physiology*; D005260:Female; D006801:Humans; D016753:Interleukin-10; D008218:Lymphocytosis; D008297:Male; D064887:Observational Studies as Topic; D016176:T-Lymphocyte Subsets / Q000276:immunology*; D013601:T-Lymphocytes / Q000166:cytology / Q000378:metabolism*
chemical_list: D016207:Cytokines; D016753:Interleukin-10
keywords: Cytokine; infection; inflammation; lymphocyte; mobilization; physical activity