Int J Sports Med 1994; 15(6): 311-318
DOI: 10.1055/s-2007-1021066
Immunology

© Georg Thieme Verlag Stuttgart · New York

Differential Expression of Interleukin-2 Receptor Alpha and Beta Chains in Relation to Natural Killer Cell Subsets and Aerobic Fitness

S. G. Rhind1 , P. N. Shek1 , 2 , S. Shinkai3 , R. J. Shephard1 , 2 , 4
  • 1Programme in Exercise Sciences, Graduate Department of Community Health, University of Toronto, Toronto
  • 2Defence and Civil Institute of Environmental Medicine, North York
  • 3Department of Hygiene, Ehime University School of Medicine, Ehime, Japan
  • 4School of Physical and Health Education, University of Toronto, Toronto, Ontario, Canada
Further Information

Publication History

Publication Date:
14 March 2008 (online)

Abstract

Immunophenotyping by dual parameter flow cytometry was used to compare the expression of interleukin-2 receptor α and β chains on lymphocyte subsets in the peripheral blood of 7 trained and 6 untrained volunteers (respective V̇O2max 57.0±6.1 and 39.0±4.5ml·kg-1 · min-1). Venous blood samples were collected at least 36 h after the most recent exercise session. The trained subjects had higher circulating counts (109 · 1-1) of total leukocytes (5.80±0.83 vs. 4.63±0.21, p<0.05), granulocytes (3.14±0.72 vs. 1.90±0.30, p<0.05), and NK cells (CD16+ 0.32±0.14 vs. 0.16±0.05, p<0.05; CD56+, 0.41±0.14 vs. 0.21±0.03, p<0.01), but lower lymphocyte counts than their sedentary peers (1.90±0.22 vs. 2.26±0.25, p<0.05). Counts for T cells (CD3+) and B cells (CD19+), and the CD4+/CD8+ ratio did not differ between the two subject groups.

The p55-IL-2 receptor α expression (CD25+: 0.63±0.11 vs. 0.69±0.17) was unrelated to training, but the p70-75-IL-2 receptor β expression was higher in the active group (p70/Mik-β1 +: 0.42±0.09 vs. 0.20±0.06, p<0.001; p75/TU27+: 0.36±0.08 vs. 0.17±0.07, p<0.005). Beta chain co-expression was also higher on NK cell subsets (p<0.001) in trained than in sedentary subjects. Aerobic power was strongly correlated with IL-2Rβ expression (r = 0.914, p<0.001 for Mik-β1; r = 0.884, p<0.005 for TU27). We conclude that physical conditioning is associated with an increase in IL-2 receptor β expression on lymphocytes as assessed by the proportion of circulating p70-75-IL-2Rβ positive NK cells. Such changes could enhance protection against both infectious diseases and cancer. Longitudinal studies are now needed to explore the causal nature of this association.

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