The Formation of Stable E-Rosettes by Human T Lymphocytes Activated by Phytohemagglutinin

Abstract

Sheep red blood cells (SRBC), when incubated with human peripheral blood lymphocytes (PBL), ² form rosettes (1). The lymphocytes that participate in rosette formation by adhering to SRBC are generally believed to be T lymphocytes (2). These rosettes have been shown to disintegrate rapidly if incubation of the reaction is carried out at 37°C (3). In striking contrast, however, is the behavior of rosettes formed by human thymus cells, which are highly stable and do not disintegrate even after prolonged incubation at 37°C (4). Galili and Schlesinger (5) reported that human PBL, when treated by allogeneic stimuli in mixed lymphocyte cultures, were resistant to the degradative effects of 37°C incubation on the rosettes formed with SRBC. They suggested that the T lymphocytes were activated in mixed lymphocyte cultures to form stable E-rosettes.