Concanavalin A-induced activation of human T cell subpopulations.

The proliferative response to concanavalin A (Con A) in human peripheral lymphocytes is dependent on the presence of adherent cells. OKT 8-positive cells respond less well to Con A than OKT 4-positive cells, especially to high concentrations of the activator. The response in both subpopulations of cells is dependent on the number of adherent cells added, the dose of the mitogen used, the day of testing as well as the presence of lymphocyte-produced factors. The data presented in the paper clearly show the importance of caution in evaluation of results obtained by in vitro-induced mitogen activation due to the number of known and unknown variables that affect the magnitude of the response.