In vitro kinetics of functional parameters of macrophage activation with lymphokines and its relation to tumor cell cytostasis.

Effect of PPD-induced lymphokine on in vitro activation of peritoneal macrophages of mice was studied. During 15 min of incubation, promotion of macrophage spreading was observed even at 64 fold dilution, but the rate of spreading was rather inhibited after 48 hr. Phagocytosis of formalinized sRBC was stimulated after 30 min and 24 hr of incubation. Full cytostatic activity of macrophages was obtained after 48 hr of incubation with 8 and 32 fold diluted lymphokine-containing supernatants, but PPD alone did not render the macrophages cytostatic until that time. The lymphokine activity to render macrophage cytostatic was in parallel with the activity to induce macrophage spreading. Relation of these parameters in activation process of macrophages in vitro was discussed.