MODULATION OF HUMAN T-LYMPHOCYTE ROSETTE FORMATION BY AUTONOMIC AGONISTS AND CYCLIC NUCLEOTIDES

[摘要] Early rosette formation by T [thymus-derived] lymphocytes appears to be modulated by cyclic nucleotides. Dibutyryl cyclic AMP 10-2 M inhibited E [sheep erythrocyte] rosette formation up to 83%, while 10-6 M 8-bromo-cyclic GMP increased rosette formation maximally to 67.4% with less pronounced effect at increased concentrations. T lymphocyte receptors for .beta. adrenergic, .alpha. adrenergic and muscarinic cholinergic agonists appear to influence rosette formation. Isoproterenol 10-2 M induced 67.3% inhibition, while phenylephrine 10-5 M and carbamylcholine 10-4 M were associated with enhanced rosette formation of 67.2% and 57.8%, respectively. Selective blockade with propranolol, phentolamine and atropine indicated the presence of separate receptor sites. The lack of effect of histamine at concentrations of 10-3 M and above suggests the absence of specific receptors on peripheral human T lymphocytes.