Lymphocyte Receptor Movement Induced by Sheep Erythrocyte Binding

When lymphocytes are exposed to reagents such as anti-immunoglobulin which cross-link cell surface determinants, those determinants may be drawn toward one pole of the cell into a “cap” (see References 2, 3). Sheep erythrocytes bound to mouse spleen rosette-forming cells induce receptor redistribution similar to that produced by anti-immunoglobulin in two respects: 1) the kinetics and proportion of cells participating are highly temperature-dependent, and 2) the movements require active metabolism, but not protein synthesis. Erythrocyte-induced capping is slower than anti-immunoglobulin-induced capping and involves a smaller proportion of binding cells. By immunofluorescence the surface immunoglobulin is usually seen to move with the erythrocytes, but in about half the cases, the clearing of immunoglobulin is incomplete. Anti-immunoglobulin accelerates erythrocyte-induced capping, but fails to involve a larger proportion of cells unless a second order of cross-linking is introduced.