Effects of levamisole on T lymphocyte colony formation by cells from bone marrow aspirates.

Levamisole has been added to cultures of bone marrow and peripheral blood mononuclear cells stimulated by phytohaemagglutinin (PHA). T lymphocytes colony-forming cells (TL-CFC) in the peripheral blood produce a characteristic biphasic dose--response curve in cultures containing levamisole but the characteristics of the dose--response curve seen when levamisole is added to mononuclear cells obtained from bone marrow aspirates are strikingly different. The results suggest that the mixtures of bone marrow and blood obtained by aspiration contain different proportions of the cells which influence TL-CFC than either blood, or by implication, bone marrow alone.