Erythrocyte morphology and clustering of fluorescent anti-A immunoglobulin.

Abstract

PLASMA membranes of many cells are fluid, with the protein and lipid components mobile in the plane of the membrane1,2, as changing distribution patterns of fluorescent labelled lectins and antibodies bound to cell surfaces have shown1–4. Such observations have not been made with intact human erythrocytes, which are thought to be an exception5–7. Ferritin-labelled concanavalin A (con A)8 and soybean agglutinin (unpublished results of C. Kuettner, A. Staehlin, and J.A.G.) have been shown to be randomly arranged on the membranes of intact erythrocytes. But some clustering of con A receptors on the membranes of intact erythrocytes was shown by freeze etching when con A-coated erythrocytes were treated with anticon A antibodies8. We now report evidence for clustering of fluorescein-labelled anti-blood group A antibodies on the surfaces of intact human A erythrocytes associated with alteration of erythrocyte morphology.