Concanavalin A and Other Lectins in the Study of Tumor Cell Surface Organization

Abstract

Cell surface structures of two mouse ascites tumors were studied using lectins. The tumors are sublines of the spontaneous mammary adenocarcinoma TA3 in strain A, differing in two main characteristics. Subline TA3-St grows only in syngeneic mice and has high expression of H-2 antigens. Subline TA3-Ha, in contrast, proliferates in all mouse strains, and has low amounts of exposed H-2 antigens. Concanavalin A (Con A), phytohemagglutinin (PHA) and Helix pomatia anti A hemagglutinin (HP) were used in agglutination tests, in binding experiments with ¹²⁵I-labelled lectins and also in fluorescence studies with FITC-labelled lectins.

Con A and PHA agglutinated the TA3-St cells but not the TA3-Ha cells. However, fluorescein-labelled Con A and PHA were bound to all cells (> 90%) of both sublines. Moreover both cell types contained an identical number of Con A receptors. The same result was obtained when the number of PHA receptors on the two sublines was compared.

HP agglutinated TA3-Ha cells but not TA3-St cells. However, in this case, the difference in agglutinability between the lines was due to the presence or absence of HP receptors. All TA3-Ha cells contained large numbers of HP receptors. In contrast the majority (> 90%) of the TA3-St cells lacked HP receptors.

This investigation was supported by the Contract Grant No. NIH-NCI-E-69-2005 and the Swedish Science Research Council Grant No. B 3485-003.