E-receptors mediate the attachment of activated T-lymphocytes to human red blood cells: evidence from studies with monoclonal antibodies and simple sugars.

Lectin-stimulated human T-lymphocytes display the capacity of forming stable E-rosettes with sheep red blood cells (SRBC) and of forming rosettes with allogeneic and autologous erythrocytes (RBC). Fractionation experiments indicated that the same subpopulation of lymphocytes displays both of these characteristics. Exposure of T-lymphocytes stimulated with concanavalin A (Con A) or phytohemagglutinin (PHA) to T11 monoclonal antibody (directed against the E-receptor) completely blocked the formation of rosettes with human RBC. Monoclonal antibodies to other T-cell surface markers (Leu 4, T4, T8 and OKT9) had no such effect. The formation of human RBC rosettes and stable E rosettes by PBL stimulated for 2 to 8 days by Con A was inhibited to a similar extent by dilutions of T11 monoclonal antibody. Lectin-stimulated PBL were exposed to various sugars to determine their effect on human RBC rosette formation. Rosette formation was inhibited over 80% with 2-deoxy-D-glucose and by 50-70% with D-mannose, while the other sugars tested had either less effect or none. The present findings support the concept that E-receptors on the surface of human T lymphocytes play a role in the recognition of carbohydrate containing "self" structures.