Mobilization of gammadelta T lymphocytes in response to psychological stress, exercise, and beta-agonist infusion

Brain Behav Immun. 2009 Aug;23(6):823-9. doi: 10.1016/j.bbi.2009.03.003. Epub 2009 Mar 24.


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.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Adrenergic beta-Agonists / administration & dosage
  • Adrenergic beta-Agonists / pharmacology*
  • Carbon Dioxide / blood
  • Cell Count
  • Exercise / physiology*
  • Female
  • Flow Cytometry
  • Heart Rate / drug effects
  • Heart Rate / physiology
  • Hemodynamics / physiology
  • Humans
  • Infusions, Intravenous
  • Isoproterenol / administration & dosage
  • Isoproterenol / pharmacology
  • Lymphocyte Subsets / drug effects
  • Lymphocyte Subsets / physiology
  • Male
  • Oxygen / blood
  • Oxygen Consumption / drug effects
  • Oxygen Consumption / physiology
  • Social Environment
  • Stress, Psychological / immunology*
  • T-Lymphocytes, Cytotoxic / drug effects*
  • T-Lymphocytes, Cytotoxic / immunology*
  • Young Adult


  • Adrenergic beta-Agonists
  • Carbon Dioxide
  • Isoproterenol
  • Oxygen