EFFECTS OF SOLUBLE INTERLEUKIN-1 RECEPTOR AND TUMOR-NECROSIS-FACTOR RECEPTOR, RESPECTIVELY, ON THE IL-1-INDUCED AND TNF-ALPHA-INDUCED DNA-SYNTHESIS OF ACUTE MYELOBLASTIC-LEUKEMIA BLASTS IN-VITRO

This study demonstrates that soluble interleukin-1 receptor and tumor necrosis factor receptor modulate their corresponding cytokine-induced DNA synthesis of acute myeloblastic leukemia (AML) blasts in a dose-d ependent, bimodal fashion; at lower concentrations they enhanced, whil e at high concentrations they inhibited, the cytokine-mediated effects . Furthermore, the concentrations of endogenously produced IL-1 beta a nd TNF-alpha were found to be significantly (p < 0.01) higher in super natants of AML cells cultured in the presence of corresponding soluble receptors compared to their levels in supernatants of cells growing i n the absence of these molecules. Our data might suggest that the atte nuation of the spontaneous decay of IL-1 beta as well as TNF-alpha act ivities by soluble receptors may account for their ability to augment some of their effects.