Stimulation of colony formation and growth factor production of human T lymphocytes by wheat germ lectin

Wheat germ lectin (WGL) induced proliferation of T-lymphocyte colony-forming units (TL-CFU) from human peripheral blood mononuclear cells (PBMC) in a one stage agar culture needing higher cell numbers than phytohaemagglutinin (PHA). However, WGL preactivated TL-CFU in a first stage liquid culture for the growth of PHA-dependent T-lymphocyte colonies in a subsequent agar culture. These results suggested that WGL and PHA have biological activities in common. WGL and PHA both induced the expression of Interleukin 2 (IL-2) receptors by PBMC to become responsive to IL-2, although production of IL-2 by WGL-stimulated PBMC was low compared with PHA-stimulated PBMC. This might account for the low proliferative response of PBMC to WGL.