Stress regulates the lymphocyte homing receptor CD62L (L-selectin)

Based on a previous study showing that panic disorder patients had increased expression of naïve phenotype lymphocytes (CD45RA+ and CD62L+), increased plasma cortisol, as well as decreased interleukin-2 (IL-2) producion, we hypothesized that changes in the percentage of expression of these lymphocyte surface molecules could be related to the substances released by the hypothalamic-pituitary-adrenal (HPA) axis and possibly associated to panic disorder (cortisol, IL-2, serotonin and epinephrine). In order to study the altered expression, blood mononuclear cells of normal volunteers were stimulated with mitogen, in the presence of dexamethasone, IL-2, serotonin and epinephrin. CD62L is decreased by IL-2 in vitro. Serotonin and epinephrine did not promote changes in the expression of these surface molecules. The results of the ex vivo study are in agreement with a previous clinical study with panic patients. It could be suggested that stress is responsible for certain immunologic dysfunctions and new studies should be conducted.