Characterization of autologous erythrocyte rosette-forming cells in Minnesota miniature swine

Abstract

The percentage of porcine lymphocytes capable of binding autologous erythrocytes was determined with an assay previously shown to optimize detection of spontaneous sheep erythrocyte rosette-forming cells (S-RFC). Approximately 57–66% of porcine thymocytes, 7–22% of lymph node, tonsil, and Peyers patch, and 1–6% of spleen and peripheral blood lymphocytes were found to rosette with autologous erythrocytes. Such autologous erythrocyte rosett-forming cells (A-RFC) were nonphagocytic, surface immunoglobulin negative, and were demonstrated to be T cells by mixed resetting with porcine and sheep erythrocytes. The high incidence of A-RFC in thymus and low incidence among peripheral lymphoid cells (as compared to S-RFC) suggested that the autologous erythrocyte receptor was shed from or masked in the membrane of the majority of T cells as they exited the thymus. Enzymatic digestion of the surfaces of peripheral lymphoid cells by bromelain was shown to enhance the incidence of A-RFC, indicating that this receptor for self was masked in the membrane of the majority of peripheral T cells. The numbers of A-RFC in peripheral lymphoid tissues may be a reflection of thymic function regulating discrimination between self and nonself among maturing T-lymphocyte populations.