Pharmacologic and biochemical modulation of human T-lymphocyte colony formation: hormonal influences

The generation of T-cell colonies from human peripheral blood lymphocytes is a sensitive in vitro measure of cell-mediated immunity, considered to be under different and/or additional regulatory controls than short-term liquid cultures. The influences of steroids (aldosterone, estradiol, diethylstilbestrol, hydrocortisone, prednisolone, progesterone, testosterone), prostaglandins (PGA1, PGA2, PGB1, PGB2, PGE1, PGE2, PGF1 alpha), bradykinin, cyclic adenosine monophosphate (AMP), cyclic guanosine monophosphate (GMP), epinephrine, glucagon, histamine, insulin, luteinizing hormone, luteotropic hormone, serotonin, and thyroxin on the generation of both T-cell colonies in semisolid phase and induction of transformation in liquid culture was assessed in parallel assays. Steroids uniformly suppressed both types of culture systems, although colony formation appeared more sensitive by several hours of magnitude. In contrast, significant differences in the response of lymphocytes in colony formation assay, compared to liquid transformation, was noted for the other agents. Prostaglandins significantly inhibited colony formation even in the presence of as little as 10(-12) M PGE2; however, liquid culture responses were suppressed only by higher concentrations (10(-5) M) and enhanced transformation was found at lower concentrations (10(-9) M). Bradykinin, glucagon, and luteinizing hormone did not significantly influence either colony formation or liquid transformation. In contrast, cyclic AMP inhibited and cyclic GMP stimulated colony formation and liquid transformation. Histamine, insulin, epinephrine, and serotonin all had significant positive or negative influences on colony formation in concentrations that produced no detectable effects using conventional liquid transformation assays. Finally, correlation analysis of drug effects for each system extends the thesis that these assays quantitate different parameters of T-cell function. T-lymphocyte colony formation is a promising diagnostic tool for rapid screening of immune modulating agents.