Mobilization of gd T lymphocytes in response to psychological stress, exercise, and b-agonist infusion

• Published in: Brain, behavior, and immunity behavior, and immunity, 2009-08, Vol.23 (6), p.823-829
• Main Authors: Anane, L H, Edwards, K M, Burns, V E, Drayson, M T, Riddell, N E, van Zanten, JJCSV, Wallace, G R, Mills, P J, Bosch, JA
• Format: Article
• Language: English
• ISSN: 0889-1591
• DOI: 10.1016/j.bbi.2009.03.003

The mobilization of cytotoxic lymphocytes, such Natural Killer (NK) cells and CD8 super(+) 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 (gd) 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 b-agonist infusion on the mobilization of gd T lymphocytes. Three separate studies compared lymphocytosis in response to an acute speech stress task (n=29), high (85%W sub(m) sub(a) sub(x)) and low (35%W sub(m) sub(a) sub(x)) intensity concentric exercise (n=11), and isoproterenol infusion at 20 and 40ng/kg/min (n=12). Flow cytometric analysis was used to examine lymphocyte subsets. gd 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 b-agonist infusion. The mobilization of gd T lymphocytes was greater (in terms of % change from baseline) than that of CD8 super(+) T lymphocytes and less than NK cells. This study is the first to demonstrate that gd T cells are stress-responsive lymphocytes which are mobilized during psychological stress, exercise, and b-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.