Cytoskeletal control of redistribution of surface membrane receptors in hairy cells.

The redistribution of surface membrane immunoglobulin (SmIg) and concanavalin A (Con-A) was studied in peripheral mononuclear cells of three patients who had hairy cell leukemia. Fluorescein-labeled polyvalent goat antihuman immunoglobulin and fluoresceinated Con-A were used as ligands. The capping of ligand-receptor complexes was temperature-dependent and was more prominent at 37 C. A significant drop in the percentages of SmIg and Con-A capping was observed when cytochalasin B was added. In contrast, no decline in the percentages of SmIg and Con-A capping was seen in the presence of colchicine. The inhibitory action of cytochalasin B on the capping of SmIg and Con-A receptors in hairy cells suggests that these receptors are integral macromolecules of the plasma membrane and their redistribution is regulated by cytoskeletal structures.