The effect of concanavalin-A (Con A) stimulation on lymphocyte subpopulations.

It has been shown that suppressor T lymphocytes can be activated by plant mitogens as Con A. In order to see if there is any change in lymphocyte surface markers in addition to functional activity, lymphocyte subpopulations (E, EA gamma, EAC rosette forming cells) were determined in 18 healthy controls and 16 patients with ataxia-telangiectasia (AT) after 18-24 hour incubation of lymphocytes with or without Con A (10 micrograms/ml per 2 x 10(6) lymphocytes). Without any incubation, the percentage of EA gamma-RFC was higher and E-RFC was lower in AT patients than in controls. In healthy controls the percentage of EA gamma-RFC significantly increased after incubation with Con A, while the patient group did not show any significant difference. In contrast, the percentage of E-RFC cells in AT group showed significant increase after Con A incubation, while this difference was not significant in healthy controls. There was no significant difference in percentage of EAC-RFC with or without Con A incubation in healthy controls and AT patients. These differences between patient and control groups can be explained by the different features in circulating lymphocyte subpopulations.