Antiproliferative and differentiative effects of recombinant interleukin-4 on a granulocyte colony-stimulating factor-dependent myeloblastic leukemic cell line

Abstract

The effect of recombinant human interleukin-4 (IL-4) on a granulocyte colony-stimulating factor (G-CSF)-dependent human myeloblastic leukemic cell line, OCI-AML1a, was investigated. IL-4 suppressed the clonogenic cell growth in methylcellulose culture, inhibited the uptake of 3H thymidine in a dose-dependent manner at 5 to 100 U/mL, and consequently suppressed the growth of clonogenic cells in short- and long-term suspension cultures. In addition, IL-4 markedly increased the number of adherent cells. These adherent cells were α-naphthyl-butyrate (α-NB) esterase-positive and showed macrophage-like appearance, increased expression of CD14, CD11b, CD23, and Ia, and significantly decreased clonogenicity. On the other hand, nonadherent cells growing in suspension showed only slight increase in proportion of α-NB esterase-positive or monocyte/macrophage-like cells and increased CD23 expression by an addition of IL-4. The clonogenicity of the nonadherent cells was not significantly influenced by IL-4. By addition of the media conditioned by OCI-AML1a cells in the presence of IL-4, the clonogenic cells growth of OCIAML1a cells was suppressed and adherent cells were markedly increased. The suppressive and differentiative effects on OCI/AML1a cells of the conditioned media and IL-4 itself were almost completely abolished by anti-IL-4 antibody. Furthermore, the neutralizing antibodies against transforming growth factor-β2 (TGF-β2), tumor necrosis factor-α (TNF-α), or IL-6 did not influence the effect of recombinant IL-4. Taken together, IL-4 was shown to suppress the growth and induce differentiation toward adherent macrophage-like cells of the G-CSF-dependent myeloblastic cell line. The effect of IL-4 may be direct, and not secondary via inducing production of other cytokines such as TGF-β, TNF-α, or IL-6 by leukemic cells. © 1991 by The American Society of Hematology.