ANTHRAX LETHAL TOXIN-INDUCED MITOGENIC RESPONSE OF HUMAN T-CELLS

Bacillus anthracis lethal toxin (PALF) stimulated the proliferation of human peripheral blood T-cells in vitro. Activation of T-lymphocytes by PALF required the presence of monocytes and did not result from a c ollaborative effect between T-cells and B-cells. PALF acted directly o n monocytes and independently of T-cells. The monocytes contributed to the proliferation of T-cells by secretion of mediator(s). The mitogen ic activity of the lethal toxin was dependent on its metalloprotease a ctivity.