Effects of concanavalin A and a succinylated derivative on lymphocyte proliferation and cyclic nucleotide levels

To better define cell surface-related changes involved in lymphocyte activation, we studied native concanavalin A (Con A) and succinylated concanavalin A (Suc-Con A) for their effects on proliferation and cyclic nucleotide levels of human peripheral blood lymphocytes. At optimal mitogenic concentrations, the two forms of Con A induce equivalent proliferation; however, the mitogenic activity of Con A progressively decreases above 50 mug/ml. In contrast, the mitogenic activity of Suc-Con A is not decreased even at 250 mug/ml.