title: Mobilization of gammadelta T lymphocytes in response to psychological stress, exercise, and beta-agonist infusion.
abstract: The mobilization of cytotoxic lymphocytes, such Natural Killer (NK) cells and CD8(+) T cells, during stress and exercise is well documented in humans. However, humans have another cytotoxic lymphocyte subset that has not been studied in this context: the Gamma Delta (gammadelta) T lymphocyte. These cells play key roles in immune processes including the elimination of bacterial infection, wound repair and delayed-type hypersensitivity reactions. The current study investigated the effects of stress, exercise, and beta-agonist infusion on the mobilization of gammadelta T lymphocytes. Three separate studies compared lymphocytosis in response to an acute speech stress task (n=29), high (85%W(max)) and low (35%W(max)) intensity concentric exercise (n=11), and isoproterenol infusion at 20 and 40 ng/kg/min (n=12). Flow cytometric analysis was used to examine lymphocyte subsets. gammadelta T lymphocytes were mobilized in response to all three tasks in a dose-dependent manner; the extent of mobilization during the speech task correlated with concomitant cardiac activation, and was greater during higher intensity exercise and increased dose of beta-agonist infusion. The mobilization of gammadelta T lymphocytes was greater (in terms of % change from baseline) than that of CD8(+) T lymphocytes and less than NK cells. This study is the first to demonstrate that gammadelta T cells are stress-responsive lymphocytes which are mobilized during psychological stress, exercise, and beta-agonist infusion. The mobilization of these versatile cytotoxic cells may provide protection in the context of situations in which antigen exposure is more likely to occur.
authors.affiliation: School of Sport and Exercise Sciences, University of Birmingham, Edgbaston, Birmingham, UK.
authors.forename: Leila H
authors.initials: LH
authors.lastname: Anane
authors.forename: Kate M
authors.initials: KM
authors.lastname: Edwards
authors.forename: Victoria E
authors.initials: VE
authors.lastname: Burns
authors.forename: Mark T
authors.initials: MT
authors.lastname: Drayson
authors.forename: Natalie E
authors.initials: NE
authors.lastname: Riddell
authors.forename: Jet J C S Veldhuijzen
authors.initials: JJ
authors.lastname: van Zanten
authors.forename: Graham R
authors.initials: GR
authors.lastname: Wallace
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Mills
authors.forename: Jos A
authors.initials: JA
authors.lastname: Bosch