EFFECTS OF CYTOKINES ON BETA-ADRENOCEPTOR FUNCTION OF HUMAN PERIPHERAL-BLOOD MONONUCLEAR-CELLS AND GUINEA-PIG TRACHEA

In asthma, a beta-adrenoceptor dysfunction may be the consequence of an active disease state rather than a fundamental abnormality. In the present study the possible involvement of T lymphocytes in beta-adrenergic impairment was investigated by studying the effects of lymphocyte-derived mediators on beta-adrenoceptor function of human peripheral blood mononuclear cells (PBMCs) and guinea pig trachea. Supernatants of phytohemagglutinin- or concanavalin A-activated PBMCs from either persons with asthma or healthy persons inhibited isoprenaline stimulated cyclic adenosine 3',5'-monophosphate (cAMP) production of PBMCs after 20 hours of preincubation. These supernatants also inhibited beta-adrenoceptor function of PBMCs from patients with asthma to the same extent. The isoprenaline stimulated cAMP production of PBMCs was not altered after a 2-hour preincubation period with human interleukin-1 (IL-1), IL-2, IL-3, IL-4, granulocyte-macrophage colony-stimulating factor (GM-CSF) and interferon (IFN-gamma). In contrast, after 20 hours of preincubation, stimulated cAMP praduction of PBMCs was significantly diminished, with 63% by IL-1 (40 U/ml, p < 0.01), with 36% by IL-2 (100 U/ml, p < 0.05), with 37% by IFN-gamma (1000 U/ml, p < 0.05), and with 21% by GM-CSF (100 U/ml, p < 0.05). Preincubation of guinea pig tracheal segments with IL-1, IL-2, IL-4, or GM-CSF during 1 or 3 days did not affect the EC50 values or the maximal relaxation of isoprenaline dose response curves.