Surface localization of wheat germ agglutinin and concanavalin A binding sites on normal human blood cells: an ultrastructural histochemical study

In order to determine the extent and variations in surface concavanalin A (CON A) and wheat germ agglutinin (WGA) labeling of different varieties of normal blood cells, gluraraldehyde-fixed human blood cells were exposed to CON A-gold labeled horseradish peroxidase (CON A-HRP-G) and WGA-gold labeled ovomucoid (WGA-OVO-G) histochemical methods. The resultant particulate reaction product permitted assessment of binding and number of gold particles per micrometer of cell surface. Particle counts and data were subjected to statistical analysis. Six subjects (three female and three male) were used and compared in this study. In spite of moderate variations in surface labeling of the various types of leukocytes, erythrocytes and platelets within a given subject, determinations of mean labeling values for similar cell varieties proved quite similar between subjects with the given lectin. WGA and CON A had substantially different labeling densities on the various hemic cells. WGA surface labeling of all types of hemic cells, with the exception of platelets, showed far more labeling than was found with CON A. WGA mean labeling of the grouped subjects was significantly higher for each variety of leukocyte than for either erythrocytes or platelets although this distinction was not always evident in an individual subject. With CON A, mean labeling density for each of hemic cell types showed significant differences between each of the hemic cell varieties. Erythrocytes had only minimal CON A binding while monocyte and platelet populations represented the most reactive of the hemic cells. No difference was noted between corresponding cell varieties in the female vs. male subjects.