Propranolol enhances in vitro interleukin 2 receptor expression on human lymphocytes

Interleukin 2 receptor (IL-2R) expression was assessed, using anti-Tac monoclonal antibody, after incubation of human lymphocytes with the beta-adrenoceptor antagonist propranolol (PRO). One-hour incubation of mononuclear cells (MNC) with PRO resulted in an increase of Tac positive cells. The greatest rise was observed with a PRO concentration of 10(-6) M (29% ring-stained cells compared with 0% in the control group). Cells cultured for 3 days with PRO showed a lower proportion of Tac positive cells (11%). Fifty-one per cent of MNC cultured with PHA for 3 days expressed IL-2R. Addition of PRO to PHA cultures increased IL-2R expression even more (65%). Enhancement of IL-2R expression after only 1 h incubation with PRO may be due to exposure of formerly synthesized receptor, which can be uncovered by some agents such as PRO.