Enhancement of the in vitro colony-forming capacity of human T lymphocytes induced by levamisole.

The colony-forming capacity of normal peripheral blood mononuclear cells and of TG-depleted cell suspensions induced by PHA was investigated in the presence of different concentrations of levamisole. The results obtained demonstrate that: (1) the drug enhances significantly the number of colonies formed by both mononuclear cells and TG-depleted cells at concentrations ranging from 5 x 10(-6) to 5 x 10(-8 M; (2) this stimulatory activity results from a direct effect on T cells; and (3) adherent accessory cells are unaffected by the in vitro treatment with levamisole.