[Mechanism of suppression of human peripheral blood lymphocyte proliferation by platelet activation factor]

The influence of the phospholipid platelet activation factor (PAF) was studied on PHA-stimulated proliferation of peripheral blood lymphocytes in patients with bronchial asthma and normal subjects. It was found that influencing on the whole population of lymphocytes PAF suppressed proliferation mainly of T-cells. Besides, the influence of PAF on lymphocyte proliferation seemed to be mediated by monocytes since removal of monocytes from the whole population of mononuclear cells abolished the suppression of lymphocyte proliferation induced by PHA. Pretreatment of lymphocytes with PAF antagonist--BL 8705 almost completely blocked the suppression of lymphocyte proliferation induced by PHA.