[Effects of thymosin on human blood lymphocytes in vitro]

The activity of thymosin obtained from calf thymus was examined in the tests in vitro: the reaction of spontaneous rosette formation, blasttransformation reaction to PHA and the reaction of leucocyte migration inhibition. It was demonstrated that the activity which stimulates T-lymphocytes would appear only in cases where donor lymphocytes show depletion in terms of rosette formation and blasttransformation. In some patients thymosin was found to produce the in vitro activation of cell anti-tumor immunity.