title: The Effects of Age and Latent Cytomegalovirus Infection on NK-Cell Phenotype and Exercise Responsiveness in Man.
abstract: The redeployment of NK-cells in response to an acute bout of exercise is thought to be an integral component of the "fight-or-flight" response, preparing the body for potential injury or infection. We showed previously that CMV seropositivity impairs the redeployment of NK-cells with exercise in the young. In the current study, we examined the effect of aging on the redeployment of NK-cells with exercise in the context of CMV. We show here that CMV blunts the exercise-induced redeployment of NK-cells in both younger (23-39 yrs) and older (50-64 yrs) subjects with older CMV(neg) subjects showing the largest postexercise mobilization and 1 h postexercise egress of NK-cells. The blunted exercise response in CMV(pos) individuals was associated with a decreased relative redeployment of the CD158a+ and CD57+ NK-cell subsets in younger and older individuals. In addition, we show that aging is associated with a CMV-independent increase in the proportion of NK-cells expressing the terminal differentiation marker CD57, while CMV is associated with an age-dependent decrease in the proportion of NK-cells expressing the inhibitory receptors KLRG1 (in the younger group) and CD158a (in the older group). Collectively, these data suggest that CMV may decrease NK-cell mediated immunosurveillance after exercise in both younger and older individuals.
authors.affiliation: Laboratory of Integrated Physiology, Department of Health and Human Performance, University of Houston, 3855 Holman Street, Houston, TX 77204, USA.
authors.forename: Austin B
authors.initials: AB
authors.lastname: Bigley
authors.affiliation: Laboratory of Integrated Physiology, Department of Health and Human Performance, University of Houston, 3855 Holman Street, Houston, TX 77204, USA.
authors.forename: Guillaume
authors.initials: G
authors.lastname: Spielmann
authors.affiliation: Laboratory of Integrated Physiology, Department of Health and Human Performance, University of Houston, 3855 Holman Street, Houston, TX 77204, USA.
authors.forename: Nadia
authors.initials: N
authors.lastname: Agha
authors.affiliation: Laboratory of Integrated Physiology, Department of Health and Human Performance, University of Houston, 3855 Holman Street, Houston, TX 77204, USA.
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Simpson
mesh_terms: D000328:Adult; D000375:Aging; D018959:CD57 Antigens / Q000378:metabolism; D003586:Cytomegalovirus Infections / Q000378:metabolism / Q000473:pathology*; D015444:Exercise; D005434:Flow Cytometry; D006801:Humans; D007694:Killer Cells, Natural / Q000166:cytology / Q000276:immunology / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D010101:Oxygen Consumption; D010641:Phenotype; D054342:Receptors, KIR2DL1 / Q000378:metabolism; D055815:Young Adult
chemical_list: D018959:CD57 Antigens; D054342:Receptors, KIR2DL1