Generation of activated lymphocytes. Analysis of giant SRBC rosettes.

Giant SRBC rosette-forming cells were detected in samples of mitogen-stimulated human peripheral blood lymphocytes. When the concentrations of mitogens were varied, the amount of [3H]TdR incorporated by the lymphocytes also varied. In general, the higher the amount of [3H]TdR incorporated, the higher were the percentages of giant rosettes. Hence the percentages of rosettes constituted a reliable index of mitogenic responses. Lymphocytes were stimulated by mitogens and cultured in the presence of cardiac glycosides or inhibitors of the synthesis of DNA, RNA or protein. The generation of giant SRBC rosette-forming cells was found to be dependent on RNA and protein synthesis and the integrity of membrane Na+ K+ ATPase, but not on DNA synthesis.