Evidence that active and stable E-rosette forming cells belong to different human T lymphocyte subpopulations

Abstract

Human T Lymphocytes form spontaneous E-rosettes with sheep erythrocytes. Cells with high affinity E-receptors can be differentiated by their formation of active (aE) or stable (sE)-rosettes; therefore, experiments were performed in order to determine if active and stable E-rosettes are formed by different populations of T lymphocytes. "Enriched" and "depleted" fractions of aE-RFC were separated on Ficoll-Hypaque after fresh peripheral blood lymphocytes were mixed with SRBC under aE-rosette conditions. Enrichment of aE-RFC did not induce a simultaneous increase in the number of sE-RFC. Furthermore, upon incubation with Con A, a significant increase in the percentage of sE-RFC was detected in the aE-RFC "depleted" preparation. Fractionation of lymphocytes which had been cultured with Con A into sE-"enriched" and "depleted" populations again showed that aE-and sE-RFC do not co-separate in to the same fractions. Analysis of T cell-enriched cultures, prepared from peripheral blood lymphocytes either by rosetting with SRBCaet or fractionation on nylon wool columns, which were stimulated with Con A and then fractionated into aE-or sE- "enriched" and "depleted" populations clearly showed that enrichment of aE-RFC results in a decrease in the number of sE-RFC and viceversa. These data strongly support the idea that cells forming active and stable E-rosettes belong to different populations of human T lymphocytes.