Formation of total, active and stable E-rosettes by human lymphocytes stimulated with con A derivatives

Peripheral blood lymphocytes from healthy human volunteers where incubated for 48 hr with 10 micrograms/ml of native Con A or its dimeric derivatives, succinyl- and acetyl-Con A. The percentage of total-active and stable E-rosettes were determined before and after incubation. There were no differences among the three forms of the lectin. Stable E-rosettes exhibited the most dramatic effects from Con A stimulation. They increased from approximately 2% in control cultures to 20-25% in stimulated cultures. Treatment with the Con A inhibitor alpha-Methyl-D-mannoside after Con A stimulation did not affect the rosette formation. Our results suggest that redistribution of membrane receptors on stimulated lymphocytes is not responsible for increased E-rosette formation after Con A stimulation since dimeric forms of Con A are not able to induce membrane receptor redistribution.