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-dependent, bimodal fashion; at lower concentrations they enhanced, while at high concentrations they inhibited, the cytokine-mediated effects. Furthermore, the concentrations of endogenously produced IL-1 beta and TNF-alpha were found to be significantly (p < 0.01) higher in supernatants of AML cells cultured in the presence of corresponding soluble receptors compared to their levels in supernatants of cells growing in the absence of these molecules. Our data might suggest that the attenuation of the spontaneous decay of IL-1 beta as well as TNF-alpha activities by soluble receptors may account for their ability to augment some of their effects.