Studies on lymphokine activity in concanavalin A-stimulated lymphocyte supernatants using the macrophage-electrophoretic-mobility-test (MEM-test).

Blood lymphocytes from guinea pigs and human donors were incubated with varying amounts of soluble Con A or, in the human system, with Sepharose-bound Con A for 60 min and 24 h at 310 K. The cellfree lymphocyte supernatants were incubated with guinea pig peritoneal macrophages which were measured in a cell electrophoresis apparatus "Parmoquant II" to detect lymphokine activity. Differences were found in the slowing capacity of short-term (60 min) and long term (24 h) incubations. In the latter mobility reduction was higher at comparable Con A concentrations. Greatest macrophage slowing was found at Con A concentrations of 5--10 micrograms Con A/10(6) lymphocytes in the guinea pig system and of 40--50 micrograms Con A/10(6) lymphocytes in the human system. But there was no great difference in the heights of the macrophage slowing at the optimal Con A concentration indicating no species restriction for human lymphokine(s) in our experiments. Stimulation of lymphocytes seems to be possible with Sepharose-bound Con A during a long-term incubation as tested in the human system.