title: Pokeweed mitogen inhibition of protein synthesis in cultured lymphoblastoid lines.
abstract: Pokeweed mitogen (PWM) and ricin are both lectins derived from plant seeds. They are glycoproteins and share the ability to agglutinate a variety of animal cells including erythrocytes. The effect of these two lectins on protein synthesis was studied in four long-term lymphoblastoid lines (8866 and GM1531, which are B cell lines; and CCRF/CEM and MOLT 4, which are T-cell lines). Ricin (50 micrograms/ml) completely inhibited protein synthesis by 2 hr in both B-cell and T-cell lines as measured by the uptake to [3H]leucine. The PWM appeared more specific and at a concentration of 500 micrograms/ml inhibited protein synthesis only in B-cell lines (8866 and GM1531). This effect was maximal at 5 hr. To investigate the reason for the differential effect of PWM on T and B cells, 125I-labeled PWM was incubated with 8866, MOLT 4, and CCRF/CEM to see if a significant difference in binding to B cells and T cells could be demonstrated. It does not appear that differential effect on T and B cells is due to a difference in the amount of PWM bound. On the other hand it is possible that the B cells may bind some toxic subcomponent of the PWM preparation that the T cells do no bind because of a difference in composition or arrangement of cell surface glycoproteins.
mesh_terms: D000116:Acetylgalactosamine / Q000494:pharmacology; D000117:Acetylglucosamine / Q000494:pharmacology; D001402:B-Lymphocytes / Q000378:metabolism*; D002460:Cell Line; D006801:Humans; D011043:Pokeweed Mitogens / Q000378:metabolism / Q000494:pharmacology*; D014176:Protein Biosynthesis; D012276:Ricin / Q000494:pharmacology; D013601:T-Lymphocytes / Q000378:metabolism*
chemical_list: D011043:Pokeweed Mitogens; D012276:Ricin; D000116:Acetylgalactosamine; D000117:Acetylglucosamine