Modification of the biological activities of concanavalin A by anti-concanavalin A

Concanavalin A (Con A) bound to cell membrane glycoproteins, may be dissociated from the membrane receptors by competitive ligands such as alpha-methyl-D-mannoside. Addition of antibody to Con A to the system forms complexes of antibody and Con A which are still bound to the membrane receptors. Such complexes are not dissociable from the membrane by alpha-methyl-D-mannoside. Presence of the complexes on the membrane is monitored by radioactive label or by passive lysis of the cells with guinea pig complement. Antibody to Con A can completely suppress Con A mediated stimulation of lymphocytes as measured by incorporation of tritiated thymidine. However production of lymphokines involved in migration inhibition, enhancement of plaque forming cells or blastogenesis are differentially suppressed by antibody to Con A.