Effect of wheat germ agglutinin on the interleukin pathway of human T lymphocyte activation

J Immunol. 1985 Jan;134(1):314-23.

Abstract

Wheat germ agglutinin (WGA) inhibits proliferation of human peripheral blood mononuclear cells (PBMC) induced by mitogens and antigens. We investigated the mechanism by which WGA inhibits PHA-induced human lymphocyte proliferation with regard to the interleukin pathway. Our data revealed that although PBMC-proliferation was markedly suppressed by WGA, levels of IL 2 activity in WGA-inhibited cultures were not reduced, but instead were increased, suggesting failure to utilize IL 2. Furthermore, the addition of exogenous IL 2 failed to overcome the suppression. Consistent with these observations, culturing PBMC with PHA plus WGA markedly decreased the number of high-affinity IL 2 receptor per cell, as determined by binding of purified [3H]IL 2, relative to cultures containing PHA alone. WGA immobilized on support beads bound detergent-solubilized IL 2 receptors from PHA-activated T cells, but did not bind human IL 2. However, WGA did not competitively block the binding of [3H]IL 2 to PHA-induced lymphoblasts. These results suggest that WGA inhibits lymphocyte proliferation by binding to and decreasing the number of high-affinity IL 2 receptors displayed on T cells, without impairing IL 2 production.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Cells, Cultured
  • DNA Replication / drug effects
  • Humans
  • Interleukin-2 / immunology*
  • Kinetics
  • Lectins* / pharmacology
  • Lymphocyte Activation*
  • Phytohemagglutinins / pharmacology
  • Receptors, Immunologic / analysis
  • Receptors, Interleukin-2
  • T-Lymphocytes / immunology*
  • Wheat Germ Agglutinins

Substances

  • Interleukin-2
  • Lectins
  • Phytohemagglutinins
  • Receptors, Immunologic
  • Receptors, Interleukin-2
  • Wheat Germ Agglutinins