Abstract
Introduction:
CD8
+
T lymphocytes (CD8TLs) express β-adrenergic receptors (βAR), which bind the neurotransmitter norepinephrine and stress hormone epinephrine released during inflammation, trauma, and psychological stress. Little is known about the functions of this βAR expression on CD8TLs.
Methods:
Volunteers were exposed to a psychological stressor (N=24). Flow cytometry identified CD8TL subsets by CCR7, CD27, CD28 and CD45RA expression. Adrenergic receptor subtype expression was determined by micro-array. The effects of βPAR stimulation on IFN-γ production in activated CD8TLs was tested
in vitro
using PMA/Ionomycin.
Results:
Stress caused selective migration of effector-memory (CCR7
−
CD27
−
CD28
−
) CD8TLs into the blood (+148%,
p
<.001). An 8-fold up-regulation of the β
2
AR was demonstrated in effector-memory cells as compared to naïve CD8TLs. Stimulation of the β
2
AR subtype completely inhibited IFN-γ production.
Conclusion:
These results show that β
2
AR stimulation enhances peripheral immune surveillance in a highly selective manner, and might protect against excessive cytokine release during inflammation and stress.