The activation of blast transformation and DNA synthesis in human peripheral blood lymphocytes by wheat germ agglutinin.

Wheat germ agglutinin (WGA) has been shown to induce blast transformation and DNA synthesis in a minor subpopulation of human peripherl blood T lymphocytes (PBL). These cells enter DNA synthesis between 24 and 48 hr after stimulation, and demonstrate maximal blast transformation after 48 hr. In cultures of Ficoll/Hypaque purified PBL, the activation appears to be aborted 48 to 72 hr after WGA stimulation. After that time DNA synthesis is arrested and activated cells are rapidly lost from culture. The addition of N-acetyl glucosamine to cultures within 2 hr after WGA stimulation results in an increase in the proportion of cells activated and in the amount of DNA synthesized per cell. These experiments suggest that the abortive response may be due to the presentation of superimposed positive and negative signals.