Human lymphocyte-sheep erythrocyte rosette formation: Some characteristics of the interation

Abstract

Sheep red blood cell rosette (SRBC-R) formation was evaluated and utilized as a human T cell marker for lymphocytes from normals and selected patients; 69–82% of the blood lymphocytes of normal individuals and 90–100% of human thymocytes form SRBC-R. In double-labeling experiments in which the B lymphocytes are first labeled with either aggregated human immunoglobulin or anti-immunoglobulin and then SRBC added, the vast majority of B cells do not form SRBC-R. However, rare cells are noted that show B cell markers and are also SRBC-R. Lymphocytes from most patients with chronic lymphocytic leukemia (CLL) showed predominence of anti-lg and aggregate staining and low percentages of SRBC-R. Therefore, these appeared to represent B cell leukemias. One case, however, showed no anti-lg or aggregate staining but 88% SRBC-R and thus appeared to be a T cell leukemia. These relationships were also found in hypogammaglobulinemia patients with relative B cell deficiency. Rosette formation was not inhibited by anti-immunoglobulin sera including specific anti-light chain sera. Electron microscopic studies of the SRBC-R suggest that there are relatively few sites of attachment between the reactive lymphocyte and SRBC. This binding is distinguished from binding of complement-coated SRBC to the C3 receptor-bearing lymphocyte, in which broad zones of attachment between lymphocyte and erythrocyte are observed.