Effect of wheat germ agglutinin on T lymphocyte activation.
Wheat germ agglutinin (WGA) is low mitogenic or nonmitogenic for human T lymphocytes and inhibits phytohemagglutinin (PHA)-induced mitotic response of the lymphocytes. In this study, the effect of WGA was analyzed in terms of interleukin 2 (IL2) production, expression of IL2 receptor, and IL2 responsiveness of the T lymphocytes. WGA as well as PHA could induce IL2 mRNA and IL2 production and also elevate cytoplasmic free Ca2+ concentration. The IL2 production was reduced by inhibitors of calmodulin and protein kinase C. The IL2 receptor (Tac) expression was induced at about 20% of the lymphocytes by WGA and the expression induced by PHA was not blocked by the addition of WGA. The lymphocytes precultured with WGA for 3 days could proliferate by the addition of IL2 after removal of WGA. The IL2-dependent proliferation of PHA-blasts was blocked by the addition of WGA. These results indicate that WGA inhibits T lymphocyte proliferation by inhibiting the responsiveness of the lymphocytes to IL2 but not by interfering with IL2 production and IL2 receptor expression.
D002118:Calcium / Q000378:metabolism; D002147:Calmodulin / Q000037:antagonists & inhibitors; D006801:Humans; D007376:Interleukin-2 / Q000032:analysis / Q000096:biosynthesis*; D008213:Lymphocyte Activation; D014066:Palatine Tonsil / Q000166:cytology; D010835:Phytohemagglutinins / Q000494:pharmacology; D011493:Protein Kinase C / Q000037:antagonists & inhibitors; D012333:RNA, Messenger / Q000096:biosynthesis; D011971:Receptors, Immunologic / Q000378:metabolism; D015375:Receptors, Interleukin-2; D013601:T-Lymphocytes / Q000032:analysis / Q000276:immunology* / Q000378:metabolism; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014909:Wheat Germ Agglutinins / Q000037:antagonists & inhibitors / Q000494:pharmacology*
D002147:Calmodulin; D007376:Interleukin-2; D010835:Phytohemagglutinins; D012333:RNA, Messenger; D011971:Receptors, Immunologic; D015375:Receptors, Interleukin-2; D014909:Wheat Germ Agglutinins; D011493:Protein Kinase C; D013755:Tetradecanoylphorbol Acetate; D002118:Calcium